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STANDARD SPECIFICATION for MATERIALS and WORKMANSHIP (SECTION 2) For the MECHANICAL ENGINEERING SERVICES INSTALLATIONS M & E Design Est a t es O f f ic e G ib b et H il l R o a d T el : 0 2 4 7 6 5 2 2 3 4 0 5 C o v ent r y C V 4 7 A L F a x : 0 2 4 7 6 5 2 4 4 4 4 Revision: Description: 1st Edition Date: 03/05/2007 Prepared By: A.J.C Checked By: SECTION 2.2. – PLANT ITEMS 2.2.1. General Plant............................................................................................1 126.96.36.199. Pumps and Cold Water Pressurisation Plant........................................1 188.8.131.52. Direct Electric Water Heaters ...............................................................4 184.108.40.206. Pneumatic Hot Water Expansion Vessel ..............................................6 220.127.116.11. Calorifiers.............................................................................................6 2.2.2. Pressurisation For Hot Water Heating Systems ........................................7 18.104.22.168. General ................................................................................................7 22.214.171.124. Sealed Diaphragm Vessel Systems .....................................................8 126.96.36.199. Constant or Intermittent Running Pump Systems .................................9 2.2.3. Heat Emitters ............................................................................................9 188.8.131.52. Radiators..............................................................................................9 184.108.40.206. Convectors.........................................................................................10 220.127.116.11. Underfloor Heating .............................................................................12 18.104.22.168. Electric Tubular Heaters.....................................................................12 2.2.4. Air Conditioning And Ventilation Installations ..........................................12 22.214.171.124. Air Handling Units and Fans...............................................................12 126.96.36.199. Cooling Coils......................................................................................20 188.8.131.52. Air Heater Batteries............................................................................22 184.108.40.206. Air Filters............................................................................................24 2.2.5. Terminal Units.........................................................................................30 220.127.116.11. Fan Coil Units.....................................................................................30 2.2.6. Refrigeration Plant ..................................................................................32 18.104.22.168. Reciprocating Chillers ........................................................................32 22.214.171.124. Condensers........................................................................................37 2.2.7. Refrigeration Plant Accessories ..............................................................40 2.2.8. Pressurisation Equipment .......................................................................41 126.96.36.199. General ..............................................................................................41 188.8.131.52. Alarm Facilities...................................................................................42 184.108.40.206. Controls..............................................................................................42 220.127.116.11. Testing and Commissioning ...............................................................43 2.2.9. Pipework, Valves, And Ancillaries ...........................................................43 2.2.10. Insulation ...............................................................................................44 2.2.11. Controls .................................................................................................45 2.2.12. Rotary Screw Liquid Chillers ..................................................................46 2.2.13. Acoustic And Vibration Isolation.............................................................55 18.104.22.168. General .............................................................................................55 22.214.171.124. Silencer Performance........................................................................57 126.96.36.199. Construction......................................................................................57 188.8.131.52. Reactive Silencers (For Heavy Industry) ...........................................59 2.2.14. Anti-Vibration Mountings ........................................................................59 184.108.40.206. General .............................................................................................59 220.127.116.11. Caged Spring Mounts........................................................................60 18.104.22.168. Rubber Mattress................................................................................61 SECTION 2.2. – PLANT ITEMS 22.214.171.124. Resilient Hangers..............................................................................61 126.96.36.199. Rubber or Neoprene Mounts .............................................................61 188.8.131.52. Pipework Isolation .............................................................................62 184.108.40.206. Plant Bases.......................................................................................62 220.127.116.11. Flexible Connections .........................................................................63 2.2.15. Motors, Belts, And Guards .....................................................................63 18.104.22.168. Motors...............................................................................................63 22.214.171.124. Variable Speed Drives for HVAC Induction Fan and Pump Motors....65 126.96.36.199. Protection of the Induction Motor.......................................................66 188.8.131.52. Motor and Starter Cabling .................................................................66 184.108.40.206. Starter Displays.................................................................................66 220.127.116.11. Electromagnetic Compatibility and Radio Frequency Interference.....70 18.104.22.168. Power Factor Correction ...................................................................70 22.214.171.124. Lubrication ........................................................................................71 126.96.36.199. Protection..........................................................................................71 188.8.131.52. Motor Control Equipment..................................................................72 184.108.40.206. Remote Push Buttons ......................................................................73 220.127.116.11. V-Belt Drives ....................................................................................73 18.104.22.168. Guards .............................................................................................73 SECTION 2.2. – PLANT ITEMS 2.2.1. General Plant 22.214.171.124. Pumps and Cold Water Pressurisation Plant In the installation of the equipment the following publications shall be taken into consideration: i. Guidance note PM5 Part C from the Health and Safety Executive. ii. Water Supply (Water Fittings) Regulations 1999. (a) General Requirements For particular technical requirements of pumps and pressurisation units refer to technical schedules and Particular Specification. The Contractor shall verify with the Engineer before pump sets and pressurisation units are ordered that the following items are not required: a) Hour run meters for each pump. b) Ammeters for each pump or one for the pump set. c) Interface unit on pump for addressing with the building management system. If an addressable interface unit is required, it is the Contractors responsibility to confirm with the Engineer the extent of monitoring required, before pumps and/or booster plant is assembled. d) Anti-condensation heater. e) Locking hand/off/auto switches. AJC 05/07 Section 2.2. / 1 SECTION 2.2. – PLANT ITEMS It is the Contractors responsibility to liaise directly with the pump manufacturer and building management system supplier to ensure that the interface units supplied on the pump sets are fully compatible with the chosen building management system and all pump conditions requiring monitoring have been fully addressed. Although estimated values of pump duty are given in the Schedules, this does not relieve the Contractor of the responsibility for providing pumps capable of delivering the required quantity of water, and for being suitable for the temperatures and pressures involved. All LTHW, HTHW, chilled water, condenser water etc, circulating pumps shall have isolation valves on the discharge and inlet ports with strainers on the inlet and non-return valves on the discharge connections. Public health services (cold water, softened water, domestic hot water etc) shall not have strainers installed unless indicated. (b) General Construction Pumps shall comply with the requirements of BS EN 60335, BS 4082 Parts 1 and 2 and BS 5257 as applicable. Pumps should be ‘type’ tested in accordance with the requirements of BS EN ISO 9906 and shall be selected to give the correct fluid flow rate. Test certificates and performance curves shall be provided. Pumps and their drives shall be segregated such that failure of pump seals shall not result in damage to drive motors. The pump casing shall be split to ensure easy maintenance including the removal of half casing and impellers, without disturbing any of the water pipe connections or valves. AJC 05/07 Section 2.2. / 2 SECTION 2.2. – PLANT ITEMS Where pumps have glands they shall be so arranged that the removal of the packing can be carried out with the minimum disturbance. The design of the pump shall be such that no external source of water supply is required for gland sealing. Precautions shall be taken to prevent gland leakage water entering the bearing housings. Where bearings are of the ball or roller type the inner face shall be fitted directly onto the shaft and shall be located by a machined shoulder on the shaft. Where the pumps are operated intermittently, special care shall be taken to prevent brinelling of the faces while the pumps are not in operation. All bearings shall be oil tight. In the case of vertical spindle pumps the weight of the pump impeller and shaft shall not be taken by the motor bearings, but by a thrust bearing for which ample access shall be provided for examination and maintenance. Provision shall be made at each end of the bearing to prevent oil or grease being thrown off outside the bearing housing or creeping along the shaft. In the case of vertical spindle pumps pumping town or treated water, all bearings which are situated below water level shall be water lubricated. Pumps with bearings requiring cooling water shall be provided with all the necessary pipework, valves, strainers and header tanks for this purpose. All couplings and any intermediate shafting shall be efficiently guarded. Where pumps and motors are mounted on a common bedplate, the bedplate shall be of ample proportion and stiffness to withstand all loads likely to be experienced in service. Anti-vibration protection shall be provided in accordance with the relevant clauses of this Specification. The Contractor shall ensure that the complete unit is efficiently balanced to eliminate noise and vibration. Belts, where fitted, shall be correctly aligned and tensioned. AJC 05/07 Section 2.2. / 3 SECTION 2.2. – PLANT ITEMS 126.96.36.199. Direct Electric Water Heaters These shall be of one of the following types, with a water capacity and electrical loading as indicated. (a) Cistern Type – for wall or floor mounting compromising water chamber and ball valve, insulated with polyurethane foam or fibreglass, the whole enclosed within a corrosion-proofed steel casing finished in white stoved enamel. The heating unit shall be controlled by a stem type thermostat adjustable between 32°C - 82°C. The unit shall be provided with suitable connections for cold water inlet, overflow and hot water outlet. The break tank shall be fitted with a metallic 15mm ball valve to BS 1212: Part 2 and fitted with polythene float. Refer to Particular Specifications for detail. (b) Storage Type – cistern fed. The construction shall be generally as for the cistern type above, except that there shall be no integral break tank. The unit shall be provided with suitable connections for cold water inlet and hot water outlet and vent. Refer to Particular Specification for details. (c) Open Outline Wall Mounted Type The construction shall be generally as for cistern type above. The unit shall be provided with a suitable connection for cold water supply and a swivel spout for hot water delivery. Refer to Particular Specification for details. AJC 05/07 Section 2.2. / 4 SECTION 2.2. – PLANT ITEMS (d) Instantaneous Type The cold water inlet shall be connected to a solenoid valve incorporating a water filter to give ON/OFF control of water to the unit. A restrictor valve shall be fitted to compensate for water pressure fluctuations. A control panel to the front of the casing shall incorporate a temperature selector device and a push-button control to activate the solenoid valve and heater element. A self resetting thermal cut out shall be incorporated in the unit, to protect against water supply failure and prevent excess temperature. A neon indicator shall be provided on the control panel to give indication of ‘power on’ to the unit. The whole shall be enclosed in a sheet steel with stoved enamel finish casing. A swivel spout shall be fitted for water delivery. Refer to Particular Specification for details. (e) Vented Point-of-Use Heater Point-of-use electric hot water heater shall be suitable for under or over sink/basin use. The heater shall be 7 or 10 litre capacity, special alloy sheathed immersion element for long life and resistant to hard water 1kW/3kW rating, as indicated, anti-frost device, temperature lock control for user safety, over temperature safety device, plastic or copper water chamber and long life moulded plastic outer casing. The point of use heater shall only incorporate the heater manufacturer’s vented taps/mixer assembly to ensure that any steam build up is vented safely to atmosphere. Refer to Particular Specifications for details. AJC 05/07 Section 2.2. / 5 SECTION 2.2. – PLANT ITEMS 188.8.131.52. Pneumatic Hot Water Expansion Vessel Pneumatic hot water expansion vessels shall be to BS 6144 and shall be WRc approved and listed. Vessels shall contain an EPDM rubber bag (WRc approved material) with an access hatch in accordance with BS 470 and constructed from low carbon pressed steel to BS EN 10028-7. 184.108.40.206. Calorifiers Calorifiers shall be manufactured in accordance with BS 853. They shall be provided with mild steel shell and tubeplates. Heating surface shall be manufactured from solid drawn copper and shall prevent vibration of the tube bundle. Tube bundles shall be withdrawable. End caps and headers shall be manufactured from cast iron and shall be provided with a flanged connection to the main shell. Pipe connections shall be flanged to BS EN 1092-1 for pipes 65mm diameter and above. They shall be screwed to BS 21 for smaller sizes. Calorifiers shall be provided as horizontal units, unless specifically described as vertical elsewhere in this specification. Calorifiers shall be provided with mild steel channel and angle support frames to the manufacturer’s standard detail. Frames shall be finished in grey primer. Each calorifier shall be provided with the following mountings. The mountings shall comply with the appropriate Sections of this Specification. (i) Primary flow and return connections with isolation valves and commissioning sets on water to water calorifiers. (ii) Controls as described elsewhere in this Specification. (iii) Secondary flow and return connections, with isolation valves. (iv) Drain connections. AJC 05/07 Section 2.2. / 6 SECTION 2.2. – PLANT ITEMS (v) Temperature gauge and pressure gauge on the shell in the calorifiers. (vi) Self sealing combined temperature and pressure test point on the primary and secondary flow and return connections on hot water units. (vii) Safety valve and drain pipe mounted on the shell. The valve shall be enclosed spring type complying with BS EN ISO 4126-1. 2.2.2. Pressurisation For Hot Water Heating Systems 220.127.116.11. General In the installation of the equipment the following publications shall be taken into consideration: (a) Guidance note PM5 Part C from the Health and Safety Executive. (b) Water Supply (Water Fittings) Regulations 1999. (c) Department of the Environment Standard Specifications M&E No. 3 (1986). (i) Pressurisation shall be effected by one of the following methods:- o Nitrogen gas pressurisation system o Sealed diaphragm vessel system o Constant running pump system (ii) Pressurising systems and their controls shall be arranged to fail-safe. (iii) Pressurising equipment shall be of packaged construction with provision for single connection to boiler plant and to the boiler plant control systems. Where practicable it shall be mounted on a common base frame. (iv) Pressurising equipment controls shall be arranged with lockable isolating valves and drain valves which safely enable control functions to be tested whilst the boiler plant remains in service. AJC 05/07 Section 2.2. / 7 SECTION 2.2. – PLANT ITEMS (v) Pressurising pumps shall be seized having due regard for the expected system operating conditions. (vi) Provision shall be made for quick filling the heating system in parallel with the make-up water system provided for normal service. (vii) The pressurisation equipment shall be subject to the Client’s insurance company’s inspection. (viii) All pipework connections shall conform to the relevant section of this specification and the equipment shall be fitted with a drain valves to enable the complete draining in isolation from the heating system. 18.104.22.168. Sealed Diaphragm Vessel Systems a. These shall not be used to pressurise HTHW systems. b. The equipment shall be provided as purpose made sets comprising feedwater connections, holding tank(s), pump(s), expansion vessel(s) with internal flexible diaphragm(s), heating system connections and all necessary controls, safety devices and power connections. c. The expansion vessels shall be constructed in accordance with BS 4814 and shall have replaceable diaphragm. Unless otherwise indicated vessels shall be Grade 1. d. The make up water system shall include a cumulative meter and shall be controlled to deliver water at rates consistent with recording accuracy. e. Each set shall have a pump or duplicate pumps as indicated. The duty pump shall be controlled by a pressure sensor set to ensure minimum static pressurisation of the heating system. Where duplicate pumps are required, duty, standby and changeover controls shall be provided (as for Gas Pressurisation Systems). Pumps shall be installed with strainers and isolating valves, and with non-return valves as appropriate. AJC 05/07 Section 2.2. / 8 SECTION 2.2. – PLANT ITEMS 22.214.171.124. Constant or Intermittent Running Pump Systems a) The equipment shall be provided as purpose made sets compromising feedwater connections, holding tanks, duplicate pumps, expansion vessel(s), connections to the heating systems and all necessary controls, safety devices and power connections. b) A strainer, non-return valve and isolating valves shall be provided for each pump. The connection to each heating system shall be through pipes and/or vessels having sufficient volume to contain the total quantity of water expanded from the heating system whilst any boiler is firing through its temperature control differential range. Pressure vessels shall meet the requirements as for Gas Pressurisation Systems. 2.2.3. Heat Emitters 126.96.36.199. Radiators Steel radiators shall be fabricated from not less than 1.25mm thick mild steel, welded at the seams and strengthened by spot welding between waterways. They shall be free from distortion. All radiators shall be tested at works to a hydraulic gauge pressure of 6.9 bar unless otherwise indicated. The radiator heating surface provided in any room shall be not less than the areas indicated. Radiators shall be supplied and be finished with one coat of primer before leaving works. Where radiators are required other than steel panel type, details will be provided in the Particular Specification. The positions and heights above floor of all radiators shall be confirmed with the Engineer. A minimum clearance of 100mm shall be provided between the floor and the underside of any pipe serving a radiator. The minimum clearance between the floor and the underside of the radiator shall be 150mm. Radiators shall be kept clear of walls when supporting brackets and stays are built-in, otherwise the clearance shall be in AJC 05/07 Section 2.2. / 9 SECTION 2.2. – PLANT ITEMS accordance with the manufacturer’s standard bracket details. Radiators shall be provided with union valves, with non-metallic wheel handles on flow connections and with lockshield on return connections, unless fitted with thermostatic radiator valves. An air cock or air vent plug shall be fitted to each radiator and be arranged so that the water-ways can be completely evacuated of air when operated. Supports for radiators against lightweight partitions shall be designed to transit the weight to the floor and shall be screwed to or built into the floor; top stays may be screwed to the partition to provide stability to the radiator. Where radiators are fed by a straight section of pipework which is beneath the radiators and is more than 10m long, the radiator brackets shall be of the suspended pattern or other approved type designed to permit free movement due to expansion and contraction of the pipework. (Pipe sets of under 225mm shall be deemed straight pipework). When supporting column radiators fixed to lightweight partitions each bracket shall be screwed on to a vertical strut of not less than 50x6mm thick mild steel flat arranged to transmit the weight to the floor; the bottom of the strut shall be fixed to the floor. Radiators shall be supported in accordance with manufacturer’s recommendations. The Contractor shall include for taking down radiators once for painting by the Main Contractor, and re-fixing when painting is completed. The contractor shall also include for existing radiators to be disconnected, taken down and thoroughly washed out, and re-fixed after being wire- brushed and painted by the Main Contractor where indicated. 188.8.131.52. Convectors Convectors shall be of types, ratings and dimensions as indicated. The manufacturer’s declared ratings shall have been obtained from tests. AJC 05/07 Section 2.2. / 10 SECTION 2.2. – PLANT ITEMS Unless otherwise indicated heater elements shall be enclosed in casings purpose made by the convector manufacturer. The casings shall have air inlet openings at the bottom and outlet grilles at the top, fitted with internal dampers operated by lever or knob on the outside of the casing. The casings shall be free from rough edges and shall be treated with a rust inhibitor and finished with primer. The elements shall be of copper or steel tubes fixed securely to the flow and return headers with non-ferrous fins not thinner than 1mm bonded to the tubes. Copper tubes shall meet the test requirements of BS EN 1057 R250. The position and heights above floor of convectors shall be agreed with the Engineer. Where recessed or built-in convectors have been indicated the Contractor shall supply details of the openings and of any fixings or framing required. Wall-mounted convectors shall be secured by screws or bolts passing through holes in the back plate or frame of the unit, and a resilient gasket shall be inserted between the edges of the back panel and the finishes at the sides and top to prevent streaking of walls. A minimum clearance of 100mm shall be provided between the floor and any pipe serving a wall mounted convector. Two supports shall be provided for each wall mounted convector not exceeding 1.25m long and three supports for each convector longer than 1.25m. Convectors shall be provided with air cocks accessible from the front or side without dismantling the casings. Convectors shall be provided with union valves, with non-metallic wheel handles on flow connections and with lockshields on return connections, unless thermostatic control valves are fitted. The casing of fan assisted convectors shall be lined with sound absorbent material to minimise the emission of noise. The motor controllers shall be integral with the convector casings. The motors shall be resiliently mounted. The sound power level of the fan when operating shall be within the limits of the noise rating criterion as indicated. Air filters shall be of a permanent and cleanable type and shall be easily removable. AJC 05/07 Section 2.2. / 11 SECTION 2.2. – PLANT ITEMS Special requirements for local thermostatic booster clock control shall be as indicated. 184.108.40.206. Underfloor Heating The Underfloor heating system shall comprise polybutylene pipe laid on custom made backing plates designed for the purpose, installed below the floor screed as part of the make-up of the floor. The floor shall have sufficient insulation in the make-up to comply with the thermal requirements in the current Building Regulations. The system shall include all accessories and a heating circuit manifold, suitable for connection of flow and return heating pipes. Accessories shall include system plate joining clips, edge insulation strip, damp proof membrane thermometers, drain cocks and air vents, room thermostat and control valve as necessary. 220.127.116.11. Electric Tubular Heaters Electrical tubular heaters shall be as schedules elsewhere in this specification. 2.2.4. Air Conditioning And Ventilation Installations 18.104.22.168. Air Handling Units and Fans (a) General Requirements This section of the specification is written with packaged, air-handling plant as standard, however, the individual component specifications will also apply to such air-conditioning and ventilation plant constructed from separate components, in association with builders work chambers, or similar. All individual components of packaged air handling units shall comply with the appropriate Sections of this Specification unless otherwise indicated. AJC 05/07 Section 2.2. / 12 SECTION 2.2. – PLANT ITEMS (b) Construction Each assembly shall be of compact construction and shall consist of a rigid metal framework, with sheet metal insulated cladding at least 1.2mm thick, strengthened as necessary to prevent distortion and drumming. The insulation shall be 25mm thick minimum, and comply with the relevant clauses in this section covering insulation. The cladding shall be easily removable using quick release fasteners to obtain access for inspection and maintenance. All items shall be assembled by means of bolts, nuts, anti-vibration lock washers and nuts or approved quick release fastenings. All panels shall be of double skin construction, and built-in lifting points with eye bolts shall be provided. (c) Dampers, Filters and Fans Where air mixing sections are required the damper controls shall be suitable for connection to a single damper motor; a motor mounting bracket shall be provided. The arrangement of dampers shall ensure adequate mixing. A regulating damper shall be provided at the outlet of all air handling units to enable the air volume required to be correctly balanced. This damper shall be locked in position, once the correct air volume has been established. Unless otherwise indicated high capacity bag filters shall be installed having an efficiency of not less than 90% when tested in accordance with ASHRAE 52-76 dust arrestance test (or Eurovent 4/5).Bag filters shall be preceded by washable or throw away type panel filters as indicated. Both types of filters shall be supported on a galvanised steel framework, constructed to ensure that no noise, distortion or vibration occurs when the systems are operating. AJC 05/07 Section 2.2. / 13 SECTION 2.2. – PLANT ITEMS Edge seals shall be incorporated to ensure that all air entering the unit shall pass through the filters. The seal shall not be affected by the removal of the filters. Both types of filters shall have manometers fitted to indicate the pressure drop across the media. Filter Clean and Change Filter labels shall be provided on manometers across both filters. Fan shall be either forward or backward bladed centrifugal type, Vee belt driven to BS 3790. Unless otherwise indicated fan motors shall be mounted internally in the unit. Noise and vibration from the fans and motors shall be isolated from the building by means of the use of anti- vibration mountings, flexible connections and attenuators. (d) Anti-Condensation Features Where units incorporate humidifying plant and/or cooling coils the internal surfaces of the units liable to be affected by any free water produced shall be protected with anti-corrosion paint or a similar finish. Such units shall have adequate drain trays to collect water; the drain trays shall be extended, or other means of collection shall be provided, to ensure the removal of any water deposited or condensed in adjacent sections. Trays collecting cooled water shall be insulated to prevent condensation on the outer surface of the tray. All drain trays shall incorporate a deep seal trap of adequate depth to prevent air escaping when the plant is in operation. (e) Thermal Insulation Thermal insulation shall be securely fixed to all sections handling heated or cooled air; and in the latter case it shall include a vapour seal. Thermal insulation shall be at least 25mm thick and of a material having a thermal conductivity less than 0.04 W/m°C. Where thermal (or acoustic) insulation is fitted internally it shall be securely fixed and shall be either inherently proof against erosion or protected against erosion; in areas where there may be free moisture or condensation the insulation shall have surface protection to prevent waterlogging. AJC 05/07 Section 2.2. / 14 SECTION 2.2. – PLANT ITEMS (f) Fans – General Requirements Fans shall be capable of giving the specified performance when tested in accordance with BS 848. Although estimated values of the resistance to airflow of items of equipment may be indicated this does not relieve the Contractor of the responsibility for providing fans capable of developing sufficient pressure to deliver the required air volume through the system. The Contractor shall make his calculations of the system resistance available to the Engineer for checking. The make and design of fans shall be approved by the Engineer and evidence supporting claimed noise levels and fan efficiencies shall be submitted for approval prior to placing the order. Where fans are supplied with noise attenuators full details of the attenuators shall be given. Belt driven fans shall be fitted with pulleys suitable for V-belts; pulleys of the taper lock type may be used for drives up to 30 kW output. Alternatively, and in any case above 30kW output, pulleys shall be secured to the fan and the motor shafts by keys fitted into machined keyways. Pulleys shall be keyed to the fan shaft in the overhung position. Keys shall be easily accessible so that they can be withdrawn or tightened and they shall be accurately fitted so that the key head does not protrude beyond the end of the shaft. Machined bolts, nuts and washers only shall be used for the assembly of fans; all bearing surface for the heads of bolts or washers shall be counterfaced. Holding down bolts for fans and motors shall be square in section under the head or be fitted with lugs to prevent them turning in the fan base plate when the nuts are tightened. Any fan which is too large or too heavy for safe manhandling shall be provided with eyebolts or other lifting facilities to enable mechanical lifting equipment to be used. Means of electrical isolation shall be provided at each fan. AJC 05/07 Section 2.2. / 15 SECTION 2.2. – PLANT ITEMS (g) Centrifugal Fans Unless otherwise indicated centrifugal fans larger than 7.5 kW output shall be of the backward bladed type having fan total efficiencies of not less than 78%. Below 7.5 kW fans may be either forward curve or backward curve type. Fan casings shall be constructed of mild steel plates with angle stiffeners and base angles to ensure freedom from drumming and shall be suitable for operation at the maximum static pressure of the system. Fan casings shall be constructed so that impellers can be easily withdrawn after installation. Outlets shall be flanged and inlets shall be flanged or spigoted as indicated except that for suction pressures greater than 1000 Pa where inlets shall be flanged. Impellers shall be of mild steel (or aluminium where indicated) of riveted or welded construction, with spiders or hubs of robust design, and shall be capable of running continuously at ten per cent in excess of normal speed. Impellers shall be keyed to a substantial mild steel shaft and the impellers with shaft shall be statically and dynamically balanced and tested for overspeed before leaving the maker’s works. Shaft bearings of belt driven single inlet fans shall be truly aligned and rigidly mounted. Double inlet, double width fans shall have a pedestal mounted bearing at each side of the fan. Fan bearing shall be ring oiled sleeve bearings, or ball or roller type. Where silence is important the bearing pedestal shall not be attached to the fan casing, and ring oiled sleeve bearings shall be applied. Unless otherwise indicated centrifugal fans shall be driven by electric motors through V-belt drives. (h) Axial Flow Fans Axial flow fans shall be either the single stage type or the multi-stage contra-rotating type with each impeller mounted on an independent motor, and having an efficiency of not less than 60%. Casings shall be rigidly constructed of mild steel stiffened and braced to obviate drumming and vibration. Cast iron or fabricated steel feet shall be provided where necessary for bolting to the base of supports. Inlet and AJC 05/07 Section 2.2. / 16 SECTION 2.2. – PLANT ITEMS outlet ducts shall terminate in flanged rings for easy removal. The length of the duct casing shall be greater than the length of the fan(s) and Motor(s) in order that the complete section may be removed without disturbing adjacent ductwork. Electrical connections to the motor(s) shall be through an external terminal box secured to the casings. The external terminal box shall be connected to the conduit system by means of a looped flexible connection. Impellers shall be of steel or aluminium; the blades shall be secured to the hub or the blades and the hub shall be formed in one piece. The hub shall be keyed to a substantial mild steel shaft and the whole statically and dynamically balanced. Blades shall be of aerofoil section. Shafts shall be carried in two bearings which may be ball, roller or sleeve type. Lubricators shall be extended to the outside of the casing. Where axial flow fans are driven by a motor external to the fan casing the requirements for pulleys and V-belt drives and guards as specified elsewhere shall be met. Unless otherwise indicated a guard is not required for any part of a drive which is inside the fan casing. An access door of adequate size shall be provided, in the fan casing or adjacent ductwork. Where axial flow fans of the bifurcated type are indicated the motors shall be out of the airstream. Motors may be placed between the two halves of the casings in the external air or may be placed within the fan casing provided that effective ventilation is given to the motor. Where hot gases or vapours are being handled the motor and the bearings shall be suitable for operation at the temperature they may experience. Fans which do not connect to a suction or discharge duct shall be supplied with a bellmouth inlet, or discharge as required. (i) Propeller Fans Impellers shall be of steel or aluminium and shall be fastened to the hub or the impellers and hub shall be formed in one piece. The bearings may be ball, roller, or sleeve type. Propeller fans may be ring mounted AJC 05/07 Section 2.2. / 17 SECTION 2.2. – PLANT ITEMS or diaphragm mounted or in a casing as indicated. Where they are mounted in a casing the casing shall be longer than the length of the fan and the motor. The casing shall be of steel, shall have flanged ends and shall incorporate an inspection door. A terminal box shall be mounted externally on the casing. The tip speed of fans shall not exceed 20m/s. Propeller fans shall not be installed to work against a resistance of more than 50Pa. (j) Protectively Coated Fans and Special Enclosures Protectively coated fans shall meet the appropriate requirements of the preceding clauses relating to fans generally and to particular types of fans; the form of protection shall be as indicated. Where a protective coating is required for use with corrosive gases the coating shall cover all parts of the complete fan, motor and casing assembly which will be in contact with the corrosive gases. No fan shall be installed if the protective coating has been damaged in any way. Flame-proof enclosures shall comply with the requirements of BS EN 60079 for the appropriate gas group. BS 229:1957 (Specification: Flameproof Enclosures of Electrical Apparatus) remains current to maintain validity of existing certificates and to grant supplementary certificates. (h) Mechanical Roof Extract Fans The fans used in roof extract units shall meet the appropriate requirements of the preceding clauses relating to fans generally and to particular types of fans. Cowls and bases shall be of weatherproof material e.g. steel galvanised after manufacture, aluminium, aluminium magnesium alloy or glass fibre, or as indicated. Enclosures shall be formed so as to ensure a weatherproof fit to the building structure. Adequate access to motor terminals and lubricating points shall be provided by means of hinged cowls or otherwise as appropriate. Backdraught dampers and/or fire release dampers shall be provided where indicated. AJC 05/07 Section 2.2. / 18 SECTION 2.2. – PLANT ITEMS Apart from means of electrical isolation at each unit, additional isolation shall be provided as indicated. (l) In-Line Centrifugal and Mixed Flow Fans In-line centrifugal and mixed flow fans may be incorporated subject to the approval of the Engineer provided that full details of ratings, noise level, dimensions and construction are given in the tender. Fans of these types above 7.5 kW output will not normally be accepted. (m) Twin Fan Units Duplicate fan assemblies shall comply with the appropriate sections of this specification for the fans themselves and shall incorporate automatic or manual changeover facility as indicated. A non-return damper arrangement shall be fitted to prevent short circuiting. (n) Window and Wall Fans Window and/or wall fans shall be incorporated where indicated. Such fans will be to the particular manufacturer’s standard construction. All wall mounted fans must be installed by the use of a sleeve built into a wall for both solid and cavity wall constructions. The sleeve shall be of such length as to span the total thickness of the wall. Such fans may be either square or circular to the agreement of the Engineer. Back-draught dampers shall be incorporated into both wall and window type fans. (o) Ceiling Fans For purpose of de-stratification, ceiling fans shall be used where indicated. AJC 05/07 Section 2.2. / 19 SECTION 2.2. – PLANT ITEMS The blades shall be made from high grade steel with an epoxy polyester powder coated finish and shall be factory matched and electronically balanced in sets of three. Downrods shall be of steel tube with epoxy polyester powder coating and be complete with suspension kit and loop. Motors shall be suitable for operating temperatures up to 40°C. All ceiling fans shall be capable of reverse operation. 22.214.171.124. Cooling Coils (a) General All air cooling casings shall be of sheet steel not less than 1.2mm thick with angle framing at each end drilled ready to receive the counter flanges on the connecting ductwork and shall be galvanised after manufacture. Cooler batteries shall be constructed either of copper tubes with copper gills or fins, tinned after manufacture, or of copper or aluminium tubes with aluminium gills or fins, as indicated, the secondary extended cooling surfaces shall be bonded to the primary cooling tubes. Headers for copper tube batteries shall be of copper, bronze or cast iron; for aluminium tube batteries they shall be of aluminium or steel. The bottom of a casing shall be made in the form of a watertight drip tray complete with drain connection. The drain shall be fitted with a water seal to prevent the ingress and discharge of air to and from the system; the drain pipe shall be run to the nearest sump or gully. A separate drain trough shall be provided for at least each 1.2m height of coil. Water shall not be carried over from a cooler into the airstream; an eliminator section shall be fitted where necessary to prevent carry-over. The resistance to air flow shall not exceed 125 N/m2 and the face velocity shall not exceed 2.5m/s. Before leaving the maker’s works coolers shall be tested to 1½ times the working pressure or to 700 kPa whichever is the greater. Eliminator plates shall be fitted if the face velocity exceeds 2.25 m/s. AJC 05/07 Section 2.2. / 20 SECTION 2.2. – PLANT ITEMS Cooling coils shall be supported so that their weight is not transmitted to ductwork and so that they can be removed without disturbing adjacent ductwork. Inspection doors shall be provided on both the upstream and downstream sides of the cooler. On any system where the static pressure at the cooler exceeds 750 Pa (75mm of water) airtight cover boxes shall be provided over the headers and bends; provisions shall be made for draining the cover boxes. Coils with fins which have been badly damaged during transport or erection or which have become fouled or coated with builders material will not be accepted. (b) Chilled Water Coils Coils shall be arranged in a contra-flow pattern, with the flow of chilled water entering at the leaving air end and leaving at the entering air end. The flow and return connections and headers shall be so arranged to ensure an equal flow of water through all the tubes. Provision shall be made for expansion of the tubes, for effective venting of the cooler battery headers and tubes. Connections up to and including 65mm bore shall be screwed or flanged; connections 80mm diameter and above shall be flanged. Isolating valves shall be provided on inlet and outlet connections, arranged so as to facilitate removal of the cooling coils. Chilled water cooling coils shall be tested and rated in accordance with BS 5141: Part 1. (c) Refrigerant Direct Expansion Air Cooling Coils Coils shall be provided with refrigerant distributors, and connections to the tubes shall be designed to ensure an equal flow of refrigerant to each tube. Return (or suction) connections shall be arranged so as to ensure complete drainage of any oil in the cooler. Coolers shall be dehydrated and sealed after manufacture. AJC 05/07 Section 2.2. / 21 SECTION 2.2. – PLANT ITEMS The thermostatic expansion valve which shall incorporate an external equaliser line shall maintain the design degree of superheat at the evaporator outlet; the remote sensing bulb shall be securely fixed to the evaporator outlet piping in a position where the degree of superheat can be correctly sensed. All refrigerant spaces shall be tested at the maker’s works. 126.96.36.199. Air Heater Batteries (a) General Casings shall be of galvanised sheet steel not less than 1.2mm thick with angle framing at each end drilled ready to receive the counter flanges on the connecting ductwork. Heaters shall be supported so that their weight is not transmitted to ductwork and so that they can be removed without disturbing adjacent ductwork. Inspection doors shall be provided on both the upstream and downstream sides of the heater. The casing shall be airtight to meet the air pressure requirements of the system with appropriate arrangements to accommodate expansion where applicable. Air heating coils shall be tested and rated in accordance with BS 5141: Part 2. (b) Hot Water and Steam Types The heater battery shall be one of the following types:- a) Copper tubes with non-ferrous gills or fins, fitted into copper or bronze headers. b) Copper tubes with non-ferrous gills or fins, fitted into steel or cast iron headers. c) Mild steel tubes with mild steel gills or fins, fitted into steel headers, the whole protected against corrosion. AJC 05/07 Section 2.2. / 22 SECTION 2.2. – PLANT ITEMS d) Aluminium tubes with aluminium gills or fins, fitted into aluminium or steel headers. For types (a) and (b) above the copper tubes shall comply with the test requirements specified in the relevant standards and the secondary extended heating surface shall be of either aluminium or copper. The secondary heating surface shall in all cases be bonded to the primary heating tubes. Where anti-frost heaters are fitted in fresh air intakes they shall be low resistance plain unfinned tube heaters. The flow and return connections and headers shall be arranged to ensure an equal flow of water or steam through the tubes. Connections up to and including 65mm bore for pressure up to 350kPa shall be screwed or flanged; connections 80mm diameter and above for all sizes where the heating media pressures are above 350kPa shall be flanged. Provision shall be made for expansion of the tubes, for effective venting of the heater battery and the connections and for draining of the heater battery. Isolating valves shall be provided on inlet and outlet connections, arranged so as to facilitate removal of the heater battery. On any system where the static pressure at the heater exceeds 750 Pa (75mm of water) airtight cover boxes shall be provided over the headers and bends. The resistance to air flow of the heater shall not exceed 65Pa and the face velocity shall not exceed 4m/s. Before leaving the maker’s works the heater shall be tested to 1½ times the working pressure or to 700kPa whichever is the greater. (c) Electric Type Electric air heaters shall consist of a number of heating elements of the enclosed non corrodible type mounted in a sheet steel casing. The elements shall be so installed that they can be removed for cleaning or renewal without dismantling ductwork. The surface temperature of the AJC 05/07 Section 2.2. / 23 SECTION 2.2. – PLANT ITEMS elements shall not exceed 150°C. A high temperature limit device with hand reset button shall be incorporated. Each element shall be complete with a second set of terminals to operate a failure warning light. The control of electric air heaters, shall be interlocked with an air flow control of the vane or pressure type which shall isolate the heating elements from the electricity supply in the event of failure of air flow. The heater shall be arranged with elements of the same number, or a multiple of the number, of steps as the control required. All heaters and heater sections of more than 3kW loading shall be balanced over three phases and the complete heater bank shall be arranged for balanced operation on a 3-phase 4-wire system and be stepped by the controller in 3 kW stages, unless otherwise indicated. Below 3 kW the stepped loadings shall be in 1kW increments. The connections from each element shall be taken to a readily accessible terminal box arranged for conduit entry. Each heater section shall be separately fused and the neutral point of all 3-phase star- connections sections shall be brought out to a link in the terminal box. Near any hot areas the wiring insulation shall be of appropriate quality. The total resistance of the heater to air flow shall not exceed 25 Pa and the velocity through the free area shall not exceed 6m/s. The installation of electric heater batteries shall comply in all respects with the requirements of the local Fire Authority and wiring in accordance with the 16th Edition of the IEE Regulations. 188.8.131.52. Air Filters (a) General Filters shall operate to at least the efficiencies specified in this Section. They shall be complete with holding frames sufficiently robust to ensure that no distortion occurs in operation. All filters shall be installed with edge seals which shall prevent air bypassing the filters. The seals shall AJC 05/07 Section 2.2. / 24 SECTION 2.2. – PLANT ITEMS remain effective even though the cells are periodically removed and refitted. Filters shall be arranged so that there is easy access for cleaning and/or removal and refitting. A differential pressure gauge of the inclined manometer type shall be provided for each filter bank and the gauge shall be fixed in such a position outside the casing that it is accessible and easily read. Where indicated, variable ranges pressure switches shall be installed at each filter bank to provide remote indication when a filter requires servicing. One set of spare filter media shall be provided including a servicing rack where applicable. A differential pressure gauge of the dial or inclined manometer type shall be provided for each filter bank and shall be fixed in such a position outside the duct system that it is accessible and easily read. The gauge shall be marked to show maximum pressure differential indicating a filter change requirement. Air velocity through filters shall be such that the clean resistance (or operating resistance of automatic filters) as indicated is not exceeded and that filter fabric or oil is not carried over into the system. Filter assemblies shall be of a standard type and dimensions and shall be such that replacement filter medium is readily available from a number of manufactures. The Contractor shall provide to the contract one spare set of filter media, that he shall hand to the Engineer upon completion of the Contract. (b) Fire Precautions Where a flameproof filter medium is specified the material shall comply with the following requirements when tested in accordance with the relevant standard. (i) Duration of flaming No test specimen shall continue to flame for more than 8 seconds after the igniting flame has been removed. AJC 05/07 Section 2.2. / 25 SECTION 2.2. – PLANT ITEMS (ii) Extent of after-glow After-glow shall not spread beyond the area of material damaged by flaming. (iii) Length of material which chars or melts The average length of material which chars or melts on the six specimens shall not exceed 85mm and the maximum length of the charred or melted material in any one specimen shall not exceed 115mm. Where washable type flameproof filters are offered or specified the filter medium shall comply with the requirements above both before and after the washing treatment prescribed in the appropriate standard. Where the filter medium is required to be flameproof and the filter is built into sheet metal ducting, the ducting shall be not less than 1.6mm thick for at least 1.8m upstream and 1.8m downstream of the filter; the immediate frames or cases of the filter elements shall be of material complying with BS 476: Part 1, clause 7, Class 1. For viscous types of filter the liquid shall have a flash point not less than 180°C. (c) Dry Replacement Media Type Filters The air velocity at the face of the filter shall not exceed 3.0m/s. Filters of this type shall have an efficiency of not less than 90% based on the tests specified in ASHRAE 52-76 Dust Spot efficiency of Eurovent 4/5. (d) Open Cell Plastics Type Filters The filter medium shall be processed open cell foamed plastics and shall be washable. The element shall be supported on plastics coated steel wire formers with a metal frame. The face velocity shall not exceed 2.25m/s. Filters of this type shall have an efficiency of not less than 90% based on the tests specified in BS EN 779. AJC 05/07 Section 2.2. / 26 SECTION 2.2. – PLANT ITEMS (e) Viscous Unit Type Filters The design and construction shall be such that it is impossible to see any light through the filter cell initially and after the filter has shaken down during use. The face velocity shall not exceed 2.25m/s. Filters of this type shall have an efficiency of not less than 90% based on the tests specified in BS EN 779. Sufficient oil shall be supplied for initial operation plus one complete recharge. Any equipment or tools required for cleaning or recharge shall be provided at a convenient location adjacent to the unit. Instructions for the cleaning of the filter shall be mounted in a permanent manner adjacent to the filter bank. (f) Automatic Viscous Type Filters The filter shall comprise the complete equipment including motor, drive and viscous fluid tank. There shall be easy access to the tank containing the fluid. Tools and containers required for the removal of sludge shall be provided. The face velocity shall not exceed 2.5m/s and the operating resistance shall not exceed 125Pa. Filters of this type shall have an efficiency of not less than 90% based on the test specified in BS EN 779. The rate of the drive shall be set at the factory to give the required filtration at the operating resistance. The rate of drive shall be slow enough or the filter shall incorporate shielding devices, to ensure thorough draining from the freshly wetted surfaces, and no carry-over of oil. The unit shall be supplied complete with a replacement change of viscous fluid. (g) Automatic Fabric Roll Type Filters AJC 05/07 Section 2.2. / 27 SECTION 2.2. – PLANT ITEMS The filter shall comprise the complete assembly of filter frame, motor and drive and filter medium. The filter shall operate automatically, with provision for manual starting and stopping of filter movement; unless otherwise indicated automatic filter movement shall be controlled by the resistance across the filter. Provision shall be made for visual warning that the end of the clean filter medium is approaching. The driving motor shall be automatically switched off when the end of the filter medium is reached. Unless otherwise indicated the resistance of the filter shall not exceed 125Pa under normal operating conditions; the air velocity through the filter medium shall not exceed 2.5m/s. Filters of this type shall have an efficiency of 95% based on the tests specified in BS EN 779. Where the motor and/or gearbox is mounted in the air stream the electrical insulation and/or lubricants shall be suitable for the temperature range of the system. (h) Electrostatic Type Filters The filter shall include a baffle or mesh to ensure even air flow, an ionizer section, a collecting section, frames to hold the main sections and capable of being built into a filter bank, and complete with automatic washing plant. Where indicated the washing plant shall include the pump to provide the pressure at the washing nozzles, the hot water storage cylinder and the necessary pipework, fittings and valves. Where the filter is built into sheet metal ducting the enclosing ducting shall be watertight and two watertight access doors with glazed portions for inspection purposes, two bulkhead light fittings and a drain connection shall be provided. Where the filter is built into a builder’s work enclosure the doors and light fittings shall be provided by the Contractor and handed to the Main Contractor for building-in. The electrical control panel shall include all necessary rectifier and transformer equipment, circuit-breakers, a milliameter, washing control panel and a light to indicate that power is on and a device to prevent the panel being opened when the power is on. An interlock shall be provided to prevent wash down while the filter is energised. Access to high voltage areas at filters shall be protected by safety interlocks including the discharge to earth of HT equipment. Adjacent to all access doors there shall be clear AJC 05/07 Section 2.2. / 28 SECTION 2.2. – PLANT ITEMS indication of the danger of high voltage. On the larger models platforms and ladders shall be provided for access to the valves, spray nozzles and the travelling mechanism of the washing plant. Spare spray nozzles shall be provided to replace 10% of the total installed. Sufficient spare ionizer wires shall be provided to replace 50% of the total. The filter shall have an efficiency of not less than 90% based on the tests specified in BS EN 779. All wiring between the filter control panel and the filter cells shall be carried out by the filter manufacturer. (i) Inertial Separation Filters Inertial separation filters shall be constructed from precision formed cells of pressed and continuously welded construction, the cells being incorporated into a main duct or transition housing. The cells shall be manufactured from Corten steel or other such steel that is resistant to corrosion and erosion. The cells shall be arranged so that 90%of the air entering will leave by the clean side, the remaining 10% of the air will pass through bleed slots located at the far end of the unit. The bleed air shall convey the dirt particles into a collection box from which these particles will be drawn away from the filter by an axial fan forming an integral part of the inertial separator. The duty of the fan will be such that the dirt particles will be conveyed from the filter and deposited as indicated. AJC 05/07 Section 2.2. / 29 SECTION 2.2. – PLANT ITEMS 2.2.5. Terminal Units 184.108.40.206. Fan Coil Units (a) General Fans, filters, cooling coils, heating coils, motors and thermal and acoustic insulation shall comply with the appropriate Sections of this Specification, with the following exceptions or alternatives: i. Fans may be of the forward curved centrifugal type and may be of aluminium, reinforced glass fibre or rigid plastic material. ii. Air Filters may be of nylon fibre, glass fibre or cellular plastics material and shall have a minimum efficiency of 60% when tested in accordance with BS EN 779. iii. Motors shall be quiet running and shall have sleeve bearings either factory lubricated for life or with large oil reservoirs to minimise servicing. Motor windings and electrical components shall be impregnated or protected to avoid trouble from condensation. (b) Casings Casings shall be of sheet steel not thinner than 1.2mm and shall be protected against corrosion and finished inside and outside with stoved primer. All corners shall be rounded. Casings shall include space for pipework connections and valves, and there shall be ready access to the fan and motor, the filter, the damper, the drain pan, and pipework connections and valves. (c) Components Fans shall be of the centrifugal type. Cooling and heating coils shall be at least two-row and shall include an air cock. All units shall include an easily removable and replaceable air filter capable of treating the total AJC 05/07 Section 2.2. / 30 SECTION 2.2. – PLANT ITEMS air volume. Drain pans shall be either of sheet steel protected against corrosion or of plastic or reinforced glass fibre material and shall be arranged, and insulated where necessary, so as to ensure that no condensation is formed on the underside. Drain pans shall be large enough to collect all condensate from the coil, return bends and pipework connections and where indicated the valve pack; they shall be removable and shall have a slight fall to the drain connection. (d) Arrangement of Units The arrangement of units, i.e. whether they be wall, floor or ceiling mounted, the position of inlet and outlet grilles if any, the need for sheet metal casing etc, shall be as indicated. Where units are concealed, the Contractor shall ensure that adequate access is provided for the removal of a complete unit. (e) Controls, Dampers and Grilles Fan coil units shall have a control giving at least two running speeds and an ‘OFF’ position. They shall have connections for both fresh and recirculated air and if required shall include a damper which shall be adjustable to give up to 25% fresh air. Outlet grilles shall be adjustable to enable the direction of airflow to reset. On floor mounted units, supply grilles shall be on the top of the unit. (f) Noise Levels Casings shall be lined with material to act as both thermal and acoustic insulation (in accordance with sections 2.8 of this Specification). Fan and motor assemblies shall be complete with anti-vibration mountings. Noise data shall be provided and shall be based on tests in accordance with the Standard Test Code, or similar tests; full details of the testing technique and procedure shall be given by the Contractor. The data given shall include an octave band analysis of the sound power level of the unit. AJC 05/07 Section 2.2. / 31 SECTION 2.2. – PLANT ITEMS 2.2.6. Refrigeration Plant 220.127.116.11. Reciprocating Chillers (a) General Requirements This section deals with mechanical refrigeration plant and ancillaries for vapour compression refrigeration plant using halogen hydrocarbon refrigerants. All items of plant whether supplied separately or as a factory assembled package unit shall comply with the following sub-section unless superseded by the Particular Specification. Evaporators and Water Cooled Condensers shall be constructed to comply with BS 5500. The rating of al air to liquid chilling packages having a nominal cooling capacity above 7kW shall be tested for rating and performance in accordance with BS EN 14511. The refrigerant plant shall include compressor(s), evaporator(s) and condenser(s) all as indicated to suit the application for the work, the items shall be correctly matched to ensure satisfactory operation. The heat rejected at the condenser under maximum design conditions shall include the design heat load absorbed at the evaporator, the heat equivalent of the work done by the compressor and any other heat gains of the system. A full charge of refrigerant and lubricating oil shall be supplied together with all items necessary for the satisfactory functioning of the system. Complete control and instrumentation equipment including safety devices shall be included. Where a BMS system is specified for the project all refrigerant plant and equipment shall be suitable via the various controls, to be compatible with and controlled by the BMS systems. AJC 05/07 Section 2.2. / 32 SECTION 2.2. – PLANT ITEMS Packaged assemblies shall be resiliently mounted on a combined base plate and tubular framework requiring only the external water and electrical connections to be made on site. Complete data of plant operation and maintenance is to be made available to the Engineer together with a Schedule of Spare Parts and Repair Information at least four weeks before the issue of a practical completion certificate. (b) Compressors Hermetic sealed motor compressors may be used with the manufacturer’s standard equipment where they are supplied, as an entire refrigeration system and shall be completed at the Factory. Semi-hermetic and open type compressors shall be suitable for the type of refrigerant specified in the Particular Specification, and environmentally friendly. To comply with present day requirements, the refrigerant gas to be used in all compressors (unless circumstances dictate otherwise) shall be R134a. All compressors shall be driven by electric motors and may be of the reciprocating, centrifugal or screw type. Speed shall be such that the noise is kept to a reasonably low level consistent with the application and location of the machines. The complete compressor unit shall be mounted on an anti-vibration base reducing transmissibility from compressor to structure to below 10% of the untreated vibration rate. The Contractor shall supply all necessary foundation bolts. When one compressor is specified it shall be designed for the maximum cooling load; where two or more compressors are required the maximum cooling duty of the refrigeration unit shall be divided equally between the number of compressors. Lubrication shall be automatically arranged to suit either frequent starting of the compressor (under thermostatic control), or where AJC 05/07 Section 2.2. / 33 SECTION 2.2. – PLANT ITEMS compressors are required to run for prolonged periods without inspection. An oil separator shall be fitted to the compressor discharge line and shall be of the float and needle valve type and shall have an automatic return to the compressor crank case. Crank case oil heaters shall be provided and shall operate when the compressor is shut down. Semi-hermetic compressors shall include the following features:- i. All parts of the electric motor shall be suitable for contact with refrigerants and the associated lubricating oils, additional motor protection shall be provided against failure or partial failure of the gas cooling system. All valves on the refrigerant circuits shall be located in a readily accessible position and shall be provided with seal caps. ii. A rotary mechanical seal shall prevent loss of refrigerant at the driving shaft and the seal shall be effective for both long operating periods and short rest periods without leakage. Open compressors shall include or be suitable for the following:- i. Either direct drive of belt drive as indicated. ii. Compressor shall be dynamically balanced to minimise noise and vibration from internal rotating parts. iii. Isolating valves shall be open into recessed guides to keep operating sounds to a minimum. iv. Constructed to have low pressure drops to maximise efficiency. All compressors of duty in excess of 35kW cooling capacity shall incorporate capacity control and shall start unloaded. Hot gas by-pass capacity control shall not be used unless specifically indicated. Where low pressure cut outs are specified they shall be used to control the operation of the compressor, in which case the low pressure cut-out shall be the self restoring type with adjustable working differential. AJC 05/07 Section 2.2. / 34 SECTION 2.2. – PLANT ITEMS Liquid receivers shall be complete with inlet and outlet service valves, and a liquid sight glass be mounted vertically in the liquid line with integral filter. Means shall be provided for oil to return to the crank case from the suction gas header and for refrigerant gas (but not oil) to return to the suction manifold from the crank case. Crank case oil heaters shall be provided and shall operate when the compressor is shut down. An oil pressure relief valve or a bleed from the oil pump discharge back to the crank case shall be provided. Suction gas entry to the compressor shall be designed to reduce gas velocity so as to assist in releasing any entrained oil or dirt. Suction gas strainers shall be fitted. The following fittings shall be provided for all types of compressor:- a) Suction and discharge stop valves. b) Suction and discharge refrigerant gas pressure gauges with means of isolation. c) Oil pressure gauge. d) Oil sight glass. e) High and low pressure adjustable safety controls. f) Semi-hermetic compressors shall include the following features: i. The oil pump shall operate equally well under either direction of rotation. ii. Where the motor rotor is overhung a support bearing of adequate width shall be provided. iii. Additional motor rotor protection shall be provided against failure or partial failure of the gas cooling system. AJC 05/07 Section 2.2. / 35 SECTION 2.2. – PLANT ITEMS Compressors shall not be connected to run in parallel (i.e. with common discharge and/or suction lines). Where, to increase availability, it is required that any compressor shall be capable working with any condenser or evaporator, cross connections shall be provided and all major plant items shall be valved for isolation. (c) Evaporators Evaporators shall be designed in accordance with BS 5500 and the current standard practice, being suitable for direct expansion, chilled water or brine as required. Evaporators for water chilling installations unless otherwise indicated shall be of the shell and tube heat exchanger type. The evaporator shell, tube plates and end covers shall be of steel or cast iron; the tubes shall be of copper and may be of extended surface piping. The end covers shall be removable and the plant shall be arranged so that there is adequate space for cleaning and removal of the tubes. Isolating valves and flow and return connections shall be provided. Evaporators may be either the flooded type or the dry expansion type. The flow of refrigerant to dry expansion type evaporators shall be controlled by a thermostatic expansion valve(s); the flow of refrigerant to flooded type evaporators may be controlled by either a float device or a thermostatic expansion valve. In dry expansion type evaporators the velocity of refrigerant and the design of the refrigerant passages shall ensure that any oil present is carried over to the compressor. In flooded type evaporator to the compressor. Unless otherwise indicated the design evaporating temperature for direct expansion air coolers and for dry expansion shell and tube water chillers shall not be less than -1°C; for flooded evaporators it shall be not less than +1°C. A thermostatic expansion valve shall maintain the design degree of superheat at the evaporator outlet; the remote sensing bulb shall be securely fixed to the evaporator outlet piping in a position where the degree of superheat can be correctly sensed. Thermostatic expansion valves shall incorporate an external equaliser line. AJC 05/07 Section 2.2. / 36 SECTION 2.2. – PLANT ITEMS 18.104.22.168. Condensers (a) Air Cooled Condensers Condensers shall have copper tubes with aluminium fins or copper fins, where indicated; and for installations handling saline air they shall have copper tubes with copper fins. Condensers with fins which have been badly damaged during transport or erection or which have become choked or coated with builders’ materials will not be accepted. Minor irregularities in the fins shall be combed straight. Where air-cooled condensers are sited within a building and serve a compressor larger than 2.25kW the air outlet shall be ducted to the external air; condenser fan shall be capable of overcoming the extra resistance of this ducting. The condenser frame, supports and enclosure shall be of galvanised steel. For saline, sand laden or corrosive atmospheres extra protective finishes shall be included by the Contractor and agreed with the Engineer. Where air-cooled condensers are mounted outside buildings, weatherproof motors must be provided and the condenser enclosure shall be designed to protect the fan, motor, drive and finned coils from the weather, including solar radiation. Externally mounted condensers shall discharge air vertically upwards unless they are protected by an integral wind deflection shield or a purpose-made builders work baffle. Where an air-cooled condenser will have to operate under conditions of much lower air temperatures than the design maximum (e.g. UK winter as compared with UK summer) a means of maintaining condenser pressure shall be incorporated. This may be achieved by modulation of the outlet dampers and/or by-pass dampers by condenser flooding or by fan volume control. Where there are three or more condenser fans, control may be effected by sequencing of these fans. Where modulation of the outlet damper only is used the fan motor shall be of adequate size to deal with the minimum extra load and shall in any case be switched off by the dampers when they are closed. Fans shall comply with the relevant Section of the Specification. AJC 05/07 Section 2.2. / 37 SECTION 2.2. – PLANT ITEMS Evaporate condensers shall have their refrigeration coils tested to the same pressures as air-cooled condensers. The condenser coils shall be copper or steel galvanised after manufacture; they shall not be finned. The fan arrangement may be either forced or induced draught and fans shall be of the centrifugal type complying with the relevant Section of the Specification. Fans manufactured from steel shall be galvanised after manufacture and where mounted externally the motors shall be weatherproof. Each evaporative condenser shall include:- a) water circulating pump b) strainer on pump suction c) tank with make-up connections, ball-valve, overflow and drain d) water distribution system e) water eliminator section The evaporative condenser tank, water distribution system, eliminator section, the casing and the framework shall be of steel galvanised after manufacture or of non-corrodible material; in addition all external surfaces shall be painted and the tank interior shall be painted with bitumastic or other corrosion-resistant paint. Measures shall be taken to prevent electro-chemical corrosion at junctions between dissimilar metals. Evaporative condenser coils shall be fitted so that they can be withdrawn. There shall be access to the fan bearings, the fan motor, the pump and motor, the strainer and ball valve. Where evaporative condensers have to operate under conditions of much lower external air temperatures than the design maximum a means of maintaining condensing pressure shall be incorporated. This may be achieved by modulation of air inlet and air outlet dampers or by AJC 05/07 Section 2.2. / 38 SECTION 2.2. – PLANT ITEMS intermittent or variable speed operation of the fan(s). Where modulation dampers are used fans shall be arranged to stop when the dampers are fully closed. Evaporative condensers shall include a drain line with a needle valve or other metering device for blowdown purposes. These shall be fitted on the pipeline from the pump delivery to the water distributor. The line shall be run to drain and provision shall be made so that initial setting of the metering valve can be carried out. (b) Water Cooled Condensers Shell and tube condensers shall have their shells and refrigerant spaces tested to the pressures as for air cooled condensers. Tubes and water side spaces shall be tested to 700 kPa or 1½ times the working pressure, whichever is the greater. Condenser tubes shall be of copper and may be finned. Tube plates shall be of steel or bronze, shells shall be of steel and end covers shall be either cast iron or steel. For use with sea water and aggressive waters special non-ferrous alloys must be used for tubes and tube plates. Shell and tube condensers shall have removable end covers and there shall be adequate access to remove and clean the tubes. Pipework shall be arranged to allow a minimum of dismantling in order to achieve access to the tubes. Means of venting and draining the side water shall be provided. Inlet and outlet valves shall be provided on both water and refrigerant circuits. Shell and tube condensers shall perform the required duty under the given conditions or condenser water supply quantity and flow and return temperatures. For systems having a cooling capacity in excess of 70kW, and smaller where indicated, the temperature of the water leaving the condenser shall be maintained constant irrespective of the temperature of the entering cooling water. Such control shall be by means of a thermostat in the condenser water return pipework, acting upon a three- way valve or a device sensitive to condenser refrigerant pressure. AJC 05/07 Section 2.2. / 39 SECTION 2.2. – PLANT ITEMS 2.2.7. Refrigeration Plant Accessories Every refrigerating system shall be protected by a pressure relief device. Each system with an air-cooled or evaporative condenser shall have a liquid receiver complete with two stop valves, a sight glass, charging connection and a purge valve. Relief valves shall be fitted on liquid receivers and water condensers for plant larger than 17.5 kW cooling capacity. Liquid receivers on plant smaller than 17.5 kW cooling capacity may, alternatively, have a fusible plug. Water-cooled condensers on systems larger than 17.5 kW cooling capacity shall have a liquid receiver capable of holding a complete charge. Either the water cooled condenser or the associated liquid receiver shall have a purge valve. A capped valved connection shall be provided for refrigerant charging. All major items of plant shall be dried at the factory and filled with a holding charge of refrigerant or inert gas; all openings shall be sealed. During erection care shall be taken to prevent the entry of moisture. A dehydrator shall be fitted in the refrigerant pipework. In addition to the suction gas and lubricating oil strainers fitted to the compressor, a liquid line strainer shall be fitted to protect the expansion valve or float valve; any pressure regulating device fitted in the suction line shall also be protected by a strainer. Where an evaporator pressure regulating device is fitted, an additional gauge indicating evaporator pressure shall be provided, complete with means of isolation. Each compressor of more than 10 kW cooling capacity shall have a discharge gas silencer. In dry expansion type systems the liquid leaving the condenser shall be sub-cooled and the refrigerant gas leaving the evaporator shall be super-heated. For compressors greater than 200kW cooling capacity this shall be achieved by means of a purpose made heat exchanger. AJC 05/07 Section 2.2. / 40 SECTION 2.2. – PLANT ITEMS 2.2.8. Pressurisation Equipment 22.214.171.124. General An artificial head shall be maintained on the chilled water system by means of a pressurisation unit of the type as described under the heating section of the Specification. (Clause 2.2.2.) In the installation of the equipment the following publications shall be taken into consideration:- a) Guidance note PM5 (Part C) from the Health and Safety Executive, entitled “Automatically Controlled Steam & Hot Water Boilers”. b) Water Supply (Water Fittings) Regulations 1999. c) Department of the Environment, Standard Specification M&E No.3. The reference to steam and hot water boilers in the above publications shall be deemed to refer to refrigeration plant and chilled water systems for this section. The type and/or use of nitrogen pressurisation equipment will be dependant upon the capacity of the chilled water system, and the construction of the equipment shall be in accordance with manufacturers standard details and the following British Standards:- a) Spillage tank BS 417 Part 2 b) Flanges BS EN 1092 - 2 c) Pressure vessels BS EN 286 d) Bronze valves BS 5154 e) Cl valves BS EN 1171 & BS EN 12334 f) Ball valves BS 1010, Part 2 g) Electrics Current IEE Regs h) Remaining Items BS as applicable AJC 05/07 Section 2.2. / 41 SECTION 2.2. – PLANT ITEMS An electrical isolator shall be installed adjacent to each unit. A low-pressure switch shall be fitted and set for connecting to interlock the chiller. A high-pressure switch shall also be fitted, which shall be connected in series with the low-pressure switch. The system valve on the unit shall be connected to the return header (chiller inlet). 126.96.36.199. Alarm Facilities Additional warning devices shall be provided which shall operate on high-pressure and low water level conditions in the unit cylinder, in addition to operating as standard on low-pressure conditions. An additional low water level lock-out control so arranged that when extra low water level conditions arise, the warning system operates and must be reset manually. This low water level switch shall be installed in the spill tank, set to open the pump circuit at approximately 100mm above the suction pump. In the event of low water in the system, indication shall be shown at the chiller control panel. The chiller safety valve setting shall be set at 1.5 bar above the maximum working pressure of the pressurising unit. 188.8.131.52. Controls Interlocking pressure switches shall be provided and connected to the appropriate terminals on the control panel, which will prevent the chiller from starting until the correct operating pressure has been reached. Duty and standby pressure pumps shall be provided, arranged for automatic change over. Solenoid pressure relief valves, safety valves and any other components for a satisfactory and safe working unit shall also be provided. All controls shall be arranged to fail safe. AJC 05/07 Section 2.2. / 42 SECTION 2.2. – PLANT ITEMS 184.108.40.206. Testing and Commissioning The Contractor shall include for full tests to be carried out at the manufacturers factory and include for a further test at site prior to commissioning with notice given for the test to be witnessed by the Engineer. The Contractor shall include for commissioning of the pressurisation unit(s). 2.2.9. Pipework, Valves, And Ancillaries All refrigerant pipework and all necessary fittings and ancillaries shall be supplied for the complete erection of the plant(s) at site. Pipework for refrigerant circuits shall be of refrigeration quality copper tube. Joints shall be flanged, brazed, welded or made with soldered capillary fittings. Pipelines shall be firmly secured and measures shall be taken to prevent vibration weakening joints and connections. In particular, the suction and delivery pipes from the compressor shall incorporate an adequate length of armoured flexible pipework, which shall be capable of withstanding the prescribed test pressures. After erection, the whole of the refrigeration pipework shall be pressurised and tested for leaks. Pipework shall be designed and run so that any oil in the compressor discharge refrigerant which passes through the oil separator (where fitted) is carried through the system and returned to the crankcase. At any point where a large quantity of oil may accumulate an oil separator and a means of returning the oil to the compressor crankcase shall be provided. All necessary suction, delivery, liquid, gauge and charging valves shall be provided so that all major portions of the system may be isolated for maintenance. In particular the refrigerant circuit shall be arranged so that any thermostatic expansion valve may be removed without the necessity of ‘pumping-down’ the system. AJC 05/07 Section 2.2. / 43 SECTION 2.2. – PLANT ITEMS Valves required for compressors, liquid receivers etc, shall be of either diaphragm or bellows type or be packed valves complete with a back seating and a seal cap suitable for use on refrigeration systems. The liquid refrigerant regulating valves shall be of the thermostatic expansion type preferably multi-outlet with pressure distribution and shall be provided with thermal elements of the ‘liquid charged’ type and a removable fine wire-mesh liquid strainer. Magnetic liquid valves shall be installed in the liquid line before the expansion valves. The magnetic valves shall be provided with manual lifting device or alternatively a valved by-pass. Compressors shall not be connected to run in parallel unless specified in the Particular Specification or as indicated on the drawings, in which case all major plant items that are cross-connected shall be valved for isolation. When the refrigeration plant includes buffer tanks to provide a storage of chilled water or brine, the temperature of the liquid is to be maintained and controlled by capillary tube immersion type thermostats. Thin walled stainless steel phial pockets are to be fixed securely in the tank to receive the phial and isolate it from the contents of the tank, at both the upper and lower part of the tank(s). 2.2.10. Insulation Generally the requirements of the Section 2.8. - ‘Thermal Insulation’ shall apply. Refrigerant discharge and liquid lines need not normally be insulated, but where exposure to solar radiation is likely they shall be shielded or insulated with a 12mm thickness of a material having a thermal conductivity of less than 0.04 W/m°C and weatherproofed with a material having a reflective or light coloured finish. AJC 05/07 Section 2.2. / 44 SECTION 2.2. – PLANT ITEMS The suction line from the evaporator to the compressor shall be insulated with a material having a thermal conductivity of less than 0.04 W/m°C and at least 12mm thick for pipes of up to 76mm diameter and 19mm thick for pipes of 108mm diameter and above. This insulation shall be protected by a vapour barrier which shall not be broken between joints of sectional material or at discontinuities at valves or brackets. Shell and tube evaporators shall be insulated with at least a 25mm thickness of materials having a thermal conductivity of less than 0.04W/m°C. This material shall be protected by a vapour barrier and further protected by a painted sheet metal casing. The insulation and protection shall be so arranged that the end covers can be removed without damage to the insulation. 2.2.11. Controls A solenoid valve shall be fitted in the liquid line to each evaporator, except high pressure float controlled flooded evaporators, to prevent the flow of liquid refrigerant to the evaporator when the compressor is not running. Each compressor of 35kW cooling capacity and above shall be provided with an oil pressure failure control. Where the stopping of a compressor of more than 35kW cooling capacity (or less where indicated) is not controlled by suction pressure i.e. it is controlled by air or water temperature criteria, and the evaporator is at a higher level than the compressor, a pump-down cycle shall be incorporated. The control signal shall initially close the liquid line solenoid valve and the compressor shall then pump down to a pre- determined suction pressure. For each shell and tube evaporator a flow switch shall be fitted in the chilled water pipeline. The flow switch shall prevent the compressor(s) starting unless the chilled water is flowing and shall stop the compressor(s) if the flow falls below a safe minimum. Additionally a chilled water low temperature limit thermostat shall be provided and AJC 05/07 Section 2.2. / 45 SECTION 2.2. – PLANT ITEMS shall stop the compressor(s) if the leaving water temperature drops below a set value. The flow switch and the thermostat shall each be connected in a separate circuit independent of all other control circuits; they shall not be wired in series. 2.2.12. Rotary Screw Liquid Chillers (a) General This section deals with mechanical refrigeration plant and auxiliaries with compressors operating on the screw principle and using halogen hydrocarbon refrigerants. All items of plant whether supplied separately or as a factory assembled package unit shall comply with the following sub-sections unless superseded by the Particular Specification. Evaporators and water cooled condensers shall comply with BS 5500 and the whole machine shall perform and be certified in accordance with ARI Standard 550-90. The refrigeration plant shall include an open drive rotary screw type compressor, evaporator and condenser(s) all as indicated to suit the application for the work; the items shall be correctly matched to ensure satisfactory operation. The heat rejected at the condenser under the maximum design conditions shall include the design heat load absorbed at the evaporator, the heat equivalent of the work done by the rotary screw compressor and any other heat gain from the system. A full charge of refrigerant and lubricating oil shall be supplied together with all items necessary for the satisfactory functioning of the system. Complete control and instrumentation equipment including safety devices shall be included. Where a BMS system is specified for the project all refrigeration plant and equipment shall be suitable via the various controls to be compatible with and controlled by the BMS system. AJC 05/07 Section 2.2. / 46 SECTION 2.2. – PLANT ITEMS Packaged assemblies shall be resiliently mounted on a combined base plate and suitable framework, requiring only the external water and electrical connections to be made on site. Complete data of plant operation and maintenance is to be made available to the Engineer together with a schedule of spare parts and repair information at least four weeks before the issue of a practical completion certificate. The duty, chilled water temperatures and other pertinent data is given in the Particular Specification. To comply with the present day requirements the refrigerant gas preferred in all compressors will be R66 or equivalent. All exterior surfaces shall be protected with a high quality coat of durably alkyd modified vinyl enamel machinery paint. (b) Compressor The compressor shall be an open-drive, rotary twin-screw type. The compressor housing shall be of cast iron, precision machined to provide minimal clearance for the rotors. The rotors shall be manufactured from forged steel and use asymmetrical profiles operating at a maximum speed of 2975 at rpm at 50 Hz. The compressor shall incorporate a complete anti-friction bearing designed to reduce power and increase reliability; four separate cylindrical roller bearings to handle radial loads and two 4-point angular contact ball bearings to handle axial loads. The compressor shall have an integral oil reservoir to assure a constant supply of oil to the bearings at all times. A spring actuated positive seating check valve shall be incorporated into the compressor housing to prevent rotor backspin during shutdown. The shaft seal shall be a spring loaded carbon ring with precision capped collar cooled by low pressure oil. Capacity control shall be achieved by the use of a slide valve to provide fully modulating control from 100% down to 10% of full load. The slide valve shall be actuated by oil pressure, controlled by external solenoid AJC 05/07 Section 2.2. / 47 SECTION 2.2. – PLANT ITEMS valves through the micro computer control centre. The unit shall be capable of operating with lower temperature cooling tower water during part-load operation in accordance with ARI Standard 550-90. If the unit cannot operate at the minimum load the manufacturer shall provide a hot-gas-bypass system to allow operation at 10% load, and advise the minimum load and power input of the unit at the point hot-gas-bypass is actuated. (c) Lubrication System An adequate supply of oil shall be available to the compressor at all times. During start-up and run-down, this shall be achieved by oil reservoirs in the compressor, or by prelube and postlube oil pump operation. During operation, oil shall be delivered by positive system pressure differential or full time operation of an oil pump. An oil reservoir shall be located in the compressor to lubricate bearings in the case of a power failure. An immersion oil heater shall be provided, temperature actuated, to effectively remove refrigerant from the oil. An external, replaceable cartridge, oil filter shall be provided along with manual isolation stop valves for ease of servicing. An oil eductor shall be provided to automatically remove oil which may have migrated to the evaporator and return it to the compressor. The oil separator shall be of a horizontal design with no moving parts, and shall provide effective oil separation before the refrigerant enters the heat exchangers. A refrigerant cooled oil cooler shall be provided to allow operation of the chiller over the full range of operating conditions. (d) Compressor Motor Drive The motor shall be 2-pole, continuous duty, squirrel cage induction type, and shall have an open drip-proof enclosure. Motor full-load amperes at design conditions shall not exceed motor nameplate (FLA). Motor shall be designed for use with the type starter specified. Motor shall be factory mounted and directly connected to the compressor to provide compressor/motor alignment. Coupling shall have an all metal AJC 05/07 Section 2.2. / 48 SECTION 2.2. – PLANT ITEMS construction with no wearing parts to assure long life, and no lubrication requirements to provide low maintenance. For units utilising remote electro-mechanical starters, a large 14 gauge (minimum) steel terminal box with gasketted front access cover shall be provided for field connected wiring. There are six terminals (three for high voltage) brought through the motor casing into the terminal box. Jumpers shall be furnished for three lead types of starting. Overload/overcurrent transformers shall be furnished with all units. (e) Evaporators Evaporators shall be of the shell-and-tube, flooded type designed for 20 bar working pressure on the refrigerant side and be tested at 30 bar. Shell shall be fabricated from rolled carbon steel plate with fusion welded seams, have carbon steel tube sheets, drilled and rearmed to accommodate the tubes, and intermediate tube supports spaced no more than 1300mm apart. The refrigerant side shall be designed, tested and stamped in accordance with ASME Boiler and Pressure Vessel Code, Section V111-Divsision1. Tubes shall be high-efficiency, internally enhanced type. Each tube shall be roller expanded into the tube sheets providing a leak-proof seal and be individually replaceable. Water velocity through the tubes shall not exceed 3.5 m/s. Liquid level sight glasses shall be located on the side of the shell to aid in determining proper refrigerant charge. The evaporator shall have a refrigerant relief device to meet the requirements of the ASHRAE 15 Safety Code for Mechanical Refrigeration. Water boxes shall be removable to permit tube cleaning and replacement. Outlet water connections flanged to the appropriate BS flange table shall be provided. Water boxes shall be designed for 10 bar working pressure and be tested at 15 bar. Vent and drain connections with plugs shall be provided on each water box. During transit from factory to site a protective covering shall be furnished to the motor control centre and unit mounted controls. Water nozzles shall be capped with fitted plastic enclosures. AJC 05/07 Section 2.2. / 49 SECTION 2.2. – PLANT ITEMS (f) Condensers Condensers shall be of the shell and tube type, designed for 20 bar working pressure on the refrigerant side, and shall be tested at 30 bar. Shell shall be fabricated from rolled carbon steel plate with fusion welded seams, have carbon steel tube sheets, drilled and reamed to accommodate the tubes and intermediate tube supports spaced no more than 1300mm apart. A refrigerant sub-cooler shall be provided for improved cycle efficiency. The refrigerant side shall be designed, tested and stamped in accordance with the ASME Boiler and Pressure Vessel Code, Section V111-Division. Tubes shall be high-efficiency, internally replaceable type. Each tube shall be roller expanded into the tube sheets providing a leak proof seal, and be individually replaceable. Water velocity through the tubes shall not exceed 3.5m/s. The condenser shall have refrigerant relief devices to meet the requirements of the ASHRAE 15 Safety Code for Mechanical Refrigeration. Water boxes shall be removable to permit tube cleaning and replacement. Outlet water connections flanged to the appropriate BS flange table shall be provided. Water boxes shall be designed for 10 bar working pressure and be tested at 15 bar. Vent and drain connections with plugs shall be provided on each water box. (g) Refrigerant System Refrigerant flow to the evaporator shall be metered by a single fixed orifice with no moving parts. The condenser shell shall be capable of storing the entire system refrigerant charge during servicing. Isolation from the rest of the system shall be by manually operated isolation valves located at the inlet and outlet of the condenser. Additional valves shall be provided to facilitate removal of refrigerant charge from the system. AJC 05/07 Section 2.2. / 50 SECTION 2.2. – PLANT ITEMS (h) Micro Computer Control Centre Where specified in the Particular Specification the rotary screw chiller(s) shall be provided with a micro computer control centre all as described below. The micro computer control centre shall be able to interface with a BMS system, where such a system specified. The interface shall be capable of the following: i. Remote chiller Stop/Start ii. Reset of chilled water temperature iii. Reset of current limit iv. Plant status v. Chiller operating or failed vi. Chiller is shut down on a safety requirement, needing reset vii. Chiller is shut down on a re-cycling safety need. Each micro computer control centre shall be in a locked enclosure, factory-mounted, wired and tested. The control centre shall include a 40 character alphanumeric display showing all system parameters in the English language with numeric data in metric units. Digital programming of essential set points through a colour coded, tactile-feel keypad shall include: - leaving chilled water temperature - percent current limit - pull down demand limiting - seven-day time clock for starting and stopping chiller - pumps and tower (complete with holiday schedule) AJC 05/07 Section 2.2. / 51 SECTION 2.2. – PLANT ITEMS - remote reset temperature range All safety and cycling shutdowns shall be enunciated through the alphanumeric display and consist of day, time, cause of shutdown, and type of restart required. Safety shutdowns shall include:- - high condenser pressure - low oil pressure at compressor - clogged oil filter - high oil temperature - high oil pressure - high compressor discharge temperature - low evaporator pressure - motor controller fault - sensor malfunction Cycling shutdowns shall include:- - low water temperature - cooler/condenser water flow interruption - power fault - internal time clock - anti-recycle System operating information shall include: - return/leaving chilled water temperatures - return/leaving condenser water temperature - evaporator/condenser refrigerant pressures - oil pressures at compressor and oil filter differential - percent motor current - evaporator/condenser saturation temperatures - compressor discharge temperature - oil temperature - percent slide valve position - operating hours - number of compressor starts AJC 05/07 Section 2.2. / 52 SECTION 2.2. – PLANT ITEMS Security access shall be provided to prevent unauthorised change of set points, and to allow local or remote control of the chiller. (i) Factory Installed Compressor Motor Starter The chiller manufacturer shall furnish a reduced voltage solid-state starter for the compressor motor. Starter shall be factory-mounted and wired on the chiller. The starter shall provide, through the use of silicon controlled rectifiers, a smooth acceleration of the motor without current transitions or transients. The starter enclosure shall be NEMA 1, with a hinged access door with lock and key. Electrical lugs for incoming power wiring shall be provided. Protective devices shall include: - phase rotation protection - single phase failure protection - momentary power interruption protection - high/low line voltage protection Starter shall include: - three leg sensing overloads - 120 volt control transformer for all unit controls - non-fused disconnect switch Three-phase voltage and current readings shall be co-ordinated with the unit control centre, with digital readout on the display. (j) Remote Electro-Mechanical Compressor Motor Starter Where the Particular Specification calls for remote starting of the rotary screw compressor, the starter shall be furnished in accordance with the chiller manufacturer’s starter specification. AJC 05/07 Section 2.2. / 53 SECTION 2.2. – PLANT ITEMS (k) Start-up and Operator Training The chiller manufacturer shall include the services of a factory-trained, field service representative to supervise the initial start-up and full concurrent operator instruction. (l) Chilled Water Storage Tanks Chilled water storage vessels shall be constructed from single sheet mild steel plate to BS EN 14620. The storage tanks shall be circular and in a vertical format, and supported on mild steel legs. The inlet pipe shall be arranged to turn down and discharge through a stainless steel perforated plate, towards the bottom of the tank. The outlet pipe shall be arranged to turn down from the top of the tank, via a stainless steel perforated plate and leave the vessel from the vertical side. A drain shall be provided from the bottom of the tank, and a de-aeration connection shall be taken from the top of the tank. A 600mm diameter inspection cover shall be provided at the lower part of the storage vessel. Thermostat pocket shall be provided at the top and bottom of the storage vessel. The Contractor shall submit a shop drawing of the storage vessel for the Engineer’s approval. The storage tank shall be thermally insulated in accordance with the relevant part of this Specification. AJC 05/07 Section 2.2. / 54 SECTION 2.2. – PLANT ITEMS 2.2.13. Acoustic And Vibration Isolation 220.127.116.11. General The noise produced by the installation in the spaces served, in any adjacent buildings and in the open air surrounding plant rooms shall be kept as low as possible with due regard being made to the local environment. This shall be specially considered in the selection of fans (including those for condensers and cooling towers), motors, fan coil units and terminal units, grilles and diffusers and the internal finish and arrangement of distribution ducting. Account shall be taken of the effects of regenerated noise, duct breakout noise, noise emanating from prime movers and diffusers and any other items affecting the final sound level in the room. The sound level in the space served, due to the equipment, shall not exceed with the recommended design criteria given in the table below unless otherwise indicated. AJC 05/07 Section 2.2. / 55 SECTION 2.2. – PLANT ITEMS Recommended Design Type of Environment NR 20 Concert halls, broadcasting and recording studios board rooms. Private dwellings, hospital rooms, NR 25 television studios, theatres, cinemas, large conference rooms. Libraries, museums, court rooms, NR 30 schoolrooms, hospital operating theatres and wards, hotel bedrooms, executive offices, boardrooms. Halls, corridors, lobbies, cloakrooms, NR 35 restaurants, large staff offices, design offices, small stores, small conference lecture rooms. Departmental stores, shops, supermarkets, cafeterias, canteens, NR 40 general offices, workshop offices, toilets washrooms, reception areas, laboratories, recreation rooms. NR 45 Typing pools, offices with business machines, kitchens, computer rooms. NR 50 Light engineering workshops. NR 60 Foundries, heavy engineering works. AJC 05/07 Section 2.2. / 56 SECTION 2.2. – PLANT ITEMS 18.104.22.168. Silencer Performance All silencers shall provide a dynamic insertion loss at the operating temperature of not less than that indicated. The Contractor shall provide the insertion losses expected from the silencers proposed, under the operating conditions, and this data shall be derived from tests carried out in accordance with BS EN 150 7235. All silencers shall have a static pressure loss, under maximum operating conditions, of not greater than that indicated. The manufacturer’s quoted pressure losses shall be derived from test carried out in accordance with BS EN 150 7235. Where a silencer location is known the Contractor shall indicate the expected effect of turbulence due to adjacent elements on the quoted pressure losses. The Contractor shall provide with the insertion loss data, information relating to the silencer generated octave band sound power spectrum (125 – 8 kHz) at the operating conditions. 22.214.171.124. Construction Dissipative Silencers (For the H&V Industry) The outer casings of all duct silencers shall be constructed strictly in accordance with the appropriate specification in the material specified for the ductwork. It is the Contractor’s responsibility to determine whether the high or low pressure code is required in the absence of an instruction from the Engineer. All silencers shall be fitted with drilled angle flanges, to the relevant Code. The method of installing acoustic elements into the casing shall not infringe this specification or cause unacceptable air leaks. Acoustic elements shall incorporate full aerodynamic leading and trailing edges (not square ends), and the inert, rot and vermin proof non-hygroscopic and non-combustible mineral wool or glass fibre acoustic medium shall be packed to a density of not less than 48 kg/m3 shall have a fibre-glass tissue facing, and be retained by a perforated steel sheet facing. Where required, for water or grease AJC 05/07 Section 2.2. / 57 SECTION 2.2. – PLANT ITEMS laden duties, an impervious but acoustically transparent membrane may be fitted behind the perforated metal facing. Where acoustic elements form splitters within the silencer, the arrangement shall be with half-width splitter fixed to each side wall of the casing and preferably with the splitters vertical. The configuration should have a regular splitter/airway dimension across the full width of the silencer. However, it is the responsibility of the Contractor to ensure that the parallel splitter elements in the silencer are correctly orientated for the adjacent duct geometry, particularly when silencers are located near bends, bifurcations, etc. Horizontal splitters should be suitably stiffened to prevent flexing and restriction of the airways, and will normally be limited to silencers having a module width of 900mm or less. In the case of circular silencers, all internal acoustic elements shall comprise mineral or glass-fibre as the acoustic medium, as specified above for rectangular silencers, retained by a perforated galvanised metal facing, or other approved infill protection membrane. When silencers are actually manufactured in modules, each unit shall be shop assembled and this specification, together with the manufacturer’s own guarantee and performance ratings, shall apply to the unit as a whole. Silencer units shall be delivered to site with blocked ends to prevent the ingress of rubble, etc, during installation, and reduce the risk of damage. The direction of air flow through the silencer shall be clearly marked on the casing. Engine Absorptive Exhaust Silencer casings shall be manufactured from a suitable heavy gauge sheet steel, with all seams and joints continuously welded. All internal splitter elements shall be manufactured from suitable gauge steel, with adequate precautions taken to allow sufficient freedom of movement to overcome expansion and thermal shock. AJC 05/07 Section 2.2. / 58 SECTION 2.2. – PLANT ITEMS These internal elements shall be packed with an inert, rot and vermin proof, non- hygroscopic and non-combustible mineral wool or glass fibre acoustic medium of 96 kg/m3 minimum density, protected by a layer of glass fibre cloth, behind the perforated steel facing. The same remarks relating to performance for duct silencers shall apply to engine silencers. 126.96.36.199. Reactive Silencers (For Heavy Industry) The outer casings of all silencers shall be constructed from a suitable heavy gauge mild steel with all seams and joints continuously welded. Acoustic elements within the silencer shall be designed and constructed with due allowance made for differential expansion and thermal shock. All silencers shall also be fitted with suitable flanges and drain plugs and shall be manufactured and finished with due allowance made for the operating temperatures and environmental conditions. Silencers shall be delivered to site with blocked ends to prevent ingress of rubble, etc, during installation and reduce the risk of damage. The direction of air flow through the silencer shall be clearly marked on the casing. 2.2.14. Anti-Vibration Mountings 188.8.131.52. General All dynamic machinery shall be isolated from the building structure by vibration isolators and/or vibration isolation materials which shall be purpose designed and selected to suit the machinery. Where plant that is isolated has connecting pipework, that pipework shall be independently supported such that no load is transferred to the isolated equipment. A flexible connection shall be used between the pipework and the equipment. Where required, the mountings/hangars shall be provided with a positioning or restraining device, which will prevent the equipment position changing if its load changes, for example, during draining down of the equipment or other maintenance. AJC 05/07 Section 2.2. / 59 SECTION 2.2. – PLANT ITEMS The device shall consist of a stud passing through an oversize hole with a nut and locknut providing restraint. A fibre or neoprene washer should be fitted between nut and restraining member, leaving a clearance of at least 1mm. All mountings shall provide the static deflection under the equipment weight, shown in the schedules. Mounting selection should allow for any eccentric load distribution or torque reaction, so that the design deflection is achieved on all reaction, due to mountings under the equipment, under operating conditions. It is the Contractor’s responsibility to ensure that all mountings are suitable for the loads operating and the environmental conditions which will prevail. Particular attention should be paid to mountings which will be exposed to atmospheric conditions in order to prevent corrosion. All mountings shall be colour coded or otherwise marked, to indicate their local capacity, to facilitate identification during installation. 184.108.40.206. Caged Spring Mounts Each mounting shall consist of cast telescopic top and bottom housing constraining one or more helical steel springs, of 50mm minimum diameter, as the principal isolation elements. The mountings shall incorporate a built-in levelling device, and resilient inserts as guides for the upper and lower housings. The housing should be designed to allow visual inspection after installation. The bottom plate shall be fitted with a 6mm thick neoprene pad bonded to it to reduce high frequency flanking. When in use with equipment having a fluid weight in excess of 25% of the total empty equipment weight a suitable hold-down or restraining device shall be incorporated. The springs shall be selected to have at least 50% overload capacity before becoming coil bound. AJC 05/07 Section 2.2. / 60 SECTION 2.2. – PLANT ITEMS All spring mounts shall be designed such that the lateral spring stiffness is equal to the vertical stiffness. The static deflection shall not be less than that indicated. The mountings shall also be selected for all items of plant with stiffness to cater for any eccentric weight distribution over the unit base. An equal static deflection shall be provided on all mounts, to avoid the possibility of flanking caused by the plant tilting and rendering one or more of the mounts ‘solid’. All nuts, bolts or other elements used for adjustment of a mounting shall incorporate locking mechanisms to prevent the isolator going out of adjustment as a result of vibration, accidental or unauthorised tampering. 220.127.116.11. Rubber Mattress Where rubber mattresses are indicated they shall be of the studded rubber carpet type loaded to 24 kg/m using an insitu or precast concrete overslab. 18.104.22.168. Resilient Hangers All resilient hangers shall be of the two element design, with helical spring and neoprene in-shear elements mounted in a steel cage pre- drilled and tapped at top and bottom to receive threaded hanger rods. The resilient hangers shall have a static deflection of not less than that indicated. 22.214.171.124. Rubber or Neoprene Mounts The mountings shall consist of a steel top plate and base plate completely embedded in colour coded oil resistant neoprene/rubber for easy identification of rated load capacity. The mountings shall be moulded with non-skid ribbed construction on the top plate and base plate to eliminate the need for bolting. All mountings, however, shall be equipped with bolt holes in the base plate and taped holes in the top plate so that they may be bolted to the floor and equipment where required. AJC 05/07 Section 2.2. / 61 SECTION 2.2. – PLANT ITEMS 126.96.36.199. Pipework Isolation All active pipework shall be isolated on resilient mountings/hangers up to the structural penetration adjacent to the service shaft, for the first 100 pipe diameters or the first 10m of the pipe run, whichever is the greatest. Thereafter oversized brackets having neoprene inserts shall be installed, generally for larger ‘live’ pipework, but also for smaller ‘live’ pipework where friction losses exceed 280 Pa/m2 per metre run. 188.8.131.52. Plant Bases Anti-vibration mountings of the following types shall be provided where appropriate. a) Anti-Vibration Rails An A.V rail shall comprise a steel beam with height-saving brackets at each end. The steel sections must be sufficiently rigid to prevent undue strain in the equipment. b) Steel Plant Bases Steel plant bases shall comprise an all-welded steel framework of sufficient rigidity to provide adequate support for the equipment. The frame depth shall be approximately 1/10 of the longest dimension of the equipment with a minimum of 150mm. This form of base may be used as a composite A.V rail system. c) Concrete Inertia Base for Steel Springs These shall consist of an all-welded steel framework with height- saving brackets and a frame depth of approximately 1/12 of the longest dimension of the equipment with a minimum depth of 150mm. The bottom of the frame shall be blanked off and concrete (2300 kg/m3) poured in over steel reinforcing rods positioned 35mm above the bottom. The total weight of the base shall be at least 1.5 times the equipment total weight. Framework for split case pumps shall be extended in width to allow for provision of supports for suction and discharge elbows. AJC 05/07 Section 2.2. / 62 SECTION 2.2. – PLANT ITEMS d) Concrete Inertia Base for Neoprene Mounts/Pads These should comprise a concrete inertia base of sufficient size to permit support for all parts of the equipment base, such as suction and discharge elbows on centrifugal pumps. The inertia base should be cast onto a permanent bottom shuttering and supported on neoprene mounts or pads, the whole resting on a plinth as required. It should be noted that the construction of concrete bases on cork, expanded polystyrene or mineral wool slabs is not normally permitted. Where neoprene pads are used, small areas of pad must be equally spaced to provide the correct deflection. The number, dimensions and locations of such pads should be advised to the Contractor by the supplier. 184.108.40.206. Flexible Connections All items of plant containing rotating components, such as pumps and refrigeration equipment shall be connected by means of armoured type flexible connections, which shall be suitable for at least twice the working pressure of the system to which it is installed. Pipework shall be firmly anchored each side of flexible connections. Electric motors shall be connected by means of flexible electrical conduit. 2.2.15. Motors, Belts, And Guards 220.127.116.11. Motors Motors and associated control panels shall generally be supplied and installed by the Mechanical Engineering Services Contractor and the Electrical Engineering Services Contractor shall continue the circuit for each motor control to the respective motor terminals. All motors shall be totally enclosed fan-cooled type and, where necessary, flameproof. Motors installed in external locations shall be provided with anti-condensation heaters. Motor terminals shall be of the stud type, totally enclosed and accessible. Rubber insulation shall not AJC 05/07 Section 2.2. / 63 SECTION 2.2. – PLANT ITEMS be used for connections from the windings to the terminals. A 9mm diameter earthing stud shall be provided on the motor carcass. Holding down bolts shall not be used for earthing purposes. Each motor shall be fitted with a totally enclosed dust proof terminal box either suitable for screwed conduit entry or provided with a capable box as necessary. For motors above 1kW the terminal box shall be sealed from the internal air circuit of the motor. All joints shall be flanged with gaskets of neoprene or similar material. Motors shall operate at all loads without undue vibration and with the least practicable amount of noise. A.C motors shall be capable of operating continuously under rated output conditions at any frequency between 48 and 51 Hz together with ± 10% voltage variation. A.C motors up to and including 110kW shall generally be provided for operation from a low voltage, 3 phase 50 HZ supply and those above 110kW from a medium voltage 3-phase 50Hz supply. A.C motors up to and including 7½ kW shall generally be suitable for direct on line starting at full voltage. When started in this manner the current shall not exceed 6 times full load current. Motors exceeding 7½ kW shall have starting currents limited to approximately 250% of the full load current at 100% full load torque utilising:- Squirrel-cage high-torque motors employing auto-transformer starters. Slip-ring motors employing rotor resistance starters and continuously rated brush gear without brush lifting devices. If, for any reason, the above methods of starting could cause undue ‘run-up’ time for a particular motor, then alternative methods of starting may be employed. Motors operating in an ambient temperature not exceeding 40°C shall be insulated with at least Class F insulation but where the ambient AJC 05/07 Section 2.2. / 64 SECTION 2.2. – PLANT ITEMS temperature is likely to exceed this figure, or where the motor temperature may be appreciably affected by conducted heat, Class H insulation shall be used unless otherwise approved. Motors for operation at medium voltage shall have Class F insulation. All motor shall be provided with gland plates, conduit thread or standard cable boxes and glands. Conduit shall not be connected direct to a motor. The conduit shall be terminated in a through type galvanised conduit box and continued to the appliance with flexible metallic tubing. Where M.I.M.S cable connects a motor or other vibrating appliance it shall be taken direct into the terminal box. A coil shall be formed in the cable to take up the relative movement between the machine and the solid base. A bare tinned copper earth conductor of approved cross section shall be provided to connect the frame of the motor to the earth termination in the controlling isolator or distribution board. 18.104.22.168. Variable Speed Drives for HVAC Induction Fan and Pump Motors General Variable speed drives shall use micro processor control together with PWM technology for the speed control of HVAC fans and pumps. Selection of the induction motor and corresponding inverter shall be sized taking into account the full load current rating of the motor. Consideration shall also be taken of the motor efficiency and power factor which for all practical purposes should be as high as possible. Should derating be required the waveform effects are to be considered and, taking into account the motor re-rating curves which should detail the constant torque range, the constant kW range and the reduced kW range depending upon the temperature rise of the windings and class of insulation. Consideration will also be required to derate the output power available in order to prevent the motor from overheating due to the additional losses caused by the inverter supply. Derating will also have to be considered when assessing the load and operating speed range. The inverter drive package associated with variable speed fans shall be AJC 05/07 Section 2.2. / 65 SECTION 2.2. – PLANT ITEMS supplied by the Air Handling Unit manufacturer and those associate with variable speed pumps by the controls manufacturer. 22.214.171.124. Protection of the Induction Motor Motors used in conjunction with variable speed drives shall have thermistors built into the windings to activate the control circuits and disconnect the supply for all or any of the typical motor faults: a) Sustained overload b) Excessive or incorrect duty cycle operation c) Prolonged reduced or over voltage or incorrect frequency d) Excessive ambient temperature in motor location e) Restricted or impaired ventilation f) Single phasing g) Stalled or locked rotor The built-in thermistors should be carefully insulated from and embedded in the motor windings prior to impregnation with terminal leads brought out of the motor terminal box for connection to the control device. The thermistors shall be the semi-conducting resistance type with a positive temperature co-efficient and with a fixed reference temperature of 160ºC. 126.96.36.199. Motor and Starter Cabling All inverter control wiring should be screened and the screen shall be earthed at the inverter connection rail. Power cable to the motor shall be enclosed in earthed screen cable with separate earth connections to the motor frame and variable speed controller. Cables connecting the thermistors to the control contactor should also be earthed screened. 188.8.131.52. Starter Displays The variable speed drive starter shall have the facilities to be programmable. Value settings which are to be adjusted should follow a format similar to the details below: AJC 05/07 Section 2.2. / 66 SECTION 2.2. – PLANT ITEMS Parameter Range Minimum frequency 0 to max speed (Hz) Maximum frequency Min to full speed (Hz) Acceleration time 0.2 to 600 secs Deceleration time 0.2 to 600 secs Timed current limit Up to 150% FLC Thermal current limit 0 to 105% FLC Low frequency boost 0 to 25% of max output voltage voltage at 0Hz Slip compensation 0 to 25Hz DC braking level 0 to 7.1% Serial I/O address 0 to 99 Previous trip condition 0 to 255 Security code Volts/Hertz 25 to 480 Hz ratio AJC 05/07 Section 2.2. / 67 SECTION 2.2. – PLANT ITEMS The bit parameters which are to be adjusted when the drive has stopped and the security code has been set are as follows: Code Parameters Speed or torque control mode Auto or manual start-up Dynamic or DC braking Auto or fixed boost Economy of fixed V/Hz ratio Open loop or encoder feedback Master or slave operation Ramp or coast to halt Indicates frequency or load on display Terminal or keypad control Serial I/O parity check 0-20mA, 4-20mA, 20-4mA Define serial I/O baud rate (4800 or 9600 bps) Set all parameters to default value Switching frequency and base speed set-up AJC 05/07 Section 2.2. / 68 SECTION 2.2. – PLANT ITEMS Faulty conditions which are to be displayed in the event of a fault will include: Fault Loss of current loop Under voltage External trip Over voltage Power supply failure Time trip Motor thermistor trip Overcurrent Ready to go Hardware fault (internal) Operating criteria for the microprocessor controlled variable speed drive will be as follows: Speed range 0-100/220/480 Hz Operating temp -10 to +50ºC (subject to derating at high switching frequency) Max output current 150% x FLC for 30 secs Altitude performance 1000 metres maximum, derate 1% per 100m between 1000m and 4000m Output waveform Sinecoded PWM with selectable frequency switching PWM switching Selectable at 2.9, 5.9, 8.8 or 11.7 kHz Faults status relay Volt free 3A @ 240v AC changeover Current loop control 0-20mA, 4-20mA, 20-4mA Protection Thermal trip AJC 05/07 Section 2.2. / 69 SECTION 2.2. – PLANT ITEMS Control Inputs Control Outputs Set speed (Hz) Speed – 0 to 10v at 5mA representing 0 to max speed Set torque Torque -0 to 10v at 5mA representing 0 to 150% FLC Run Aux Supply – 24v DC @ 50mA Stop Forward/reverse Local/remote Serial i/p Drive trip Drive reset Encoder Thermistor (Motor Protection) 184.108.40.206. Electromagnetic Compatibility and Radio Frequency Interference Equipment purchased for variable speed drives shall conform to the following international standards: IEC 555 parts 1 and 3 IEC 801 parts 2-6 220.127.116.11. Power Factor Correction Where central power factor correction control centres are not provided static capacitors shall be supplied and installed for connection of individual A.C motor drives. Capacitors shall be totally enclosed, paper insulated, oil impregnated dielectric type complying with BS EN 60831 and having weatherproof enclosure. AJC 05/07 Section 2.2. / 70 SECTION 2.2. – PLANT ITEMS Each capacitor shall be rated to provide a reactive landing KVAr not exceeding 85% of the no load KVAr of the motor to which it is connected. Capacitor ratings shall be so chosen that the whole of the Plant motors, when operating normally, at designed load, shall have an overall power factor not less than 0.95 lagging. Capacitors shall be fitted to each motor having a rating of 4kW and above. Capacitors shall be mounted on, or adjacent to, motors in non- hazardous areas, and for hazardous areas the capacitors shall be grouped outside the area. Each capacitor shall be provided with taped conduit entry or with cable boxes and glands to suit the type of cable specified. 18.104.22.168. Lubrication Provision shall be made for the efficient lubrication of all bearings, including ball and roller bearings. This should preferably be by the use of separate oil cups of the self sealing type of grease nipples for each point. Grease nipples wherever possible shall be of a uniform type. Where automatic lubricators are fitted provision for emergency hand lubrication shall also be provided. All lubrication filling points shall be located in easily accessible positions. Where practicable, extension piping shall be provided to bring lubrication points to a common access position. Lubrication shall be possible external to guards with machinery in motion. 22.214.171.124. Protection The following protection shall be provided:- Motors up to 1kW – fuses and thermal or magnetic overloads Motors 1-30 kW – fuses, thermal overload and single-phasing protection Motors 30 kW and above – fuses and earth fault and thermal overload, single-phasing protection. AJC 05/07 Section 2.2. / 71 SECTION 2.2. – PLANT ITEMS Motors controlled via PWM variable speed starters shall be provided with thermistors embedded in the windings. 126.96.36.199. Motor Control Equipment All motor control gear and all ancillary apparatus shall have all windings, contracts and all current carrying and live parts and components insulated with Class ‘A’, ‘B’ or Class ‘C’ materials as required by the temperature in which the particular apparatus will operate. All motor control gear equipment supplied in the form of a panel or cubicle unit shall fully comply with the requirements of BS EN 60439-1 for the fault capacity specified. Test certificates in accordance with BS EN 60439-1 shall be provided. The current rating of a contactor for direct start motor drives shall be not less than 120% of the FLC of the motor. All contacts in air shall be solid silver or silver faced and all contactors and control equipment shall be designed for not less than forty operations per hour. In the event of any control gear and ancillary apparatus being energised by a supply other than the supply for the motor circuit, the isolator shall incorporate auxiliary contacts such that when the motor is isolated the auxiliary supply to the control gear and/or motor is also isolated on all poles. All control equipment shall have a clear schematic diagram on durable material fixed permanently within each lid or cover. All starters shall be manufactured in accordance with BS EN 60947 – 4- 1 and insulated with Class ‘A’, ‘B’ or ‘C’ materials as required by the temperature in which the particular apparatus will operate. All starters shall have integral normal manual “start” and “stop/reset” push button of the diaphragm type. The “stop/reset” buttons shall have AJC 05/07 Section 2.2. / 72 SECTION 2.2. – PLANT ITEMS mushroom heads and shall be coloured red; the “start” buttons shall be coloured green and shall be shrouded to prevent inadvertent operation. Where starters are to be erected in damp situations, such as unheated pumping chambers or outside, they shall comply with the requirements specified and shall have an internal electrical heater arranged to C maintain the starter temperature at not less than 18° by means of thermostatic control. 188.8.131.52. Remote Push Buttons Each contactor starter shall be provided with a separate metal-cased “stop” push-button remote control station mounted adjacent to the motor in an approved position. The stop push-button shall have a red mushroom head and must remain in the closed position after being operated and shall be provided with reset facilities. 184.108.40.206. V-Belt Drives V-belt drives shall comply with BS 3790 and shall be capable of transmitting at least the rated wattage output of the motor with one belt removed; unless otherwise indicated not less than two belts per drive shall be used. Pulleys shall be exactly aligned. The Main Contractor shall ensure that the holdings down bolts grouted in by the Contractor are positioned to ensure correct alignment. Provision shall be made for positive adjustment of the tension in V-belt drives. 220.127.116.11. Guards Guards shall be provision for all open unprotected intakes to centrifugal flow fans; for open unprotected intakes to exhausts from axial flow fans; for open, unprotected and easily accessible intakes to an exhaust from propeller fans; for V-belt drives; for drive couplings and elsewhere as indicated. For fans the guards shall be manufactured by the fan maker of galvanised steel wire mesh not greater than 25mm, attached to a rigid galvanised steel rod framework. AJC 05/07 Section 2.2. / 73 SECTION 2.2. – PLANT ITEMS For V-belt drives the guards shall be of galvanised steel wire at least 2.5mm diameter mesh not greater than 25mm spacing, attached to a rigid galvanised steel framework of rods not less than 10mm diameter. Guards shall be readily removable to permit belts to be changed. Adequate access panels shall be provided in the side of a guard to allow tachometer readings of the two shafts to be taken and belt tension to be tested. Allowance shall be made in the dimensions of the guard and the size and position of access panels for the adjustment of the motor on its slide rails. Where duplicate motors are provided and fixed for fans or compressors the spare motor shall be complete with slide rails and be fixed in position ready for operation. The guard provided shall be either a double guard or a single guard specially designed to protect both directions of drive. All fixings and mountings for both positions shall be supplied and fitted and changeover of the guard and drive shall be simple and quick. AJC 05/07 Section 2.2. / 74 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.1 General ......................................................................................................1 2.3.2 Definitions of Systems and Pipework Materials ..........................................2 2.3.3 Pipe Erection..............................................................................................6 2.3.4 Pipework Clearances .................................................................................7 2.3.5 Pipework Fittings........................................................................................8 2.3.6 Black Steel Pipework Installations ............................................................11 2.3.7 Galvanised Steep Pipework Installation....................................................13 2.3.8 Copper Pipework Installations ..................................................................15 2.3.9 Stainless Steel Pipework Installations ......................................................17 2.3.10 Flux and Excess Solder............................................................................19 2.3.11 PVC Pressure Pipework ...........................................................................19 2.3.12 UPVC Pipework .......................................................................................20 2.3.13 MUPVC Pipework.....................................................................................21 2.3.14 MDPE Pipework (Below Ground) .............................................................22 2.3.15 Cast Iron Above Ground Sanitation Pipework (Mechanically Jointed).......23 2.3.16 Conventional Cast Iron Above Ground Sanitation Pipework .....................24 2.3.17 UPVC Rainwater Installation ....................................................................24 2.3.18 Aluminium Rainwater Installation..............................................................25 2.3.19 Cast Iron Rainwater Installation................................................................26 2.3.20 Flanged Joints..........................................................................................27 2.3.21 Welding of Metallic Pipe Joints .................................................................28 2.3.22 Welding of Plastic Pipe Joints...................................................................28 2.3.23 Tests for Welders Qualifications (General) ...............................................29 2.3.24 Tests for Welder Qualification Steel Pipes................................................30 2.3.25 Tests for Welder Qualification Copper Pipes ............................................32 2.3.26 Radiographic Examinations......................................................................32 2.3.27 Pipework Cleanliness ...............................................................................33 2.3.28 Pipework Supports ...................................................................................34 2.3.29 Pipework Expansion.................................................................................39 2.3.30 Anchor Points...........................................................................................40 2.3.31 Sleeves and Floorplates...........................................................................40 2.3.32 Air Venting and Draining...........................................................................41 2.3.33 Dirt Pockets..............................................................................................42 2.3.34 Test Points ...............................................................................................42 2.3.35 Flushing Connection.................................................................................43 2.3.36 Valves, Taps, Cocks, Strainers, Etc..........................................................43 18.104.22.168 General.............................................................................................43 22.214.171.124 Valve Requirements .........................................................................44 SECTION 2.3. – PIPEWORK AND FITTINGS 126.96.36.199 Domestic Hot, Cold, and Fire Water Services Isolation Valves .........46 188.8.131.52 Water Level Control Valves (Float Operated)....................................49 184.108.40.206 Mixing Valves ...................................................................................51 220.127.116.11 LTHW, Chilled Water, and Condenser Water Valves ........................52 18.104.22.168 Radiator Valves ................................................................................53 22.214.171.124 Thermostatic Radiator Valves...........................................................54 126.96.36.199 Commissioning Stations ...................................................................54 188.8.131.52 Check Valve/Non Return Valves.......................................................54 184.108.40.206 Strainers ...........................................................................................55 220.127.116.11 Drain Cocks......................................................................................56 18.104.22.168 Automatic Air Vents ..........................................................................56 22.214.171.124 Pressure Reducing Valves................................................................56 126.96.36.199 Safety and Relief Valves...................................................................57 188.8.131.52 Urinal Water Conservation Devices ..................................................58 184.108.40.206 Valve Labelling .................................................................................59 220.127.116.11 Thermometers, Pressure and Altitude Gauges .................................67 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.1 General This section of the Specification covers the general requirements of piped services installations, including pipework, fittings, valves etc. All pipework and fittings shall be installed, stored and transported in accordance with manufacturer’s recommendations. All pipework shall be installed to allow for thermal movement. All pipework shall be free from surface or general corrosion and without any scaling pitting, excess weathering or damage. Any pipework so affected shall be removed from site and replaced at no cost to the contract. Each length of pipework shall have at least one coloured identification band or identifying mark when delivered. All pipework shall be supplied in the standard manufactured straight lengths but not less than 6m long except where shorter specific or flanged lengths between fittings are actually required. Prolonged storage in sunlight may lead to degradation of thermoplastic pipe and fittings due to the combined effect of heat and ultra violet radiation. Therefore temporary covering shall be used wherever possible to prevent exposure. Pipes should not be subjected to excess of temperatures variation within the pipework stack or storage facilities. All pipework shall be stored on flat level ground free from sharp stones etc. and stacked to heights not exceeding manufacturer’s recommendations. Side bracing of pipe storage facilities stacks should be provided to prevent stack collapse. Smaller pipes may be ‘nested’ inside larger pipes. Any pipework installation containing fluids shall be installed so that the complete system can be drained down quickly, easily and without disruption AJC 05/07 Section 2.3. / 1 SECTION 2.3. – PIPEWORK AND FITTINGS to other services. Where it is required to shorten any pipe, it shall be cut off square and cleanly with an approved pipe cutting machine. 2.3.2 Definitions of Systems and Pipework Materials For the purpose of this Specification, the following definitions relating to differing types of hydraulic and vapour systems and associated materials, shall apply unless stated otherwise in Section 3 where Section 3 shall apply. a) Low Temperature Hot Water (L.T.H.W.) Heating System A system open or closed to the atmosphere which operates at temperatures C, up to a maximum of 95° and does not form part of a M.T.H.W. or H.T.H.W. heating injection system. L.T.H.W. shall be installed utilising black mild steel tube heavyweight to BS EN 10255 up to and including 150mm. For pipe sizes above 150mm to be to BS EN 10216-1 or BS EN 10217-1, wall thickness as called for under Section Three of this Specification. Where copper pipework is called for under Section 3 pipework to BS EN 1057 R250 shall be used. b) Medium Temperature Hot Water (H.T.H.W.) Heating System A system, open or closed to the atmosphere, which operates between a temperature range of 95° C C-120° and up to an operating pressure of 3.5 bar gauge. M.T.H.W. shall be installed in black steel or copper tube as clause 2.3.2(a). c) High Temperature Hot Water (H.T.H.W.) Heating System A system, closed to the atmosphere, which operates at temperatures above 120°C. H.T.H.W. shall be installed utilising black mild steel tube heavyweight as clause 2.3.2.a). AJC 05/07 Section 2.3. / 2 SECTION 2.3. – PIPEWORK AND FITTINGS d) Steam Services Steam heating and/or steam distribution system with a working pressure up to a maximum of a 10 bar. Steam systems shall be installed utilising black mild steel tube heavyweight as clause 2.3.2.a). e) Condensate Systems open to the atmosphere collecting products of a steam system which operates at temperatures up to a maximum of 100°C. Condensate systems shall be installed utilising light gauge copper tube to BS EN 1057. If steel tube specified under Section Three of this Specification pipework shall be as paragraph 2.3.2.a). f) Domestic Hot Water Service (D.H.W.S.) System A system open or closed to the atmosphere which produces potable hot C water up to a maximum of 65° for domestic use. Domestic hot water service systems shall be installed utilising light gauge copper tube to BS EN 1057 R250. g) Cold Water Service (C.W.S.) System Systems open or closed to the atmosphere which provides potable cold water for domestic use. Cold water service systems shall be installed as follows: (i) Internal Within Building: Light gauge copper to BS EN 1057 R250. (ii) Buried Pipework External to Building: Light gauge soft copper to BS EN 1057 R290. OR Blue polyethylene to BS EN 12201 (for pipes up to and including 63mm) For above 63mm WAA Information and Guidance 4-32-03 (ISSN 0267- 0305) is applicable. OR AJC 05/07 Section 2.3. / 3 SECTION 2.3. – PIPEWORK AND FITTINGS P.V.C. to BS EN 1452 as called for under Section Three of this Specification and/or to comply with the requirements of the local Water Authority. h) Chilled Water Service A system open or closed to the atmosphere typically operating below 15°C C and as low as 5° for cooling processes. Chilled Water Services shall be installed in black steel tube as Clause 2.3.2.a). i) Condenser Water Service A system open or closed to the atmosphere for cooling water system, average operating temperature 40°C. Condenser Water Services shall be installed in black steel tube as Clause 2.3.2 (a). j) Condensate Drains A system open to the atmosphere draining cooling systems average operating temperature up to a maximum of 15°C. Condensate drains shall be installed in either rigid unplasticised P.V.C. to BS EN 1452 Class ‘D’ or copper tube BS EN 1057 R250 as called for under Section Three of this Specification. k) Fire Mains A hose reel system open to atmosphere either fed directly from the mains or pumped via break tank to serve first aid fire fighting. Fire mains shall be installed in copper as Clause 2.3.2.(f) or in steel as Clause 2.3.2.(a) as called for under Section Three of this Specification. l) Dry Riser Systems of dry pipework open to atmosphere which will remain dry for use by the Fire Authority in the event of an emergency. Dry riser shall be installed in black steel tube as Clause 2.3.2.(a). AJC 05/07 Section 2.3. / 4 SECTION 2.3. – PIPEWORK AND FITTINGS m) Sprinklers A system open to atmosphere connected to a suitable water supply to provide automatic fire protection to designated areas. Sprinklers shall be installed in black steel tube as Clause 2.3.2.(a). n) Compressed Air A system of pipework which conveys air from a compressor plant to pneumatic equipment. Compressed air shall be installed utilising steel tube BS EN 10255 galvanised after manufacture. o) Oil Fuel Lines A system of pipework carrying fuel oil from storage vessels open to atmosphere serving oil burning equipment. Oil fuel lines shall be installed in black steel tube as Clause 2.3.2.(a). p) Gas Service A system of pipework for conveying either manufactured gas (1st family), natural gas (2nd family) or L.P.G. (3rd family) as indicated in Section Three. Gas pipework shall be installed as follows: i) Internal Within Building: Black mild steel tube heavyweight to BS EN 10255. Where copper pipework is called for under Section Three of this Specification, then light gauge copper to BS EN 1057 R250 shall be used. ii) Buried Pipework External to Building: Medium density polythene to BS 7281 or as called for under Section Three of this Specification and/or to comply with the requirements of the local Gas Authority. q) System Cold Water Feeds, Vents, and Overflows The above shall be installed utilising light gauge copper to BS EN 1057 R250 throughout. AJC 05/07 Section 2.3. / 5 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.3 Pipe Erection All pipes on straight runs shall be lined up with facilities for the pipes to be rotated for the process of welding joints, in order to minimise bottom welding. Pipes shall be run with a slight rise or fall as required. All pipes shall follow the lines of walls indicated on the drawings, unless the site conditions prevent this, in which case the runs may be varied to suit the site conditions, subject to the agreement of the Engineer. Uncovered pipes shall be located not less than 25mm or more than 40mm clear of walls. Insulated pipes shall be located so that the insulation is not less than 15mm or more than 25mm clear of walls. All pipes shall be fitted well clear of the floor when situated in rooms, to permit cleaning beneath the pipes. Where possible a 115mm clearance shall be left between the underside of the pipes and the finished level of the floor and in no case shall the pipe be less than 100mm clear of the floor. The Contractor shall ensure that the installation looks neat and tidy and that there is accurate spacing between pipes, valves and joints etc, all symmetrically lined up. Similarly all directional changes in groups of pipes shall be taken from common radius points. Adequate space must be left for the application of the insulation and for separate insulation of each pipe. Special care shall be taken before final assembly and closing up to ensure that all pipes are properly cleaned out and free from flux grit, scale and jointing material. Ends of pipes temporarily unconnected for any reason shall be closed with plastic caps. Plugs shall not be used for this purpose. All PVC, UPVC, MUPVC, and polypropylene pipework passing through fire walls/floors shall incorporate intumescent fire sleeves to BS 476: Part 20 where required by the Building Regulations. Where approved by the Engineer, other methods of protected fire sleeves indicated within the Building Regulations may be installed. All pipework shall be installed so as to allow for any possible expansion or AJC 05/07 Section 2.3. / 6 SECTION 2.3. – PIPEWORK AND FITTINGS contraction of the pipework. Where thermoplastic pipes are to be installed in locations likely to be permanently exposed to prolonged periods of sunlight, the materials life may be extended by painting. This shall be in accordance with the manufacturer’s recommendations. PTFE thread sealant tape shall meet the performance requirements of BS 5292: Type C in addition to which, it shall justify additional Type C tests on steel pipe threaded to BS 21 for taper/taper and taper/parallel joints in all sizes up to 50mm (2”) nominal bore. For sizes up to 25mm (1”) the Appendix L test pressure shall be at least 10 bar and for sizes above 25mm (1”) the Appendix L test pressure shall be less than 5 bar. In all cases on steel pipe up to 50mm (2”) nominal bore the wrapping technique shall be in accordance with BS 7786, i.e. a single wrap with 50% overlap. PTFE tape shall meet the above requirements and shall be wound on a spool marked with the statement “Satisfies BGC/1M/16”, the wrapping technique and the sizes of pipe on which it is known to be suitable. Other PTFE tapes shall not be used. 2.3.4 Pipework Clearances Pipes shall be so fixed as to give the following minimum clearances between the pipe or insulation (where specified) and adjacent surfaces as follows: Wall – 25mm Ceilings – 100mm Finished Floor – 100mm Adjacent Pipes, both insulated – 25mm Adjacent Pipes, both uninsulated – 150mm Adjacent Pipes, only one insulated – 75mm Adjacent Pipes, to conduit or trunking insulated – 25mm Adjacent Pipes, to conduit or trunking insulated – 100mm AJC 05/07 Section 2.3. / 7 SECTION 2.3. – PIPEWORK AND FITTINGS Under no circumstances shall pipes be spaced close together and enclosed in a common insulating covering. Notwithstanding the above minimum clearances, sufficient clearance shall be allowed to facilitate easy application of thermal insulating material of the thickness specified in the Insulation Sections of the Specification. 2.3.5 Pipework Fittings a) L.T.H.W. Heating, M.T.H.W. Heating, Chilled Water Condenser Water Systems, Fire Services, Oil Fuel Lines and Gas Services. Shall be erected utilising easy sweep black malleable iron fittings to B.S.143 of the bonded type as manufactured by Messrs. Crane Ltd on pipework sizes up to and including 50mm. Disconnecting joints shall be made with ‘Navy’ type brass seated unions, Crane fig No.289 or boxed flanges to B.S.T.’E’. For pipework 65mm and above, black heavyweight welding fittings to B.S.1965 shall be used. All pipework 65mm and over in plant rooms shall be welded. Where copper pipework is called for under Section Three of this Specification, fittings shall be in accordance with Clause 2.3.5. (c). b) H.T.H.W. Heating Systems Shall be erected throughout utilising black heavyweight welding fittings to B.S.1965, irrespective of pipe size and location. c) D.H.W.S. Systems On pipework up to and including 54mm, copper capillary fittings integral solder ring to B.S.864 shall be utilised as manufactured by Messrs. I.M.I. Yorkshire Fittings Limited. For pipework 67mm and above, either bronze welded gunmetal fittings or end AJC 05/07 Section 2.3. / 8 SECTION 2.3. – PIPEWORK AND FITTINGS braze capillary fittings shall be used as manufactured by Messrs. Donald Brown (Brownall) Limited, Messrs. Delta Fittings Limited, or I.M.I. Yorkshire Fittings Limited. All fittings to be suitable for potable water. Disconnecting flanges shall be provided to B.S.T.’E’. on 67mm pipework and above. d) C.W.S. Systems Where copper pipework is specified under Section Three of this Specification, then fittings shall be in accordance with Clause 2.3.5. (c) above. e) System Cold Water Feed, Vents and Overflows In accordance with Clause 2.3.5. (c) f) Steam Services Shall be erected throughout utilising black mild steel B.S.1965 “heavy” seamless for welded joints or heavyweight wrought iron BS EN 10241 for screwed joints. g) Condensate Shall be high duty capillary fittings as manufactured by Messrs. I.M.I. Yorkshire Fittings Limited. h) Condensate Drains Shall be either copper capillary type fittings as manufactured by Messrs. I.M.I. Yorkshire Fittings Limited or U.P.V.C. fittings in accordance with tube manufacturer’s recommendations. i) Compressed Air Shall be as Clause 2.3.5.(a) but galvanised after manufacture. AJC 05/07 Section 2.3. / 9 SECTION 2.3. – PIPEWORK AND FITTINGS j) Bends, Elbows, Tees Long radius elbows, twin elbows and sweep tees shall be used throughout, except on drain points and venting points where they shall be square. Reducing tees shall be used in preference to equal tees and reducers. Where reducers are used, they shall be eccentric on horizontal pipework, or concentric on vertical pipework, bushings or connectors will not be allowed. All fittings shall be of the same material and finish as the tube to which they are fitted. k) Unions Unions shall be used only where necessary to facilitate erection and maintenance of equipment, or as indicated on the contract drawings. Where used, they shall be of the ‘Navy’ type consisting of two screwed halves with ground spherical faced joints between two gunmetal seats up to and including 50mm diameter. l) Flanges Flanges for M.S. pipework shall conform to BS EN 1092-1, and be of forged steel, machined full face, and welded or screwed to the pipe. They shall conform to the appropriate B.S. Table for the pressure and temperature to which they will be subjected, but shall not be of lower standard than PN10. Welding flanges shall be of the boss slip-on-type. Flanged joints shall be made with well graphited klingerite full face joint rings and approved jointing compound. Taylors brass or nickel corrugated rings may, where applicable, be utilised, but again full faced. Black bolts and nuts with washers shall conform to B.S.4190 with no more than 15mm thread protruding through the nut. Bolts on chilled water systems shall be sheradized. AJC 05/07 Section 2.3. / 10 SECTION 2.3. – PIPEWORK AND FITTINGS Flanges to be employed on 65mm diameter tube and above. Bolts used to effect cold-draw on expansion fittings shall be removed after pulling up and replaced by bolts of the correct length. m) Dezincification and Electrolytic Action of Fittings Used on Copper Installations Should the water serving the building be known to cause dezincification, materials used on services must be zinc free, and shall be of all gunmetal construction. Suitable insulating nipples shall be used at connections of dissimilar metals on water supply services to minimise electrolytic action. n) Offsets All bends and offsets are to be made utilising proper bending machines, and are to be used in preference to fittings at all times. The work shall be carried out in a neat and workmanlike manner in accordance with the opinion of the Engineer. Where this work is not considered to be of an acceptable standard by the Engineer, then the work shall be removed and reinstated at no additional cost to the Contract. 2.3.6 Black Steel Pipework Installations (a) Pipework The whole of the black steel tube systems shall conform to BS EN 10255 and are to be of welded construction throughout the pipe bores of 50mm and above unless indicated otherwise. Below 50mm the use of screwed joints and fittings will be permitted, but only where the pipework is visible, or where access along its length has been specifically provided. All pipework shall have plain ends machined and bevelled for butt welding, pipes specially cut to length shall also be similarly finished. Piping must be cut with a saw or special tool. The use of bevelled wheel cutters will not be allowed. All pipes are to be reamoured or filed to ensure full diameter. AJC 05/07 Section 2.3. / 11 SECTION 2.3. – PIPEWORK AND FITTINGS (b) Bends and Fittings On pipe sizes 15mm to 40mm inclusive, ‘hot’ pulled bends formed on site will be permitted provided their radius is not less than 2.5 times the internal diameter. On pipe sizes 50mm and above bends shall be shop made preferably at one end of a length of pipe and the radius of the bend being not less than 2.5 times the internal diameter of the pipe unless otherwise specifically approved. Bends of corrugated, polygonal butt or other pattern will not be permitted unless specially approved by the Engineer. Tee pieces shall be formed by the direct welding of the branch pipe to the main with a branch taken in an ‘easy sweep’ from the main. Great care must be taken to ensure that branch pipes are correctly ‘saddled’ to fit the main and the completed weld in no way obstructs the bore of the main or branch pipe. Reduction in pipe diameters shall be obtained by butt welding tapered pieces; the taper pieces are to be of a standard length and arranged eccentrically where necessary to avoid air pockets and facilitate drainage. It is permissible for the Contractor to use branch bends, bends and reducing sockets of the seamless type with bevelled ends. Where screwed fittings are used they shall be black heavyweight malleable iron to BS 143 and BS 1256 with taper thread to BS 21 and an approved joint either using fine standard hemp with jointing compound or alternatively PTFE tape shall be used. Excess jointing materials shall be removed after the joint has been made. Wrought steel pipe fittings shall be manufactured from mild steel by a seamless or welded process to BS EN 10241. Welded fittings shall be BS 1965: Part 1 for steel tube to BS EN 10255 and be manufactured by a forged seamless process from mild steel. AJC 05/07 Section 2.3. / 12 SECTION 2.3. – PIPEWORK AND FITTINGS For tube to BS EN 10216 and BS EN 10217 fittings shall be as follows:- Nominal Size Wall Thickness Outside Diameter (mm) (mm) (mm) 175 2.6 194 200 5.6 219 250 6.3 273 300 7.1 324 350 10.0 356 (c) Joints Except where flanged joints are required for connections to plant, valves and expansion bellows, the pipe joints shall be welded on site by an approved fusion welded process. The distance between pipe joints shall not be less than 5.5 metres except where essential for delivery, erection and dismantling for maintenance of Plant. Flanged joints on pipes and on valves shall be of a type to suit the maximum working pressure (PN rating) and temperature of the pipework installation in which they are fitted. Flanges must also be suitable for use with the liquids for which they are applied. On all pipework up to 50mm size unions shall be used at all dismantling points. These shall be of the ground-in spherical seat type and jointed to the pipe-work in an approved manner. Above 50mm diameter flanged connections shall be used. 2.3.7 Galvanised Steep Pipework Installation (a) Pipework and Fittings All galvanised steel pipework and fittings shall be heavyweight quality to BS EN 10255 unless otherwise indicated. Up to and including 65mm diameter all fittings shall be screwed to BS AJC 05/07 Section 2.3. / 13 SECTION 2.3. – PIPEWORK AND FITTINGS 21 and shall be of high grade galvanised malleable iron type. Pipes of 80mm diameter and above shall have flanged connections jointed as specified below. Pipework must be cut with a saw. The use of bevelled wheel cutters will not be allowed. All pipes are to be reamoured or filed to ensure full diameter. All galvanised and steel pipework and fittings shall be installed strictly in accordance with manufacturer’s recommendations. Prefabricated steel pipework to the specified grade shall be manufactured in workshop conditions and welded in accordance with section 2.3.22. Prefabricated galvanised mild steel pipework for sanitary installation shall be in accordance with BS 3868. Prefabricated pipework that has been cut and modified on site shall be sent off-site for re-galvanising. On no account will site applied cold painting treatment to the galvanised coating be accepted, unless the area to be painted is extremely small, and with prior approval of the Engineer. (b) Joints Unions must be of the conical bronze ground seat type. The use of long screwed connectors will not be permitted. For sanitation and rainwater pipework (non-pressurised) joints, the use of mechanical gasketted joints (bolted) may be used with approval of the Engineer. Screwed fittings shall be jointed utilising PTFE thread to BS 7786, see Clause 2.3.3. Fine stranded hemp with jointing compound may be used but not on domestic hold and cold water services installations. Excess jointing material shall be removed after the joint has been made. AJC 05/07 Section 2.3. / 14 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.8 Copper Pipework Installations (a) Pipework All above ground copper pipework on hot, cold, water and fire fighting services (where specified) is to be BS EN 1057 R250 unless otherwise indicated. Where copper pipework has been specified for underground services, it shall be to R290. All copper tube shall be manufactured from phosphorus deoxidised non-arsenical copper to BS EN 1976 and BS EN 1978 and shall be suitably “kite marked” by a licensed manufacturer. Copper pipework cast into concrete slabs shall be to BS EN 1057 R250, but with a polypropylene coating, with inner void between outer copper pipework surface and inner plastic wall profiled to trap air. Where water or air temperatures or conditions are likely to weaken soft C soldered joints, i.e. at temperatures in excess of 100° or where excessive pressure may occur and on all pipework handling condensate produced from a pressurised steam service, irrespective of temperature or pressure, brazing, hard or silver soldering with heavy duty fittings shall be used throughout. Where pipework is likely to become wet i.e. shower areas, copper pipework and fittings shall be chromium plated. Copper pipework installed underground shall be wrapped in two layers of Denso tape (followed by a good covering of Denso paste). All copper pipework and fittings shall be installed strictly in accordance with manufacturer’s recommendations. See Section ‘Inspection, Commissioning & Testing’ for random inspection and testing of copper pipework water services for lead contamination from use of lead based solders. AJC 05/07 Section 2.3. / 15 SECTION 2.3. – PIPEWORK AND FITTINGS (b) Fittings Fittings for copper pipework up to and including 67mm shall be in accordance with BS 864: Part 2 and manufactured by a BSI British Standard kite mark licensee. On pipework 76mm and over the fittings are to be an equal standard to BS 864 in terms of tolerance and test pressure. Integral solder ring, compression and end feed fittings size ranges and associated methods of jointing are described in the section entitled “Soldered and Compression Joints”. (Clause 2.3.8. (c)). Pipework shall be installed with adequate unions or flanges to allow the disconnection of pipework for maintenance and test procedures to be easily and satisfactorily carried out. (c) Soldered and Compression Joints All capillary joints up to and including 67mm diameter shall be non- dezincifiable copper alloy factory made fittings with integral ‘Lead Free’ soft soldier jointing rings. All heavy duty capillary joints up to 54mm diameter shall be non- dezincifiable inhibited aluminium, brass or gunmetal (alloy LGZ) manufactured fittings with integral lead-free copper/silver/phosphorus had solder (silver brazing alloy to BS EN 1044) jointing rings. All fittings are to be stamped with the manufacturer’s logo to denote a lead free component and shall be manufactured by BSI British Standard kite mark licensee. All end fittings up to and including 107mm diameter shall be non- dezincifiable copper, gunmetal alloy factory made fittings. For sizes up to and including 67mm lead free soft solder shall be utilised and for 76 and 108mm diameter sizes lead free copper/silver/phosphorus hard C solder with maximum working temperature of water of 220° (silver brazing alloy to BS EN 1044) shall be utilised. Fittings are to be AJC 05/07 Section 2.3. / 16 SECTION 2.3. – PIPEWORK AND FITTINGS manufactured by a BSI British Standard kite mark licensee. Important note: End feed fittings shall only be used when written consent is gained from the Engineer. Composition of lead free solder for integral soft solder fittings and end feed fittings up to and including 67mm shall be either 1% copper/99% tin or 3% silver/97% tin to conform with the draft amendment BS 864. Lead based solder to BS 219 will not be permitted under any circumstances. The Engineer reserves the right to have removed from site all lengths of pipework made with the use of lead based solder. All compression joints up to and including 54mm diameter shall be non- dezincifiable copper alloy to BS 864. Couplings shall be fitted strictly in accordance with manufacturer’s recommendations, particular attention being given to cleanliness, lack of distortion of the pipe and ensuring full insertion depth and over-tightening of the compression joint. The Contractor shall ensure that any pipework to be brazed is prepared correctly and in accordance with the Heating and Ventilating Contractors Association. Prior to any brazing or bronze welding being undertaken a composite test piece shall be submitted and approved by the Engineer. The Engineer reserves the right to inspect, cut-out at random, any suspect capillary joints for laboratory analysis to determine if lead solder has been used in jointing pipelines. Should it be proven that lead based solders have been used, then the Engineer may instruct the Contractor to totally remove all the pipework installation and reinstate with new pipework installation using lead-free solder for capillary joints. This work, if instructed, will be carried out at the Contractor’s expense. 2.3.9 Stainless Steel Pipework Installations (a) Pipework All stainless steel pipework shall be thin walled tubing to BS EN 10312. AJC 05/07 Section 2.3. / 17 SECTION 2.3. – PIPEWORK AND FITTINGS All supports or clips and associated screws, bolts, and washers etc. are to be stainless steel and shall be spaced as indicated. All stainless steel pipework and fittings shall be installed and stored in strict accordance with manufacturer’s recommendations. (b) Fittings All compression and capillary fittings shall be manufactured from grade 304 S15 stainless steel. Pipework shall be installed with adequate unions or flanges to allow the disconnection of pipework for maintenance and test procedures to be easily and satisfactorily carried out. (c) Adhesive Bonding, Soldered and Compression Joints All stainless steel capillary fittings and pipework up to and including 42mm shall be adhesive bonded, utilising an anaerobic adhesive, as approved by the Water Research Centre, such as Loctite 638 or similar and approved. Adhesive bonding shall not be used on pipework carrying or discharging water at or in excess of 80°C. All stainless steel pipework and capillary fittings up to and including 28mm o.d. shall be soft soldered incorporating lead free soft solder (for water and steam up to 100°C.) All stainless steel pipework and capillary fittings 35mm and over shall be silver soldered to BS EN 1044 incorporating lead free materials. The Engineer reserves the right to inspect, cut-out at random, any suspect capillary joints for laboratory analysis to determine if lead solder has been used in jointing pipelines. Should it be proven that lead based solders have been used, then the Engineer may instruct the Contractor to totally remove all the pipework installation and reinstate AJC 05/07 Section 2.3. / 18 SECTION 2.3. – PIPEWORK AND FITTINGS with new one using lead-free solder for capillary joints. This work, if instructed, will be carried out at the Contractor’s expense. All stainless steel compression joints up to and including 54mm diameter shall be grade 316 stainless steel with 303 nuts. Stainless steel couplings shall be fitted strictly in accordance with the manufacturer’s recommendations, particular attention being given to cleanliness, lack of distortion of the pipe and ensuring full insertion depth. Over-tightening of the compression joint shall be avoided. 2.3.10 Flux and Excess Solder Flux shall be of an appropriate type for making copper capillary joints of an appropriate phosphoric acid type suitable for stainless steel capillary joints and by an approved manufacturer. Flux shall conform to the Water Company requirements and be WRc approved, be biodegradable and water soluble for flushing out. Flux shall not support micro-biological growth in water. Excess solder shall be removed after jointing. Self cleaning types of flux shall not be used. The Engineer reserves the right to have removed from site all lengths of pipework made with the use of salt- cleaning flux materials. 2.3.11 PVC Pressure Pipework (a) Pipework Metric size PVC pressure pipe up to and including 315mm diameter shall be to DIN 8061/2 or DIN 8063 as applicable and ISO 727. Imperial size PVC pressure pipe up to and including 12” diameter shall be to BS 3505 or BS 3506 as applicable and BS 4346. All PVC pipework and fittings shall be installed strictly in accordance with manufacturer’s recommendations. AJC 05/07 Section 2.3. / 19 SECTION 2.3. – PIPEWORK AND FITTINGS (b) Fittings Metric PVC fittings up to and including 315mm diameter shall be to DIN 8063. Imperial PVC fittings up to and including 12” diameter shall be to BS 4346: Part 1 and be manufactured by a British Standard kite mark licensee. (c) Joints PVC pressure pipework and fittings shall be jointed by solvent cement in accordance with manufacturer’s recommendations and BS 4346: Part 3. Excess cement shall be removed after jointing. PVC solvent cement shall not support micro-biological growth in water. Gaskets and seals shall be made from EPDM unless otherwise stated with the Particular Specification or the Contract Drawings. Pipework shall be installed with adequate unions or flanges to allow the disconnection of pipework for maintenance and test procedures allowing the aforementioned to be easily and satisfactorily carried out. PVC pipework installations shall incorporate manufactured expansion units or expansion loops to allow for the relief of thermal movement in accordance with manufacturer’s recommendations. 2.3.12 UPVC Pipework (a) Pipework and Fitting for Above Ground Installation UPVC pipework and fittings from 82mm diameter up to and including 160mm diameter shall be to BS 4514 and manufactured by a British Standard kite mark licensee. All UPVC pipework and fittings shall be stored and installed strictly in accordance with manufacturer’s recommendations. (b) Joints AJC 05/07 Section 2.3. / 20 SECTION 2.3. – PIPEWORK AND FITTINGS UPVC pipework and fittings shall be jointed by solvent cement and/or seal ring joints in accordance with manufacturer’s recommendations. Pipework shall be installed with adequate unions or flanges to allow the disconnection of pipework for maintenance and test procedures to be easily and satisfactorily carried out. UPVC pipework installations shall incorporate seal ring joints or thermal movement limiters to allow for the relief and control of thermal movement. Seals shall be made from natural or synthetic rubber unless otherwise stated with the Particular Specification or the Contract Drawings. To accommodate expansion for both horizontal and vertical runs the pipes must be free to move through the pipe clip/holder bat and seal ring socket so that a gap exists between the end of the pipe and the socket register as recommended by the pipe manufacturer. For long horizontal suspended runs a thermal movement limiter shall be installed where indicated on the drawings. An expansion joint must be fitted between two securely fixed points not less than 1m apart or not more than 4m apart for soil pipes and 2m apart for vent pipes. NB. Thermal movement limiters shall be securely fixed to soffit of ceiling etc. by use of mild steel/angle framework to act as anchors. 2.3.13 MUPVC Pipework (a) Pipework and Fittings MUPVC pipework and fittings up to and including 50mm diameter shall be to BS 5255 and manufactured by a British Standard kite mark licensee. All MUPVC pipework and fittings shall be installed and stored strictly in accordance with manufacturer’s recommendations. AJC 05/07 Section 2.3. / 21 SECTION 2.3. – PIPEWORK AND FITTINGS (b) Joints MUPVC pipework and fittings shall be jointed by solvent cement and seal ring joints in accordance with manufacturer’s recommendations. Pipework shall be installed with adequate unions or flanges to allow the disconnection of pipework for maintenance and test procedures to be easily and satisfactorily carried out. MUPVC pipework installations shall incorporate seal ring joints to allow for the relief and control of thermal movement as recommended by the pipework manufacturer. Seal rings shall be made from natural or synthetic rubber unless otherwise indicated. To accommodate expansion for both horizontal and vertical runs, the pipes must be free to move through the pipe clip/holder bat and a seal ring socket so that a gap exists between the end of the pipe and the socket register as recommended by the pipe manufacturer. An expansion joint must be fitted between two securely fixed points not less than 1m apart as previously described. 2.3.14 MDPE Pipework (Below Ground) (a) Pipework and Fittings Medium Density Polyethylene (MDPE) pipework and fittings for water use (Blue) up to and including 63mm diameter external shall be to BS 6572, manufactured by a British Standard kite mark licensee and WRc – W1S.04.32.02 and for pipework 90mm (external) up to and including 400mm diameter shall be to WRc - W1S.04.32.03 and WRc - W1S.04.32.04. AJC 05/07 Section 2.3. / 22 SECTION 2.3. – PIPEWORK AND FITTINGS (b) Joints MDPE pipes and fittings shall generally be jointed by means of electrofusion or flanged fittings. Compression fittings shall also be permitted for pipework up to 63mm diameter. Pipework shall be installed with adequate unions or flanges to allow the disconnection of pipework for maintenance and test procedures to be easily and satisfactorily carried out. 2.3.15 Cast Iron Above Ground Sanitation Pipework (Mechanically Jointed) (a) Pipework and Fittings Cast iron pipework and fittings up to and including 300mm diameter shall be to DIN 19522 and ISO 6594 as manufactured by a European foundry as indicated. Cast iron pipework and fittings shall be installed strictly in accordance with manufacturer’s recommendations. (b) Joints Cast iron pipes and fittings shall be jointed by means of mechanical couplings to BS EN 877 incorporating synthetic rubber gaskets (EPDM or nitrile) in accordance with BS EN 681 and utilising stainless steel nuts and bolts or set screws. Couplings shall be fitted strictly in accordance with manufacturer’s recommendation, particular attention being given to cleanliness, lack of distortion of the pipe and ensuring full insertion depth. Bolts shall be tightened alternatively so that the gap between couplings is even on both sides (where applicable) and to the specified torque settings. AJC 05/07 Section 2.3. / 23 SECTION 2.3. – PIPEWORK AND FITTINGS Pipework shall be installed with adequate demountable joints to allow the disconnection of pipework for maintenance and test procedures to be easily and satisfactorily carried out. European/British Standard cast iron pipework systems shall not be mixed within a completed installation. 2.3.16 Conventional Cast Iron Above Ground Sanitation Pipework (a) Pipework and Fittings Conventional cast iron spigot and socket pipework and fittings up to and including 150mm diameter shall be to BS 416 as manufactured by a British Standard kite mark licensee as indicated. Cast iron pipework and fittings shall be installed strictly in accordance with manufacturer’s recommendations. (b) Joints Cast iron pipes and fittings shall incorporate spigot and socket joints for a lead caulked joint. 2.3.17 UPVC Rainwater Installation a) Pipework and Fittings UPVC external rainwater pipework and gutter fittings shall be to BS 4576 and manufactured by a British Standard kite mark licensee as indicated. UPVC external rainwater pipework, gutters and fitting shall be strictly installed in accordance with manufacturer’s recommendations. b) Joints UPVC external pipework, gutters and fittings shall be jointed by solvent cement and/or sealing sockets. AJC 05/07 Section 2.3. / 24 SECTION 2.3. – PIPEWORK AND FITTINGS c) Thermal Movement i. Gutters-supports, fixings and connectors to gutters shall allow adequate thermal movement to take place and be in accordance with the pipework manufacturer’s recommendations. ii. Rainwater pipes: the type of jointing used for rainwater pipes shall allow for thermal movement to take place, without leakage distortion and displacement of fittings. The method of expansion shall be in accordance with the pipework manufacturer’s recommendations. 2.3.18 Aluminium Rainwater Installation a) Pipework and Fittings Aluminium heavy grade gutters and fittings shall be BS 2997. Aluminium heavy grade external down pipes and fittings shall be to BS 2997, BS EN 573, BS EN 755, and BS EN 12020. Internal aluminium rolled and seam welded pipe and fittings shall be to BS 1470: 1972: Grade T57S: H8 condition. b) External Down Pipe Jointing Aluminium down pipes shall be jointed so as to achieve a watertight joint utilising low modules, Type A (non-acetoxic) silicone sealant over a caulking material such as polyethylene backing foam with an expansion gap so as to allow thermal movement. The aluminium rainwater installation shall be installed strictly in accordance with the manufacturer’s recommendations. AJC 05/07 Section 2.3. / 25 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.19 Cast Iron Rainwater Installation a) Pipework and Fittings Cast iron pipework and fittings up to and including 150mm diameter shall be to BS EN 877 as manufactured by a British Standard kite mark licensee as indicated. European Standard cast iron pipework and fittings up to and including 150mm diameter shall be to DIN 19522 and ISO 6594 as manufactured by a European Foundry as indicated. Cast iron spigot and socket (circular and square) pipework and fittings up to and including 100mm diameter shall be to BS 460 as manufactured by a British Standard kite mark licensee with open or mastic sealed joints, as indicated. As indicated traditional circular and/or square cast iron rainwater pipework, gutters and fittings shall be to BS 460 and shall only be used for external applications. Cast iron pipework, gutters and fittings shall be installed strictly in accordance with manufacturer’s recommendations. b) Joints Cast iron pipework, with spigot ends and fittings shall be jointed by means of mechanical couplings and of a socket pattern to BS 460. Couplings shall be fitted strictly in accordance with manufacturer’s recommendations, particular attention being given to cleanliness, lack of distortion of the pipe and ensuring full insertion depth. Bolts/screws shall be tightened to the manufacturer’s specified torque settings. Conventional socketted cast iron pipework, gutters and fittings shall be jointed by means of socket and spigots to recommendations of BS 460. AJC 05/07 Section 2.3. / 26 SECTION 2.3. – PIPEWORK AND FITTINGS Cast iron gutter sockets and spigots shall be jointed with an approved putty or mastic compound which should be evenly spread along the joint. 2.3.20 Flanged Joints a. All black pipe flanges shall be screwed of the ‘slip-on’ welding type and conform to BS 10. Flanges on galvanised pipe shall be screwed, galvanised and all exposed threads shall be painted with a zinc-rich paint immediately after the flange is screwed on. Where pipework is to be galvanised after fabrication, welded flanges shall be used. All flanges shall be machined right across the jointing face and on the edges. b. Mild steel flanges shall be drilled with a slight taper in their bore and be provided with a shaped boss to facilitate welding. Flanges shall be welded neck and bore. c. Long neck welding flanges shall not be used and the practice of burning out the threads of a screwing flange will not be permitted. d. All pipework flanges shall, when in position, forming a pair, be flush with one another all round. Flanges shall, depending on the flange material, be bolted together with bronze or bright mild steel bolts and nuts complete with washers. Bolts shall project no more than one and a half threads through the nuts. Where high tensile or other special bolts or nuts are required for arduous application, approved identification of such requirement will be required at each such flange. e. Joints between flanges shall normally be made with brass corrugated rings, mineral compound rings or other approved jointing materials. AJC 05/07 Section 2.3. / 27 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.21 Welding of Metallic Pipe Joints Electric welding is to be used, except for the pipes below 80mm which may be welded by the oxy-acetylene method and the standard of welding throughout is to be in accordance with current standard practice. The Contractor shall provide written proof of this experience and his ability to employ welders capable of working to the above standard of welding. The written proof should cover experience over a period of the last 5 years, and the Contractor shall also state that he will have suitably experienced welders available to commence site work when required. Full details of the proposed method of welding, electric arc or oxy- acetylene, shall be submitted by the Contractor prior to commencement of the Contract. 2.3.22 Welding of Plastic Pipe Joints Electrofusion welded joints in medium/high density polyethylene pipework shall be made only between pipes having the same physical characteristics. Joints between pipes of different manufacturers shall only be made with specific approval of the Engineer. Hot air fusion welding of plastic materials shall only be used in workshop situations. Where hot air fusion welding is necessary on site, dictated by an unusual situation, the written approval of the Engineer shall be gained before works are carried out. Solvent welding of UPVC, MUPC, PVC or ABS plastic materials shall only be made between pipes having the same physical characteristics. Joints between pipes of different manufacturer’s shall only be made with specific approval of the Engineer. All solvent welded joints shall be made to the pipework manufacturer’s recommendations and/or to Water Industry Standard Specifications WIS No. 4-32-08, when applicable. Solvent welded joints shall, in addition to the above, conform to the following standards UPVC: BS 4346: Part 3 or BS 6209, MUPVC: BS 4346: Part 3 or BS 6209, PVC: BS 4346, Part 3. AJC 05/07 Section 2.3. / 28 SECTION 2.3. – PIPEWORK AND FITTINGS Full details of the proposed method of electrofusion and/or hot air welding shall be submitted to the Engineer by the Contractor prior to commencement of the contract. The Contractor shall provide written proof of his plastic welding experience and his ability to employ electrofusion/hot air welders capable of working to the recognised plastic welding standards. This written proof should cover experience over a period of the last 5 years, and the Contractor shall also state that he will have suitable experienced welders available to commence site work when required. When welding is to be carried out on water industry pipework, the certified welder shall be trained on a Water Industry Training Association or Pipework Manufacturer approved Water Industry training course. 2.3.23 Tests for Welders Qualifications (General) The purpose of the welder’s qualification tests is to determine the ability of welders to make sound and acceptable welds. Before any site welding on the Contract is performed, each welder shall carry out tests required in the presence of the Engineer or the Employer’s Insurance Inspector. Weld test specimens which have been suitably marked and approved shall be kept on site by the Engineer or by another responsible person so that they can be produced at any time, at the request of the Engineer. All accommodation, benches, tools, welding plant, acetylene, oxygen, electrofusion or electricity, test pieces, filler rods and electrodes, including facilities for cutting, grinding, polishing, bending and examining, which are necessary for welders qualification tests shall be provided by the Contractor. Under no circumstances shall a welder be employed on the Contract whether on or off site for welding operations other than those for which the welder is qualified. AJC 05/07 Section 2.3. / 29 SECTION 2.3. – PIPEWORK AND FITTINGS Copies and records of all test reports shall be promptly given to and kept by the Engineer. The Engineer may, at his discretion, waive the specified welders’ qualifications tests for those welders holding a current welding certificate, to an approved standard, of any of the following: H.V.A.C. B.O.C. Lloyds City and Guilds A.O.T.C. Water Industry Standards The waiver will be made provided they have been employed since the date the certificate was issued with reasonable continuity on welding the type of joint concerned. The Engineer shall have the right to refuse any welder whose work is, in the Engineer’s opinion, not to the required standard. 2.3.24 Tests for Welder Qualification Steel Pipes Each test shall be carried out in accordance with the test procedures laid down in BS 4872: Parts 1 and 3 and BS 2971. The test position shall be similar to the working conditions expected to be encountered and test pieces shall not be rotated to suit any individual welding procedure. Each test sample shall be subjected to the following examinations and tests: AJC 05/07 Section 2.3. / 30 SECTION 2.3. – PIPEWORK AND FITTINGS Butt joints on pipes up to and Visual examination and normal including 114mm o.d. tongue bend test Butt joints on pipes above Visual examination and 2 normal 114mm o.d. tongue bend tests and 2 reverse bend tests. Branch welds As above dependant on size plus macro-examination The Engineer may, at his discretion waive the macro-examination requirements. For a successful test the test weld shall conform in all respects to the requirements laid down in the above British Standard Specifications. Each welder who qualifies, shall be issued with a metal punch with an identifying number which shall be stamped adjacent to each weld made by that welder whether on or off site. Records of welders’ names and identifying numbers shall be promptly forwarded to the Engineer prior to welders commencing work. If any test sample does not reach the required standard, two further welds shall be made and tested as detailed above. Both the re-tests shall be successful for the welder to qualify for the work required in this specification. AJC 05/07 Section 2.3. / 31 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.25 Tests for Welder Qualification Copper Pipes Each gas welded joint test shall be carried out in accordance with the test procedures laid down in BS 1724. The test position shall be similar to the working conditions expected to be encountered and test pieces shall not be rotated to suit any individual welding procedure. Each test sample shall be subjected to the following tests and examinations: a. Visual examination b. Flattening test c. Macro-examination The Engineer may at his discretion waive the macro-examination requirements. For a successful test, the test weld shall conform in all respects to the requirements laid down in the above British Standard Specification. Each welder who qualifies, shall be issued with a metal punch with an identifying number which shall be stamped adjacent to each weld made by that welder whether on or off site. Records of welders’ names and identifying numbers shall be promptly forwarded to the Engineer prior to welders commencing work. 2.3.26 Radiographic Examinations The Radiographic Examination Company shall provide a report on the radiographic tests which have been made, including in interpretative results section. The report and films shall be handed to the Engineer. The material of the Image Quality Indicator shall be radiographically similar to that of the filler metal under examination. The use of X-ray and Gamma Radiation sources shall be in strict compliance with the requirements of the Ionising Radiation (Sealed Sources) Regulations 1961. AJC 05/07 Section 2.3. / 32 SECTION 2.3. – PIPEWORK AND FITTINGS The required radiograph sensitivity shall not be more than 2, and the required image details shall be readily seen on each radiograph. Radiographs which do not comply with this requirement, whatever the cause, are unacceptable and the weld in question shall be re-examined at no cost to the Contract. All interested parties shall be advised well in advance where and when radiograph tests are to be conducted, in order that appropriate precautions may be taken. 2.3.27 Pipework Cleanliness (a) Cleanliness of Pipes The Contractor shall at all times observe the installation and storage procedure as recommended by the pipework manufacturer. Pipework and similar materials shall be adequately supported and stored on properly made racks, approved by the Engineer, to prevent bending and distortion, and the ends shall be closed and threads protected by means of purpose-made end caps. The storage of pipework, or other materials, by laying them on earth will not be permitted. Care shall be exercised during the erection of pipework to ensure that foreign matter is not allowed to enter or remain in the pipes. When any portion of the installation is left open for any purpose whatsoever, the open end(s) shall be temporarily sealed with purpose- made plugs or blanking caps manufactured from metal or plastic material. Rags, paper, or similar substances shall not be used under any circumstances. A valve fitted at the end of a discontinued pipe shall not be considered satisfactory to prevent the ingress of foreign matter. AJC 05/07 Section 2.3. / 33 SECTION 2.3. – PIPEWORK AND FITTINGS Failure to comply with this instruction shall mean that the Engineer shall have the right to instruct the Contractor that pipework so left unprotected shall be dismantled for such lengths as the Engineer requests and the pipework blown through and/or cleaned at the Contractor’s expense. A black mild steel pipework installed throughout the Contract whether utilising screwed or welded joints, after erection shall be suitably wiped clean and one coat of red oxide primer paint shall be applied. This shall also apply to all mild steel brackets, drop rods, etc. (b) Pipe Cutting Piping shall be cut clean and square with the axis of the pipe, except where a bevelled edge is required for welding, using a saw, pipe-cutting tool or machine. Before installation the ends of the pipes shall be correctly prepared by filing or grinding, and any internal burrs shall be removed by filing or reaming to a distinct countersink. The Engineer may call upon the Contractor to disconnect any pipes for inspection. Should inspection reveal any neglect of reaming, the Contractor will be required to remove, re-fix and re-test at his own expense as much of the pipework as may be deemed necessary by the Engineer. 2.3.28 Pipework Supports As a general guide supports shall conform to B.S.3974 Parts 1 and 2. (a) Pipework shall be adequately supported in such a manner as to permit free movement due to expansion and contraction. The spacing of supports shall not exceed the centres given in Tables (A), (B) and (C) based upon the smallest pipe in a group. (b) All non rigid plastic pipework shall be continuously supported. (c) Pipework supports shall be arranged as near as possible to joints, and each support must take its due proportion of the pipe weight. AJC 05/07 Section 2.3. / 34 SECTION 2.3. – PIPEWORK AND FITTINGS (d) Vertically raising pipes shall, in addition, be adequately supported at the base to withstand the total filled weight of the riser. Branches from risers shall not be used as a means of support for the riser. (e) Hangers for horizontal pipework at high level shall be supported from angle or channel irons supplied by the Contractor, and suitable for building in or otherwise securing to the structure. (f) On copper pipework all pipe clips, supports or brackets shall be of cast brass construction and fixing shall be of non-corroding construction. Exposed copper pipework brackets shall be of the hospital pattern (Yorkshire No.110). (g) Insulation material shall be inserted between chilled water and incoming mains water pipework and pipework supports to obviate condensation occurring on exposed supports. This material shall be installed to the same thickness as the pipework insulation to be applied. (h) Where called for the Contractor shall support pipework within plant rooms with anti-vibration hangers. (i) Brackets in trenches shall comprise suitable steel section spanning trench walls clear of trench floor, with a pipe laid inside the section to support the pipes. Pipes shall be held in place by U-bolt guides. Where U-bolts are used as guides, the shall be bent to a radius of 1.5mm greater than the outside radius of the pipe, with the two ends threaded and secured to the supporting steel. The diameter of the road shall be 15mm for pipes of 150mm to 80mm bore, 10mm for pipes of 65mm to 40mm bore, and 5mm for pipes of 32mm bore and below. (j) A bracket on the draw off line, on hot and cold water services, is to be provided on each side of every stopcock or valve, while they shall be AJC 05/07 Section 2.3. / 35 SECTION 2.3. – PIPEWORK AND FITTINGS elsewhere arranged at appropriate equal intervals. (k) All pressure cold water and fire protection mains are to be supported as previously specified but with the purpose-made lateral anchors on both sides of each change of direction, to oppose the tendency of the bends and sets to open under pressure. (l) Detail of all pipe brackets and anchor points along with the method of incorporation to the structure shall be produced by the Contractor to a scale not less than 1:20 for approval by the Engineer/Structural Engineer a minimum of 14 days prior to the incorporation into the works. (m) Provide all clips, brackets, foundation bolts, anchor plates, washers, plugs, etc for all equipment materials supplied as part of the sub- contract. (n) Approval shall be obtained for all fixings into concrete walls, floors, ceilings and roofs. Lightweight equipment and pipework may be fixed to the building structure by screws in plastic plugs. Wood or fibre plugs shall not be used. Fixings to brickwork, blockwork and pre-cast concrete components shall not be made in the bond. Fixings to wood fitments shall be by screws. All screws fixings shall be sheradised and greased before use. Heavyweight equipment and pipework shall be fixed with masonry fixings of the expanding type. Fixings to concrete shall not exceed 30mm in depth and 6mm in diameter without written consent. Fixings shall be of the correct size and type for the fixing/load applied and these shall be agreed with the Engineer in writing prior to the commencement of the works. AJC 05/07 Section 2.3. / 36 SECTION 2.3. – PIPEWORK AND FITTINGS TABLE (A) SUPPORTS STEEL PIPEWORK SIZE OF INTERVALS FOR INTERVALS FOR VERTICAL TUBE HORIZONTAL RUNS RUNS – BARE OR LAGGED (mm) BARE LAGGED (m) (m) (m) 15 1.8 1.8 2.4 20 2.4 2.4 3.0 25 2.4 2.4 3.0 32 2.7 2.4 3.0 40 3.0 2.4 3.7 50 3.0 2.4 3.7 65 3.7 3.0 4.6 80 3.7 3.0 4.6 100 4.0 3.0 4.6 125 4.5 3.7 5.5 150 5.5 4.5 5.5 AJC 05/07 Section 2.3. / 37 SECTION 2.3. – PIPEWORK AND FITTINGS TABLE (B) SUPPORTS FOR COPPER PIPEWORK SIZE OF INTERVALS FOR INTERVALS FOR VERTICAL TUBE HORIZONTAL RUNS RUNS – BARE OR LAGGED (mm) BARE LAGGED (m) (m) (m) 15 1.2 1.2 1.8 22 1.2 1.2 1.8 28 1.8 1.5 2.4 35 2.4 1.8 3.0 42 2.4 1.8 3.0 54 2.7 1.8 3.0 65 3.0 2.4 3.7 76 3.0 2.4 3.7 108 3.0 2.4 3.7 133 3.7 3.0 3.7 159 4.5 3.7 3.7 TABLE (C) SUPPORT FOR PLASTICS PIPEWORK NOMINAL BORE INTERVALS FOR INTERVALS FOR OF PIPE HORIZONTAL RUNS VERTICAL RUNS (inches) (m) (m) ½ 0.75 1.5 ¾ to 1 1.0 1.8 1¼ 1.0 2.0 1½ 1.2 2.4 2 to 2 ½ 1.4 2.8 3 1.8 3.5 4 and over 2.0 4.0 AJC 05/07 Section 2.3. / 38 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.29 Pipework Expansion (a) Provision shall be made for movement due to expansion, either by special expansion joints, or by changes in direction of the pipework as indicated. Supports at such expansion joints shall be arranged to ensure that all expansion is taken up by the loop or changes in direction of the pipework. Where pipes are required to be pre-stressed for the purpose of reducing expansion stress under working conditions, the extent of the cold pull will be 50% of the total movement of the pipe expansion joint from cold to normal working temperatures, unless specifically noted to the contrary. Where flanged joints have been utilised for cold draw, all nuts and bolts shall be renewed after pre-stressing has taken place. Not more than 10mm of expansion vertical movement will be permitted on branches from risers unless suitable loop or change in direction is incorporated in the branch. (b) Expansion joints must be adequately supported and the pipework provided with proper guides. All bellows shall be of stainless steel single wall multiple convolution construction, with suitable end connections shall be argon-arc welded. Gunmetal female screwed ends shall be silver soldered. Bellows on domestic hot water circuits shall be so constructed that only stainless steel will be in contact with the pipe contents. Bellows shall be installed with 50% of the total calculated movement being taken up by cold draw. The recommendations of the manufacturer must be rigidly adhered to. Details of the proposed methods must be submitted to the Engineer for approval, prior to installation. AJC 05/07 Section 2.3. / 39 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.30 Anchor Points Suitable anchor points to B.S.3974 Parts 1 and 2 shall be installed where pipework expansion is occurring. Anchor points for pipework in trenches shall generally consist of mild steel channel iron framework, welded to the pipework, built into trench or adequately bolted and designed to withstand the calculated thrust. All pipework subject to movement shall be adequately guided. Guides shall have a maximum clearance around the pipe of 1.6mm. Special attention must be paid to the alignment of brackets, particularly near expansion bellows. Any cold pull-up expansion joints shall not be applied until the anchors are rigid and firm. The Contractor shall submit detailed calculations for approval by the Engineer/Structural Engineer. 2.3.31 Sleeves and Floorplates Chrome, steel or plastic floor plates, shall be fitted on each side of the sleeve which shall be of the same material as the pipe, and the ends shall finish flush with the surface. Chilled water pipework sleeve shall be of sufficient diameter to allow the insulation to be carried through, together with the vapour barrier. In kitchens and bathrooms the pipe sleeve shall project 100mm above floor level. The space between the pipe and the pipe sleeve shall be lightly caulked with glass cloth or other suitable material so that a one hour minimum of fire resistance is obtained in accordance with the latest Building Regulations. Pipes passing through sleeves in external walls of buildings, ducts, subways, etc., shall be caulked between pipe and sleeve with approved material e.g. lead wool, to form an effective and permanent AJC 05/07 Section 2.3. / 40 SECTION 2.3. – PIPEWORK AND FITTINGS vermin proof and weatherproof seal. 2.3.32 Air Venting and Draining All pipes shall be laid to fall so that they clear themselves of air naturally through vent pipes or through air bottles where deemed necessary. The Contractor shall allow adequate facilities to drain sections of work without disrupting the entire system. At venting points, air bottles shall be provided constructed of 50mm bore for pipes up to that size, the same bore as the pipes up to 80mm bore, and for pipes over that size they shall also be 80mm bore. The length of the air bottle to be 150mm – 300mm long, according to location and duty. 10mm n.b. release pipework is to be provided and shall terminate with 10mm needle valve. Where the air bottle is fixed out of reach, an extension bleed pipe shall be neatly run from the top of the air bottle to a convenient but unobtrusive position 1.2 metres from finished floor and terminated with a needle valve. Needle valves on all systems shall be suitably capped. On H.T.H.W. heating all air bottles shall be provided with a cooling leg with double valve arrangement. Automatic air vents shall be used only when specifically indicated. They shall have gunmetal or brass bodies, non-ferrous or stainless steel floats and guides, non-corrodible valves and seats. Each A.A.V. shall be controlled by a lockshield valve. Air venting devices and any air release pipes installed in exposed positions shall be insulated to prevent freezing. Drain points shall be fitted at all low points which cannot be emptied through other parts of the system. AJC 05/07 Section 2.3. / 41 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.33 Dirt Pockets Dirt pockets shall be the same material as the pipe. The dirt pocket shall be 300mm long and provided with a capped end up to and including 50mm bore pipe and blanked flange end on pipes 65mm and above. 25mm drain cocks shall be fitted to the side of the pocket 200mm from the end. Dirt pockets shall be provided at the base of all vertical pipes serving more than three floors. 2.3.34 Test Points Self-sealing neoprene rubber test points shall be installed in the following positions: 1 – on each return main immediately prior to their connection into the common return header. 1 – on both suction and delivery connections of all pump sets, between isolating valve and pump body. 1 – immediately on both inlet and outlet of items of equipment. 1 – on each port of control valves immediately adjacent to the control valve. These connections are to be used for testing and balancing purposes. Test points of this nature shall not be used for systems operating above 90°C. The Contractor is to supply suitable pressure gauges and thermometers for test purposes only and they will remain the property of the Contractor. Upon completion of the Contract a new complete boxed set of all gauges shall be handed over by the Contractor to the Client. AJC 05/07 Section 2.3. / 42 SECTION 2.3. – PIPEWORK AND FITTINGS 2.3.35 Flushing Connection On all distribution circuits to items of equipment such as fan coil units, induction units chillers, boilers etc. or any item of equipment with a restriction to flow via a coil, narrow passages etc. a continuous circuit shall be provided without allowing water to pass through the said equipment. A tight shut off isolating valve shall be provided in the connection between flow and return lines, opened only for flushing out purposes. Quick fill points with isolation valve shall be provided for flushing through. It shall be the Contractors responsibility to provide sufficient stool pieces for quick fill points, drain points and isolation valves to flush the system in sections as required, by the current edition of BSRIA publication Application Guide 8/91 ‘Pre-Commissioning Cleaning of Water Systems’. 2.3.36 Valves, Taps, Cocks, Strainers, Etc 18.104.22.168 General a) Valves shall be easily accessible and where installed in the horizontal at high level shall have the valve spindle vertically downwards, where headroom permits unless agreed otherwise by the Engineer. Where loose jumper taps and cocks are specified, these shall only be installed, either with the spindle in the horizontal plane or vertically upwards. b) Where valves are indicated as lockable the locking device shall remain attached to the valves at all times but the locking device, when unlocked shall not impede the fast opening or closing of the valve when required. c) All valves shall be installed in accordance with the manufacturer’s recommendations. d) In all instances where strainers are installed, whether on pump suction lines or small bore circuit connections, an isolating valve shall be fitted to each side of the strainer to facilitate removal and AJC 05/07 Section 2.3. / 43 SECTION 2.3. – PIPEWORK AND FITTINGS cleaning of the strainer basket. e) All valves or cocks on potable water services, softened water, cold water and hot water services shall be subject to Local Water Company requirements and shall be tested and approved and be listed in the WRc “Directory of Approved Water Fittings” available from the Water Research Centre (Water Bylaws Advisory Services, Slough, Berks). f) Valves and controlling devices shall be suitable for connections to the pipework material specified. g) All valves for Fire Fighting purposes shall comply with Fire Authority requirements, statutory requirements and British Standard Codes of Practice. h) 3-way cocks used to combine open vents shall give a clear indication of the position of the ports. A loose operating key shall be included with each cock. The drain ports shall be connected to pipework and be discharged over a tundish. i) Ball float valves for use with feed and expansion tanks shall be of the long-arm type capable of shutting off when the tank is at half capacity. j) The Contractor shall ensure that gland packing materials for valves, taps and cocks is suitable for the working temperature, pressure and media involved, inclusive of water treatment chemicals. k) All valves and installation methods shall comply with the current edition of the Water Supply (Water Fittings) Regulations 1999. 22.214.171.124 Valve Requirements In addition to valves and cocks shown on the drawings, the Contractor shall include for the installation of sufficient valves and strainers etc, as detailed below, to satisfy the Engineer that the following facilities will be AJC 05/07 Section 2.3. / 44 SECTION 2.3. – PIPEWORK AND FITTINGS available. a) Regulation of low and medium temperature hot water by means of a single commissioning set (orifice/double regulation valve) on the return, having fine mesh strainers upstream of the orifice valve, and with isolation valve installed in the flow. b) Isolation of low and medium temperature hot water by gate valves. c) Isolation of high and medium temperature hot water by parallel slide valves and gate valves with bolted bonnets. d) Isolation of secondary hot water service circulation by gate valves. Where regulation is required, orifice and double regulating valves shall be used. e) Isolation and regulation of chilled and condenser cooling water by gate, orifice and double regulating valves (single commissioning station) on the return and with isolating valve on the flow. f) Isolation of cold water services by sluice valves, gate valves and stopcocks. Where regulation is required, orifice and double regulating valves shall be used. g) Isolation of steam by parallel slide valves and mains pipework, by bonnet type gun metal gate valves on sizes 50mm and below. h) Isolation of gas services by gas cocks, lubricated plug valves, ball valves and alternatively butterfly valves. i) Isolation of de-mineralised water by diaphragm valves. j) Isolation of compressed air service by gate or diaphragm valves. k) Isolation of vacuum service by diaphragm valves. AJC 05/07 Section 2.3. / 45 SECTION 2.3. – PIPEWORK AND FITTINGS l) Valves up to and including 50mm bore shall have a compression ends to BS 864 Part 2 for copper pipework, or screwed ends to BS 21 for iron pipework and for copper to iron adapters. Valves 65mm and above shall be flanged to BS EN 1092 for steel, cast iron or copper as appropriate, and suitable for pressure rating PN 16 unless otherwise stated. All stopcocks shall be to BS 1010, with screwed ends or compression fittings as appropriate. 126.96.36.199 Domestic Hot, Cold, and Fire Water Services Isolation Valves (a) Ball Pattern Isolation Valve (15-22mm) Ball pattern isolation valves shall be of the screwdriver/lever operated type (as indicated) with brass chrome plated body and compression ends. Extended spindles shall be fitted if pipework is to be lagged. (b) Stop Valves for Above Ground Mains Cold Water (up to 50mm) Stop valves are to be straight pattern with copper alloy body manufactured to BS 1010. Stop valves incorporating an integral drain cock shall also be permitted. (c) Stop Valve for Below Ground Mains Cold Water (up to 63mm – MDPE, 54mm – COPPER, 2” – BSP Female). Underground stop valves are to be straight pattern with gunmetal body (immune to dezincification) manufactured to BS 5433. (d) Isolation Valves (up to 50mm) Isolation valves for hot and cold water services shall be gate type to BS 5154 suitable for potable water device. (e) Gate/Sluice Valve (80mm – 300mm) – Above and Below Ground AJC 05/07 Section 2.3. / 46 SECTION 2.3. – PIPEWORK AND FITTINGS The isolation gate valve shall be to BS 5163 incorporating stainless steel stem with two toroidal stem sealing rings carried in acetyl bush set within an SG iron housing. The stem nut shall be of copper alloy and the gate of the valve shall be a resilient seat pattern with nitrite rubber moulded onto an iron casting. (f) DHWS Double Regulating Valves (up to 50mm) The valves for domestic hot water pipework shall be bronze/gunmetal type to BS 5154, oblique or Y pattern. Valves shall incorporate a globe pattern seating and calibrated opening scale for commissioning purposes, and complete with locking device. (g) DHWS Three Way Valves (up to 50mm) Valves shall have bronze/cast iron body and shall be ‘L’ or ‘T’ ported with lubricated taper plug valves standard type with 734 sealant (to C withstand up to 100° operating temperature). Valves 65mm and above shall have flanged ends. (h) Fire Hydrant – Sluice Valves (up to 80mm) Fire hydrant sluice valves shall be to BS 5163 incorporating a stainless steel stem with two toroidal stem sealing rings carried in an Acetyl bush set within the SG iron housing. The stem nut shall be of copper alloy and the gate of the valve shall be of a resilient seat pattern with nitrite compound rubber moulded onto an iron casting. (i) Fire Hydrant – Screw-down Globe (up to 80mm) Fire hydrant screw-down globe valve shall incorporate a stainless steel non-rising stem with Acetyl bush set sealing device with two toroidal stem sealing rings and SG iron body with machined bronze mating surfaces. Fire hydrant outlets shall comply with BS 750 (Type 1) with 1½“ round thread gunmetal outlet unless otherwise indicated or as required by the AJC 05/07 Section 2.3. / 47 SECTION 2.3. – PIPEWORK AND FITTINGS Fire Officers/Local Authorities. Fire hydrant valve assemblies shall be externally coated with WRc approved fusion bonded epoxy powder spray 150 Micron thick (minimum). All Fire Hydrant valve assemblies shall have a 6.7 Bar working pressure and works body test pressure of 24 Bar. (j) Fire Hydrant – Frost Valve The Fire Hydrant outlet shall be fitted with a frost valve (a frost plug will not be permitted). (k) Non-Return and Backsiphonage Protection Valves Non-return Valves (up to 50mm) Non-return valves shall be the swing check valve pattern type with bronze or gunmetal bodies and conforming to BS 5154 as manufactured by a British Standard kite mark licensee, and for installation in either horizontal or vertical pipework. Non-return Valves (65mm or larger) Non-return valves shall be the swing check valve pattern type with the swinging clack operating around a stainless steel hinge pin mounted in a nylon bush with an SG iron body and conforming to BS EN 12334. (l) Double Check Valves (up to 50mm) Double check valves shall be to BS 6282 and WRc approved with the body manufactured from dezincification resistant (DZR) alloy, with a ¼” BSP centre vet tapping. (m) Rubber Diaphragm Non-Return Valve (15mm to 50mm) Rubber diaphragm non-return valves shall be the perforated cone (316 stainless steel) type with integral rubber diaphragm (diaphragm to be AJC 05/07 Section 2.3. / 48 SECTION 2.3. – PIPEWORK AND FITTINGS EPDM unless otherwise stated) contained in a two piece bronze body to BS EN 1982. (n) Rubber Diaphragm Non-Return Valves (65mm to 200mm) Rubber diaphragm non-return valves shall be the perforated cone (316 stainless steel) type with integral rubber diaphragm (diaphragm to be EPDM unless otherwise stated) contained in a two piece bronze body to BS EN 1561. (o) Combined check and anti-vacuum valves shall be to BS 6282: Part 4 and be WRc approved with the body manufactured from dezincification resistant (DZR) alloy. (p) Terminal Anti-Vacuum Valves (up to 50mm) Terminal anti-vacuum valves shall be to BS 6282: Part 2 and be WRc approved with the body manufactured from dezincification resistant (DZR) alloy. 188.8.131.52 Water Level Control Valves (Float Operated) General – Diaphragm Pattern Float Operated Valve (up to 50mm). Diaphragm pattern float operated valves shall conform to BS 1212: Part 2 with brass/gunmetal body and nylon seat and be manufactured by a British Standard kite mark licensee. The valve shall have a screwed threaded inlet with locking back nut. The body shall be demountable, so as to gain access to replace the orifice seating. The body shall incorporate a removable end cap to enable the diaphragm to be replaced. The orifice seating shall be selected to operate the valves dependent upon the incoming water supply pressure. A correctly sized ball float shall be selected to operate the valve efficiently. Reference should be made to AJC 05/07 Section 2.3. / 49 SECTION 2.3. – PIPEWORK AND FITTINGS Table 1 of BS 1212: Part 2. The valves shall be capable of accepting a working pressure of 5 Bar with a water temperature range of 0 to 65°C. A correctly sized copper ball float shall be selected to operate the valves efficiently. (a) Equilibrium Pattern Float Operated Valves (up to 100mm) Equilibrium pattern float operated valves shall be WRc approved model with brass body, double seat. Inlet sizes up to and including 50mm shall be screwed BSP and over 50mm shall be flanged PN 16. The valve shall have a gunmetal or mild steel lever arm to operate the sliding piston. The outlet shall be located within the fixed section of the valve to the tank. The valve shall be demountable and shall incorporate a flanged or screwed connection for accessibility purposes. A correctly sized copper ball float shall be selected to operate the valves efficiently. (b) ‘Aylesbury Pattern’ Float Operated Valve (up to 40mm) Aylesbury float operated valve shall incorporate a pressure compensated rotating ceramic dish with ports and chemically/biologically inert polyethylene closed cell PE foam float. (c) Delayed Action Ball Float Operated Valves (up to 100mm) (i) Canister Controlled Delayed Action Ball Float Valve (up to 50mm) Delayed action float valve shall incorporate a standard BS 1212 ball valve with separate delayed action canister containing the ball float. AJC 05/07 Section 2.3. / 50 SECTION 2.3. – PIPEWORK AND FITTINGS (ii) ‘Aylesbury Pattern’ Variable Delayed Action Ball Float Valve (up to 100mm) Variable delayed action ball valve shall incorporate a pressure compensated rotating ceramic disc with parts and a chemically/biologically inert actuator operated by the transfer of balance principle. This valve is to achieve a delayed action filing process. 184.108.40.206 Mixing Valves (a) Manually Blended Mixer Valve Manually blended mixer valve shall be of gunmetal or non-dezincifiable construction with chromium plated finish and adjustable temperature water mix control knob with cold to hot indicator label. The mixer valve shall be installed with an isolation valve, strainer and non-return valve on the hot and cold water inlets and mounted as indicated. (b) Thermostatically Operated Mixing Valve Thermostatically operated mixing valves shall be of gunmetal or brass construction with chromium plated finish. Each mixing valve shall be equipped with a suitable fixing device for wall fixing or shall be suitable for concealed or recessed application as indicated. The valves shall have a control thermostat capable of providing a constant mixed water temperature with the available hot and cold water pressures and shall have wax capsule or thermostatic spring or a fail- safe device to close the hot water inlet in the eventuality of a cold supply failure. Each valve shall be provided with a temperature regulating control lever permitting regulation of mixed water to an acceptable temperature as indicated. Where the valve is serving a range of shower fittings it shall be provided AJC 05/07 Section 2.3. / 51 SECTION 2.3. – PIPEWORK AND FITTINGS with a tamper-proof locking device on the temperature regulating knob, or as indicated. The hot and cold water supply pipes to mixing valves shall be provided with non-return valves, strainers and isolation valves. Where visible these shall be chrome plated. 220.127.116.11 LTHW, Chilled Water, and Condenser Water Valves (a) Valves and pipeline fittings up to and including 50mm shall have screwed connections. Valves and pipeline fittings 65mm and above shall be flanged to and suitable for the pressure rating indicated. (b) Valves from 15mm to 50mm nominal bore shall be gate valves to BS 5154 and be bronze related to PN25, or if agreed with the Engineer rated to PN20. Valves from 65mm to 300mm nominal bore shall be cast iron wedge disc with bronze trim and with non-rising stem to BS EN 1171. Where agreed with the Engineer, cast iron butterfly valves with EPDM liner may be used. These valves shall be to BS EN 593 and may be either lever, trigger or gear box operated as indicated. (c) Valves form 15mm to 50mm shall be of the bronze ‘oblique pattern’ double regulating type with rising stem to BS 5154 rated to PN20. Valves 65mm and above shall be of cast iron with copper alloy or stainless steel trim, of the ‘oblique pattern’ with outside screw and rising stem double regulating type to BS EN 13789. (d) Non Return Valves Non return valves for LTHW, Chilled Water and Condenser Water for sizes 15mm to 50mm shall be bronze swing type to BS 5154 rated at PN25. AJC 05/07 Section 2.3. / 52 SECTION 2.3. – PIPEWORK AND FITTINGS Non return valves from 65mm to 300mm nominal bore shall be to BS EN 12334. (e) Drain Cock Drain cocks shall be fitted to allow parts of the installation, and at all points where it is required, to drain down a particular part of the installation. Drain cocks shall be of the size indicated either 15mm, 20mm or 25mm be of bronze angle type to BS 2879 rated at PN10. The drain cocks shall either be lock shield or non-lock shield pattern as indicated. Where larger drain cocks are required for locations such as on boilers, they shall be bronze gland pattern complete with hose union drain cock and operating lever. Drain valves shall be screwed and rated to PN10. 18.104.22.168 Radiator Valves Radiator valves shall be fitted to radiators, convectors and towel rails. Radiator valves shall be straight or angle pattern as required by the location of the room emitter. Radiator valves shall be of chrome plate bronze construction to BS 2767 with screwed or compression ends rated at PN10, for steel or copper pipework installations respectively. Inlet valves shall be complete with a white polycarbonate hand wheel and outlet valves shall have a white polycarbonate lock shield, with a concealed indicator plate incorporated. All radiator valves shall be complete with a union and tail for fitting to the respective radiator connection. A radiator valve shall not be fitted where thermostatic radiator valves are AJC 05/07 Section 2.3. / 53 SECTION 2.3. – PIPEWORK AND FITTINGS indicated. 22.214.171.124 Thermostatic Radiator Valves Each radiator as indicated shall be fitted with a thermostatic radiator valve. These thermostatic radiator valves shall in general be direct acting, but where indicated remote sensors shall be used. Thermostatic radiator valves shall be of bronze or a metal construction to BS EN 2151 (1991) angle or straight pattern as required and with screwed inlet. Where used on copper or stainless steel pipework the screwed connection shall be furnished with a chrome plated compression fitting. All thermostatic radiator valves shall be chrome plated and complete with a union and tail for fitting to the respective radiator connection. 126.96.36.199 Commissioning Stations Where required for balancing purposes, double regulating valves shall be installed. Valves shall be positioned to give a minimum straight length of pipe upstream equivalent to 5 diameters and down stream equivalent to 3 diameters or as recommended by the manufacturer. All regulating devices shall be selected for the particular application such that required flow rates are achieved with valve positions more than 25% open. Commissioning sets shall be installed for balancing the system which shall consist of a double regulating valve and metering station. The pressure test fittings shall enable safe quick coupling and uncoupling of the flexible connectors from the differential pressure indicators. On MTHW and HTHW installations the quick coupling test fittings shall be protected by manual isolating valves of appropriate quality irrespective of whether the test fittings has an integral safety feature. 188.8.131.52 Check Valve/Non Return Valves The Contractor shall install were indicated check valves or non-return valves which shall be screwed to BS 21 for pipeline services up to 50mm AJC 05/07 Section 2.3. / 54 SECTION 2.3. – PIPEWORK AND FITTINGS diameter and flanged for steel, cast iron or copper as appropriate, and suitable for the pressure rating indicated. For LTHW, MTHW and condensate systems, check or non-return valves shall be selected to conform to either BS EN 12334 for cast iron, or BS 5154 for copper alloy construction. For HTHW systems check valves shall be selected to conform to BS EN 13709 or BS EN ISO 15761, steel lift, BS 1868, steel swing BS 5154, gunmetal as appropriate. For steam system check valves shall be either to BS 1868 steel swing or BS 5154 gunmetal swing, depending upon line size. 184.108.40.206 Strainers Where continuous plant operation is required and to facilitate ease of maintenance, strainers shall be of the duplex type such that the dirty side strainer can be removed and cleaned leaving the duty strainer in operation. Changeover shall be affected by a cast metal lever operated mechanism. The contractor shall install strainers on the inlet connection to each pump, chiller, heat exchanger and cooling tower and where indicated. For sizes up to 50mm the strainer shall be bronze, screwed with a Y pattern body. For sizes 65mm and above the strainer shall be flanged cast iron duplex bucket type with in-built isolating valves to facilitate emptying except where indicated. Strainers screens shall be stainless having perforation no greater than 0.8mm diameter but having a total area of not less than twice that of the pipe bore. Flow shall be internal to external through the cage. Strainers must be suitable for the appropriate LTHW, MTHW and HTHW service and flanged and pressure rated accordingly. AJC 05/07 Section 2.3. / 55 SECTION 2.3. – PIPEWORK AND FITTINGS 220.127.116.11 Drain Cocks Drain cocks shall be fitted at all low points of hot and cold water systems so as to follow the complete drain down of system. Type: screw-down cock type to BS 2879, Type 1 shall only be used on LTHW systems. On all other systems lubricated plug cock shall be used as previously specified in this section. 18.104.22.168 Automatic Air Vents Automated air vents shall be provided as indicated and wherever stated in this Specification. They shall have gunmetal or brass bodies and non- ferrous or stainless steel floats and guides and non-corrodible valves and seats. Lock shield valves shall be independent of the automatic air vent. Discharge from vent must be installed to clear insulation and all air vents and release pipes shall be installed in such a manner as to prevent freezing. 22.214.171.124 Pressure Reducing Valves Pressure reducing valves shall generally be used for reducing water, steam or compressed air pressure downstream of the valve to the required design pressure. Specialist pressure reducing valves shall be used to control and/or minimise any transfer or unreduced pressures to downstream equipment. Valves up to 50mm size shall have bronze or malleable iron bodies and may have taper screwed ends. Valves 65mm size and over shall have cast-iron bodies with ends flanged. Flanges for bronze and iron valves shall be BS 10, Table 10, when the valves are connected to flanges of imperial size. Otherwise all flanges shall comply with BS EN 1092 each according to the maximum working pressure. Valves shall be of the following types as indicated: a) Valves for reducing the pressure of apparatus not designed to AJC 05/07 Section 2.3. / 56 SECTION 2.3. – PIPEWORK AND FITTINGS withstand the maximum pressure of the high-pressure line shall be of an approved spring-loaded relay operated type. The valve seats and discs shall be renewable. Each valve shall be capable of maintaining a reduced outlet gauge pressure within 3.5 kPa of the set pressure and be installed with an excess pressure isolating protection valve on the low pressure side. b) Where apparatus on the low pressure side is capable of withstanding the maximum pressure of the high pressure line, as determined by the contractor, valves may be of the single-seated spring-loaded diaphragm type. They shall be adjustable within the specified low pressure range and shall be installed with a safety or relief valve on the low pressure side. c) Each pressure reducing valve shall be installed with an isolating valve, strainer and pressure gauge, siphon and bronze cock, relief valve and isolating valve on the down-stream side. Each pressure reducing valve shall be provided with a by-pass with isolating valves. 126.96.36.199 Safety and Relief Valves Safety and relief valves shall be suitable for the operating conditions of the systems and as required by the British Standard/Building Regulations for the boilers, calorifiers or pressure vessels to which they are connected, unless otherwise indicated. They shall be of the totally enclosed spring-loaded type with padlock. Safety valves and relief valves shall have a full-bore discharge connection piped to safe and visible positions to be agreed with the Engineer. a) Pressure Relief Valves Pressure Relief Valves (for open vented hot water system, unvented hot C) water systems, steam or unvented hot water systems above 150° up to 50mm diameter (20 DN minimum for steam and hot water boilers) shall be as follows. AJC 05/07 Section 2.3. / 57 SECTION 2.3. – PIPEWORK AND FITTINGS Gunmetal construction operating on a maximum high lift principle, good seat tightness, low lift for slight over pressures, high lift for dangerous over pressure, diaphragm protection for spring and guide surfaces, pressure setting locking facility, inspection and cleaning without altering pressure setting. Valve to comply to BS EN ISO 4126 with discharge capacity certified by A.O.T.C. Valve to be tested and listed by WRc. Valve to accommodate 1.5 Bar to 12.5 Bar pressure range. b) Temperature and Pressure Relief Valves Combined temperature and pressure relief valves for open and unvented hot water systems, shall operate independently on the elements of pressure and temperature to achieve two levels of protection. The valve shall be not greater than 50mm diameter (but not less than 20mm diameter). Gunmetal construction operating between 1 bar to 12.5 Bar and a temperature element fixed at a nominal setting of 95°C. The valve shall incorporate bubble-tight resilient seat seal, non-stick P.T.F.E. seating, high lift capacity, diaphragm protection for spring and guide surfaces, pressure setting locking facility. Inspection and cleaning shall be achieved without alteration to pressure setting. Valve to comply to BS EN ISO 4126 with discharge capacity certified by A.O.T.C. Valve to be tested and listed WRc. 188.8.131.52 Urinal Water Conservation Devices a) Hydraulic actuated water savers shall incorporate a diaphragm operated valve, hydraulic accumulator and an adjuster screw which when pre-set determines the volume of water, on a timed basis, discharged into the urinal automatic cistern. It is the Contractor’s responsibility to ensure that the correct pressure rated water saver is utilised for the respective installations. AJC 05/07 Section 2.3. / 58 SECTION 2.3. – PIPEWORK AND FITTINGS b) Electronic water savers shall include a main control unit with all standard electrical connectors for the system and provision for multi-site operation, computer and alarm terminals, hot/cold water supply isolation valve and lighting /extractor fan control (adjustable between 10-30 minutes) solenoid valve (UKWFBS listed) and either a magnetic door switch or ultrasonic detector as indicated. c) Time clock operated water saver shall include either a 24 hour or 24 hour/7 day electrically driven clock which may be adjustable by retaining pegs to achieve desired periods of operation. The clock shall be electrically interconnected to a solenoid valve (UKWFBS listed) to control water flow to the outlet connection. The clock and solenoid valve shall be enclosed within an enamelled pressed steel cabinet/box with 15mm water connection and power supply connection (240v). The whole unit shall be suitable to accept a maximum pressure of 10 Bar and a minimum pressure of 0.1 Bar. 184.108.40.206 Valve Labelling a) Plant room valves and every circuit control valve shall be provided with a brass or approved plastics label about 75x50x2mm thick, stamped or engraved with a reference number. A brief title indicating the valve duty shall be included on the label except where a valve chart is provided within the space in which the valve is housed. Wherever practicable the label shall be affixed to the adjacent structure in prominent position to identify the valve concerned. Elsewhere a purpose made light-weight steel bracket for carrying the label shall be welded to the pipework adjacent to the valve and arranged to be clear of any insulation. b) A circuit control diagram, or diagrams, schematically setting out the systems shall be fixed in a position approved by the Engineer. It shall indicate the position, function, size and reference number of all valves, be durable and non-fading, and be rigidly mounted with an unbreakable and washable finish. AJC 05/07 Section 2.3. / 59 SECTION 2.3. – PIPEWORK AND FITTINGS CATEGORY DESCRIPTION OF SERVICE A Low and medium temperature hot water, heating, chilled water services. Valves up to 50mm size. B Low and medium temperature hot water heating, chilled water services. Valves 65mm and above. C High temperature hot water heating. Valves all sizes (see individual specification for particular temperatures (pressure ratings)). D Steam services – all sizes (see individual specifications for particular pressure/temperature ratings). E Condense services – valves up to 50mm size. F Condense services – valves 65mm and above. G Hot and cold water services – valves up to 50mm size. H Hot and cold water services – valves 65mm and above (all cast iron valves shall be lined to meet water board requirements). J Compressed air services – all sizes. K Fuel oil services – all sizes (see individual specifications for particular mediums). L Gas services – all sizes. M Fire fighting – all sizes. AJC 05/07 Section 2.3. / 60 SECTION 2.3. – PIPEWORK AND FITTINGS CATEGORY ‘A’ MANUFACTURER DESCRIPTION OF VALVE CRANE G.M. Gate Valve PN20/WH D151 G.M. Gate Valve PN20/L.S. D237 G.M. Gate Valve PN20/WHCP D890CP G.M. Gate Valve PN20 L/S CP D891CP G.M. Check Valve PN16 D138 G.M. ‘Y’ Strainer PN16 D297 G.M. Draw Off Cock Hose Union D344 G.M. Emptying Cocks L/S D340 G.M. Double Regulating Valve Screwed D920 G.M. Orifice Valve Screwed D910 G.M. Orifice Measuring Device D900 G.M. Radiator Valves W/H D880 G.M. Radiator Valves L/S D881 G.M. Radiator Thermostatic Valves N/A AJC 05/07 Section 2.3. / 61 SECTION 2.3. – PIPEWORK AND FITTINGS CATEGORY ‘B’ MANUFACTURER DESCRIPTION OF VALVE CRANE G.M. Gate Valve Flanged PN16 DM160 C.I. Gate Valve Flanged PN6 FM52 C.I. Gate Valve Flanged PN10 FM57 G.M. Swing Check Valve Flanged PN16 FM492 G.M. ‘Y’ Strainer Flanged PN16 D298 C.I. ‘Y’ Strainer Flanged PN16 FM276 C.I. Double Regulating Valve Flanged PN16 DM920 C.I. Orifice Valves Flanged PN16 DM900+FM63 C.I. Orifice Measuring Device DM900 CATEGORY ‘C’ MANUFACTURER DESCRIPTION OF VALVE CRANE G.M. Gate Valve Flanged PN16 DM160 G.M. Check Valve Flanged PN16 DM118 S.S. Orifice Plate to Fit Between Flanges DM900PN25 G.M. Orifice Valve Flanged PN25 N/A G.M. Double Regulating Valve Flanged PN25 N/A Cast Steel Orifice Valve Flanged PN25 65- N/A 300mm Cast Steel Double Regulating Valve Flanged N/A PN25 G.M. ‘Y’ Strainer Flanged PN16 D298 Cast Steel ‘Y’ Strainer Flanged PN16 N/A Parallel Side Cast Steel Hinged PN16 N/A AJC 05/07 Section 2.3. / 62 SECTION 2.3. – PIPEWORK AND FITTINGS CATEGORY ‘D’ MANUFACTURER DESCRIPTION OF VALVE CRANE G.M. Globe Valve PN32 D15 G.M. Globe Valve Flanged PN16 DM6 C.I. Globe Valve Flanged PN16 FM369 C.I. Angle Globe Valve Flanged PN16 N/A G.M. Check Valve PN32 D115 G.M. Check Valve Flanged PN16 DM118 C.I. Lift Check Valve Flanged PN16 N/A G.M. Needle Valve D71 CATEGORY ‘E’ MANUFACTURER DESCRIPTION OF VALVE CRANE G.M. Gate Valve PN20 W/H D151 G.M. Gate Valve PN20 L/S D237 G.M. Check Valve PN16 D238 G.M. ‘Y’ Strainer PN16 D297 AJC 05/07 Section 2.3. / 63 SECTION 2.3. – PIPEWORK AND FITTINGS CATEGORY ‘F’ MANUFACTURER DESCRIPTION OF VALVE CRANE C.I. Gate Valve Flanged PN6 FM52 C.I. Gate Valve Flanged PN10 FM57 C.I. Gate Valve Flanged PN16 FM63 C.I. Swing Check Valve Flanged PN16 FM492 G.M. ‘Y’ Strainer Flanged PN16 D298 C.I. ‘Y’ Strainer Flanged PN16 FM276 CATEGORY ‘G’ MANUFACTURER DESCRIPTION OF VALVE CRANE G.M. Gate Valve PN20/WH D151 G.M. Gate Valve PN20 L/S D237 G.M. Gate Valve PN20/WH CP N/A Stopcocks Yorkshire Fig 508N Servicing Valve 15mm – 20mm Yorkshire 480 G.M. Gate Valve PN20 L/S CP N/A G.M. Gate Valve Flanged PN16 DM160 G.M. Check Valve PN16 D138 G.M. ‘Y’ Strainer PN16 D297 G.M. Draw Off Cock Hose Union D344 G.M. Emptying Cock L/S D340 G.M. Double Regulating Valve Screwed D920 G.M. Orifice Valve Screwed D910 G.M. Orifice Measuring Device D900 AJC 05/07 Section 2.3. / 64 SECTION 2.3. – PIPEWORK AND FITTINGS CATEGORY ‘H’ MANUFACTURER DESCRIPTION OF VALVE CRANE G.M. Gate Valve Hinged PN16 DM160 C.I. Gate Valve Hinged PN16 FM124 PN16 C.I. Swing Check Valve Flanged PN16 FM492 PN16 S.S. Orifice Valve Plate To Fit Between N/A Flanges PN25 G.M. ‘Y’ Strainer Flanged PN16 D298 ‘F’ / 9 CATEGORY ‘J’ MANUFACTURER DESCRIPTION OF VALVE CRANE G.M. Globe Valve Hinged PN32 DM15 G.M. Globe Valve Hinged PN16 DM6 G.M. Check Valve Flange PN16 N/A C.I. Check Valve Flange PN16 N/A AJC 05/07 Section 2.3. / 65 SECTION 2.3. – PIPEWORK AND FITTINGS CATEGORY ‘K’ MANUFACTURER DESCRIPTION OF VALVE CRANE C.I. Lubricated Plug Valve PN16 VB170 G.M. Check Valve PN32 D115 G.M. Check Valve PN16 N/A G.M. ‘Y’ Strainer Hinged PN16 D297 G.M. Needle Valve D71 C.I. ‘Y’ Strainer Hinged PN16 FM276 G.M. Draw Off Cock Hose Union D344 G.M. Emptying Cocking L/S D340 / L CATEGORY ‘L’ MANUFACTURER DESCRIPTION OF VALVE CRANE C.I. Lubricated Plug Valve PN16 N/A Screwed C.I. Lubricated Plug Valve PN16 Flanged N/A AJC 05/07 Section 2.3. / 66 SECTION 2.3. – PIPEWORK AND FITTINGS CATEGORY ‘M’ MANUFACTURER DESCRIPTION OF VALVE CRANE G.M. Gate Valve PN20/WH D151 G.M. Gate Valve PN20/LS D237 Cast Iron Fullway Gate Valve PN16 FM52 G.M. Globe Valve D15 G.M. Non-return Valve PN32 D132 Cast Iron Non-return Valve N/A G.M. ‘Y’ Type Strainer PN25 D138 Cast Iron ‘Y’ Type Strainer PN15 FM276 G.M. Draw Off Cock D344 Tee Ported Cocks up to 25mm N/A Dry Riser Out Valves Charles Winn 21151a Dry Riser Air Valves 2751 220.127.116.11 Thermometers, Pressure and Altitude Gauges Thermometers shall be fitted in pipes and ducts in the position indicated on the drawings and as detailed in the Specification. Suitable pockets shall be provided and fixed in the case of pipelines. Where thermometers are installed in pipelines and the diameter of the pipe is too small for the length of the standard bulb, the pipe shall be increased to the requisite diameter for a minimum length of 150mm or a necessary to allow for the proper fitting and insertion of the thermometer well. Dial thermometers shall, unless stated otherwise, be mounted with the dial in the vertical position and shall be mercury in steel type. AJC 05/07 Section 2.3. / 67 SECTION 2.3. – PIPEWORK AND FITTINGS Dial thermometers shall be calibrated in degrees Celsius with black pointer and clear black lettering and scale on a white background with not more than C C 5° per division, and not less than 2° division. Where the effective fixed working temperature is being measured, the thermometer shall be fitted with a tamper-proof loose red pointer which can be set on site to the working temperature. Obtuse angle thermometers shall be provided where necessary. The scales will be included for easy reading. Right angle or obtuse angle thermometers shall be provided when fitted to vertical pipes or vertical face of calorifiers, or ducts, etc. 100mm dial thermometer, mercury in steel shall be provided with black/C.P. case and separate M.S. pocket. Bourdon type altitude or pressure gauges shall be fitted in pipelines in the positions indicated on the drawings and where called for in later sections of the Specification. The gauges shall be scaled in metres of water head or kPa. The gauges will be 100mm diameter flangeless with white dials and black lettering and fitted with an adjustable red pointer which shall be set on site at the head of the system. Pressure or altitude gauges shall be provided with suitable syphon connections with G.M. gauge cocks 10mm diameter. Thermometers, altitude, and pressure gauges shall be of uniform pattern/appearance, and be as manufactured by Messrs Coley Limited or B.S.S. They shall however, all be of the same manufacture. The temperature or pressured gauge scales selected must ensure that the normal range of condition lies at the mid point of the full scale. AJC 05/07 Section 2.3. / 68 SECTION 2.4. – DUCTWORK AND FITTINGS 2.4.1 General ......................................................................................................1 2.4.2 Ductwork and Fittings.................................................................................1 2.4.3 Flexible Connections ..................................................................................2 2.4.4 Flexible Ductwork .......................................................................................3 2.4.5. Air Intakes and Outlets................................................................................3 2.4.6 Brackets and Supports ...............................................................................5 2.4.7 Penetrations ...............................................................................................6 2.4.8 Access Doors/Panels .................................................................................6 2.4.9 Dampers ....................................................................................................8 2.4.10 Turning Vanes/Splitters/’Deflectrols’...........................................................8 2.4.11 Test Holes..................................................................................................8 2.4.12 Ductwork Protection ...................................................................................9 2.4.13 Grilles.........................................................................................................9 2.4.14 Diffusers...................................................................................................10 2.4.15 Air Valves.................................................................................................11 2.4.16 Fire Dampers ...........................................................................................11 2.4.17 Combination Fire/Smoke Dampers...........................................................13 2.4.18 Leakage Testing.......................................................................................13 SECTION 2.4. – DUCTWORK AND FITTINGS 2.4.1 General This section shall apply to ductwork systems for normal ventilation and air conditioning installations; where specialist conveying systems or dust or fume extract systems are incorporated in the works, these shall comply with the details given in the Particular Specification. The contractor shall supply, deliver and erect ranges of ductwork as detailed on the tender drawings. All measurements required for the manufacture of ductwork shall be taken by the Contractor, or his appointed specialist ductwork contractor. Runs of ductwork may be modified, subject to the Engineer’s approval to suit site conditions or simplify duct erection. Prior to the manufacture of any ductwork the Contractor shall prepare fully detailed working drawings of the ductwork installation, based on site survey dimensions, and submit two copies to the Engineer. 2.4.2 Ductwork and Fittings All ductwork, including spigot boxes and air plenums, shall be manufactured from best quality CRCA patent flattened sheet steel continuously hot dip galvanised in accordance with BS EN 10327 and fabricated in accordance with HVCA specification DW/144, ductwork classification ‘low pressure – Class A’. All ductwork shall be designed and constructed to minimise noise, drumming, air turbulence, corrosion and the ingress and egress of water and air, and shall be installed and supported in accordance with HVCA specification/good practice guides DW/144 and DW/TM2. All circular ductwork shall be spirally wound. Bend fittings and rectangular section ductwork shall incorporate aerofoil section air turning vanes. The minimum throat radius of circular ductwork bend fittings shall be at least equal to the duct diameter unless precluded by space restrictions. Branch ducts shall enter main ducts by means of an C angle boot connection which shall have the throat at an angle of 45° and C 30° respectively, and shall be either eccentric or concentric to suit the location. The ductwork exposed to external atmosphere or corrosive fumes shall be suitably painted or otherwise protected, internally and externally as AJC 05/07 Section 2.4. / 1 SECTION 2.4. – DUCTWORK AND FITTINGS indicated. Where ducts are lined internally for acoustic attenuation the internal area shall be maintained and the sheet metal size increased accordingly. All plastic ducting shall comply with Specification DW 151 as issued by the Heating and Ventilating Contractors Association, London. Sealants shall be used for all duct joints as required to meet the specified leakage limits. These shall be of the ‘mastic’ type and shall retain their flexibility and adhesive qualities irrespective of ambient conditions for the life of the installation. For rectangular ducts up to 300mm longest side, and circular ducts up to 300mm diameter, spigot and socket joints may be sealed using 75mm wide adhesive ‘duct’ tape having a moisture repellent and lasting adhesive qualities. Cross joints on other circular ducts and all flat oval ducts shall be sealed by means of heat shrinkable one piece polyolefin sleeves, lined with hot melt adhesive and fitted prior to the application of any duct insulation. Particular care shall be taken when heating the sleeve to avoid damage to adjacent materials. Where headroom clearances are given on the Drawings or elsewhere these shall be to the lowest point of the ductwork supporting structure. 2.4.3 Flexible Connections Flexible connections shall be provided at all connections to fans and air handling units, both supply and exhaust, as well as at all points when rigid ducting crosses movement joints in the building structure. The material used shall be lead impregnated canvas, or neoprene, and shall be suitable for all conditions of temperature (ducted and ambient), pressure and noise attenuation applicable at the point of use. Connections shall be arranged to give a clearance between rigid components of not less than 50mm (2”) and not more than 150mm (6”) and, particularly where ducting is under negative pressure, shall be tight enough to avoid undue ‘necking’ or bulging at minimum extension without being stretched tight at maximum extension. Ductwork and equipment shall be carefully supported AJC 05/07 Section 2.4. / 2 SECTION 2.4. – DUCTWORK AND FITTINGS on either side of the flexible to avoid offsets, and this shall particularly apply in the case of equipment on anti-vibration mountings. Circular flexible connections shall be secured by clipbands with adjustable screw or toggle fixings; rectangular connections shall be shaped to mate with the flanges of adjacent ducting or equipment and shall be held in place by metal backing plates bolted to these flanges with the bolts passing through the material. All flexible connections shall be as manufactured by Duro Dyne Ltd or equal and approved. 2.4.4 Flexible Ductwork Flexible ducting shall be provided for connections between sheet metal ducting and terminal units, diffusers, etc. and where indicated on the drawings. Flexible ducting shall be of the pre-insulated pvc covered type for supply ducting and uninsulated for return ducting. It shall have spirally wound reinforcement to maintain the annulus of the duct and shall be as manufactured by Flexible Ducting Ltd or equal and approved, except where specifically detailed on the drawings. Flexible ducts, shall be kept to a minimum but shall not exceed 500mm in length, unless agreed with the Engineer, and shall be supported in such a way that movement or kinking of this duct is avoided. Flexible ducting shall not be used to form major changes in direction; its purpose is to accommodate minor misalignment. Connections to rigid ducting or equipment shall be made by passing the flexible ducting over purpose made spigots, equal in size to the flexible and fixing by means of hose type metal clamps screw tightened around the circumference and finally sealed with 75mm wide duct tape. 2.4.5. Air Intakes and Outlets Fresh air and exhaust air louvers shall have fixed blades angled to give adequate weather protection. Unless otherwise indicated louvres shall be AJC 05/07 Section 2.4. / 3 SECTION 2.4. – DUCTWORK AND FITTINGS constructed of aluminium with blades no less than 3mm thick braced as necessary to ensure complete rigidity, to provide a minimum of 70% of free area unless agreed otherwise by the Engineer. Where louvres are required to be supplied under this Contract they shall be handed to the Main Contractor for fixing. A galvanised steel wire screen of 6mm mesh complete with a frame of galvanised steel rod with securing lugs or of flat iron shall be provided and fixed by the Contractor on the inner side of the louvres. All louvres shall have screens to prevent the ingress of insects and birds. The louvre blades shall be so arranged as to minimise the ingress of rainwater. The Contractor shall provide the requisite builders work drawings to enable the Main Contractor to form the openings for the louvres, and subsequently build them in. Exhaust ducts carrying wet or grease laden air, e.g. laundry exhausts, kitchen canopy exhausts, etc. shall be constructed of aluminium sheet for the first 10 metres from the apparatus or canopy. This shall be to the same specification, thickness and constructional details given in the section for galvanised sheet metal ducting. Where such ductwork runs horizontally, it shall be laid to fall preferably in the direction of airflow and shall be fitted with a trapped condensate drain point at an appropriate location. Roof cowls shall be constructed of galvanised sheetmetal, suitably stiffened internally to avoid drumming, and shall be a free area such that the inlet or exhaust velocity shall not exceed 3.5m/s (700fpm). They shall be located on purpose made upstands or roof sheets constructed such that the inlet or discharge is at least 300mm above any flat roof surface to avoid bouncing rain. AJC 05/07 Section 2.4. / 4 SECTION 2.4. – DUCTWORK AND FITTINGS 2.4.6 Brackets and Supports All necessary duct hangers, brackets and supports shall be provided at centres in accordance with the requirements of DW/144. All such items shall be designed to suit the particular location and surrounding structure and details shall be passed to the Engineer for approval prior to manufacture. Where supports are to be provided or built-in by the Main Contractor or others, then full details must be provided to the Main Contractor in time to allow him to proceed with the works without delay to the agreed programme. Supports for insulated ductwork shall be located flush with the outer surface of the insulation/vapour seal, with rigid spacers installed as necessary between the support and the duct surface. For uninsulated ductwork metal to metal contact between duct and support shall be avoided by the use of suitable non-flammable rubber, plastic or felt linings. All ducts are to be adequately supported throughout and all supports are to be insulated from the ductwork by suitable fireproof anti-vibration insulation. Full allowance shall be made for the building in and fixing of all duct supports. The ductwork is to be suitably fixed and flanged such as to prevent breathing and drumming. The design of the supports is to suit the surrounding structure. Ductwork will not be permitted to rest directly on portions of the buildings except concrete slabs or substantial brick walls and then only with the approval of the Engineer. Adequate thermal insulation shall be applied as indicated. All hangers shall be fitted with locknuts and spherical washers and shall be as close as possible to the edge of the duct or insulation without touching. Methods of fixing hangers to the structure shall be agreed with the Engineer and Main Contractor before fixing commences. AJC 05/07 Section 2.4. / 5 SECTION 2.4. – DUCTWORK AND FITTINGS Except where specifically agreed by the Engineer no ductwork stiffening angles or flanges shall be used as part of the support structure, and no ceilings, light fittings or any other equipment shall be supported from the ductwork or duct support under any circumstances. Ductwork adjacent to items such as dampers, flexible connections, grilles, etc. shall be additionally supported to avoid any transmission of ducting loads to such items. 2.4.7 Penetrations Penetrations through walls, floors and roofs shall be carefully detailed to accommodate the conflicting requirements of integrity of the structure, thermal movement, prevention of noise and vibration transmission to the structure, weathering and, where applicable, fire compartmentation. Where ducts penetrate external walls and floors a flange shall be fixed and sealed to the duct suitable for flashing by the Builder. Penetrations through the flat roofs shall be completely watertight by means of a builders upstand with a metal skirt sealed to the duct and extending over and below the level of flashing on the upstand. For penetrations through pitched roofs or northlights, a purpose made roof sheet shall be provided complete with flashing plate if necessary. 2.4.8 Access Doors/Panels To comply with DW/144 the Contractor shall include for access doors or panels as shown on the drawings and as required for the following purposes: 1) Personnel access for maintenance or replacement of plant items, e.g. cooling coils, filters. 2) Routine maintenance, inspection, lubrication and adjustment of items not requiring full man access, e.g. fire dampers, fan bearings, thermostat bulbs, etc. 3) Access for cleaning purposes, e.g. kitchen extract ducts. AJC 05/07 Section 2.4. / 6 SECTION 2.4. – DUCTWORK AND FITTINGS Access doors for personnel shall be not larger than 1.4m high by 0.4m wide and shall be hinged with wedge type of door locks, at least two per door. These shall be openable at all times from inside the duct or plant, whether or not they are lockable from outside. Each door shall be fitted into a suitable frame and shall have neoprene rubber seals to ensure an airtight assembly when closed, and both door and frame shall be adequately stiffened so suit the working pressures of the installation and avoid distortion when closed or open. All access doors shall open against the air pressure except where shown otherwise on the drawings. Access for maintenance, etc. shall be not larger than 600mm high by 375mm wide and both the frame and the panel shall be stiffened to prevent any distortion at normal working pressures. They shall be fitted with neoprene rubber seals to avoid air leakage when closed, and shall be arranged such that the air pressure assists in holding the panel closed. All fastenings or clamps used to close the panel shall be such that can be undone and refixed by hand, i.e. no tools are required for access, e.g. cam latches. Panels provided for cleaning purposes shall be generally as the access panels noted above except that where installed in horizontal ducting they shall either be in the bottom of the duct or, when fitted in the side of the duct, then the bottom of the opening shall be level with the bottom of the duct to allow easy sweeping out. Cleaning access points shall be provided as necessary to allow all parts of the duct system to be properly cleaned, but in any case shall be at not less than 3m centres. Where access doors or panels are installed in insulated ductwork the supporting frame shall be extended beyond the face of the duct by a distance equal to the thickness of the insulation, and any vapour seal shall be dressed over the edge of the frame. In addition, the door or panel shall be double skinned and insulated or shall be dished to carry insulation of the same thickness as the adjacent ductwork, again with any vapour seal dressed over the panel edge. AJC 05/07 Section 2.4. / 7 SECTION 2.4. – DUCTWORK AND FITTINGS 2.4.9 Dampers Volume control dampers shall be ‘Air/Shield Series Aerofoil’ type SPG comprising double skin stainless steel opposed blades within spigotted galvanised steel casings. Each damper shall be complete with ‘Option M’ manual control comprising adjustment knob with locking facility and visual blade position indication. Backdraught shutters shall be galvanised steel spring return circular butterfly shutters as manufactured by Vent-Axia or approved equivalent. 2.4.10 Turning Vanes/Splitters/’Deflectrols’ All square rectangular bends and mitred circular bends shall be fitted with aerodynamically designed multiple turning vanes as manufactured by Senior Colman Ltd., or equal and approved. All short radius bends (i.e. throat radius less than half duct height) over 300mm high shall be fitted with splitters arranged such that the r/W ratio for each air passage shall be not less than 1.5, where r is the radius to the centre line of a particular section of the bend between splitters and W is the width of that section. Where diffuser spigots are taken directly from the main supply duct or where indicated on the drawings, ‘deflectrols’ shall be fitted in the duct to give uniform deflection of the air into the diffuse. These shall be as manufactured by Senior Colman Ltd., or equal and approved. 2.4.11 Test Holes Where shown on the drawings or where necessary for the correct regulation of the system, test holes shall be provided in ductwork and air handling plant. These shall generally be 12m diameter holes and shall be closed with purpose made rubber or PVC grommets. Test holes shall be provided to allow the following measurements: AJC 05/07 Section 2.4. / 8 SECTION 2.4. – DUCTWORK AND FITTINGS 1) All fan supply/exhaust volumes. 2) All supply/exhaust volumes in main or branch ducts. 3) Pressure drop across all plant items, e.g. cooling coil, filters, dampers, etc. In rectangular ductwork, test holes shall generally be fitted in the side of the duct; circular ductwork shall have two test holes at right angles for flow measurement. Exceptions shall apply only where access with a suitable length pitot tube would be obstructed by the adjacent structure or other services. 2.4.12 Ductwork Protection Any part of galvanised ductwork where the galvanising is damaged during manufacture or erection shall be painted with two coats of aluminium, zinc rich or other corrosion-resisting paint, to the satisfaction of the Engineer. In kitchens and dining rooms the outermost surface of exposed ductwork or insulation shall be not less than 30mm away from walls and ceilings to permit access for cleaning. 2.4.13 Grilles Grilles shall be of steel, aluminium or plastic as indicated. Steel grilles shall be protected against rusting and supplied in fully finished condition. Grilles shall be not less than the size indicated. Where no size is given they shall be capable of dealing with the air flow and distribution as indicated. All grilles except those on exposed ducting shall incorporate an edge seal. The Drawings show provisional locations but in each instance outlets shall be installed in accordance with architectural final detail drawings and reflected ceiling plans, which the Contractor shall obtain from the Main Contractor. AJC 05/07 Section 2.4. / 9 SECTION 2.4. – DUCTWORK AND FITTINGS Velocities, net airways, and distribution patterns shall give satisfactory air distribution, and be free of draughts, stratification or noise nuisance. The Contractor shall make final adjustments to air patterns when balancing. Damper assemblies and internal surfaces of outlets and take-off ductwork where visible through outlet faces, shall be painted matt black. All outlets shall be fitted truly square and in alignment. Perimeter trims shall seat hard against wall or ceiling finishes as applicable and shall properly mask the trimmed openings. Unless otherwise indicated, all fixings shall be concealed. Each supply air grille shall be complete with an opposed blade multi-leaf damper. Alternatively, in lieu of the opposed blade multi-leaf damper a rhomboidal air controller may be provided; this air controller shall control both the volume of air passing and the distribution of air across the grille face. Each supply air grille shall have two sets of separately adjustable ouvers, one set horizontal and one set vertical, all adjustable from the grille face. For up to ten grilles, one set of any tools required for adjusting the ouvers and dampers or air controllers shall be provided; from eleven to twenty-four grilles, two sets; above twenty-five grilles and more, three sets. Return air grilles may have either a single set of ouvers or bars (vertical or horizontal) or a lattice or egg crate front, or otherwise as indicated. Each return air grille shall be complete with an opposed blade multi-leaf damper or a rhomboidal air controller operable from the front. Adjustable tools shall be provided in the same pro-data as for the supply grilles. For kitchens and dining rooms both supply and return air grilles shall have quick-release sub-frames, for ease of dismantling for cleaning. 2.4.14 Diffusers Diffusers shall be of steel, aluminium or plastic (as indicated) and supplied AJC 05/07 Section 2.4. / 10 SECTION 2.4. – DUCTWORK AND FITTINGS in a fully finished conditions. Diffusers, except on exposed ductwork, shall incorporate an edge seal; diffusers mounted on ceilings shall have anti- smudge rings. Pan type diffusers may be provided except where cone type diffusers are indicated. Diffusers shall be provided with volume control dampers of the iris, flap or sleeve type which shall be adjustable from the front of the diffuser. Where the length of a vertical duct to a diffuser is less than twice the diameter neck an equalising deflector shall be fitted. For kitchens and dining rooms shall have a quick-release centre to facilitate easy cleaning. Linear diffusers shall include a control damper at the rear of the vanes giving volume control down to complete shut-off and be operated from the face of the diffuser. Linear diffusers for supply air shall have adjustable blades to give directional control of air flow. Where linear diffusers are mounted in a continuous line there shall be means of ensuring alignment between consecutive diffusers and of equalising pressure behind the vanes, over the whole length of the linear diffusers. 2.4.15 Air Valves Extract air valves shall be of the sizes indicated and be manufactured from pressed steel sheet throughout. The valve shall be supplied complete with a mounting ring of the bayonet fitting type, and finished in stove enamel to an approved colour. 2.4.16 Fire Dampers Fire dampers shall be provided in each duct passing through all structural fire compartment walls and each floor level slab and also where indicated. a) The dampers shall be rated at least equal to the surface in which they are mounted and shall be installed strictly in accordance with the manufacturer’s instructions. All fire dampers shall be provided with an external indicator showing damper position and shall be installed in a purpose made frame or flexible housing to enable the AJC 05/07 Section 2.4. / 11 SECTION 2.4. – DUCTWORK AND FITTINGS damper to deform when hot. b) The fire dampers shall have stainless steel folding blades with minimum 18 gauge fully welded corner construction casing, arranged for vertical or horizontal operation. For duct heights of 250mm and over the blades shall be outside the air stream for duct heights below 250mm blades partly in the air stream to provide a duct free area of not less than 90%. c) Fire dampers shall be complete with installation frames for building into the wall or floor. d) Access doors shall be provided in the ductwork adjacent to all fire dampers to permit inspection and replacement of fusible links. Where fire dampers are located in concealed areas such as above false ceiling, the Contractor shall ensure through the Main Contractor that adequate access is provided through the false ceiling or other concealing surface. e) It should be noted that the Contractor is at liberty to put forward for consideration by the Engineer proprietary fire dampers manufactured by firms specialising in this type of work, any such fire dampers must comply with the requirements generally referred to above and the relevant British Standards. f) Before any fire damper is manufactured a detailed drawing, in duplicate, shall be submitted to the Engineer for comment; this drawing shall indicate a typical fire damper. g) Operation shall be by combination thermal actuators and fusible link. h) Operating spindles shall be of stainless steel or other non- corrodible metal rod. AJC 05/07 Section 2.4. / 12 SECTION 2.4. – DUCTWORK AND FITTINGS 2.4.17 Combination Fire/Smoke Dampers Combination fire/smoke dampers shall be provided where indicated. 1) Each damper shall comply with clause (a), (c), (d), (e), (f) and (h) of the Fire Damper section. 2) Each damper shall have stainless steel interlocking aerofoil blades of double skin construction forming a fire resisting shield in combination with absolute maximum of impedance to the leakage of smoke and other products of combustion. 3) Operation unless otherwise indicated shall be by the external gearbox, pre-wired to give automatic AC opening or 24 volt closing with mini control panel for remote operation. Access to these dampers shall be provided as described in the Fire Damper section. 2.4.18 Leakage Testing When called for in the Particular Specification, or when the Engineer has reason to suspect that excessive leakage is occurring, the Subcontractor shall carry out leakage tests on all or part of the ductwork system as directed at no additional cost to contract. All such tests shall be carried out to the satisfaction of the Engineer, generally in accordance with HVAC publications DW/143 and DW/144, unless otherwise directed by the Engineer. 2.4.19 Labels/Identification All plant items shall be fitted with labels indicating their function, e.g. kitchen exhaust fan and the reference number as indicated on the ‘As Fitted’ drawings. These shall be of 3mm thick blue laminated plastic plate with AJC 05/07 Section 2.4. / 13 SECTION 2.4. – DUCTWORK AND FITTINGS white engraved characters, 12mm high for uppercase and numerals, 8mm high for lowercase. The labels shall be fitted on or immediately adjacent to the relevant plant items and secured by at least two round headed screws. Where services are concealed behind false ceilings, or panelling, the location of all items requiring maintenance or adjustment, e.g. fire dampers, fan coil units, etc. shall be indicated by means of 6mm diameter coloured discs fixed on the appropriate access point or panel, red for fire related items such as fire dampers and blue for all other ventilation or air conditioning equipment. For installations with more than one plant or ductwork system, all ducting shall be provided with identification/direction of flow indicators in accordance with DW/144. In addition to all plant rooms, such identification shall be provided on ducting adjacent all access points, and in particular at each floor level in the case of vertical distribution ducts. AJC 05/07 Section 2.4. / 14 SECTION 2.5. - BUILDERS WORK INCL CEANING AND PAINTING 2.5.1 General ......................................................................................................1 2.5.2 Protection to Existing Building Fabric and Furnishings ...............................1 2.5.3 Contracts....................................................................................................1 18.104.22.168 Sub-Contract ..........................................................................................1 22.214.171.124 Direct Contract .......................................................................................3 2.5.4 Cleaning and Painting ................................................................................5 126.96.36.199 Internal Surfaces Area............................................................................6 188.8.131.52 External Surfaces Area...........................................................................7 184.108.40.206 At Site.....................................................................................................7 AJC 05/07 Section 2.5. / 9 SECTION 2.5. - BUILDERS WORK INCL CEANING AND PAINTING 2.5.1 General The Mechanical Services Contractor shall include for all builders work to complete the works. An indication of the builders work is scheduled below: - 1) Protection to existing building fabric and furnishings. 2) Fixings 3) Forming of openings and chases within the structure 4) Making good openings 5) Painting 6) Suspended ceiling 7) Fire stopping 2.5.2 Protection to Existing Building Fabric and Furnishings On all floors allow to provide 2 metre wide, substantial protection to carpets in working area. This protection to be Swiftec PP90 and is to be firmly fixed in position with Swiftec Low-Tack adhesive tape. (Swiftec tel: 0161 945 1500). This protective covering and the fixing tape are to be laid strictly in accordance with the manufacturer’s instructions. 2.5.3 Contracts 220.127.116.11 Sub-Contract The cutting of holes through walls, the chasing or boring of partitions etc, and the formation of foundations, ducts and pockets will be carried out by the Main Contractor, but the Sub-Contractor will be responsible for all marking and setting out of all builder’s work that he may require. Any builder’s work carried out incorrectly because of the Sub-Contractor’s setting out, will be reinstated by the Main Contractor at the Sub-Contractor’s expense. Drilling plug holes in floors, walls, ceilings and roofs for securing services and equipment requiring screw or bolt fixings shall form part of the Works. Approval shall be obtained for all fixings into concrete walls, floors, ceilings or roofs. AJC 05/07 Section 2.5. / 1 SECTION 2.5. - BUILDERS WORK INCL CEANING AND PAINTING The Sub-Contractor shall provide all clips, brackets, foundation bolts, anchor plates, washers, plugs etc. for all equipment materials supplied under his Sub-Contract. Lightweight equipment and pipework may be fixed to the building structure by screws in plastic plugs. Wood or fibre plugs shall not be used. Fixings to brickwork, blockwork and pre-cast concrete components shall not be made in the bond. Fixings to wood fitments shall be by screws. All screw fixings shall be sheradised and greased before use. Heavyweight equipment and pipework shall be fixed with masonry fixings of the expanding type. Fixings to concrete shall not exceed 30mm in depth and 6mm in diameter without written consent. Fixings to steelwork shall be of the clamp type and no steelwork shall be cut, drilled or welded without the written consent of the Engineer. Fixings shall be of the correct size and type for the fixing load applied and these shall be agreed with the Engineer in writing prior to the commencement of works. Drilling of timber joists for the passage of pipes shall be carried out by the Sub-Contractor in positions agreed with the Engineer/Architect. If at any position it is found necessary to employ wood noggings or running boards to facilitate the fixing of pipes, etc, all such supports shall be provided and fixed by the Main Contractor unless otherwise stated. Painting of pipes, fittings, panels, etc will be carried out by the Main Contractor after completion of the work. The Sub-Contractor is responsible for ensuring that all pipe work and steel work etc is wire brushed and free from rust and immediately primed. The Main Contractor will supply all necessary excavation, pipe ducts, backfilling and reinstatement for underground pipe runs, but it will be the Sub-Contractor’s responsibility to lay the pipes. The Sub-Contractor shall supply all builder’s work drawings, for the proper execution of the work, and templates if necessary for the setting out of AJC 05/07 Section 2.5. / 2 SECTION 2.5. - BUILDERS WORK INCL CEANING AND PAINTING holes to be left in new structural work for holding down bolts and other supports. Include for supplying four copies of finally approved drawings. The Sub-Contractor will be liable to be charged for any unnecessary cutting away or making good, for which the Engineer/Architect may deem him to be responsible. The position of all holes to be cut in or through walls, floors, ceilings and elsewhere are to be approved by the Engineer/Architect before the work is put in hand. The Sub-Contractor shall restore the integrity of any smoke or fire barriers after installation in existing floors, walls and ceilings. Timely indication shall be given of any difficulties likely to be encountered in accommodating plant or equipment in the spaces available. 18.104.22.168 Direct Contract The cutting of all holes, and chases, making good, touching up with paint, etc. the lifting and replacement of all access covers to service ducts, excavation and back-filling of all trenches, removing and replacement of ceiling tiles shall be carried out by the Contractor and shall be included for in the Tender Price. Where shot fixing, drilling or cutting of structural steelwork is required to be included, then special application in writing must be made and approval received in writing before any structural steelwork is cut or drilled. Timely indication shall be given of any difficulties likely to be encountered in accommodating plant or equipment in the spaces available. The Contractor should consider in conjunction with the drawings, the actual work involved on the site, and shall allow for everything necessary for carrying out the work in the best possible manner whether specifically mentioned or not. In order to keep disturbance to a minimum, all chasing etc. shall be carried AJC 05/07 Section 2.5. / 3 SECTION 2.5. - BUILDERS WORK INCL CEANING AND PAINTING out by means of power operated cutters and drills, not percussion tools, and all fixings to the building fabric shall generally be made by use of a suitable drill and fixing plug. Should the Contractor require exact dimensions, he must take particulars upon site, and in any case he must verify the exact requirements before putting the works in hand. No claims resulting from the Contractor’s failure to do so will be allowed. Making good, building-in etc. shall be done in sound brickwork in sand lime mortar with plaster, as required, to match the existing in every respect, and all work shall be properly bonded and made good to adjoining work. Provide generally for protecting the existing structure and adjoining new work and alterations and take all precautions against damage from the new work and alterations and make good all such damage. When taking down brickwork, masonry, etc. the Contractor shall include also for the plastering rendering and tiling etc. occurring on these walls, and also for cutting back skirting, picture rails, dado rails, etc. whether specifically mentioned or not. When cutting openings, etc. the Contractor shall include for diverting service pipes, conduits, etc. as necessary, informing the Service Authorities concerned and taking all necessary precautions. Remove and cart away from time to time as it accumulates, all rubbish, debris, and old materials not described as for re-use or to be handed over. When taking up duct covers the Contractor shall include for temporary guard rails, and afterwards refix, including sealing, levelling up and re- bedding as necessary. All trenches shall be excavated to the widths and depths indicated, and the Contractor shall make his own allowance for any additional excavation required for the purpose of planking and strutting. The Contractor shall take all precautions to avoid damage to existing drains AJC 05/07 Section 2.5. / 4 SECTION 2.5. - BUILDERS WORK INCL CEANING AND PAINTING and other services during the excavations, and shall allow for making good at his own expense any damage so caused. The Contractor shall ensure the integrity of any smoke and fire barriers in walls, floors and ceilings after installation of mechanical services. Drilling plug holes in floors, walls, ceilings, and roofs for securing services and equipment requiring screw or bolt fixings shall form part of the works. Approval shall be obtained for all fixings into concrete walls, floors, ceilings or roofs. Lightweight equipment and pipework may be fixed to the building structure by screws in plastic plugs. Wood or fibre plugs are not to be used. Fixings to brickwork, blockwork, and pre-cast concrete components shall not be made in the bond. Fixings to wood fitments shall be by screws. All screw fixings shall be sheradised and greased before use. Heavyweight equipment and pipework shall be fixed with masonry fixings of the expanding type. Fixings to concrete shall not exceed 30mm in depth and 6mm in diameter without written consent. Fixings to steelwork shall be of the clamp type and no steelwork shall be cut, drilled or welded without the written consent. 2.5.4 Cleaning and Painting The Contractor shall thoroughly clean out the interior of each item or section of the Sub-Contract works and plant immediately after the execution of any work on that item or section to the satisfaction of the Engineer. The Contractor shall thoroughly clean down the Sub-Contract works in an approved manner prior to practical completion, and shall ensure that the Sub-Contract works including all plant are free from dust, dirt, moisture, and other foreign matter. The Contractor shall allow for cleaning and painting all surfaces as outlined below. Before painting or filling with oil or compound, all ungalvanised parts shall AJC 05/07 Section 2.5. / 5 SECTION 2.5. - BUILDERS WORK INCL CEANING AND PAINTING be thoroughly cleaned, free from rust, scale, burrs, grease, and moisture and all external rough surfaces shall be filled or filed flat. The following minimum painting requirements shall apply to all ferrous parts unless the Contractor can show, to the satisfaction of the Engineer that any alternative he proposes is in all respects equal or superior to the specified requirements. Generally all plant and equipment shall be delivered to site having received the finishing paint usually applied by manufacturer at Works. The manufacturer’s standard of painting shall not be less than that required by the clauses below. Pipework brackets, supports, gantries may be painted by the manufacturer offsite, or by the Contractor on-site to the standard required by the clause below. Thermal insulation shall be painted to the requirements set out in the relevant section of this Specification. 22.214.171.124 Internal Surfaces Area APPARATUS PAINTING Oil filled chambers and tanks. Epoxy based enamel. Cubicles and apparatus boxes use Three coats of paint, the fourth final in outdoors. coat being in enamel. Cubicles and apparatus boxes use One coat of bituminous primer and indoors two coats of bituminous finishing coat Ungalvanised metal, e.g. water filled chambers and tanks AJC 05/07 Section 2.5. / 6 SECTION 2.5. - BUILDERS WORK INCL CEANING AND PAINTING 126.96.36.199 External Surfaces Area APPARATUS PAINTING All ungalvanised surfaces, (other (a) On priming coat of corrosion than nuts, bolts, and washers which inhibiting paint applied immediately may be removed for maintenance after cleaning. purposes) located both internally and externally. (b) Two coats of non-glossy, oil and weather-resisting paint applied after inspection and testing and before despatch. (c) One finishing coat of glossy oil and weather resisting, non-fading paint applied after erection is completed. For equipment despatched completely assembled the final coat may be applied, at the works unless otherwise required by the Engineer. 188.8.131.52 At Site APPARATUS PAINTING Pipework, Brackets, Supports, and All surfaces to be painted one coat Gantries. of red oxide primer, followed by one undercoat and by one final coat of high gloss enamel. Exposed ungalvanised nuts, bolts, One coat of oil and weather- and washers which may be resisting, non-fading paint applied removed for maintenance. after erection. Duct covers and ironworks within Two coats of bitumastic paint. ducts. AJC 05/07 Section 2.5. / 7 SECTION 2.5. - BUILDERS WORK INCL CEANING AND PAINTING Successive coats of paint shall be easily distinguishable by shade or colour and shall be applied to a clean dry and properly prepared surface. Each coat shall be compatible with the previous coat. The colour and shade of all painted surfaces shall be to the approval of the Engineer. Protective coatings or paintwork which has been damaged during transport or erection shall be made good to the satisfaction of the Engineer before the application of any final coat. All ferrous materials including pipework, fittings, sundry iron and steel brackets shall be primed before despatch to the site. Protective coatings removed or damaged shall be thoroughly wire brushed and cleaned before re-priming. Pipework and fittings in ferrous and non-ferrous materials where buried underground or in trenches etc. must be covered in “Denso” tape prior to being insulated and covered in (except pre-insulated buried mains and Kuterlux piping). Pipework fittings and valves not insulated shall be painted to the correct colour code, of BS 1710. AJC 05/07 Section 2.5. / 8 SECTION 2.6. - PANELS, WIRING, AND CONTROLS 2.6.1. Starter/Control Panels and Cubicles – General ..........................................1 2.6.2. Mechanical Construction.............................................................................2 2.6.3. Starters .......................................................................................................7 2.6.4. Contractor Starter Units ..............................................................................8 2.6.5. Light Current Electrical Construction ...........................................................9 2.6.6. Components .............................................................................................11 2.6.7. Cabling and Terminations .........................................................................12 2.6.8. Auxiliary Power Cables .............................................................................13 2.6.9. Multipair Thermoplastic Insulated Cables..................................................14 2.6.10. Special Control and Instrumentation Cables .............................................16 2.6.11. P.V.C. Cables ...........................................................................................16 2.6.12. Conduit Installation ....................................................................................17 2.6.13. Tunking ....................................................................................................21 2.6.14. Control Switches and Interlocks ...............................................................21 2.6.15. Time Switch Control .................................................................................23 2.6.16. Instrumentation ........................................................................................23 2.6.17. System Static Pressure Gauge.................................................................25 2.6.18. Thermometers – Air Systems ...................................................................25 2.6.19. Pressure Tappings ...................................................................................26 2.6.20. Sling Psychrometer ..................................................................................26 2.6.21. Pressure Gauges .....................................................................................26 2.6.22. Building Management Systems ................................................................27 2.6.23. Cabling.....................................................................................................29 2.6.24. Sensors, Detectors and Motors ................................................................32 2.6.25. Generic System Performance Descriptions ..............................................42 184.108.40.206. LTHW System ..................................................................................43 220.127.116.11. Chilled Water System Pumps ...........................................................45 18.104.22.168. Air Handling Units.............................................................................46 22.214.171.124. Stand Alone Cooling Units................................................................49 126.96.36.199. Pump Sets (Generally) .....................................................................49 188.8.131.52. Optimum Start Control ......................................................................49 184.108.40.206. Night Purge ......................................................................................50 220.127.116.11. Compensated Control.......................................................................50 18.104.22.168. LPHW Systems – General................................................................51 22.214.171.124. Chilled Water System .......................................................................53 126.96.36.199. Power Feeds to the Air Handling Unit Lighting..................................54 188.8.131.52. Fire Alarms .......................................................................................54 SECTION 2.6. - PANELS, WIRING, AND CONTROLS 2.6.1. Starter/Control Panels and Cubicles – General All electrical equipment and associated controls shall be contained within purpose made purpose. Each panel shall be in the form of a cubicle and shall be adequate in size for the equipment that it is to contain, with sufficient clearances for access to all terminals and maintenance, and not less than 600mm in width. The degree of protection afforded by the equipment enclosure may be reduced to IP41 in accordance with BS EN 60529 where the enclosure is fitted inside another panel e.g. a motor control centre (MCC) Otherwise enclosure with BS.EN 60529. Where bus bars, switch gear and fuse boards are to be included in the control panel/cubicle, the assembly shall comply with BS.5486 form 4 construction unless otherwise specified in the particular specification. Panel anti condensation heaters shall be shrouded to prevent inadvertent contact and be controlled by means of an appropriate thermostat (range - 15oC to +15oC.) Final connection to the heaters shall be by heat resisting flexible cable. ON/OFF switches and thermostats shall be fitted within the compartment and designed to operate whenever the appropriate contactor de-energises. Where control panels are specifically identified by the Engineer for use in locations exposed to the weather, they shall include the following requirement: Push-buttons shall comply with IP65 rating. Devices with operating spindles projecting through the panel front shall be fitted with barriers or glands to prevent entry of moisture into cubicle. All other equipment shall be fitted behind approved transparent observation windows or alternatively doors, suitably gasketed. All external fixings shall be made of stainless steel. AJC 05/07 Section 2.6. / 1 SECTION 2.6. - PANELS, WIRING, AND CONTROLS 2.6.2. Mechanical Construction The panels shall be complete with cable entries and interlocked isolators. Panels shall be rigid self supporting rectangular enclosures consisting of a framework of angle and sheet metal. Lift-off access panels shall be provided with handles and mounting spigots. One or more removable metal non-ferrous gland plates shall be provided at both the top and/or bottom of the enclosure to allow for cable or conduit entry. The gland plates shall be of 3mm minimum thickness and shall be secured by means of bolts screwed into captive nuts on the enclosure. Captive nuts shall be secured to the enclosure by swagging and riveting or by welding. All nuts used in the construction of the enclosure shall be of the captive type. Bolts on removable panels shall incorporate nylon washers to prevent damage to paintwork. Modular enclosures shall have each section mechanically and electrically segregated. However, it shall be possible to gain access to each section without first removing or opening other sections. Separate sections within the main panel shall be provided to segregate starter equipment from control equipment. Each section shall be complete with its own access door, which shall be kept in a locked position, and shall be separated by a vertical steel barrier. All indicating lamps, instruments and controls shall be of the same manufacture and style to provide uniformity of appearance and to facilitate maintenance. Externally visible equipment shall be flush mounted, with minimum projection, and fixed securely to the front panel or other members. Internal equipment shall be secured to purpose made rails or mounting bars. All fixings shall incorporate shakeproof washers or other vibration resistant fastenings. Indicator lamps shall be under-run and shall be supplied from a low voltage AJC 05/07 Section 2.6. / 2 SECTION 2.6. - PANELS, WIRING, AND CONTROLS output transformer complying with BS 3535 or shall incorporate individual step-down transformers having a low voltage output. Glasses of not less than 25mm diameter shall be fitted. Where glasses are not immediately adjacent to their associated switched they shall be clearly labelled. All controls panels shall be in the form of cubicles unless otherwise indicated, and be suitable for floor or wall mounting as indicated. All control panels shall be drip-proof, fully tropicalised with uniform dimensions and matching appearance and floor panels shall be mounted on a brick/concrete plinth. Equipment racks and panels shall be fabricated steel construction, 2.5mm minimum thickness, and unless otherwise specified (or located against a wall) both front and rear access shall be provided to all racks and equipment in panels. The lowest mounted rack shall be 0.3m above floor level. The highest mounted rack shall not be above 1.8m from the floor. The panel height shall not exceed 2m. Details of all manufactured panels shall be submitted to the Engineer for approval. It shall be possible to lay removable units, including portable equipment, on any of their faces without causing damage to any components. Where necessary mechanical guards shall be fitted. Hinged doors shall be provided and arranged to lie flat back and not restrict access to the apparatus contained within the panel. Hinged doors shall be of the lift-off type, secured with integral handles and shall be flush-fitting and sealed with a gasket of rubber approved by the Engineer to prevent the ingress of dust. If complete sealing of the panels is not practicable, ant ventilators and opening must be designed to prevent the entry of water, dust, vermin and insects, and provided with air filters. Lamps shall be fitted inside each panel and so arranged that all wiring is illuminated as evenly as possible without glare. The lamps shall be controlled by the respective door switch. Before painting, metal parts shall be thoroughly cleaned free from rust, AJC 05/07 Section 2.6. / 3 SECTION 2.6. - PANELS, WIRING, AND CONTROLS scale, burs, grease and moisture. The following minimum painting requirements shall apply to all surfaces and ferrous parts unless the Contractor can show, to the satisfaction of the Engineer, that any alternative he proposes is in all respects equal or superior to the specified requirements. External colours shall be to the approval of the Engineer. (a) One priming coat of corrosion inhibiting paint applied immediately after cleaning (b) Two coats of non-gloss, weather resistant paint (c) One finishing coat of gloss and weather resisting non-fading paint to external surfaces (d) One finishing coat of matt white, weather resisting, non-fading paint to all internal surfaces All exposed screws, bolts, or other fixings shall have rounded heads with protective chrome plating. A metal plinth shall be provided with provision for bolting down the panel. Removable lifting eyes shall be provided for convenience of handing the control panel. After erection at site is completed, all external surfaces shall be cleaned down and all defects to the painted surfaces shall be made good to the approval of the Engineer. An approved locking device for all panels shall be provided under this Contract. All locks shall be provided with two identical keys. It shall not be possible to open any lock with the key of any other lock provided under this contract. Locks shall be in suites provided with master-key facilities. Keys and locks shall be impressed with the manufacturer’s serial number. A key cabinet shall be provided for each set of keys. Where forced cooling is used, the panel equipment shall be so protected AJC 05/07 Section 2.6. / 4 SECTION 2.6. - PANELS, WIRING, AND CONTROLS that no damage occurs due to failure of the forced cooling. The Contractor shall submit to the Engineers, his proposals as to how this will be achieved. Internal wiring shall be colour-coded, and in general shall be bunched and run on trays or in purpose-made slotted plastic cable trunking. Positive fixing of cable ends shall be ensured by crimped cable tags or other approved terminations. Each cable end shall be permanently identified. Grouped terminal blocks of adequate capacity and fully numbered, with permanent labels, shall be provided for al wires leading to equipment outside the panel. Terminal numbers or markings shall correspond with those used on related apparatus and wiring diagrams. Provision shall be made for the earthing of all non current-carrying metal-work with means for effective earthing to the cubicle chassis. Socket crimp type terminals shall be provided for main power terminals incorporated within a panel. Fuses shall be grouped and mounted so as to be readily accessible without danger. Fuses, terminal blocks and all items of equipment shall be readily identified by means of clearly visible labels secured to them by retentive clips or screws where practical. For each electrical air heater battery, an indicator lamp and ammeter shall be provided. For each electric motor of 37.5 kW and above, an ammeter shall be provided. Ammeters shall not be less than 75mm diameter. AJC 05/07 Section 2.6. / 5 SECTION 2.6. - PANELS, WIRING, AND CONTROLS Indicating lamp glasses on control and relay panels shall conform to the following standard and colour code in accordance with BS 4099: Part 1:- Lens Colour Application Red Shall indicate that an abnormal condition exists and that urgent operator action is required i.e. Pump or Fan etc. not operating. (a) Plant outside normal operating limits (b) Plant, instrument or other equipment faulty or in alarm state (c) Motor starter: OFF (d) Clutch or similar device: DISENGAGED (d) Valve or similar device: CLOSED White Shall indicate a normal condition: (a) Plant operating correctly (b) Trip circuit healthy (c) Alarm circuit healthy Green Shall indicate plant operating condition: (a) Isolator, circuit-breaker, switch or contactor: CLOSED (b) Motor starter: ON (c) Clutch or similar device: ENGAGED (d) Valve or similar device: OPEN Yellow Shall indicate change or impending change of condition e.g. filter blocked (a) Filter blocked (b) Temperature different from normal (c) Abnormal circuit condition (d) Isolator, circuit-breaker, switch or contactor: OPEN AJC 05/07 Section 2.6. / 6 SECTION 2.6. - PANELS, WIRING, AND CONTROLS All panels shall be equipped with a lamp test button mounted on the panel fascia. Where required this button shall be suitably IP rated. All items on the outside face of the panel shall be identified by means of white laminated plastic labels engraved with black ciphers and attached by screws. Attachment by adhesive only of any description will not be permitted. 2.6.3. Starters Starters shall comply with the requirements of BS EN 60947-4-1. Starters shall normally be rated for “intermittent” duty, but where, due to the form of thermostatic or automatic control, the number of starts is likely to exceed 15 per hour, starters for “frequent” duty shall be provided. The type of starter which will be accepted depends on the capacity of the electrical supply and the mains; in certain cases special requirements may be indicated. Generally the following types will be accepted: (a) Motors up to 0.5kW output ‘ON/OFF’ switch or direct-on-line (b) Over 0.5kW and up to 7.5kW Direct-on-line (c) Over 7.5kW and up to 25kW Star-delta, auto-transformer, or rotor resistance (d) Over 25kW Auto-transformer or rotor resistance (e) Motors requiring accurate speed control to be started by PWM soft starters. AJC 05/07 Section 2.6. / 7 SECTION 2.6. - PANELS, WIRING, AND CONTROLS For starters incorporating reduced voltage starting, the change-over of voltage shall be automatic. Starters shall be provided with combined thermal overload devices on each phase and single phasing protection, with adjustable time-lag, and an under-voltage release. They shall be arranged, unless otherwise indicated, to provide automatic re-start on restoration of mains voltage. The automatic start shall, however be implemented through a sequence timed start, to prevent all equipment re-starting simultaneously. Operating coils shall be wound for not more than 240 volts. Where a contractor is arranged for remote operation, the coil circuit shall be protected by a fuse. Terminals shall be accessible and have adequate clearances between phases and earthed metalwork. Where a starter is not enclosed in a composite panel, a door inter-locked isolating switch shall be provided. Each electric motor and electric air heater battery which is controlled from the main control panel, and is not less than 2.0m from the panel or is so situated that the panel cannot be seen from the motor or air heater, shall be provided with a local main circuit isolator. All isolators shall be capable of being locked in the off or open position. For large refrigeration plant or completely packaged water chilling units, supplied separately from the main starter and control panel, provision shall be made for any electrical interlocking which may be required between the compressor motor switchgear and the starters for the remainder of the plant. Unless otherwise indicated, where a fan is provided with duplicate motors, two starters shall be supplied; a single starter with a local changeover switch will not be accepted. 2.6.4. Contractor Starter Units Contractor starters shall comply with the requirements of BS EN 60947-4-1. Low voltage motor circuits shall be controlled by a contactor starter and an individual set of HRC fuses. The contactor shall be the normal means of stopping and starting the motor. AJC 05/07 Section 2.6. / 8 SECTION 2.6. - PANELS, WIRING, AND CONTROLS Each contactor starter shall be fitted with an isolating switch to provide isolation for maintenance and disconnection in the event of welded contacts under stalled motor conditions. The contactors shall be capable of dealing with normal and fault conditions. The contractor starter units shall be of air-insulated, metalclad type and be designed to ensure safety of operating personnel. Interlocks shall be provided to ensure that the unit access door can only be opened when the associated contactor is open and the contactor cannot be closed in the service position until the access door is closed. Auxiliary contacts fro remote interlocking and indication shall be fitted in each individual contactor starter. 2.6.5. Light Current Electrical Construction Component parts shall be so located, secured and disposed with respect to each other and structural members that they can be inspected, removed and replaced without damage to, or undue disturbance of, other parts or wiring. Components generating significant heat shall be adequately spaced from their mounting boards and from other components. All components shall be adequately supported and secured where necessary by clamps, clips or other means acceptable to the Engineer. Rivets or eyelets shall not be used for fixing items which may have to be repaired or replaced. Components shall not be mounted directly on wiring terminal blocks, unless adequately independently supported, and will not damage the terminal block. Unless otherwise agreed, all plug-in devices, units and sub-units shall be held in position by approved retainers. Pre-set controls requiring routine adjustment shall be accessible with the complete equipment and adjacent equipment in operation. A method of AJC 05/07 Section 2.6. / 9 SECTION 2.6. - PANELS, WIRING, AND CONTROLS ensuring that pre-set controls retain their adjustment shall b incorporated, and details submitted to the Engineer for approval. Soldered connections shall be made only to components specifically designed for that purpose. Flexible conductors and metallic braiding subject to flexing at their terminations shall not be soldered, but shall be fitted with crimped tags approved by the Engineer. Welded connections shall only be used subject to the approval of the Engineer. Taper pin connectors, push-on connectors etc. shall be to the approval of the Engineer. The preferred material for push-on connectors is phosphor bronze. Wires shall not be joined together except at a properly supported terminal post or tag. Grommets or bushes shall be fitted where wiring passes through metalwork. Internal wiring shall be loomed, harnessed and adequately supported by clamping troughing, or similar means. Direct point-to-point wiring shall not be used, except where approved by the Engineer. Where it is necessary to bunch cables, the wiring shall be limited to not more than 12 wires. Wiring shall be clamped into plugs and sockets in such a way that connections inside each connector cannot be subjected to injurious tensile stress. Sufficient slack wire shall be provided to enable a reconnection to be made at each end of each wire. Internal wiring shall be a minimum of 0.002mm2 cross-sectional area. Every effort shall be made to avoid installing control and signal wiring in close proximity to power wiring. Control and signal wiring shall be protected by properly grounded shielding where it is practical to do so. External wiring to and from panels shall be terminated on properly numbered multiway tag blocks. Long lengths of external type cable inside AJC 05/07 Section 2.6. / 10 SECTION 2.6. - PANELS, WIRING, AND CONTROLS panels or cubicles will not be permitted. 2.6.6. Components Transformer and inductor windings shall be vacuum impregnated or encapsulated and terminate on a terminal board mounted on the unit. Each winding and termination shall be clearly and unambiguously identified. Complete details shall be provided of the suitability of relay contact materials for the application. Relay actuating coils shall preferably be either vacuum impregnated or encapsulated. Unsealed relays or groups of relays shall be provided with a protective cover to prevent dust ingress. The covers shall be detachable without the need to remove the relays. The Contractor shall submit details of al instruments for individual approval by the Engineer. Instrument scales shall be of the anti-parallax platform type, clearly divided and indelibly marked. All indicating instruments shall be of a modular type and be accurate within 1% of full scale span. Push-button indicators with labelling and mounted on control panels shall be to the approval of the Engineer. The ratings of all indicating lamps shall be such that an average useful lamp life of 20,000 hours minimum is obtained. The design of lamp holders shall be such that replacement of the lamp is both quick and easy; access shall be from the front panel of the equipment or the cubicle or panel door. To reduce heating, and fouling of the panels, lamps which are continuously alight shall have the minimum consumption consistent with good visibility of indications in a brightly-lit room. Multi-pole connectors shall be designed such that incorrect mating cannot occur. A device approved by the Engineer shall be provided for locking each free plug or socket in the mated position. AJC 05/07 Section 2.6. / 11 SECTION 2.6. - PANELS, WIRING, AND CONTROLS The material of all components shall be resistant of flame propagation. All instruments shall be back connected on stud type terminals and identified by engraving or painting. 2.6.7. Cabling and Terminations All cables shall be anti-termite fire retardant type and all cabling shall be arranged to minimise the risk of fire and any damage which might be caused in the event of fire. The Contractor shall be responsible for protecting cables in an approved manner against mechanical damage or damage by fire where exposed inside the building. Where cable troughs are not provided the Contractor shall provide ladder racking with appropriate supports to the approval of the Engineer. Where run on racking, cables shall be secured by heavy gauge copper or plastic coated clips at intervals of not more than 1500mm. Where run on flat surfaces, cables shall be secured by spacer bar saddles at intervals of not more than 1000mm. Every cable shall be securely supported at a point not more than 1000mm from its termination and on vertical runs passing through floors, immediately above the floor. The Contractor shall be responsible for connecting his equipment to existing equipment or equipment supplied under a separate Contract, where indicated. All multicore cables shall be physically separated from power supply wiring. Joints in P.V.C or X.L.P.E cables shall be terminated in brass compression type cable glands of the correct size which shall secure the cable inner sheath and ensure effective electrical continuity between the cable armouring wires and the metal enclosure on which the cable is terminated. A copper earth link shall be taken from the cable termination point to the associated sub-switchboard or main switchboard earth bar. X.L.P.E cables shall be terminated similarly to P.VC armoured cables. Where cables are AJC 05/07 Section 2.6. / 12 SECTION 2.6. - PANELS, WIRING, AND CONTROLS required to be terminated in terminal boxes or other equipment supplied under another contract, the Contractor shall be responsible for carrying out the terminations in accordance with the requirements specified above including the supply and jointing of tails where necessary and the testing to verify correct phasing of all cores. Where single core cables are used, all necessary precautions shall be taken to prevent hysteresis. Ferrous plates through which the cables pass shall be slotted and brass glands and sockets shall be used. Single core cables shall be very rigidly clamped to prevent distortion under short circuit conditions. 2.6.8. Auxiliary Power Cables All PVC insulated power cables for use on three phase, low voltage systems shall be 600/1000 volt grade with stranded copper conductors. PVC insulated multicore auxiliary cables shall have not less than 7/0.67mm (2.5mm2) stranded copper conductors and shall be 600/1000 volt grade. They shall conform to approved National Standards and to all applicable requirements of this Specification dealing with construction of power cables unless otherwise specified. All PVC insulated multicore power and auxiliary cables shall be extruded PVC sheathed, galvanised steel round wire armoured and extruded PVC sheathed overall. The ends of each cable shall be terminated in brass, compression-type cable glands of the correct size, which shall secure the cable inner sheath and ensure effective electrical continuity between the cable armouring wires and the metal enclosures on which the cable is terminated. Cable glands fitted on outdoor equipment shall also incorporate suitable compression seals to secure the outer sheath and shall be so designed and fitted that water cannot enter the cable or the equipment through the cable termination. Where required, a barrier shall be incorporated to prevent ingress of moisture through the interstitial spaces in the cable. At all rising terminations, the cable inner sheath shall pass through the gland to terminate not less than 25mm above the gland. AJC 05/07 Section 2.6. / 13 SECTION 2.6. - PANELS, WIRING, AND CONTROLS Straight through joints for PVC and other thermoplastic insulated and sheathed cables, shall comprise a cast iron box with cone type armour clamps, jointing connections and means for providing a barrier against the entry of water into the box through the interstitial spaces in the cables. The boxes shall be suitable for filling with a bituminous or epoxy resin compound. Alternatively, boxes of cast iron or other suitable material containing a separately sealed joint sleeve and an approved armour clamping device will be considered. Other designs of straight joint may be considered, but only if documentary proof can be provided of their suitability for withstanding mechanical and electrical type approval tests witnessed and accepted by a reputable Authority. No straight through joints shall be installed without the agreement of the Engineer. The Contractor shall submit design drawings of joint boxes and outer protection boxes he proposes to use which shall be suitable for operation when buried in the ground or installed in exposed positions or in conditions of high humidity, depending upon the location approved by the Engineer. 2.6.9. Multipair Thermoplastic Insulated Cables The conductors of all thermoplastic insulated cables shall be copper and shall comply with an approved National Specification and to all applicable requirements of this Specification dealing with the construction of Power Cables. Where tinned conductors are specified their solder-ability performance shall be demonstrated in accordance with an approved Specification. The size of conductors shall be 1/0.9mm minimum. Insulation shall be PVC and the thickness approved by the Engineer. Cable cores shall be identified by colours with distinctive schemes to discriminate between PVC and polyethylene insulation. The colour schemes shall be approved by the Engineer and shall be the generally accepted schemes and rotation for the appropriate design of cable. Insulated cables shall be twisted together to form a pair. In the case of PVC insulated conductors the required number of pairs shall be laid-up to form a compact symmetrical cable with the two pair construction laid-up in quad formation. AJC 05/07 Section 2.6. / 14 SECTION 2.6. - PANELS, WIRING, AND CONTROLS Binding tapes constructed from suitable materials shall be applied with an open spiral or overlap as required between layers, where necessary, and over the laid-up structure to provide a compact uniform formation. A rip-cord to facilitate removal of the inner sheath of PVC insulated cables may be included during the application of the overall binding tape. Cables shall be armoured with one layer of galvanised steel round wires. The number and diameter of the wires shall be as indicated. The design of joint-box and any other protection box shall comply with the requirements for auxiliary cables and accessories unless otherwise approved by the Engineer. Alternative designs will only be considered if documentary proof can be provided of their suitability for withstanding mechanical and electrical type approval tests witnessed and accepted by a reputable Authority. Multipair cables shall be screened when being used for data transmission. Earthing of the screen shall be to the approval of the Engineer. Multipair cable tails shall be so bound that each wire may be traced without difficulty to the associated cable. Approved type terminals of the insertion type incorporating pressure plates shall be provided for all incoming cables. All terminals blocks and terminations shall be to the approval of the Engineer. Unless otherwise agreed each terminal shall have a removable link to facilitate signal isolation and testing. Facilities shall be provided to maintain the continuity of isolated cable screens whenever required. Provision shall be made at the top of the control panel terminal boards for the termination of all spare cores in the incoming cables. AJC 05/07 Section 2.6. / 15 SECTION 2.6. - PANELS, WIRING, AND CONTROLS The ends of every type of wire and every cable tail shall be fitted with numbered ferrules of white, with the numbers clearly engraved in black. Moisture and oil resisting insulating material having a glossy finish shall be used. The ferrules shall be of the interlocking type and shall grip the insulation. Details of the proposed ferrule numbering system shall be submitted at the earliest possible date by the Contractor to the Engineer for approval. All cabling carrying analogue direct current signals shall comply with BS 5863: Part 1. 2.6.10. Special Control and Instrumentation Cables Any special control, instrumentation and measurement cables shall be to an approved National Standard and the design and characteristics of the insulation and screening shall be adequate to meet the operating requirements of the respective circuits. Cables shall be screened and/or armoured as required and sheathed overall with extruded PVC. Cables shall be run in one length between terminal points. Where it is necessary to split or joint circuits, a marshalling box or cubicle shall be provided. Adequate spacing shall be provided between power and instrumentation cables so that mutual interference is minimised. If any special cables are required, it shall be stated in the specification Schedules and complete details of the cables provided. 2.6.11. P.V.C. Cables All sub-main circuit PVC insulated and sheathed cables shall be 600/1000 volts grade. The cable core shall be readily identifiable by colours or numbers. Where numbers are used the intervals between adjacent numbers on the same core shall not exceed 75mm. Where cables are AJC 05/07 Section 2.6. / 16 SECTION 2.6. - PANELS, WIRING, AND CONTROLS armoured they shall be covered with a single layer of galvanised steel. Cable supports shall be in accordance with relevant manufacturer’s recommendations, but no more than at 400mm horizontal and 500mm vertical maximum spacing. Cables shall be terminated in corrosion resistant brass glands with core grip armour clamps. In outdoor situations the terminating glands shall be covered with plastic shrouds filed with plastic compound to give protection against moisture and corrosion. All cables drawn into conduit shall be PVC insulated 600/1000 volts grade with copper conductor. Generally conductors shall be stranded and none smaller than 1.5mm2 will be permitted. The cables shall be looped progressively from point to point and no joints will be permitted. Cables shall not be bunched or pass through the same conduits, draw boxes or section of trunking, if derived from separate distribution fuseboards or fuse switched. The cables for each section of the installation shall be confined to the conduit and draw box system for that particular section. Cables for separate sections may, however, pass through the same adaptable box provided the circuits are separated physically by means of fixed barriers within the box and separate covers are provided for each section thus formed. The number of cables in any conduit shall not exceed those stated in the local or international Regulations. All cables shall be colour coded in accordance with local Regulations. 2.6.12. Conduit Installation Unless otherwise specified the whole of the various installations described shall be carried out in heavy gauge steel conduit. No conduit less than 20mm diameter will be permitted. All steel conduit and accessories shall be heavily galvanised. Surface installed conduit shall be supported using distance pattern saddles fixed AJC 05/07 Section 2.6. / 17 SECTION 2.6. - PANELS, WIRING, AND CONTROLS with non-ferrous screws. A separate insulated earth conductor, coloured green, shall be run in PVC conduits and earth facilities shall be provided at all terminal points. Wherever the installation is specified as being flameproof, conduit runs entering these areas shall have a barrier box inserted in the run immediately before the conduit passes into the flameproof area. All conduit work inside the flameproof area shall be carried out with solid drawn galvanised conduit and all conduit fittings, sockets and accessories shall be galvanised and certified suitable for Group 1 hazards. The ends of all conduit shall be rearmoured to remove all burrs or sharp edges after the screw threads have been cut. All dirt, paint or oil on the screwed threads of the conduit, sockets and accessories must be removed prior to erection. The ends of the conduit shall butt solidly in all couplings. Where they terminate in fuse-switches, distribution boards, adaptable boxes, non- spouted switch boxes, they shall be connected thereto by means of smooth bore male brass bushes, compression washers and sockets. All exposed threads and all bends shall be painted with an aluminium spirit paint after erection. All conduit and accessories, after being installed, shall be examined and all parts where the surface has been chipped or scratched shall be painted. All conduits shall be kept 80mm clear of water, gas and other services. The method of installing PVC conduit and fittings shall conform strictly to the manufacturer’s recommendations. In general the Clauses dealing with steel conduit shall apply. PVC tube not exceeding 25mm in diameter shall be bent cold by means of the appropriate spring and the tube shall be saddled as quickly as possible after bending. When bending large sizes of tube, the tube must be heated in the approved manner until it is pliable. A normal 90º bend shall have a radius of not less five times the outside diameter of the tubes. AJC 05/07 Section 2.6. / 18 SECTION 2.6. - PANELS, WIRING, AND CONTROLS Joints between conduit and conduit fittings shall be watertight and shall be made by means of a solvent adhesive as recommended by the manufacturer. Care should be taken to ensure that the tube is clean and free from damp and grease and in particular dust and cutting oil. The Contractor shall provide PVC tube ends and flexible covers to prevent ingress of concrete grout into the tubing and boxes. All bends are to be made on site to suit conditions and not more than two right angle bends will be permitted without the interposition of a draw box. No tees, elbows, sleeves, either of inspection or solid type will be permitted. Generally long straight conduit runs from point to point shall have draw boxes installed at maximum intervals of 10 metres. Deep boxes or extension rings on standard circular conduit boxes shall be used where necessary in order to bring the front of each box flush with the surface of the ceiling or wall. Galvanised draw wires shall be provided where conduits are not to be wired on completion or are to be wired by others. All draw boxes and junction boxes shall be of ample size to permit the cables being drawn in and out. They shall be made of malleable iron with jointing surfaces machined to ensure a dust tight joint. All circular boxes shall be provided with long spouts internally threaded incorporating a shoulder for the proper butting of the conduit and a solid brass earth terminal tapped and screwed into the base. Where the surface conduit is specified, it shall be fixed by means of distance saddles and shall terminate, in deep pattern conduit boxes. Surface conduits shall not be bent or set to enter accessories, and where they turn through the walls back outlet boxes shall be provided. Conduits shall be fixed at 1200mm centres on vertical runs and 900mm apart on horizontal runs. Conduits in ceiling cavities shall be supported independently of suspended ceiling. Where conduits cross expansion joints, the Contractor shall allow for the installation of expansion couplings at the position of the expansion joint and at right angles to it. The Contractor shall provide an earth wire between each terminal fitted in the nearest conduit boxes each side of the coupler. All flexible metallic tubing shall be galvanised watertight pattern fitted with AJC 05/07 Section 2.6. / 19 SECTION 2.6. - PANELS, WIRING, AND CONTROLS sweated brass adapters. Where conduits are laid in slab floors etc. the Contractor shall arrange for a competent person to be in attendance whilst the pouring or screeding operation is being carried out, in order to avoid damage being caused to the conduits and also to ensure that the conduit work is carried out in sound conditions, properly and efficiently installed. Particular care shall be taken when setting out conduit runs to outlet points which are to be fitted to furniture, kitchen fittings etc. The Contractor shall ascertain exact details of furniture and fittings constructions in order that all conduit work shall wherever possible be concealed. Conduits installed in chases of walls and floors shall be firmly secured by wrought iron pipe hooks or crampets and these fixings shall in themselves be sufficient to hold the conduits in place. Conduits installed in chases shall be painted with one coat of bitumastic paint before erection and a further coat shall be applied to all accessible surfaces including the hooks and crampets after erection. Care shall be taken to prevent water, dirt or rubbish entering the conduit system during erection. Screwed metal caps or plugs shall be fixed to the structure of the building independently of the conduit. Where a conduit is exposed to different temperatures (either by surrounding air conditions or by virtue o the surrounding medium with which it is in contact) at any particular time, the section of the conduit at the higher temperature shall be isolated from the section at the lower temperature by means of a conduit box filled with an approved permanently plastic compound. Such a condition would arise if a conduit running in a warmed building is run to external locations. Where conduits are to be buried in screed, the installation shall be inspected by the Engineer before screeding and screeding shall be supervised by the Contractor to ensure no damage is caused to the conduit installation. AJC 05/07 Section 2.6. / 20 SECTION 2.6. - PANELS, WIRING, AND CONTROLS 2.6.13. Tunking Where trunking is utilised shall be constructed of 1.65mm minimum thickness zinc coated mild steel and shall have a removable cover throughout its length with centre screw latch fixings. Trunking shall be rigidly fixed and supplied complete with purpose manufactured fittings, connectors, dividers, flanges, cable retaining clips, racks and copper earth continuity links. All cables installed in trunking shall be laced and identified in an approved manner. Clips shall be at 600mm centres. Vertical cable trunking shall be fitted with cable pin racks arranged to avoid any strain on the cables. All trunking shall be rust proofed, primed and painted, and fixed at intervals not greater than 1000mm. 2.6.14. Control Switches and Interlocks For the control of electrical equipment which operates independently an ‘ON/OFF’ rotary snap switch shall be fitted on the front of the panel for each item of plant. Where plant operates independently e.g. an extract fan which should not run unless the supply fan is running, an ‘ON/OFF’ switch shall be fitted for the master item and a ‘HAND/OFF/AUTO’ switch shall be fitted for each item of dependent plant. The switch positions shall be clearly labelled to show which item of plant it controls. With a ‘HAND/OFF/AUTO’ switch in the ‘AUTO’ position the dependent item of plant shall start automatically when the master item is switched ‘ON’ and shall operate automatically under the dictates of any controlling device. The operation of the switch to the ‘HAND’ position shall override any controlling devices except those which are necessary for the safe operation of the plant. Similarly the operation of a master switch to ‘OFF’ with dependant plant at ‘AUTO’ shall cause all plant to stop, in sequence where necessary e.g. allowing a fan to run on to remove heat from electric heaters or a chilled water pump to run on until refrigeration pump-down is completed, to avoid freeze-up) and with due regard for all safety controls. AJC 05/07 Section 2.6. / 21 SECTION 2.6. - PANELS, WIRING, AND CONTROLS For each electric air heater battery a ‘HAND/OFF/AUTO’ switch, an indicator lamp and an ammeter shall be provided. Associated with the ‘HAND’ setting of the switch there shall be a second rotary switch giving manual control of the heater steps independently of automatic thermostatic control. For each electric motor of 37.5kW and above an ammeter shall be provided on the panel. For cooling and air conditioning plants the master item shall be the main air supply fan shall, under automatic working conditions, cause all other plant to start in sequence and as required by the thermostatic controls. Similarly, for chilled water systems the master-item shall be the chilled water pumps and their operation shall, under automatic working, cause the refrigeration plant etc, to start. Where there are both air and water systems the main air supply fan shall be the master item for the air handling plant and the air temperature and humidity controls; the chilled water pump shall be the master item for the water handling plant, the refrigeration plant and the water temperature controls and water flow switch. Refrigeration plant shall start in sequence i.e. the chilled water pump, the condenser water pump (or evaporative condenser pump, or air cooled condenser fan) followed by the cooling tower fan (or evaporative condenser fan) where required and then the compressor. Where more than one compressor is installed they shall be arranged to start in time delayed sequence and as required by temperature control (or in some cases, refrigerant pressure control); a switch shall be provided to enable the leading machine to be selected manually (e.g. in sequence 1-2-3, 2-3-1 or 3-1-2). For each compressor of more than 35kW capacity an hours-run meter shall be provided. For boiler installations where gas tight dampers are fitted in the individual flue ways the damper shall be electrically interlocked with the firing controls to open and close when the burner is cycling and in conjunction with the AJC 05/07 Section 2.6. / 22 SECTION 2.6. - PANELS, WIRING, AND CONTROLS sequence. When the damper is in the closed position the burner controls shall be inoperative. 2.6.15. Time Switch Control Each clock control to be provided where indicated shall be driven by a synchronous motor with a self winding spring reserve of not less than 30 hours and shall include provision for one switching ‘ON’ and one switching ‘OFF’ per day. Means of omitting switching for at least two days per week and of advancing and retarding either ‘ON’ or ‘OFF’ switching or both shall be provided. 2.6.16. Instrumentation Boiler Houses 50kW and over. In boiler houses of no less than 50kW boiler rating a 20mm size socket, with a brass plug, shall be provided in each furnace front for measurement of draught over the fire. A 40mm size socket, with brass plugs for flue gas sampling shall be provided at each boiler exit and in the main chimney if common to two or more boilers. Each socket shall be 50mm long, and either welded to, or cast on the boiler furnace or flue outlet. An additional 20mm size socket with a brass plug shall be provided near to each of the 40mm size sockets. Boiler Houses in excess of 1200 kW. In boiler houses where the total boiler rating exceeds 1200 kW the following instruments shall be provided in addition to the items indicated elsewhere: (i) A smoke density indicator with indicator light connected to the audible alarm. (ii) A CO2 indicator and a flue gas temperature indicator for each boiler, or single instruments with isolating plug cocks and switches as appropriate and common connections for alternative readings from each boiler flue outlet. Alternatively the two instruments may be AJC 05/07 Section 2.6. / 23 SECTION 2.6. - PANELS, WIRING, AND CONTROLS combined. (iii) Draught gauges (two per boiler), one for the construction chamber and one for the boiler flue exit. (iv) An audible alarm, as indicated, fitted outside the boiler house and wired in parallel with the excess smoke density indicator. (v) Multi-point indicator(s) to indicate all of the following: (a) boiler water flow temperature; (b) boiler water return temperature; (c) flow header (when fitted) temperature; (d) system water flow temperature(s) (e) system water return temperature(s) (f) outdoor temperature. (vi) A sharp-edged corrosion-resistant orifice fitting or venturi shall be installed in the common flow main. The orifice shall be arranged with 15mm size valved pressure tappings and be sized to give a pressure drop between 75 and 100mb on full flow and the diameter shall be clearly stamped on a projecting metal tag; means for isolating the orifice fitting shall be provided. Venturis shall be arranged with 8mm size valved pressure tappings and be sized to give a pressure drop between 25 and 100mb at full flow; details of the design flow and related differential pressures shall be clearly stamped on a projecting metal tag. (vii) A thermometer pocket with a screwed cap shall be fitted beside each temperature sensing point connected to the multi-point indicator(s) so that a check thermometer may be inserted. The pocket shall be of steel except for copper installations where it shall be of stainless steel. AJC 05/07 Section 2.6. / 24 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (viii) A meter to record the total make-up water supplied to the system. In a hot water heating boiler house where the total boiler rating is below 1200 kW dial type thermometers shall be fixed in each boiler flow and in the common return. A dial-type thermometer shall be fixed similarly in the common flow main after the thermostatic mixing valve when one is fitted. The dial-type thermometers shall be specified elsewhere. In steam boiler houses only, the following shall be provided in addition to the instruments specified above: (i) an integrating steam flow meter in the steam header; (ii) a dial thermometer on the water outlet from the boiler feed pumps. 2.6.17. System Static Pressure Gauge A system static pressure gauge shall be provided for all air systems where the main fan power exceeds 3.75 kW; it shall consist of a small inclined manometer gauge similar to a filter gauge. One end of the gauge shall be connected to the system and the other end shall be left open to the plant room, but where fluctuations of the static pressure in the plant room may occur the gauge shall be connected across the main fan. The gauge shall be connected into the system at some point in the plant room ducting where the static pressure is steady and near its maximum. When commissioning is completed the value of the static pressure at this point shall be measured and shall be indelibly marked on the gauge as a system reference or engraved on a brass or rigid plastic name plate and securely fixed to the ductwork adjacent. The name plate shall be clear of any insulation that may be applied to the ductwork. Where a Building Management System is installed, the system reference shall also be displayed via the BMS. 2.6.18. Thermometers – Air Systems On supply air systems, duct test points as specified in clause 6.9 shall be AJC 05/07 Section 2.6. / 25 SECTION 2.6. - PANELS, WIRING, AND CONTROLS provided in the ductwork for the insertion of a thermometer in the fresh air connection, the recirculation air duct, before and after an air heater, before and after an air cooler and before and after a humidifying device as appropriate. At points where the moisture content of the air is important a second hole shall be provided for a wet bulb thermometer. Thermometers shall be mercury-in-glass type, at least 300mm long, accurate to ± 0.5ºC and scaled appropriately. Each thermometer shall be complete with a brass plug to fit the hole at the point where the thermometer will be used, and each wet bulb thermometer shall be provided with a fabric sleeve. One thermometer for each temperature point, (base on one air handling system) shall be packed in a protective casing and handed to the Engineer. Where a Building Management System is installed, measurement and display of these temperatures shall also be carried out by the BMS. 2.6.19. Pressure Tappings For each air heater and cooler battery of duty in excess of 30kW and for each shell and tube evaporator, condenser and cooling tower of duty in excess of 70kW, valved pressure tappings suitable for connection of a pressure gauge shall be fitted to the flow and return connections. A pair of pressure gauges as specified elsewhere shall be handed to the Engineer. 2.6.20. Sling Psychrometer A sling psychrometer complete with a spare wick, a small plastic bottle for distilled water and a substantial protective case shall be handed to the Engineer, for checks to be carried out during commissioning. After commissioning the sling psychrometer shall be handed to the Client. 2.6.21. Pressure Gauges Pressure gauges shall be fitted as required by other sections of this specification and shall generally comply with BS 1780 Part 2 but shall have dials calibrated both in bar and ibs/in2 from zero to not less than 1 1/3 times and not more than twice the operating pressure. Where fitted on pressure vessels and boilers, the gauges shall be as required by BS 759 with dials not less than 150mm diameter and with cases of polished brass or chromium plated metal. Where fitted elsewhere, the dials of gauges shall AJC 05/07 Section 2.6. / 26 SECTION 2.6. - PANELS, WIRING, AND CONTROLS not be less than 100mm diameter and the cases shall be of polished brass or chromium plated metal. Pressure gauges shall be fitted with lever handle cocks and siphon pipes. Gauges used specifically to indicate the altitude or head and pressure of water shall have dials not less than 100mm diameter, calibrated both in bar and metres head. In addition to the indicating black pointer, gauges shall be provided with an adjustable red pointer set to indicate the normal working pressure or head of the system. The cases shall be as for 100mm diameter pressure gauges and be fitted with lever handle cocks. 2.6.22. Building Management Systems Outstations and Controllers (i) Location and Environment Equipment shall be suitable for space conditions as follows:- Temperature 0 to 50ºC Relative humidity 10 to 90% non-condensing Air Filtration – none The equipment shall operate satisfactorily in the electrical environment associated with plantroom areas. Equipment shall be protected against the effects of conducted and radiated electrical interference. (ii) Construction All components shall be mounted within a purpose made enclosure incorporating facilities for cooling where necessary. Separately accessible compartments shall provide for: Electric components and communications equipment (this compartment to be separately lockable). AJC 05/07 Section 2.6. / 27 SECTION 2.6. - PANELS, WIRING, AND CONTROLS Relays and field wiring terminations. Electronic components mounted on one or more printed circuit boards shall be arranged in a form suitable for easy replacements. (iii) Terminations Connections to field equipment shall be arranged to avoid excessive force being applied electronic assemblies. To achieve this a field wiring terminal panel or its equivalent shall be included to physically separate wiring between electronic components from the more substantial wiring used for connections to field equipment. Terminal shall be of the screw down clamp type fixed to a purpose made mounting. All terminals shall be provided with a plug or blade disconnection device for test purposes. This device shall only be used for tests requiring circuit isolation. A test point shall be provided at the terminal for checking each part of the circuit. Terminals carrying different voltages shall be segregated in groups in accordance with IEE Regulations. All cables and terminals shall be permanently marked to indicate the respective circuit reference. (iv) Electrical Segregation and Protection All incoming low voltage power cables shall be individually shrouded and labelled: “DANGER” LEAVE TERMINAL ISOLATE AT ………………………………. BEFORE SERVICING AJC 05/07 Section 2.6. / 28 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (v) Interface Port A means shall be provided for the connection of test equipment. A provision shall also be made or the connection of a local printer or bulk memory device. Where peripheral equipment is already connected an additional separate means of connection shall be provided for test equipment. This shall be integral with the outstation and protected to the same standard as the compartment for electronic components. (vi) Power Supply and Battery Back-Up Each outstation shall have an integral power supply with battery back-up. Low voltage actuators directly controlled by the BMS, shall be powered from a power supply located at the outstation. Separate transformers independent to those of the outstation may be provided to power actuators. Fluctuations in power supply shall not affect operation of the outstation. 2.6.23. Cabling (i) General This clause refers to sensor and data transmission cables installed as part of the BMS. Cabling and conduits associated with sensors shall be installed in a manner that prevents the spurious transfer of moisture and temperature etc. from external sources to the sensing device. To reduce the possibility of dampness related problems, cables and conduits should not be laid horizontally at floor or pedestal level. (ii) Cable Types and Application Unless otherwise indicated the types of cable used shall comply with the minimum requirements of the table below: AJC 05/07 Section 2.6. / 29 SECTION 2.6. - PANELS, WIRING, AND CONTROLS Application Cable Types Data transmission between Single or multiple twisted pair cable outstations, central facilities each twisted pair individually screened and other facilities. with braided or sheet metal screen or co-axial cable. Sensor wiring between Single or multiple twisted pair cable outstation and analogue screened with braided or sheet metal input/output devices. screen. Sensor wiring between Single or multiple twisted pair cable outstation and digital or unscreened. pulsed input/output devices. The cables and installations shall comply, as applicable, with the following standards:- Standard Electrical Specification Co-axial cables shall comply with BS 5425 NOTE: The type of cable installed shall in no way prejudice the satisfactory operation of the BMS. The cross-sectional area of the installed cables shall be adequate to ensure that sensor circuit resistance limits are not exceeded. Jointing and termination of the above cable types shall comply with the General Specification. (iii) Screening and Interference Protection Data transmission cables may be installed either in separate steel or UPVC conduit or trunking. Where indicated, steel wire armoured cables may be installed without conduit or trunking. AJC 05/07 Section 2.6. / 30 SECTION 2.6. - PANELS, WIRING, AND CONTROLS Where steel conduit or trunking is not used then separation between data transmission cables or power cable shall not be less than the minimum value given in the table below. Separation shall be selected with respect to either current or voltage. In each instance the greater separation shall apply. Power Cable Minimum Separation Max. Max. (Signal Line to Voltage Operating Power Cable) Current 125V 10A 0.3m 250V 50A 0.45m 500V 100A 0.6m 5000V 800A 1.2m Parallel runs of data transmission cables and power cables shall be avoided wherever possible. (iv) Mechanical Protection Mechanical protection of all BMS cables shall be provided by the use of separate steel or UPVC conduits or trunking as specified earlier. (v) Identification All cables shall have identification sleeves at their terminations which combine the requirements of the IEE Wiring Regulations with specific circuit identification. Identification shall be consistent with the relevant wiring diagrams. “Cross-over” cables for communication between processors and terminal devices shall be marked with an ‘X’ at both ends. AJC 05/07 Section 2.6. / 31 SECTION 2.6. - PANELS, WIRING, AND CONTROLS 2.6.24. Sensors, Detectors and Motors (i) General Connections to sensors shall be by the use of screw down clamp type terminals or self locking spade connectors. Sensors shall be identified with an engraved disc displaying the following information:- a) BMS reference number for sensor. b) Type of sensor, i.e. TEMPERATURE, HUMIDITY, VELOCITY, PRESSURE etc. c) Outstation reference. Sensors in occupied spaces other than plantrooms shall be marked internally with the same information. (ii) Installation and Fixing A commissioning test point shall be located adjacent to or integral with each sensor to facilitate calibration. The test point shall be suitable for the use of test instruments such as a thermometer or pilot-static tube. Sensor fixings shall be purpose made and shall facilitate removal and replacement of the sensor element. All sensor fixings shall give adequate mechanical protection to the sensor. All sensors and transducers shall be properly stored, retaining the original packaging and not removing dust caps until immediately prior to installation. Elements sensing the temperature of a liquid shall be:- a) Provided with a steel or stainless steel pocket to allow withdrawal for servicing and inspection. AJC 05/07 Section 2.6. / 32 SECTION 2.6. - PANELS, WIRING, AND CONTROLS b) Position so that the active part of the element is not less than 12 pipe diameters down stream from a point of mixing. Elements sensing the temperature of gaseous mixtures shall:- a) Be positioned so that the element is not subjected to radiant effects. b) Be positioned to give a representative temperature. c) Be installed on a supporting framework where they are the capillary averaging type. d) Dew points sensors to be positioned such that the air adjacent to the element is known to be saturated. Elements sensing the temperature of a solid surface shall be positioned and fixed so as to give good thermal contact. Elements sensing temperature of a room. Generally the following principles shall apply. a) Position generally where shown on plan, at a height of approximately 1.7m above floor level and at least 0.5m away from any part of the heating system where fitted. b) Positions in the return air path. Elements sensing the temperature of the external air shall be positioned so as to be away from the influence of direct solar radiation. Elements sensing Humidity shall:- a) Be in a representative position in which the humidity is being measured. b) Be positioned such that air velocity is within the recommended AJC 05/07 Section 2.6. / 33 SECTION 2.6. - PANELS, WIRING, AND CONTROLS range required by the sensing element. c) Be arranged to ensure that the air reaching the element is free from airborne contaminants. d) Be arranged to give convenient access for servicing the element. Flow meters for water or steam installation should be installed in pipework having straight lengths of pipe in accordance with the meter manufacturer’s recommendations. Take off points for liquid differential pressure sensors shall be positioned not less than 20 pipe diameters after and more than 5 pipe diameter before any source of turbulence. Pressure sensors and switches shall be fitted with isolating valves or cocks. Photocells shall be fitted in such positions that they can correctly sense the appropriate light sources. (iii) Thermostats Where thermostats are used they shall have no external facility for user adjustment. Liquid expansion type thermostats shall be used for measuring internal room air temperature (-10ºC to +30ºC). Their error shall be less than ±4% of scale span. Vapour expansion type thermostat shall be sued for low temperature air cooling applications (below ±10ºC). Their error shall be less than ±1.5% of scale span. Electronic thermostats shall only be used where a fast response (less than 5 seconds) is required. Their error shall be less than 1% of scale span. All thermostats shall include a volt free contact from which a low voltage status signal can be derived. AJC 05/07 Section 2.6. / 34 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (iv) Temperature Sensors The type, error and range of temperature sensors for any particular applications shall comply with the appropriate requirements of the following table:- Conditions Range (ºC) Accuracy Sensor Type (ºC) PT100 Class A to Air -10 to +30 0.25 BS 1904 or Graded Thermistor replaceable without re-calibration PT 100 Class B to Flue Gas +30 to 850 5.0 BS 1904 or Thermo-couple to BS 4937 PT 100 Class A to Chilled Water -10 to +30 0.25 BS 1904 or Graded thermistor replaceable without calibration PT 100 Class B to Warm Water -10 to +150 1.0 BS 1904 or Graded Thermistor replaceable without calibration Temperature sensor shall not drift more than 0.1K per year. PT100 resistance temperature sensors shall have a hysteresis value of less than 0.05% AJC 05/07 Section 2.6. / 35 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (v) Humidity Sensors Humidity sensors shall:- 1) Not need re-calibration within a period of at least 12 months. 2) Have an error of less than ±5% of the set point. 3) Have an operating range of 10 to 90% RH. 4) Have a response time of less than 30 seconds. 5) Have a hysteresis value of less than +3% of the measurement range. 6) Have a drift not exceeding 5% of the measurement range per year. 7) Have a useful life span of not less than 3 years. (vi) Enthalpy Sensors Enthalpy sensors consisting of temperatures and humidity sensors shall comply with the requirements of the above clauses for temperature and humidity sensors. (vii) Exhaust Gas Analysers Exhaust gas analysers shall:- 1) Measure either oxygen, carbon dioxide or carbon monoxide concentrations as indicated. 2) Have an error less than 2% of their measuring range. 3) Have a cell or sensor life of at least 12 months. AJC 05/07 Section 2.6. / 36 SECTION 2.6. - PANELS, WIRING, AND CONTROLS They shall comply with BS 1756, Parts 1 to 5 inclusive, BS 3156 and BS 3048 (As appropriate). In addition infra-red absorption gas analysers shall comply with BS 4314. Have a response time less than or equal to 90% of sensed variable value in 20 seconds. Have a long term drift of less than 10% per year. (viii) Fuel Flow Meters and Velocity Sensors The type of flow meters to be used for particular application shall be as given below:- Fuel Type Type of Meter Gas at flow rates or up Diaphragm/bellows positive 3 to 25 m /h displacement flow meter to BS 4161, Part 5 Gas at flow rates of 25 Rotary positive displacement 3 to 600 m /h and fuel oils flow meters to BS 4161, to Class E, F, G & H Part 6 for gas. 3 (BS 2869) up to 25 m /h Gas at flow rates of over Turbine flow meters to 600 m3/h and fuel oils BS 4161, Part 6 for gas. to Class A2, C1, C2 & D (BS 2869) AJC 05/07 Section 2.6. / 37 SECTION 2.6. - PANELS, WIRING, AND CONTROLS All flow meters shall have a pulsed output frequency to suit the BMS interface that instantaneous consumption rates as well as total consumption can be calculated. The error of flow meters shall be equal to or less than ± 3% of the measured flow rate for all flows greater than 10% of the maximum flow rate of the meter. (ix) Water and Steam Flow Meters Flow meter shall be of vortex shedding or electromagnetic type. Flow meters shall have an error of less than ± 1% of the measured flow rate for all flows greater than 5% of the maximum flow rate for the meter. Flow meters shall have a turn down of 15:1 or greater. The response time of the flow meter shall be less than 6 seconds. The repeatability of flow meter shall be +0.1 to +0.5% of flow rate. (x) Air Flow Meters and Air Velocity Sensors Pitot tube air flow meters shall comply with BS 1042, Part 2.1 and have an error equal to or less than ± 5% of full scale deflection. Air velocity sensors shall:- 1) Have an error equal to or less than ± 2% of the measured flow rate. 2) Have a repeatability error equal to or less than ± 0.1% of the measured rate. Sensors shall be mounted in a straight length of ducting in accordance with the manufacturer’s recommendations. AJC 05/07 Section 2.6. / 38 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (xi) Pressure Sensors and Switches Pressure sensors shall be of the diaphragm or capsule type. Sensing elements shall be either strain gauges or linear variable differential transformer type. Pressure sensors shall:- 1) Have an error of less than ± 2% of the variable sensed value. 2) Have a response time equal to or less than 200 milliseconds. 3) Have a hysteresis value of less than 0.4% of measurement range. 4) Have a repeatability error of less than 0.25% of the measured variable. Pressure switched shall be of the diaphragm type incorporating internal protection against over pressure. All pressure shall include a volt free contact form which a low voltage static signal can be derived. Pressure switched shall have the same measurement area, response, hysteresis and repeatability as described for pressure sensors. AJC 05/07 Section 2.6. / 39 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (xii) Boiler Water Quality Analysers Boiler water analysers shall comply with the minimum requirements set out in the following table:- Items Measurement of Measurement Measurement of pH of Dissolved Total Dissolved Oxygen Solids (Tds) in Water Type of pH Electrode Electrochemical Conductivity Sensor Cells measuring Relevant BS 2586 - BS 1427 Standards Accuracy ± 1% of scale ± 5% on 200 ± 2% of reading parts per million range Minimum ± 0.01 pH 1% of full scale 0.1 micro- Sensitivity second/cm reading shall respond to 0.10 mg/litre of oxygen Response 90% in 10 sec 90% in 60 sec - Time Repeatability ± 0.02 pH 2% of full scale - Long Term ± 0.25% of 1 ppm in 30 - Drift span/month days Operating 0 to 15 pH 0.15 mg/litre 0.1000 micro Range second/cm AJC 05/07 Section 2.6. / 40 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (xiii) Air Quality Sensors By using sensing devices which respond to particular gases and/or gaseous mixtures an indication of room air quality shall be obtained. Carbon dioxide sensors shall:- (a) Have an operating range equal to or greater than 0 to 5~% concentration by volume. (b) Have a minimum period between calibration of at least 3 months. (c) Have a drift of less than 10% of the measured variable per year. (d) Have a response time equal to or less than 90% of the sensed variable value in 10 seconds. Other air quality sensors shall have an operating range, re-calibration time, drift and response time, similar to that for the carbon dioxide sensor described above. (xiv) Light Sensors Light sensors shall use photo conductive or photovoltaic cells. Unless otherwise indicated the operating range of light sensors in the visible light band. Shall be as follows:- 1) Internal 0-1000 lux 2) External (Security Lighting) 0-100 lux 3) External (Daylight) 1000-30,000 lux AJC 05/07 Section 2.6. / 41 SECTION 2.6. - PANELS, WIRING, AND CONTROLS The output of the light sensor and its amplifier where fitted, shall not deviate more than 5% from the visible light spectral response curve. The light sensor enclosure shall be constructed of a translucent material. Externally mounted sensors shall be water tight. Where a linearization amplifier is required at the sensor, it shall be incorporated in the same package and enclosed to the same standard as the sensor. (xv) Occupancy Sensors Occupancy sensors shall be of the wall mounted type having the following features:- 1) A horizontal angle of coverage of 90º and a vertical angle of coverage of 45º. 2) A sensing range equal to or greater than 8 metres. 3) A user definable “switch on” delay of up to 3 minutes, and “switch off” delay of up to 10 minutes. (xvi) Electricity Meters Electrical meters shall comply with the relevant parts of BS 5685, BS 5164 and BS 89 (as appropriate). The electrical parameters to be metres shall be as described in the Particular Specification. The measurement error shall not exceed ±1.5%. 2.6.25. Generic System Performance Descriptions This Section of the Specification gives details of the outline control requirements and specific technical parameters for typical mechanical building services arrangements. AJC 05/07 Section 2.6. / 42 SECTION 2.6. - PANELS, WIRING, AND CONTROLS 184.108.40.206. LTHW System The LTHW System will generally comprise of the following items:- Control Valves HTHW Calorifier Primary LTHW Pumps Secondary LTHW Pumps CT Secondary LTHW Pumps VT Pressurisation Unit Primary Heating Pumps These pumps are to be started and stopped on a fixed time basis. These pumps will also be enabled should any of the Frost routines be initiated. Pumps will have a run on time assigned for heat dissipation. Alarms will be raised under the following conditions:- a) Failure of lead pumps b) Failure of lag pumps c) Temperature (Flow temp greater than 90º C, Flow temp less than 10ºC) Main Heating Valves The Main Heating control valves will operate a ‘Two Position’ control schedule. End switches on each valve are to provide position ‘open’ ‘close’ to the BMS. Control and monitoring of these valves is to be provided by the existing/new Excel controller located in the plantroom. AJC 05/07 Section 2.6. / 43 SECTION 2.6. - PANELS, WIRING, AND CONTROLS LTHW Secondary Heating Pumps (VT) Compensated System The compensated radiator heating system shall be enabled via an optimum start and stop programme using a time schedule as selected by the user. Outside air temperature and space temperature sensor(s) shall be used for reset facilities. The calculated flow set point temperature shall be used to modulate the three port control valve to maintain the correct flow temperature at the flow sensor. The following safety features shall be incorporated within the system:- (i) The VT control valve shall only operate and control if the water flow has been proven utilising the pressure differential switch. (ii) Frost and condensation protection if the space temperature falls below 10ºC. The duty pump shall be not be started until the space temperature has risen by at least 2ºC above the set point. Alarms will be raised under the following conditions:- a) Failure of lead pump b) Failure of lag pump c) Temperature (Flow temp greater than 90ºC, Flow temp less than 10ºC) Underfloor Compensated Heating System The under floor heating system shall be enabled by an optimum start and stop arrangement utilising a time schedule programme. A calculated set point of flow temperature shall be dependant upon outside air temperature. The calculated flow set point temperature shall be used to modulate the three port control valve to achieve a maximum temperature of 45ºC. The following safety features shall be incorporated within the system:- AJC 05/07 Section 2.6. / 44 SECTION 2.6. - PANELS, WIRING, AND CONTROLS 1) The VT control valve shall only operate and control if the water flow has been proven utilising the pressure differential switch. 2) Frost and condensation protection if the space temperature falls below 10ºC (user adjustable). The duty pump shall be started until the space temperature has risen by at least 2ºC (user adjustable) above the set point. 3) A safety direct acting high limit valve shall be provided, such as to protect the under floor pipework etc, in the event of failure of the control valve. This is to ensure that the flow temperature does not exceed 45ºC. Should the high limit valve be activated this shall be monitored by the BMS to generate an alarm. The function shall be manual reset. 220.127.116.11. Chilled Water System Pumps The Chilled Water system shall generally comprise the following items: Chiller CHW Pumps Pressurisation Unit Control Valves The CHW pumps are to be started and stopped on a fixed time basis. These pumps will also be enabled should any of the Frost routines be initiated. Chiller to be energised following successful CHW water flow being detected. Alarms will be raised under the following conditions:- a) Failure of lead pump b) Failure of lag pump c) Temperature d) Chiller Common fault AJC 05/07 Section 2.6. / 45 SECTION 2.6. - PANELS, WIRING, AND CONTROLS 18.104.22.168. Air Handling Units The following describes the mode of operation of the above plant. The air handling plant serves one discreet zone in with respect to time scheduling requirements. Each time schedule will be agreed with the Client prior to commissioning. The air handling plant shall be a constant discharge temperature arrangement with sequential control of the Dampers, Pre-heat coil, reheat and CHW coils to satisfy the downstream constant temperature demand. An economiser cycle will control the dampers for Summer/Winter operation switching the dampers from modulation to minimum position, the intention being to reduce the load on the cooling coil. The economiser decision does not enable or disable the chiller, this will enable anytime CHW valves open. Outside Air (OA) is used for free cooling (to supplement the CHW system) anytime the OA enthalpy is below the economiser setpoint. OA enthalpy considers total heat and will take advantage of warm low enthalpy OA and will block out moist OA. During commissioning the minimum fresh air damper position shall be set up in conjunction with the Mechanical engineer. For normal off conditions both the supply and extract drives shall be stopped. All control valves will be at closed position. The inlet and outlet dampers shall be motorised closed. Normal frost protection via the primary heating medium shall still be available if required. Room Sensors located in all areas will provide an average temperature input to the AHU control sequence. The system components shall be as described within the BMS points. AJC 05/07 Section 2.6. / 46 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (i) Inlet And Exhaust Air Damper Arrangements The dampers shall be closed during a shutdown period. The dampers shall open when the BMS signals a plant operation to commence. When each damper reaches the fully open position a damper end switch shall be made to signal to the BMS that the damper is open, thus allowing the fan to start. Should the damper end switch fail to operate the fan shall be held off and an alarm given. The dampers shall be closed whenever a fan fail signal is received, Or a Normal OFF is commanded by the BMS. (ii) Low Pressure AHU Heating Coils The low-pressure hot water modulating valves to the heating coil shall be positioned in the closed mode condition when the plant is not operational. The frost, cooling, pre-heat and reheat coils shall all be sequentially controlled for energy efficiency. (iii) Cooling Coils The operation of the cooling coil shall be sequenced in relation to the other components of the air handling unit. Maximum benefit shall be taken from utilising free cooling from the fresh air. To achieve the discharge temperature from the supply air handling unit the cooling coil shall modulate the 3 port valve to achieve the required output. No air handling unit within the new development requires relative humidity regulation control therefore, all air handling plants shall be sequentially operated to regulate temperature accordingly. The chilled water modulating valve shall be positioned to the closed position when the cooling plant shutdown signal is received. The chilled water cooling valve shall modulate to the fully open position during a shutdown period when a below ambient temperature is received. All for frost protection purposes. No action shall be taken when the air plant is operational and the BMS signals a low outside temperature exists. AJC 05/07 Section 2.6. / 47 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (iv) Constant Volume Supply Fans The supply fan shall be disabled when the BMS signals a shutdown period. The supply fan shall operate at constant speed to provide air at the design volume. When the BMS signals for the air handling plant (or fan) to operate the supply fan when used in conjunction with a respective exhaust fan and heat recovery device shall not function the same are fully operating under the dictates of the BMS system. The operation of the supply fan shall be proven utilising a pressure differential switch. When the proven signal is not achieved, following a 30 second (adjustable) start up period, a fan failure warning signal shall be sent to the BMS and the fan operation signal shall be removed. The fan operation signal shall be disabled when a freeze thermostat incorporated in the system has tripped. A hand/off/auto selector switch shall be located on the MCC to serve the fan. The supply fan motor(s) shall be hard wired to the selector switch and to the extract fan failure (where appropriate) and to the damper proving end switches etc. (v) Constant Volume Extract Fan The fan operational signal shall be disabled if a supply fan (where appropriate) fail signal is achieved by the BMS. The extract fan shall be disabled when the BMS signals a shutdown period. The fan shall operate at a constant speed to achieve the design air volume when the BMS signals for the plant to operate. The fan operation shall be proven utilising pressure differential switch. When the proven signal is not achieved, following a 30 second (adjustable) start up period, a fan failure warning signal shall be sent to the BMS and the fan operation signal shall be removed. Should the extract fan have an associated supply fan these shall be interlocked so that they operate in unison? The hand/off/auto selector switch shall be located on the motor control centre. The extract fan motor shall be hard wired to this selector switch, (and the supply fan where appropriate). AJC 05/07 Section 2.6. / 48 SECTION 2.6. - PANELS, WIRING, AND CONTROLS (vi) Filtration Media The BMS shall monitor the cleanliness of all filters associated with the air handling systems and that described for the containment suite. This shall be achieved using pressure differential switches. The controls and commissioning specialist shall liaise with one another to ensure that all pressure differential switches are set up in accordance with a filter media manufacturers recommendations. 22.214.171.124. Stand Alone Cooling Units The data hub room shall be served by independent direct expansion split cooling units to maintain reasonable comfort temperatures etc. The power feeds to serve these systems shall be derived from a local distribution board. 126.96.36.199. Pump Sets (Generally) Run and standby pump sets shall be activated should there be a demand signal present from any downstream system. Upon activation of any pump set the flow shall be verified using a pressure differential switch prior to the enabling of any downstream secondary system. Failure to detect a flow shall result in an alarm being generated on the BMS and on the MCC lamp indication display. This sensor shall be continually monitored throughout the pump operation period. Where pump sets consist of run and standby units, these shall also be provided with auto changeover arrangements. Pump failure is monitored using a pressure differential switch (I per set). Weekly duty pump rotation shall be provided (BMS dictated) by software activation. During the start up of a pump set the signal from the pressure differential switch shall be ignored to prevent nuisance alarms. 188.8.131.52. Optimum Start Control When a circuit is under an optimum start programme then the system shall calculate the plant initiation time to achieve the required occupancy start time. This plant initiation time shall be based upon trended external ambient AJC 05/07 Section 2.6. / 49 SECTION 2.6. - PANELS, WIRING, AND CONTROLS temperature data prior to the day of operation and shall be continually adjusting itself to adapt to the changing seasonal conditions. Corrections to the pre-heat time shall be made should the set points not be achieved for the required occupancy time. The programme shall be self learning. 184.108.40.206. Night Purge The night purge uses cool, night outside air to pre-cool the spaces before mechanical cooling is turned on. Outside temperature. Outside RH or dewpoint and space temperature are all analyzed. 100% OA is admitted under the following conditions. OA > Summer/Winter changeover point. OA < Space temperature by a specified RH or determined differential. OA dewpoint < 16ºC. Space temperature above some minimum for night purge. 220.127.116.11. Compensated Control Following the preheat cycle when all circuits are at their maximum design set points, the compensated circuits shall schedule the flow temperature inversely proportional to the ambient outside air temperature. In addition, the BMS shall monitor the air temperature (averaging) sensors within the spaces served by the VT system. This averaged signal shall be sued as a feed back signal to reset the compensated flow temperature. AJC 05/07 Section 2.6. / 50 SECTION 2.6. - PANELS, WIRING, AND CONTROLS 18.104.22.168. LPHW Systems – General The VT system shall be allocated a time schedule to allow the user to vary the occupancy times. Variable Description Value Primary LPHW flow temperature 70ºC (max) Primary LPHW return temperature 40ºC – AHU heating coils 50ºC – Fan Coil Unit/VT Circuits Variable temperature radiator circuit flow temperature 70ºC to 20ºC Underfloor heating flow temperature 45ºC Underfloor heating return temperature 40ºC Concrete soffit slab temperature (night set back) 18ºC (adjustable) Frost protection activated 3ºC and below Lowest external ambient Minus 5ºC temperature Variable temperature circuit set points for optimum start 20ºC programmes AJC 05/07 Section 2.6. / 51 SECTION 2.6. - PANELS, WIRING, AND CONTROLS Each heating system shall have a ‘night set back’ facility so that a minimum air temperature shall be maintained to minimise deterioration of its finishes and optimise pre-heat periods. This function shall be user adjustable. Frost protection shall be provided by the following means:- Stage 1: Outside air temperature: Plus 3ºC System action: Activate all pump circuits and open all valves. LTHW All plant associated with the primary LTHW system shall derive their power from the motor control centres. Upon receipt of a demand signal from any plant outstations, the respective system shall function. Plant operation shall continue until or demand signals have been de-energised. LPHW – Safety and Maintenance features i. Lead pump operation shall be rotated to ensure even wear. ii. Pump operating hours shall be trend logged to assist the Clients maintenance programme. iii. Each item of plant shall have an event register, in that the alarms associated for each piece of equipment shall be logged stating the date and time of each alarm. This shall allow the user to record a history of plant failure. iv. Upon the receipt of a plant shut down signal, the sequence of operation shall be the reverse of that described for start up. v. Upon loss of power all controls contactors and relays shall return AJC 05/07 Section 2.6. / 52 SECTION 2.6. - PANELS, WIRING, AND CONTROLS to the off conditions. When power is reinstated all peripheral plant shall be automatically reset ready to operate. vi. Should the external ambient temperature fall below three degrees centigrade all pumping circuits shall be activated sequentially as a frost protection measure? vii. All pumps shall be run for a fixed period each week (say 5 minutes) to ensure lubrication of bearings and prevent seizure of moving parts. This function shall be extended to all valve and damper activators. Care should be taken that when this maintenance procedure is carried out that it is not detrimental to the controlled environmental conditions and the plant itself i.e. to be carried out outside normal operating periods. 22.214.171.124. Chilled Water System The operation and function of any chilled water pump set shall be identical as that described for the LTHW systems. The system set points shall be derived at commissioning. All plant associated with the chilled water system shall derive their power/control from the respective motor control centre. Chilled Water Systems – Safety and Maintenance Features i. Lead pump operation shall be rotated to ensure even wear. ii. Pump operating hours shall be trend logged to assist the Clients maintenance programme. iii. Each item of plant shall have an event register, in that the alarms associated for each piece of equipment shall be logged stating the date and time of each alarm. This shall allow the user to record a history of plant failure. iv. Upon loss of power all controls contactors and relays shall revert AJC 05/07 Section 2.6. / 53 SECTION 2.6. - PANELS, WIRING, AND CONTROLS to the off condition. Once the pumps are stopped the control valves within the system shall revert to the closed position. v. All pumps shall be run for a fixed period each week (say 5 minutes) to ensure lubrication of bearings and prevent seizure of moving parts. This function shall be extended to all valve and damper activators. Care should be taken when this maintenance procedure is carried out that it is not detrimental to the controlled environmental conditions and the plant itself i.e. to be carried out outside normal operating periods. 126.96.36.199. Power Feeds to the Air Handling Unit Lighting The bulkhead lighting within each air handling unit shall be powered from the motor control centre. The individual circuits shall be provided to serve the respective air handling units. Reference shall be made to the ventilation section of this specification to ascertain the interfacing necessary. 188.8.131.52. Fire Alarms When a fire alarm is received by the control panels (hard wired), all plant shall be stopped except:- There shall be a fire alarm override switch located on each main control panel which when in the ‘Test Position’ shall enable the buildings fire alarm system to be tested without stopping any item of plant. When in this test position an alarm is raised to both the respective panel (lamp) and to the remote site terminals until the switch is placed back into the ‘Normal’ mode of operation. If the fire alarm results in any of the duty plant failing and the standby plant starting on a ‘Return to Normal mode’ all items of plant shall receive a ‘Reset’ command to return the duty item of plant back to the lead item. A manual reset switch is also fitted on the panel to perform the above ‘Reset’ command in the event of plant failure. AJC 05/07 Section 2.6. / 54 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK 2.7.1 General ......................................................................................................1 2.7.2 Programme ................................................................................................1 2.7.3 Information .................................................................................................1 2.7.4 Fuel for Testing ..........................................................................................2 2.7.5 Test Instruments.........................................................................................2 2.7.6 Commissioning Standards..........................................................................2 2.7.7 Testing .......................................................................................................3 2.7.8 Specialist Systems and Equipment ............................................................5 2.7.9 Failure under Test ......................................................................................6 2.7.10 Cleansing ...................................................................................................6 2.7.11 Purging.......................................................................................................9 2.7.12 Ductwork Cleaning .....................................................................................9 2.7.13 Water Treatment ........................................................................................9 2.7.14 Water Softening .......................................................................................11 2.7.15 Chlorination..............................................................................................11 2.7.16 Tabulation of Results................................................................................12 2.7.17 Setting to Work.........................................................................................12 2.7.18 Operational Tests.....................................................................................12 2.7.19 Instructions on Completion .......................................................................13 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK 2.7.1 General This section outlines overall procedures for balancing, commissioning, and setting to work of various standard types of system and equipment, together with the preferred methods of recording the results of such operations for inclusion in the Operating and Maintenance instruction described in Section 2.1. Notwithstanding the recommendations of the following clauses, it is recognised that all projects present separate individual difficulties and for this reason the Sub-Contractors’ proposals for balancing, commissioning and setting to work of the project works shall be discussed with and agreed by the Engineer prior to commencing such work. This shall apply particularly to procedures for specialist systems, services and equipment not specifically detailed in the following clauses. 2.7.2 Programme The Sub-Contractor shall be responsible for co-ordinating his commissioning works with both the Main Contractor and other trades on site, including also his own Sub-Contractors and specialist suppliers, in order to ensure that his entire works are complete and proven to the satisfaction of the Engineer by the handover date given in the overall contract programme. In this respect, the Engineer shall be notified in advance of the commissioning programme to allow him adequate time to arrange all site visits necessary to inspect, witness and approve the works. Failure to give such notice to the Engineer may result in the tests, etc. having to be repeated at his convenience and all responsibility for additional costs, charges and delays to Contract shall rest with the Sub-Contractor. 2.7.3 Information Should the Sub-Contractor require any design information additional to that given in the Particular Specification and drawings, this shall be requested from the Engineer no less than four weeks prior to the programmed start date for the commissioning work. AJC 05/07 Section 2.7. / 1 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK No delays to contract on the grounds of lack of design information will be allowed. 2.7.4 Fuel for Testing Except when detailed otherwise in the Particular Specification, any fuel, water and electricity reasonably required for testing and commissioning purposes shall be free of charge to the Sub-Contractor. If in the opinion of the Engineer, however, the Sub-Contractor consumes inordinate amounts of fuel, water or electricity during testing and commissioning, or is required to repeat tests and demonstrations due to faulty workmanship or negligence on his part, then the nett cost of such additional or wasted fuel, water or electricity shall be deducted from his Final Account in order to limit the liability of the Employer in this respect. 2.7.5 Test Instruments All instruments and equipment necessary for the proper testing, balancing, commissioning and witness testing of the works shall be provided free of charge by the Sub-Contractor. The particular type, size, rating and quantity of the instruments required shall be agreed with the Engineer prior to commencing this work, but shall in all cases be appropriate to the type of installation. Instruments shall be kept available on site until the various witness tests have been completed to the satisfaction of the Engineer. 2.7.6 Commissioning Standards Commissioning of all installations incorporated into the works under this section of the Specification shall be carried out by professionally fully experienced commissioning Engineers. Where specialist suppliers have been specified commissioning of their relevant installation may be carried out by their own Engineers. AJC 05/07 Section 2.7. / 2 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK Commissioning shall generally take place in compliance with the following commissioning codes issued by the C.I.B.S.E. and BSRIA: Series A - Air Distribution Systems. Series B - Boiler Plant. Series C - Automatic Control Systems. Series R - Refrigerating Systems. Series W - Water Distribution Systems. AG 1/2001 AG 2/89.3 AG 3/89.3 AG 20/95 All necessary test points, test holes, commissioning devices, etc. shall be incorporated into the works during installation to enable full and successful commissioning to take place. Any possible future claim for the inclusion of test points, etc. for any reason whatsoever will not be entertained. ‘Plumbing’ systems will be checked to ensure that adequate flow rates are obtained at ranges of outlets with all outlets open, WC’s flush satisfactorily, etc. Motor control centres and control panels will be fully tested on site on completion of the installation whether or not these have been tested at works. This will ensure that all field supplied items such as flow switches, pressure switches, etc. are operating correctly and that the field wiring is corrected installed. 2.7.7 Testing On completion of each installation or service or sections of such installations or services, all necessary tests shall be carried out to the pressures listed below. No part of the works shall be insulated or rendered inaccessible prior to successful completion of testing to the satisfaction of the Engineer. This may entail testing in sub-sections of each of the installations installed and all associated costs to allow this to occur shall be AJC 05/07 Section 2.7. / 3 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK deemed to be incorporated and form part of the Contract. (a) Plant and Equipment Manufacturer’s certificates of tests for all items of plant and equipment shall be provided by the Contractor. (b) Pipework (i) Heating, Chilled Water, and Condenser Water 7.0 bar or twice the working head whichever is the greater hydraulically for 30 minutes for all screwed pipework. 7.0 bar or twice the working head whichever is the greater hydraulically for 1 hour for all welded pipework with simultaneous hammer testing of joints. (ii) H.W.S and T.C.W.S. 3.5 bar or twice the working head whichever is the greater hydraulically for 30 minutes. (iii) M.C.W.S. All external mains shall be pressure tested to 14.0 bar hydraulically for 30 minutes. This test shall be carried out by the Contractor and witnessed by the Water Department’s inspector prior to backfilling of any trenches. 0.7 bar hydraulically for 30 minutes for internal mains. (iv) Gas 30millibar for 30 minutes or 11- times mains pressure, whichever is the greater. This test shall be carried out AJC 05/07 Section 2.7. / 4 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK to B.S. CP331 and to the entire satisfaction of the representative of the Local Gas Board who shall also be called upon to witness all tests on gas mains. (v) Sanitary Pipework Air test equal to 65mm water gauge. Prior to commencing air tests all water seals on all sanitary appliances and floor gullies must be fully charged with water and all open ends of pipework, i.e. vents and outfalls must be adequately plugged. Water tests may be called for but will only apply to horizontal runs of plumbing and drainage pipework and/or the section of drainage pipework below the lowest sanitary appliance. (vi) Ductwork All ductwork shall be tested upon completion, either as a whole, or in sections if required to enable progress to be maintained. This clause shall apply to all ductwork, both high and low velocity, and shall be in accordance with DW/144. All test holes in ductwork utilised for testing and balancing shall be fitted with air tight, removable plugs. 2.7.8 Specialist Systems and Equipment Where appropriate or where instructed by the Engineer, the Sub-Contractor shall arrange for specialist systems and/or equipment to be commissioned by the particular manufacturer, manufacturer’s agent or contractor involved in the supply and installation of such items. This section would generally include items such as automatic controls, coal handling plant, incinerators, autoclaves, water treatment plant, cooling towers, etc. AJC 05/07 Section 2.7. / 5 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK The foregoing list is not intended to be comprehensive or exclusive and, again, commissioning arrangements must be discussed and agreed with the Engineer prior to starting work. It shall be the Sub-Contractor’s responsibility to ensure that all specialised suppliers are aware of their obligations in respect of providing a commissioning service and of submitting their results for approval in an agreed form, and also to ensure that such specialists co-ordinate and complete their work in accordance with the overall contract programme. 2.7.9 Failure under Test Should any section of the works on test not conform to this section of the Specification the Contractor must carry out all remedial work as necessary at his own expense to ensure the installations ultimately do so conform. If the Contractor fails to do so within a period of time not exceeding seven days the Engineer shall call upon the Contractor to remove all sections of the works where test results cannot successfully be achieved and reinstate the whole of the section at no additional cost to the Contract. Alternatively, the Engineer reserves the right on behalf of the Client to instruct via the Main Contractor other parties to rectify the defective work. Should this occur then all direct and indirect costs associated in making good defective work shall be deducted from the Contractor’s interim valuations and subsequently be offset against his final account. 2.7.10 Cleansing After the pipework systems have been hydraulically pressure tested cleansing shall take place, being carried out in four main stages: (i) Pre-Flushing All riser drains, dirt pockets and coarse filters on pumps etc. shall be removed and cleaned. All sensitive equipment such as A.H.U.’s, Chiller Units, Condensers, AJC 05/07 Section 2.7. / 6 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK Boilers, and Multi-Directional control valves shall be isolated or by- passed. Where appropriate sufficient temporary loops must be installed to ensure pipework distribution runs can be circulated and flushed during the cleaning programme. This is to prevent large particle size deposits causing restriction of flow or blockages. Valved stabbings shall be required immediately downstream from the main system pumps on the flow and return headers. Strainers should remain in situ to filter out released deposits and sediment. System must be fully filled and vented. This system pumps must be able to provide good flow rates and suitable drain available to dispose of effluent. After flushing has commenced, strainers are to be removed for cleaning periodically to ensure maximum flow rates. Continuous monitoring of the discharge water shall be carried out to test for suspended solids and dissolved iron. Pre-flushing shall be regarded as complete when the strainers are found to be remaining clean and satisfactory tests obtained for dissolved iron levels. Note: It may be necessary to isolate parts of the system in sequence to ensure thorough flushing. (ii) Chemical Cleaning (Non-Acidic) This shall be carried out to remove light surface rust, grease, and oil. It will also assist in dislodging adhering welding slag. Chemical cleaning shall be carried out using external pump and tank as a dosing point. Testing shall be carried out during cleaning from various points in the system to ensure full mixing of the chemical AJC 05/07 Section 2.7. / 7 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK solution and assess the effectiveness. Iron levels shall be monitored until cleaning is complete. Strainers shall also be removed and cleaned during this stage. (iii) High Velocity Flushing This shall be achieved by use of external pumps and tanks to ensure velocities of 3 metres/second are obtained in long horizontal runs. Pressure gauges shall be fitted on the external pump to ensure that over-pressurisation does not occur, and that flow and returns can be balanced. The external temporary high velocity pump and tank shall be set up with the delivery pipe connected to the system flow and return discharge to a suitable drain. Flow rates shall be checked throughout each system using an external meter. Continue as for initial flushing until all checks indicate a clean system with no residual cleaning chemicals and very low iron residuals. Sensitive equipment previously isolated can now be put back on-line and flushed separately before reconnecting and all temporary by- passes removed. All units must be flushed before being put on-line, as it cannot be assumed that they contain clean water. (iii) Chemical Treatment Addition (a) The corrosion inhibitor to be used shall be added in the external pump and tank or by use of the dosing pot (if installed). (b) The recirculating system pumps shall be used to completely mix the treatment throughout the system. AJC 05/07 Section 2.7. / 8 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK (c) Tests shall be carried out to ensure that treatment levels are to Treatment Supplier’s recommendations. (d) The system shall be vented to ensure complete filling and final samples taken for record purposes and laboratory tests. 2.7.11 Purging All gas outlet supplies shall be nitrogen purged in accordance with the Gas Safety (Installation and Use) Regulations. 2.7.12 Ductwork Cleaning All ductwork shall be supplied, stored, and installed on site in accordance with DW/TM2 – Guide to Good Practice – Internal Cleanliness of New Ductwork installations. The level of cleanliness for all ductwork systems unless indicated otherwise in Section Three shall be to Intermediate Level. If this minimum standard is not met the Contractor shall be instructed to clean the whole of the ductwork installations at no cost to the Contract. 2.7.13 Water Treatment (a) General Fully automatic water treatment systems shall be provided for the addition and control of chemicals to the system provided. All equipment, water treatment chemicals, testing equipment and service shall be provided by a single company, to ensure system compatibility, with accreditation with B.S.I. for BS 5750, Quality Assurance. All necessary piping, fittings, valves and labour for installation and commissioning shall be provided together with one year’s supply of AJC 05/07 Section 2.7. / 9 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK chemicals. Testing equipment shall be provided for determining treatment levels. A service programme and contract shall be provided for one year from initial start-up to ensure proper selection, application and control of the water management programme including training of operating personnel on necessary chemical handling, feeding and control techniques. (b) Heating and Chilled Water Systems Conductivity control shall be provided utilising controller, conductivity cell, dosing pump mounted on a chemical solution tank set complete with low level switch. For hot water heating systems, a sample cooler shall be supplied to meet Health and Safety Regulations. The chemicals shall comply with all local and National Water Authority Regulations and have the necessary Health and Safety information on the container label. (c) Cooling Water Systems Cooling water systems shall be provided with a water meter/conductivity controller dosing and bleed system utilising controller, contact head water meter, inhibitor pump, chemical solution tank, low level switch, conductivity cell, and bleed off line arrangement. Organic fouling shall be prevented utilising two chemically dissimilar biocides, controller, dosing pumps, and solution tanks with low level switches. The chemicals shall comply with all local and national Water Authority Regulations and have the necessary handling and safety information on the container label. AJC 05/07 Section 2.7. / 10 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK 2.7.14 Water Softening Water softening shall be achieved by means of a base exchange softener. The unit shall comprise softener tank, brine tank, contact lead with water meter and booster pump for re-generation. 2.7.15 Chlorination The hot and cold water services supply installations shall be chlorinated prior to setting to work. Storage tanks and pipework shall be flushed through to remove all deposits then re-filled and the make-up supply isolated. The tank water shall be chlorinated and left for at least one hour to give a measured free chlorine level of at least 50 p.p.m. in the water. Each draw-off fitting should be successively opened, working away from the tank, and should be closed when the discharging water begins to smell of chlorine. The tank must not be allowed to empty and must be re-filled and chlorinated as necessary. The system shall remain charged for a further one hour. Re-check the free chlorine level and if less than 30 p.p.m. the process must be repeated. The system should now remain charged for a further 16 hours and then thoroughly flushed out with clean water until the free chlorine level is no greater than that of the incoming mains supply. During the chlorination process, suitable DANGER hazard warning notices must be attached to all outlets. Calorifiers should be valved off. AJC 05/07 Section 2.7. / 11 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK 2.7.16 Tabulation of Results Certificates of tests for all plant or materials tested at the maker’s works shall be furnished by the Contractor to the Engineer. Performance test data for all items of plant and equipment will also be required. All tests carried out on site shall be ultimately witnessed by the Engineer or his representative and these tests properly recorded. All commissioning figures will also be required to be recorded and tabulated. This shall include all control set points, valve and damper positions etc. The manner in which the test, commissioning and performance figures are recorded shall be agreed with the Engineer at least four weeks prior to the commencement of any tests or commissioning. Within a period of seven days immediately after the successful completion of any testing or commissioning duplicate copies of test certificates and tabulated commissioning figures shall be forwarded to the Engineer. Upon finalisation of the Contract and immediately prior to handover all approved test, commissioning and performance sheets shall be incorporated into the owners maintenance and operating manuals called for under this Specification. 2.7.17 Setting to Work The Contractor shall include for setting to work after testing all items of plant and equipment installed under this Contract. The relevant manufacturer of all major items of equipment will be called upon to be present during the initial starting of any specialist item. 2.7.18 Operational Tests Following satisfactory commissioning of the works, the completed installation shall be operated under normal working conditions (as far as practical) for a period of five working days, during which time records shall be kept of the overall performance of the installation e.g. temperatures AJC 05/07 Section 2.7. / 12 SECTION 2.7. - TESTING, COMMISSIONING AND SETTING TO WORK achieved, any faults or failures noted and corrected, etc. Should any serious defects or failures occur during this period, they shall be corrected and the operational tests repeated until a complete five day period of operation is achieved without such problems, and the issue of a Certificate of Practical Completion will not be considered until such trouble- free operation has been demonstrated. 2.7.19 Instructions on Completion During the operational tests or at some other mutually convenient date prior to Handover, the Sub-Contractor shall instruct the nominated representative(s) of the Employer in the correct and efficient use of the completed installation, systems, and equipment, all in accordance with the O and M instructions issued for the project and including, where applicable, advice and demonstrations on simple fault finding, maintenance and repair. Where specialist systems and equipment are installed as part of the works, the Sub-Contractor shall arrange for such instructions to be given by the specialist supplier or contractor at no additional cost to contract. AJC 05/07 Section 2.7. / 13 SECTION 2.8. – THERMAL INSULATION 2.8.1. General.......................................................................................................1 2.8.2 Hot Water and Steam Systems ..................................................................3 2.8.3 Chilled and Cold Water Systems ................................................................8 2.8.4 Warm Air Ductwork Insulation ..................................................................13 SECTION 2.8. – THERMAL INSULATION 2.8.1. General The whole of the thermal insulation works shall be carried out in strict accordance with BS 5970, 1981 and BS 5422, 1990 for Thermal Insulation or whichever British Standard is relevant at the time the works are being carried out. a) Protection The Insulation Contractor shall be responsible for the protection of all completed work, existing work and surrounding structures and equipment during the completion of the Contract. Normally plastic sheeting is acceptable but where work is being carried out over specialist equipment, e.g. control panels, the Contractor is to allow for the provision of plywood sheeting. b) Scaffolding The Insulation Contractor shall provide all necessary scaffolding, trestles, ladders, etc. c) Storage All insulation materials are to be crated or boxed. No materials are to be brought on site in a “loose” condition. All materials are to be delivered dry and stored on site in a dry atmosphere and in accordance with the manufacturer’s recommendations. Materials must not be stored in a manner which will constitute a fire hazard. Materials must be in a suitable condition at time of use, otherwise they will be rejected and replaced at no additional cost to the Contract. d) Application Insulation shall only be applied after required pressure tests have been completed and the required finishes applied, e.g. zinc oxide paint to steel pipework, etc. AJC 05/07 Section 2.8. / 1 SECTION 2.8. – THERMAL INSULATION All surfaces are to be cleaned prior to the application of the insulation. e) Clearing Waste Materials Waste shall be cleared away from site on a daily basis. f) Site Safety All tins of adhesive and paint shall be sealed at the end of the day’s work and returned to the central store. Where cellular plastic insulating materials are in use, the Insulation Contractor shall take the necessary precautions as detailed in H.S.E. Guidance Note GS3. The Insulation Contractor shall inform both the Services Contractor and the Main Contractor of any special precautions necessary with regards to certain materials and adhesives. Allowance is to be made for sealing or screening areas of the site as required. g) Health Hazards The Insulation Contractor must comply with Clause 6.11 BS 5970 1981 which concerns the detrimental effect on health of materials. h) Fire and Explosion Hazards The Insulation Contractor must ensure that the insulation and finish shall comply with the necessary fire rating, degree of flame spread and level of fume production as required by the Fire Officer or Building Regulations Department and as detailed in BS 476. These criteria especially apply in escape staircases and corridors. The insulation must not allow fire breaks and stops to be breached. i) Material Characteristics All materials used on the Contract for insulation purposes shall be resistant to vermin, insect and fungal growth, odourless and non-hygroscopic. AJC 05/07 Section 2.8. / 2 SECTION 2.8. – THERMAL INSULATION The materials must be suitable for application to the surface being covered. j) Correct Thickness and Finish The Insulation Contractor shall, as required by the Engineer, cut out sections from the finished covering, to ensure the correct thickness has been applied. Material of the incorrect thicknesses shall be removed and the correct material fitted at the Insulation Contractor’s expense. 2.8.2 Hot Water and Steam Systems a) General This part of the thermal insulation section of the Specification applies to pipework and associated equipment carrying water or steam in the C C temperature range 15° to 250° and includes heating, steam and condensate, condenser water and domestic hot water services. For Temperatures above this level it will be necessary for the Insulation Contractor to calculate the required thicknesses in accordance with BS 5422 1990. Copies of these calculations must be submitted to the Engineer for approval and acceptance. b) Materials The Materials used for insulation of pipework shall be pre-formed rigid sections of glass fibre, bonded with a heat resistant binder all in accordance with BS 3958 Part 4 1982. OR C C Pipework operating between 15° and 120° including domestic hot water, low temperature and medium temperature heating water and condensate AJC 05/07 Section 2.8. / 3 SECTION 2.8. – THERMAL INSULATION shall be insulated with Koolphen rigid phenolic foam manufactured to comply with BS 3927: 1986 Table 1 Type A. C C Pipework operating between 121° and 250° shall be insulated with performed rigid glass fibre as above. c) Finish The following finishes shall be applied to all insulation unless otherwise stated elsewhere in this Specification: (i) Plantrooms Depending upon the project concerned one of the following finishes shall be applied: EITHER 22 swg hammered or polished aluminium cladding of pre-formed sheets and fittings to be applied over the basic insulation. This insulation is to be firmly secured using metal bands prior to the application of the cladding. The cladding is to be neatly fixed by means of pop rivets at 150mm centres. Seam edges shall be cut straight with a 50mm overlap. Seams must be kept from open view and the number of sheets used in intricate areas kept to a minimum. Openings in the cladding for test points, gauges, etc. are to be pre-cut, concentric, and have clean edges. No patching will be allowed. OR Isogenopak shall be applied employing similar criteria to the above. OR Sections complete with a pre-finished facing which shall attain Class ‘O’ rating. The facing shall be aluminium foil laminate having a 50mm AJC 05/07 Section 2.8. / 4 SECTION 2.8. – THERMAL INSULATION overlap for fixing the sections. All sections shall be close butted and longitudinal overlaps and butt joints sealed with Chilstix CP85 adhesive or equal. Butt joints shall be secured with matching Class ‘O’ self-adhesive tapes supplied by the insulation supplier. The whole shall be secured without distortion by 25mm wide polished metal bands fixed at 300mm centres. Bends, fittings, etc. are to be formed by using plain insulation, mitred to fit, covered with insulation canvas and sealed with Kooltherm Chilseal CP50, or equal, the fitting then being painted to match the remainder. (ii) Occupied Spaces Where insulated pipework passes through areas which are occupied, and the insulation is exposed to view, the finish applied, unless otherwise stated in Section Three, shall be of the pre-finished type as described under the plantroom section. (iii) Unoccupied Spaces This section concerns service ducts, ceiling spaces, roof voids, etc. Rigid pre-formed sections shall be utilised, prefinished with white cotton canvas. The canvas is to form a hinge along one side and 50mm overlap on the other side and on one end. The overlap and butt joints shall be sealed with Kooltherm Chilseal CP50. Bends and fittings shall be mitred using the prefinished material and sealed in a similar manner. The whole being secured, without distortion, by 25mm bands fixed at 300mm centres. d) External Pipework Pipework whether exposed to the elements or running through external service trenches, passing into cooling tower chambers, or through areas having high humidity levels, shall be insulated with Koolphen or Glassfibre (see 2.4.2. (b)) preformed sections secured by metal bands and wrapped AJC 05/07 Section 2.8. / 5 SECTION 2.8. – THERMAL INSULATION with 0.8mm polyisobutylene sheeting to provide a weather and vapour seal. Joints are to be overlapped 50mm and sealed with Kooltherm Chilstix CP85 adhesive or equal. At terminations of the insulation, at valve boxes etc. the sheeting is to be lapped and sealed thus maintaining the continuity of insulation and protective coating. OR By means of aluminium cladding as described for plant rooms Clause 2.4.2. c)(i) but with all longitudinal and circumferential joints tightly sealed against water penetration. e) End Caps Terminations of insulation shall be fitted with metal end caps. The caps are to be constructed from polished aluminium, pre-formed and arranged to secure the insulation without causing distortion. f) Insulation of Adacent and Parallel Pipes All pipework must be insulated separately. They are not to be “married” together with insulation material under any circumstances. g) Valve Bodies, Flanges, and Unions All valve bodies, flanges, strainers, and unions are to be thermally insulated. In areas where the insulation is finished with aluminium cladding the valve and flange boxes shall be purpose made from the same material and lined with the required thickness of insulation. The enclosures are to be easily removable and fitted with metal clasps. In other areas the valves and flanges shall be insulated and finished by means of enclosures made from the same material as that insulating the pipework. The enclosures are to be both removable and replaceable and be secured by means of metal bands. (Refer to figures 15, 16, 17, 28, and 29 BS 5970 1981.) AJC 05/07 Section 2.8. / 6 SECTION 2.8. – THERMAL INSULATION h) Flexible Connections Flexible connections shall be insulated using three layers of mineral fibre rope around the flexible coupling, the rope windings being secured by adhesive and then wrapped with glass silk cloth. The cloth is to be overlapped 50mm and sealed by the Kooltherm Chilseal PC50 or equal the final finish being applied in accordance with the remainder of the installation. Where metal cladding is used on pipework the glass cloth shall be painted to match the general finish. (Refer to figure 25, GS 5970 1981.) i) Expansion Bellows Expansion bellows shall be thermally insulated using mineral fibre mat of the same thermal conductivity as that for the pipework. A pre-formed 0.5mm metal shield is to be constructed around the bellows to allow free movement. The mineral fibre mat shall pass over the shield and be fixed to the pipework insulation by means of securing bands. The whole should be finished in accordance with the general pipework finish. (Refer to figure 26, BS 5970 1982). j) Miscellaneous Pipework In addition to the general distribution pipework the Insulation Contractor must allow for insulating all cold feed and open vent pipework which is likely to be filled with water; all their bottles and associated bleed pipes; and equipment drains up to two metres from the equipment carrying the heated water. In cooling tower installations where tower pumps are sited externally, the Insulation Contractor shall also allow for insulating the section of pipework between the base tank and pump inlet, the pump impellor casing, excluding the motor, and the discharge pipe, all this insulation being weather sealed. The finish being as described in section d). k) Painting The Insulation Contractor shall allow for painting of uninsulated iron and AJC 05/07 Section 2.8. / 7 SECTION 2.8. – THERMAL INSULATION steel work, all valve handles, gas lines, open vents, air bottle bleed pipes and equipment drains, etc. in all plantrooms. The surfaces concerned are to be wire brushed, painted with one coat zinc oxide, one undercoat/primer and finished with a top coat in colour to be agreed with the Engineer. l) Identification The Insulation Contractor shall supply and fix pipework identification in accordance with B.S. 1710. Non-ferrous colour bands shall be used to indicate the type of service, pipe size and direction of flow. The bands are to be installed at spacings of 6 metres or in accordance with the relevant standard. They are also to be fitted on either side of the equipment, pumps, three port valves and at the point of entry and exit from areas e.g. plantrooms, boiler rooms, etc. A sample of the band is to be submitted to the Engineer for his approval prior to the commencement of work. m) Cleaning Prior to the Handover of the Installation the Insulation Contractor must clean the whole of the thermal insulation within his Contract. This cleaning shall include the removal of paint drips, dust, oil, etc. from floors, walls, and all other surfaces. 2.8.3 Chilled and Cold Water Systems a) General This part of the thermal insulation section of the Specification must clean C the whole pipework etc. carrying water in the temperature range 3° to C 15° and includes chilled water systems associated with air conditioning and process plant, mains cold water systems and pipework carrying chilled condensate. For temperatures below this level it will be necessary for the Insulation Contractor to calculate the relevant thicknesses in accordance with B.S. 5422 1990. AJC 05/07 Section 2.8. / 8 SECTION 2.8. – THERMAL INSULATION Copies of these calculations must be submitted to the Engineer for approval and acceptance. All pipework, etc. after cleaning is to be painted with one coat of Kooltherm KP14 or equal, anti-condensate paint prior to the application of any insulation. b) Materials The materials used for insulation of pipework shall be pre-formed rigid sections of glass fibre, bonded in accordance with B.S. 3958 Part 4 1982, and pre-finished with a while lacquered aluminium foil laminate providing Class ‘O’ fire rating. The facing is to provide a hinge on one side of the section and a 50mm overlap on the other to ensure sealing. Once sealed the whole is to form a continuous vapour barrier and shall be finally secured without distortion or damage by 25mm wide polished metal bands at 300mm centres. The horizontal overlap and butt joints are to be sealed with Foster Sealfas 30-36. Butt joints are to be wrapped with type T217FR (Class ‘O’) tape as manufactured by Messrs. Idenden Adhesives Limited or equal. Bends, fittings, etc. are to be formed by using plain insulation mitred to fit, covered with canvas, impregnated with Foster Sealfas 30-36 and allowed to set. All joints are to be wrapped using type T217FR (Class ‘O’) tape. 100m wide tape shall be used for all circumferential joints, with 50mm wide tape being used on joints around bends and fittings. OR Preformed sections of Koolphen rigid phenolic foam manufactured to comply with BS 3927: 1986 Table 1 Type A pre-finished as above. Overlaps to be sealed with Kooltherm Chilstix CP85, butt joints to be foil tape wrapped. Bends, fittings to be performed using plain insulation mitred to fit, covered AJC 05/07 Section 2.8. / 9 SECTION 2.8. – THERMAL INSULATION with canvas impregnated with Kooltherm Chilseal CP50. At the termination of all insulation the vapour barrier must be maintained, by the use of canvas cut to shape, impregnated with Foster Sealfas 30-36 or Kooltherm Chilseal CP50 and being left to set. The joint around the cap shall be wrapped in (Class ‘O’) foil tape, and a metal end cap fitted. All joints, fittings, end caps, etc. shall be painted to match the pre-finished colour of the general insulation. The thickness of material to pipework is to be in accordance with the attached table. c) Finish (NOTE: THE VAPOUR BARRIER MUST BE CONTINUOUS AND UNPUNCTURED IN ALL CASES, WITH GREAT CARE TAKEN WHEN APPLYING FINISHES.) (i) Plantrooms Depending upon the project concerned one of the following finishes shall be applied. EITHER 22 swg hammered or polished aluminium sheeting OR Isogenopak OR Sections complete with a pre-finished facing. All as described in Section 2.8.2. c) (i) of this Specification. However, in order to ensure the vapour seal is not punctured, metal bands at 300mm centres may be utilised as an alternative to pop rivets. AJC 05/07 Section 2.8. / 10 SECTION 2.8. – THERMAL INSULATION (ii) General Distribution The pipework running through both occupied and unoccupied areas shall be finished as described in Sections 2.8.2. c) (ii) and (iii) of this Specification but it must be continuously vapour sealed. d) External Pipework All as described in Section 2.8.2. d) of this Specification. e) Wall Sleeves Where chilled water services are sleeved and pass through walls or sections of structure, the insulation and vapour seal must be installed continuously through the sleeve. f) End Caps All as described in Section 2.8.2. e) of this Specification. g) Insulation of Adjacent and Parallel Pipes All as described in Section 2.8.2. f) of this Specification. h) Plump Bodies, Valves, Flanges and Unions All pump bodies, valves, flanges, strainers, and unions shall be thermally insulated and vapour sealed. After cleaning they are to be painted with one coat of Foster Sealfas 30-36 or Kooltherm KP14 protective coating paint prior to the application of any insulation. In areas where the insulation is finished with aluminium cladding, the insulation applied to the fitting is to be secured with metal bands and the joints sealed with type T217FR tape to give a vapour seal. The cladding is then to be fixed over this insulation without puncturing the vapour seal. AJC 05/07 Section 2.8. / 11 SECTION 2.8. – THERMAL INSULATION Where aluminium cladding is not applied, enclosures made from the same material as that insulating the pipework are to insulate the various types of fitting. The enclosures are to be both removable and replaceable and be secured by means of metal bands. The finish of all enclosures shall be as that for the remainder of the pipework installation. (Refer to figures 11, 28, and 29 of BS 5970 1981). i) Flexible Connections All as described in Section 2.8.2. h) of this Specification. j) Expansion Bellows All expansion bellows shall be thermally insulated generally as Section 2.8.2. i) of this Specification except that the mineral fibre is to be impregnated with Foster Sealfas 30-36 or Kooltherm Chilseal CP50 in order to maintain a vapour seal. k) Miscellaneous Pipework All as described in Section 2.8.2. j) of this Specification with the additional note that a vapour seal must also be provided. l) Supports All pipework and equipment which is to be insulated in accordance with this section of the Specification shall be supported in such a manner that a complete thermal break between pipework/equipment and supports is provided and maintained at all times. The material used can be either wood, hard rubber, or Koolphen high density support inserts, however, it must not deteriorate nor be water absorbent. The vapour barrier formed by the insulation is to be taken over such supports in order to retain continuity (Refer to figure 9, BS 5970 1981). AJC 05/07 Section 2.8. / 12 SECTION 2.8. – THERMAL INSULATION m) Gauge and Test Points Where openings have been formed in the insulation for removable gauges or test points, a purpose made plug is to be provided, attached to the adjacent insulation, which, on removal of the piece of equipment, can be inserted in the opening, thereby maintaining the vapour seal. n) Electrical Bonding Where the I.E.E. Regulations require the pipework to be electrically bonded it will be necessary for sections of cable to pass through the insulation and, hence, through the vapour barrier. In these instances the cable will be plastic sheathed and the insulation and vapour barrier bonded to the sheathing with a suitable adhesive. o) Painting All as described in Section 2.8.2. k) of this Specification. p) Identification All as described in Section 2.8.2. 1) of this Specification. q) Cleaning All as described in Section 2.8.2. m) of this Specification. 2.8.4 Warm Air Ductwork Insulation a) General This section of the Specification concerns air movement systems, both supply and extraction, which are carrying air having a temperature generally C in the range 15° to 30°C. Insulation shall be applied to all supply ductwork irrespective of location and extract ductwork being used for heat reclamation purposes, which passes through plantrooms, above false ceilings, down service shafts and through AJC 05/07 Section 2.8. / 13 SECTION 2.8. – THERMAL INSULATION non-conditional spaces. Where equipment is installed in distribution ductwork, e.g. heater batteries, noise attenuators, balancing dampers, etc., these shall also be insulated in the same materials as the remainder of the ductwork. b) Material All rectangular ductwork and associated equipment shall be insulated by means of slabs of rigid fibre glass insulation trimmed to size. The insulation is to be bonded to the sides and top of the ductwork by means of Foster Safetee Ductfas 81-99 adhesive. The insulation on the underside of ducts shall also be additionally secured by utilising purpose made pins fixed at 300mm centres. All circular or oval ductwork and associated equipment shall be insulated using flexible fibre glass insulation slabs cut and trimmed to size. The insulation is to be bonded as for rectangular ducts. The thickness of material to be used shall be in accordance with the attached table. OR Slabs of Koolphen rigid phenolic foam trimmed to size bonded to the ductwork by means of Kooltherm KP31 general purpose contact adhesive. c) Finishes The following finishes are to be supplied to all insulation: (i) Plantrooms Depending on the project one of the following finishes shall be applied: EITHER 22 swg hammered or polished aluminium cladding or pre-formed sheets and fittings to be applied over the basic insulation. This insulation is to be AJC 05/07 Section 2.8. / 14 SECTION 2.8. – THERMAL INSULATION firmly secured using metal bands prior to the application of the cladding. The cladding is to be neatly fixed by means of pop rivets at 150mm centres. Longitudinal joints shall be formed by creasing the sheets to form a sharp edge, fixings then being applied from the top or bottom of the ductwork. All the cladding shall be self supporting and made rigid by means of wooden battens which are to be installed to allow the panelling to be fixed and strengthened. All seam edges are to be cut straight and all duct edges parallel. Where openings occur for access doors, damper drives, test holes, etc. they are to be properly formed in the cladding and trimmed with purpose made edging pieces. No patching will be allowed. OR Fibre glass or Koolphen insulation shall be applied, pre-finished with white lacquered aluminium foil laminate providing a facing having Class ‘O’ fire rating. The sheets of insulation are to be trimmed to suit the shape. All joints are to be formed by means of a butt, jointed with adhesive and sealed with 100mm wide tags matching self-adhesive Class ‘O’ tape supplied by the insulation supplier. The longitudinal edges of the duct shall be protected by means of a white plastic 75mm angle, fixed to the insulation by a suitable adhesive. Where openings occur for access doors, damper drives, test holes, etc. they are to be properly formed in the cladding and the edges sealed with 50mm wide tape as used for the joints. No patching will be allowed. (ii) General Distribution Where ductwork and associated equipment are installed in both occupied and unoccupied areas fibre glass or Koolphen insulation shall be applied, all as described in the preceding paragraph above (Section 2.8.4. c) (i) of this Specification). (iii) External Ductwork All ductwork which is exposed to the elements, runs through external AJC 05/07 Section 2.8. / 15 SECTION 2.8. – THERMAL INSULATION service shafts, passes through cooling tower chambers, or through areas having high humidity levels which are likely to cause the formation of condensation on the ductwork, shall be either insulated or treated. Where the ductwork is transferring warm air which is to be used for heating or reclamation purposes, the ductwork shall be insulated in accordance with item Section 2.8.4. b) of this Specification and then overwrapped with 0.8mm thick polyisobutylene sheeting in order to form a weather and vapour seal. All joints in the sheeting shall be overlapped by 50mm and sealed with Foster Ductfas 81-22 or Kooltherm Chilstix CP50 adhesive. OR Aluminium clad as described under Clause 2.8.4. c) (i) but with all longitudinal and circumferential joints tightly sealed against water penetration. Where the ductwork is carrying air which is not useful heat, the Insulation Contractor is to allow for painting this with two coats of bituminous paint. This paint finish shall also be applied to all flanges, damper boxes, access doors, etc. When painted, all dampers and access doors should remain operable, and must not show any signs of non-operation due to the application of paint. d) End Capping Where terminal insulation terminates at walls, items of plant, etc. the exposed end of the insulation shall be capped by means of a 75mm white plastic angle. The angle is to be joined to the insulation with a suitable adhesive. e) Insulation of Adjacent and Parallel Ducts All ductwork runs must be insulated separately. They are not to be “married” together with insulation material, under any circumstances. AJC 05/07 Section 2.8. / 16 SECTION 2.8. – THERMAL INSULATION f) Removable Equipment All ductwork may require to be removed from the ductwork for servicing, the insulation and cladding shall be installed in such manner that it can be detached and replaced without disturbing the remainder of the installation. g) Identification All as described in Section 2.8.2. 1) of this Specification. Identification symbols shall be fixed on either side of items of plant, at the entry an exit of all plantrooms and at the recommended intervals throughout the ductwork distribution. h) Cleaning All as described in Section 2.8.2. m) of this Specification. 2.8.5 Chilled Air Ductwork Installations a) General This section of the Specification concerns air movement systems, both supply and extraction, which are carrying air having a temperature generally C in the range -2° to 15°C. Insulation shall be applied to all supply ductwork and extraction ductwork being used for heat reclamation purposes which passes through plantrooms, above false ceilings; down service shafts and through non- conditioned spaces. It shall also be applied to fresh air intake ductwork between the point of entry and heater batteries. Where systems are installed which operate utilising “free cooling”, with temperatures dropping into the range mentioned above. The whole of the system shall be insulated in accordance with this section of the Specification. b) Material All as described in Section 2.8.4. b) of this Specification. A vapour barrier AJC 05/07 Section 2.8. / 17 SECTION 2.8. – THERMAL INSULATION must however always be provided. Where the vapour seal is punctured by fixing pins the area is to be coated with Foster Ductfas 81-22 or Kooltherm Chilstix CP50 and then covered with (Class ‘O’) matching self-adhesive tape. As an alternative to pins, metal bands at 300mm centres applied over the insulation shall be acceptable. All joints shall be sealed with adhesive and then tape applied over the joints. The tape is to be 100mm wide and be of matching (Class ‘O’) self- adhesive type. At the termination of insulation a 50mm lap shall be formed by cutting the insulation but retaining the cover. This lap is to be sealed to the exposed edge of the insulation with Foster Ductfas 81-22 or Kooltherm Chilstix CP85 adhesive and taped over with (Class ‘O’) tape. The joint must continue to form a vapour barrier. Where fittings occur in the ductwork installation, e.g. supply grille plenum boxes, volume control dampers, attenuators, zonal batteries, etc. these are to be insulated to the same standard as the remainder of the installation and sealed and jointed in a similar manner in order to maintain the vapour seal. The Insulation Contractor must ensure that Air Cooler Batteries under positive fan pressure have been tested by the Contractor for no air leakage prior to insulation. The thicknesses of material to be used shall be in accordance with the attached table. c) Finishes The following finishes are to be applied to the insulation unless otherwise stated elsewhere in the Specification. In all cases a vapour seal must be maintained. AJC 05/07 Section 2.8. / 18 SECTION 2.8. – THERMAL INSULATION (i) Plantrooms All as described in Section 2.8.4. c) (i) of this Specification except that the vapour sealing must be continuous and not penetrated. Where the pre-finished surface is used, the longitudinal edges of the insulation shall be protected by means of a white plastic 75mm angle, fixed to the insulation by a suitable adhesive. (ii) General Distribution All as described in Section 2.8.4. c) (ii) of this Specification except that the vapour sealing must be continuous and not penetrated. (iii) External Ductwork All as described in Section 2.8.4. c) (iii) of this Specification. d) Wall Sleeves Where chilled air ductwork having a vapour seal passes through walls and sections of the structure a sleeve is to be introduced into the structure to allow the duct or fire damper and associated insulation to pass through without a break in the insulation or vapour barrier occurring. The insulation must provide the same period of protection as the fire damper to which it is applied. e) End Capping Where thermal insulation terminates an end cap shall be formed which shall also be a vapour barrier. The cap is to be formed by cutting back the insulation to leave an overlap which is then to be sealed to the exposed edge of the insulation. The joint is then to be taped with matching (Class ‘O’) self-adhesive tape and plastic angle strip fixed around the termination by means of a suitable adhesive. AJC 05/07 Section 2.8. / 19 SECTION 2.8. – THERMAL INSULATION (f) Insulation of Adjacent and Parallel Ducts All as described in Section 2.8.4. e) of this Specification. g) Removable Equipment All as described in Section 2.8.4. e) of this Specification. h) Flanges Where flanges occur in the ductwork, they are to be treated with the full thickness of insulation and the vapour seal maintained over them. Where access to equipment is necessary, a duct has to be capable of removal for movement of plant, (see above), the flanges should be accessible. i) Supports Generally in a similar manner to that described in Section 2.8.3. o) of this Specification. j) Access Doors Access Doors installed in ductwork carrying chilled air should generally be pre-insulated. However, where this is not possible a removable panel is to be formed in the insulation which is to cover the door, the joint between the panel and remainder of the insulation being sealed with 100mm wide tape to maintain a vapour seal. The removable panel is to be fitted with handles and an identification label applied. k) Electrical Bonding All as described in Section 2.8.3. n) of this Specification. l) Identification All as described in Section 2.8.2. 1) of this Specification. m) Cleaning AJC 05/07 Section 2.8. / 20 SECTION 2.8. – THERMAL INSULATION All as described in Section 2.8.2. m) of this Specification. 2.8.6 Hot Water Tanks and Vessels a) General This section of the Specification applies to tanks and vessels which are to contain heating water, domestic hot water and condensate in the C temperature range 15° to 250°C. For temperatures above this level it will be necessary for the Insulation Contractor to calculate the thicknesses in accordance with BS 5422 1977. Copies of these calculations must be submitted to the Engineer for approval and acceptance. For temperature below this level see Section 2.8.7. of this Specification relating to chilled and Cold Water Tanks and Vessels. b) Materials The materials to be used for the insulation of all tanks and vessels shall be slabs of fibre glass. For rectangular vessels these are to be rigid slabs, whilst for circular or oval vessels they are to be semi-rigid. The sheets shall be bonded with a heat resistant binder, unless otherwise stated later. OR C Tanks and vessels operating in the temperature range of 15° to 120°C shall be insulated with Koolphen rigid phenolic foam. On rectangular vessels rigid slabs. On circular vessels slotted laminate (Flatwrap). The thickness of the insulation applied shall be in accordance with the attached table. For circular and oval tanks and vessels the slabs are to be trimmed as necessary to follow the contours of the vessel and sealed to the surface of AJC 05/07 Section 2.8. / 21 SECTION 2.8. – THERMAL INSULATION the vessel with a suitable adhesive. The insulation shall then be further secured by means of 25mm wide metal bands applied circumferentially at 300mm centres. The application of the bands must not distort the insulation. For rectangular tanks and vessels the bands shall be applied horizontally with the insulation on the underside also secured by purpose made pins fixed at 300mm centres. All the edges of the tank or vessel shall be protected from damage by means of a 75mm plastic angle applied to the surface of the insulation by means of a suitable adhesive. c) Finishes 22 swg hammered or polished aluminium or Isogenopak cladding shall then be applied. The cladding shall be fitted in sheets with a minimum of joints and seams utilised. All dished or oval ends are to be pre-formed. Where necessary wooden blocks, battens or high density phenolic foam shall be provided within the insulation to enable the cladding to be self supporting and prevent distortion. All seam edges are to be cut straight and overlapped by 50mm, the seam being joined by either screws or rivets at 150mm centres. All seams wherever possible shall be kept from open view. Where openings occur in the cladding for test points, gauges, etc. they are to be pre-cut and have clean edges. When rectangular vessels are being clad all edges shall be formed by creasing the sheeting and then forming the joint on the top or bottom of the vessel. Where vessels are sited externally or are subject to low temperatures and excessive condensation of dampness, they shall be insulated with the basic fibre glass panels and bands, etc. However, this shall then be overwrapped in 0.8mm thick polyisobutylene sheeting in order to provide a weather and vapour proof seal. All joints are to be overlapped by 50mm and sealed with Foster Ductfas 81-22 adhesive. AJC 05/07 Section 2.8. / 22 SECTION 2.8. – THERMAL INSULATION OR Plain Koolphen slabs and weatherproofed with Kooltherm VICRYL CP10 applied in accordance with the manufacturer’s technical data sheet. OR Aluminium clad as described under Clause 2.8.4. c)(i) but with vapour seal applied prior to fitting of cladding and all longitudinal and circumferential joints sealed against water penetration. d) Manholes and Access Doors Where manholes and access doors occur in vessels the Insulation Contractor is to make all due allowances for forming a removable and insulated panel. Where the manhole or access door is flush with the surface of the vessel a panel is to be formed in the insulation. This panel is to consist of thermal insulation fixed to a section of cladding by a suitable adhesive and purpose made pins. The cladding shall be larger than the opening concerned to enable the panel to be secured into the main body of the insulation by means of self tapping screws. The shape of this panel is to be perfectly concentric and the edges filed smooth. (Refer to figure 30, BS 5970 1982). Where the manhole or access door is raised from the surface of the vessel, the insulation and cladding is to be formed in such a manner that it runs up the neck of the manhole. The lid of the manhole is to be insulated by means of pre-formed cap formed from the cladding and incorporating the necessary thickness of insulation for the manhole cover. The manhole cap is to fit over the cover and neck and be secured to the main body of the insulation by means of a minimum of four metal quick release catches. e) Heater Coil Chests Where removable chests occur for heating coils in calorifiers and vessels, these are to be completely insulated. AJC 05/07 Section 2.8. / 23 SECTION 2.8. – THERMAL INSULATION A metal enclosure, similar to a valve box, is to be constructed in two halves with metal fastenings. The box shall be lined with the appropriate thickness of insulation and of sufficient size and detail to enclose the whole of the chest whilst allowing provision for pipework connections. The enclosure shall be complete with a flanged face which is to be used to secure the enclosure to the main body by means of self tapping screws at 150mm centres. f) Removable Sections of Equipment Where tanks and vessels contain other removable sections, the Insulation Contractor is to allow for making the relevant section of the insulation and cladding removable, in a similar manner to paragraphs d) or e) above whichever is more appropriate. g) Supports All hot water storage vessels shall be insulated from supporting frameworks, cradles and brackets by means of wooden supports. The Contractor is to make all due allowances for providing these supports which are to be either hard rubber or hard wood and be shaped to the contours of the vessel. The supports shall be non-distorting and non-water absorbing and have two layers of a damp proofing material placed between the vessel and support. h) Cleaning All as described in Section 2.8.2. m) of this Specification. 2.8.7 Chilled and Cold Water Tanks and Vessels a) General This section of the Specification applies to tanks and vessels which are to C C contain water in the range 3° to 15° and includes chilled water systems associated with air conditioning and process plant and cold water storage systems associated with domestic installations and heating systems. AJC 05/07 Section 2.8. / 24 SECTION 2.8. – THERMAL INSULATION For temperatures below those stated it will be necessary for the Insulation Contractor to calculate the required thickness in accordance with BS 5422 1990. Copies of these calculations must be submitted to the Engineer for approval and acceptance. For temperatures above this level see Section 2.8.6. of this Specification relating to Hot Water Tanks and Vessels. b) Materials The materials used for the insulation of all tanks and vessels shall be slabs of fibre glass. For rectangular vessels these are to be rigid slabs, whilst for circular or oval vessels they are to be semi-rigid. The sheets shall be bonded with a heat resistant binder, unless otherwise stated later. OR Class ‘O’ faced Koolphen rigid phenolic foam. On rectangular tanks flat slabs shall be used. On circular tanks slotted laminate shall be used. The thickness of the insulation applied shall be in accordance with the attached table. For circular and oval tanks and vessels the slabs are to be trimmed as necessary to follow the contours of the vessel and sealed to the surface of the vessel by means of Foster Safetee Ductfas 81-99 or Kooltherm KP31 adhesive. All slabs are to be butted together and sealed with adhesive, the insulation then being overwrapped with good quality canvas and the whole vapour sealed by applying two coats of Foster Sealfas 30-36 or Kooltherm Chilseal CP50. For rectangular tanks and vessels the slabs shall be prefinished with a white lacquered aluminium foil laminate coating providing Class ‘O’ fire rating. The insulation shall be bonded to the sides and top of the vessel by means of Foster Safetee Ductfas 81-99 or Kooltherm KP31 adhesive, with the insulation on the underside also secured by purpose made pins fixed at 300mm centres. AJC 05/07 Section 2.8. / 25 SECTION 2.8. – THERMAL INSULATION At the edges of the tank or vessel shall be protected from damage by means of a 75mm plastic angle applied to the surface of the insulation by means of a suitable adhesive. Where the vapour seal is punctured by fixing pins the area shall be coated with Foster Ductfas 81-22 or Kooltherm Chilstix CP85 and then covered with matching (Class ‘O’) type. All joints shall be sealed with adhesive and then tape applied over the joints. The tape is to be 100mm wide and be of the (Class ‘O’) type. At the termination of insulation a 50mm lap shall be formed by cutting the insulation but retaining the cover. This lap is to be sealed to the exposed edge of the insulation with Foster Ductfas 81-22 or Kooltherm Chilstix CP85 adhesive and taped over with (Class ‘O’) tape. The joint must continue to form a vapour barrier. c) Finishes The following finishes are to be applied to the insulation unless otherwise stated elsewhere in the Specification. In all cases a vapour seal must be maintained. i. Plantrooms Depending on the project concerned, one of the following finishes is to be applied. EITHER All circular and oval vessels, as well as some rectangular vessels, shall be clad with 22 swg hammered or polished aluminium, or Isogenopak cladding applied over the vapour sealed finish. Generally otherwise as Section 2.8.6. c) of this Specification. OR AJC 05/07 Section 2.8. / 26 SECTION 2.8. – THERMAL INSULATION Where a prefinished rigid sheeting has been utilised this may be left without any further cladding being applied. All water storage tanks in tank rooms shall be insulated by means of a 75mm plastic angle applied to the surface of the insulation by means of a suitable adhesive. ii. External Where tanks or vessels are sited externally, or are subject to low temperatures and excessive condensation or dampness, the tank shall be insulated as previously described. However, this shall then be overwrapped in 0.8mm thick polyisobutylene sheeting in order to provide a weather and vapour proof seal. All joints are to be overlapped by 50mm and sealed with Foster Ductfas 81-22. OR Waterproofed with Kooltherm VICRYL CP10 applied in accordance with the manufacturer’s technical data. OR Aluminium clad as described under Clause 2.8.4. c)(i) but with vapour seal applied prior to fitting of cladding and all longitudinal and circumferential joints sealed against water penetration. d) Manholes and Access Doors Generally as described in Section 2.8.6. a) of this Specification. However, a continuous compressible foam rubber strip shall be secured to the cladding round the manhole thus ensuring that, when the manhole is secured with quick release toggles, the flange is compressed on the foam strip and the vapour seal maintained. AJC 05/07 Section 2.8. / 27 SECTION 2.8. – THERMAL INSULATION e) Flanged Tanks Where tanks are constructed from plates bolted together by means of external flanges, the insulation shall be applied in such a manner that the complete thickness of insulation covers the end of all flanges. f) Removable Sections of Equipment All as described in Section 2.8.6. f) of this Specification. To maintain the vapour seal between sections, a continuous compressible foam rubber seal strip shall be provided throughout the length of the joint. The two sections of the joint shall then be secured by means of quick release toggles which, when applied, cause the rubber to compress and the vapour seal to be maintained. g) Supports All as described in Section 2.8.6. g) of this Specification. h) Cleaning All as described in Section 2.8.2. m) of this Specification. 2.8.8 Boiler Smoke Pipes a) General This part of the Specification concerns all single skin mild steel and stainless steel, smoke and exhaust pipework which occurs in boiler rooms, plantrooms, service risers, etc. It does not apply to multiple skin systems unless specifically required elsewhere in this Specification. b) Materials The materials to be used for all insulation of smoke pipes and exhaust pipes shall be rigid slabs of 50mm fibre glass, bonded with a heat resistant binder and suitable for use with the relevant temperature of the flue or exhaust AJC 05/07 Section 2.8. / 28 SECTION 2.8. – THERMAL INSULATION pipework concerned. The Insulation Contractor must at time of Tender ascertain the surface temperature of the flue or exhaust pipe if not stated in the documentation. No extra cost will be permitted for want of knowledge under any circumstances. Metal spacing pieces shall be provided around the pipe at 300mm centres to provide an air gap between flue and insulation of 25mm. The insulation shall be applied in pre-cut lengths having bevelled edges, wrapped with scrim cloth coated with Foster Safetee Ductfas 81-99 or Kooltherm Chilstix CP85 and secured by means of 25mm metal bands at 300mm centres to coincide with the location of the spacer pieces. The bands must secure but must not cause any form of distortion. All bends shall be insulated by forming a “lobster back” arrangement of trimmed slabs. The insulation is to have a 25mm air gap between flue pipe and insulation and be secured by means of scrim cloth, cut to size, impregnated with Foster Safetee Ductfas 81-99 or Kooltherm Chilstix CP85, and allowed to set. c) Finish In plantrooms the insulation shall be clad with 22 swg hammered or polished aluminium sheeting applied over the insulation, generally as described in Section 2.8.2. c)(i) of this Specification. In service risers the flue shall be wrapped with good quality white canvas, the seams and joints secured with Foster Sealfas 30-36 and then secured with 100mm wide polished metal bands at 300mm centres. Where the flue runs through areas exposed to external conditions, but where thermal insulation is required, e.g. loading bays, etc. the basic insulation shall be overwrapped with 0.8mm polyisobutylene sheeting. All joints and seams are to be overlapped by 50mm and sealed with Foster Ductfas 81-22 or aluminium clad as described in Clause 2.8.2. d). AJC 05/07 Section 2.8. / 29 SECTION 2.8. – THERMAL INSULATION d) Access Doors All access doors shall be insulated in a manner consistent with the remainder of the flue. Extended handles are to be provided on these panels to allow for the addition of the insulation. e) Pipe Sleeves Where flues or exhaust pipes pass through fire compartments, a metal sleeve shall be built into the structure. The gap between the flue and sleeve is to be sealed with a semi-rigid fire resisting mastic. AJC 05/07 Section 2.8. / 30 SECTION 2.8. – THERMAL INSULATION Tables Table 1 – Circulating Water and Steam. Thermal Insulation Thicknesses (Glass Fibre) Fluid Temperature Pipe Size Nominal 3°C 10°C 60°C 80°C diameter (mm) 15 38mm 25mm 25mm 25mm 20 38mm 25mm 25mm 25mm 25 38mm 25mm 25mm 25mm 32 38mm 25mm 25mm 25mm 40 38mm 25mm 38mm 38mm 50 38mm 25mm 38mm 38mm 65 50mm 38mm 38mm 38mm 80 50mm 38mm 38mm 38mm 100 50mm 38mm 38mm 38mm 150 50mm 38mm 50mm 50mm 200 63mm 38mm 50mm 50mm 250 63mm 38mm 50mm 63mm 300 63mm 38mm 50mm 63mm AJC 05/07 Section 2.8. / 31 SECTION 2.8. – THERMAL INSULATION Table 1 – Circulating Water and Steam (continued). Thermal Insulation Thicknesses (Glass Fibre) Fluid Temperature Pipe Size Nominal 116°C 150°C 200°C 250°C diameter (mm) 15 25mm 32mm 38mm 38mm 20 25mm 32mm 38mm 50mm 25 25mm 32mm 50mm 50mm 32 38mm 32mm 50mm 50mm 40 38mm 38mm 50mm 50mm 50 38mm 38mm 50mm 63mm 65 38mm 38mm 63mm 75mm 80 38mm 50mm 63mm 75mm 100 50mm 50mm 75mm 75mm 150 50mm 63mm 75mm 100mm 200 50mm 63mm 100mm 100mm 250 63mm 63mm 100mm 100mm 300 63mm 75mm 100mm 100mm AJC 05/07 Section 2.8. / 32 SECTION 2.8. – THERMAL INSULATION Table 2 – Circulating Water and Steam. Thermal Insulation Thicknesses (Glass Fibre) Pipe Size Internal Pipework External Pipework 15 38mm 38mm 20 38mm 38mm 25 38mm 38mm 32 38mm 38mm 40 38mm 38mm 50 25mm 38mm 65 25mm 38mm 80 25mm 25mm 100 25mm 25mm 150 25mm 25mm 200 25mm 25mm 250 25mm 25mm 300 25mm 25mm AJC 05/07 Section 2.8. / 33 SECTION 2.8. – THERMAL INSULATION Table 3 – Storage Tanks and Vessels Thermal Insulation Thicknesses (Glass Fibre) Water Temperature 3°C 10°C 60°C 80°C Insulation Thickness 63mm 50mm 50mm 63mm Water Temperature 116°C 150°C 200°C 250°C Insulation Thickness 63mm 75mm 100mm 100mm Table 4 – Ductwork Thermal Insulation Thicknesses (Glass Fibre) Temperature difference Rigid duct insulation Flexible duct insulation between ducted air and ambient air 10°C 40mm 50mm 25°C 50mm 50mm 50°C 65mm 75mm AJC 05/07 Section 2.8. / 34 SECTION 2.8. – THERMAL INSULATION Table 5 – Hot Pipes and Vessels Thermal Insulation Thicknesses Pipe Size (mm) Koolphen Phenolic Foam Glassfibre N.B. O.D. DHW UP LTHW MTHW HTHW OR STEAM TO 80°C UP TO UP TO 150°C 200°C 95°C *120°C 15 21 15 15 20 32 38 20 27 15 20 20 32 38 25 34 15 20 20 32 50 32 42 20 20 20 32 50 40 48 20 20 20 38 50 50 60 20 20 20 38 50 65 76 20 25 25 38 63 80 89 20 25 25 50 63 100 114 20 25 25 50 75 125 140 20 25 25 63 75 150 168 20 30 30 63 75 200 219 25 30 30 63 100 250 273 25 30 30 63 100 300 324 25 35 35 75 100 VESSELS AND FLAT 30 35 40 100 100 SURFACES * Thickness shown under MTHW may be used for HTHW provided that the temperature does not exceed 120°C. On pipework with screwed joints a minimum thickness of 20mm shall be used to allow for the larger diameter of the screwed fittings. AJC 05/07 Section 2.8. / 35 SECTION 2.8. – THERMAL INSULATION Table 6 – Cold Pipes And Vessels Thermal Insulation Thicknesses (Koolphen) Pipe Size Coldwater Chilled Refrigeration Water N.B. O.D. C 6° to 12°C C 2° to 5°C 0°C -10°C -20°C (mm) (mm) 15 21 15 20 20 30 35 20 27 15 25 25 30 35 25 34 15 25 25 30 40 32 42 15 25 25 30 40 40 48 15 25 25 30 40 50 60 15 25 25 35 40 65 76 20 30 30 35 40 80 89 20 30 30 35 40 100 114 20 30 30 40 50 125 140 20 30 30 40 50 150 168 20 35 35 40 60 200 219 20 35 35 50 60 250 273 20 35 35 50 60 300 324 20 35 35 50 60 VESSELS AND 25 40 40 50 70 FLAT SURFACES On pipework with screwed joints a minimum thickness of 20mm shall be used to allow for the larger diameter of the screwed fittings. AJC 05/07 Section 2.8. / 36 SECTION 2.8. – THERMAL INSULATION Table 7 – Ductwork Thermal Insulation Thicknesses (Koolphen) Temperature difference between Thickness of Koolphen ducted air and ambient air. Insulation 10°C 20mm 25°C 25mm 50°C 30mm Recommended Thickness of Koolphen To Protect Against Freezing On Cold Water Services Table 8 (Based on BS 5422) The use of insulation alone will not give complete protection against the freezing of water in pipes under all ambient conditions. If the ambient temperature remains low enough for sufficient time and the movement of water is slow or the water is static, freezing will eventually take place. Small pipes and valves are particularly vulnerable. AJC 05/07 Section 2.8. / 37 SECTION 2.8. – THERMAL INSULATION 8 (a) Recommended thickness of Koolphen which will give reasonable protection against freezing during normal occupation of buildings. Pipe Size Indoor Pipes Outdoor Pipes 15mm 20 25 20mm 20 25 25mm 20 25 32mm 20 25 40mm 20 25 50mm 20 25 65mm 20 25 80mm and above 20 25 8 (b) Recommended thickness of Koolphen required where ambient C temperature is -10° for 12 hours and water is static. Pipe Size Indoor Pipes Outdoor Pipes 15mm 256* 178* 20mm 186* 87* 25mm 112* 47* 32mm 60 25 40mm 50 20 50mm 30 20 65mm 25 20 80mm and above 25 20 * Where some of the theoretical thicknesses shown in Table 8(b) are impractical, then other means of protection, (e.g. heat tracing) should be used with a nominal 25mm of insulation over the pipe and heat tracer to conserve energy. NIFLAN rigid preformed pipe insulation with a factory applied P.I.B. weatherproof covering shall be used for this purpose. AJC 05/07 Section 2.8. / 38
"STANDARD SPECIFICATION for MATERIALS and WORKMANSHIP SECTION reciprocating screw"