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					                                            TM-1 Turbine
                                        Table of Contents

TM-1     Turbine ............................................................................…………...........TM-1.1
  TM-1.1 Purpose and Function ................................………………………..........TM-1.1
  TM-1.2 Drawings .....................................................……………………........TM-1.1
  TM-1.3 Standards and Codes .......................................………………….........TM-1.1
  TM-1.4 Not Used .......................................................……………………….......TM-1.2
  TM-1.5 Rated Conditions ..........................................……………………….......TM-1.2
  TM-1.6 Quantities and Descriptions ..........................……………………..........TM-1.2
  TM-1.7 Spare Parts ......................................................………………………....TM-1.4
  TM-1.8 Operation and Control of Equipment .............…………………….....TM-1.4
  TM-1.9 Shop Assembly ............................................………………………........TM-1.4
  TM-1.10 Hydraulic Conditions ...................................……………………...........TM-1.4
  TM-1.11 Operating Conditions ......................................………………….........TM-1.5
  TM-1.12 Turbine Characteristics ....................................………………….........TM-1.5
  TM-1.13 Data Required with Bid Price .........................…………………............TM-1.5
  TM-1.14 Speed ...............................................................……………………........TM-1.6
  TM-1.15 Efficiency Guarantee .......................................…………………...........TM-1.6
  TM-1.16 Cavitation Guarantees .....................................…………………........TM-1.7
  TM-1.17 Spiral Case .......................................................…………………….......TM-1.8
  TM-1.18 Stay Ring ........................................................…………………........TM-1.10
  TM-1.19 Hydrostatic Pressure Test ..............................……………………........TM-1.12
  TM-1.20 Head Cover ....................................................………………….........TM-1.12
  TM-1.21 Turbine Aeration ........................................……………………........TM-1.13
  TM-1.22 Bottom Ring .....................................................…………………......TM-1.14
  TM-1.23 Discharge Ring .................................................………………….......TM-1.15
  TM-1.24 Draft Tube Liner ...............................................………………….......TM-1.15
  TM-1.25 Draft Tube .........................................................………………….......TM-1.16
  TM-1.26 Runner ...............................................................…………………......TM-1.16
  TM-1.27 Shaft ...................................................................…………………......TM-1.19
  TM-1.28 Guide Bearing ....................................................………………….......TM-1.21
  TM-1.29 Lubricating Oil ..................................................…………………......TM-1.23
  TM-1.30 Shaft Water Seal ...............................................………………….......TM-1.23
  TM-1.31 Guide Vanes and Operating Mechanism ......…………………...........TM-1.24
  TM-1.32 Servomotors ............................................………………….................TM-1.25
  TM-1.33 Turbine Pit Liner, Walkways, Platforms and Stairways .......................TM-1.27
  TM-1.34 Drains ....................................................................…………………...TM-1.28
  TM-1.35 Not Used ................................................................………………….TM-1.28
  TM-1.36 Service Air Compressors ......................................…………………....TM-1.28
  TM-1.37 Electrical ................................................................………………….TM-1.28
  TM-1.38 Not Used ................................................................………………….TM-1.28
  TM-1.39 Installation Equipment, Wrenches, Tools and Fixtures ........................TM-1.28
  TM-1.40 Contractor‟s Design Calculations and Data …………………………TM-1.29
  TM-1.41 Pressure Regulator ……………………………………………………TM-1.30
  TM-1.42 Inspection and Tests ……........................................…………….....TM-1.32
Appendix A Unit 3 Turbine Index Test



                                                    TM-1.i
                                     TM-1 Turbine

Kajakai Hydroelectric Project
Addition of Unit 2
Technical Specification
TM-1 Turbine
TM-1.1 Purpose and Function
1       The turbine to be supplied under this specification shall be installed in an existing
turbine bay to complete the three-unit powerhouse. It shall be constructed to suit the existing
water passages and powerhouse layout.
2      The dimension and weights of the assembled parts shall be within the capacity and
hook approaches of the existing 115-ton powerhouse crane.
3        The turbine shall be designed and constructed to provide a high degree of reliability
with minimum maintenance and shall be of rugged construction suitable for the operating
environment and resources of the Employer. The equipment shall incorporate features to
facilitate inspection and maintenance and to minimize maintenance requirements. Emphasis
shall be placed on reliability, minimizing maintenance and protection of equipment rather
than on maximizing turbine efficiency. The design shall be tolerant of misalignment and
deformation of the concrete structures.
4      The Contractor shall integrate the design of the turbine, generator, governor, inlet
valve and pressure regulator to meet all specified requirements without conflict between the
characteristics of the individual parts.
TM-1.2 Drawings
The accompanying drawings form part of this specification.
TM-1.3 Standards and Codes
1      The equipment shall comply with the requirements of the latest revision of the
following standards where applicable.
       CEA                    Hydroelectric Turbine-Generator Units Guide for Erection
                              Tolerances and Shaft Alignment
       IEC 60041              International Code for the Field Acceptance Tests of Hydraulic
                              Turbines
       IEC 193                Model Acceptance Tests of Hydraulic Turbines
       IEC 60609              Cavitation Pitting Evaluation in Hydraulic Turbines, Storage
                              Pumps and Pump-Turbines
       ISO 1940-1             Mechanical Vibration - Balance Quality Requirements of Rigid
                              Rotors - Part 1: Determination of Permissible Residual
                              Unbalance
       ASME                   Boiler and Pressure Vessel Code, Section VIII, Division I
                              ASTM As specified herein
       ANSI/IEEE 810          Hydraulic Turbine and Generator Integrally Forged Shaft
                              Couplings and Shaft Runout Tolerances



                                           TM-1.1
                                     TM-1 Turbine

       NEMA MG5.1 - 3.04 Standards for Vertical Hydraulic Turbine Generator Shaft
                         Runout Tolerances

2      Unless otherwise stipulated in this section of the specification, the equipment shall
comply with the requirements and the latest revisions of the applicable standards as listed in
Section TG-3.
3       If this specification conflicts in any way with any of the above standards or codes, the
more stringent requirement shall govern. However, the Contractor shall bring these conflicts
to the Engineer‟s attention to permit discussion at least
4      weeks prior to finalizing of Contractor‟s design.
TM-1.4 Not Used
TM-1.5 Rated Conditions
1       The station is operated from an existing storage reservoir providing continuous power
using the available head and flow.
2      The turbine shall be capable of continuous, stable operation at speed-noload and at
any output between that which corresponds to normal minimum turbine discharge, and
maximum unit output, and under any head within the range specified in TM-1.10. Such
operation shall be without objectionable surges in power output or detrimental vibrations.
Acceptable fluctuations in power output shall be those which do not exceed plus or minus
2%. Acceptable levels of vibration are those which are in the “good” range per VDI Standard
2056.
3      The rated conditions shall be established by the Contractor based on the limiting
conditions described elsewhere in the specifications and the operating requirements specified
above. The nameplate rating shall be subject to acceptance by the Engineer.
4       The net head on the turbine shall be calculated in accordance with IEC 60041, Figure
2. The total head at the turbine inlet shall be measured at the piezometer taps on the spiral
case inlet pipe.
TM-1.6 Quantities and Descriptions
1      The Contractor shall design, supply and install one turbine consisting of the
following.
 Quantity Description
 1        vertical shaft Francis type hydraulic turbine including spiral case, head cover,
          bottom, discharge and stay rings, guide bearing, shaft seal
 1 lot    guide vanes and operating mechanism
 2        servomotors for guide vanes
 1        turbine aeration system including piping, valves, instrumentation
 1 lot    turbine pit platforms, walkways and stairs
 1 lot    runner blade templates
 1        turbine design report
 1 lot    shop and field tests



                                            TM-1.2
                                   TM-1 Turbine

2   This work includes
     turbine shaft to suit generator flange; detail design to be coordinated with the
         generator design
       shaft seal water filtration system
       guide bearing oil cooling system, if required by Contractor‟s design
       turbine pit liner
       draft tube liner
       all anchors, turnbuckles, fixtures, machine pads, jacks and foundation bolts for
         field alignment and installation
       all painting materials and test equipment for field painting and touch up painting
       all special tools and devices for handling, assembly, installation, erection,
         dismantling at site
       all equipment, tools, instruments and devices for conducting field tests
       all welding materials and equipment for site welding
       any other item not specified above but necessary to complete the manufacture,
         assembly, machining, erection, commissioning and testing
       all instruments, control and safety devices
       oil for the first filling of the turbine guide bearing oil system, including oil for
         flushing
       piping and electrical terminations and tie-ins to existing facilities
       interconnecting wiring and piping between various parts of the equipment within
         the turbine pit (for piping and wiring outside turbine pit see other sections of the
         specification), including all couplings, valves, flanges, junction boxes, electrical
         enclosures required for continuation of piping and wiring outside turbine pit.
3   The Contractor shall assume responsibility for
     field checking of the location and dimensions of all structures, equipment, piping
         or other services that may affect its work
       field checking of all its connections to, or interfacing with, existing structures,
         equipment, piping or other services
       quality of all materials and workmanship supplied by the Contractor entering into
         the completed work
       rigid adherence to the dimensions of parts as shown on drawings
       strength of all parts of the turbine when subject to the most adverse load
         conditions
       ratings guaranteed in Contract
       satisfactory performance of the entire work under all specified operating
         conditions without signs of undue strain and without breakdown, cracking,
         damage or deterioration of any of the parts due to faulty or unsuitable material,
         design, workmanship, handling, storage, transportation, assembly or erection
         procedure
       freedom from excessive pitting of any part of the turbine under the specified
         operating conditions in accordance with the Contractor's guarantee
       freedom from abnormal vibration under the specified operating conditions.




                                         TM-1.3
                                     TM-1 Turbine

TM-1.7 Spare Parts
The Contractor shall supply specified spare parts, special tools and devices where detailed in
the Commercial Schedules and shall supply recommended spare parts for 2 years operation.
Spare Parts for field testing and acceptance trials shall be provided by the Contractor. All
spare parts shall be identical electrically and mechanically to the corresponding parts in the
equipment, and shall be suitably packed and clearly marked ready for long-term storage
indoors.
TM-1.8 Operation and Control of Equipment
The turbine shall be operated locally from the actuator cubicle on the turbine floor, from the
governor cubicle on the main floor and from the control room. The Contractor shall provide
all equipment, apparatus and devices to achieve the specified methods of operation and
control. The Contractor shall also provide all wiring and conduits between the turbine and
governor and other equipment.
TM-1.9 Shop Assembly
1      All equipment, fabrications and structures covered by the specifications shall be fully
assembled, as far as practical, in the Contractor's shop for inspection by the Engineer. All
necessary adjustments shall be made in the shop to achieve the specified tolerances.
2      Prior to dismantling, each assembly shall be permanently and clearly matchmarked in
the shop to facilitate site erection. Dismantling shall be done only to the point required for
shipping. In particular, there shall be minimum disconnection of electrical wiring.
3       The Contractor shall complete the application of protective coatings in its shop as
specified in TG-14.
4      Shop assembly shall include, but not be limited to
       assembly of all fabrications sectionalized for transportation
       assembly of stay ring to spiral case plate sections
       tower assembly.
TM-1.10 Hydraulic Conditions
1       The general arrangement of the intake, power tunnel, water passages, draft tube and
tailrace is as shown on the drawings.
2      The operating conditions are as follows:
       Centerline of unit distributor 962.0 m
       Headwater level
              - maximum (post spillway gate installation) el 1045.0 m
              - normal (present) el 1033.5 m
              - minimum el 1012.0 m
       Tailwater Level
              - maximum (flood) el 972.0 m
              - minimum el 962.5 m
              - normal el 962.8 m



                                           TM-1.4
                                       TM-1 Turbine

3      The turbine shall be designed to operate safely for extended periods of time at full
power under any head within the range of heads specified.
TM-1.11 Operating Conditions
1       The turbine will normally be required to operate, alone or in parallel with one or both
existing units, as a base load unit. During high reservoir levels, the unit could be running at
maximum output continuously.
TM-1.12 Turbine Characteristics
1      The Contractor shall submit to the Engineer a detailed report outlining how the
turbine characteristics have been determined. This shall include the details of any previous
model tests used as a basis and any computer simulation performed to determine turbine
characteristics from similar units or models. The report shall list all input data used for
models or computer simulation, the output data obtained, a description of the methodology
with reference to any recognized standards which are applicable, and justification of the
characteristics derived in terms of existing units designed by the Contractor. The report shall
include:
     sample calculations for all calculated parameters, including efficiency, cavitation and
       runaway speed
       comparison of results with the guarantee requirements of the specifications.
       model test curves for (where model used as basis)
       unit power, unit discharge, efficiency versus speed for various guide vane openings
       relation of power output, efficiency and discharge to the cavitation coefficient `sigma'
         for various guide vane openings and speeds corresponding to the head range to be
         encountered in service
       relation of runaway to guide vane opening at not less than three net heads (design,
         minimum and maximum)
       `Hill' diagram
       curves for the turbine to be supplied showing
       relation of efficiency, turbine output and discharge quantities with cavitation limits
         indicated
       relation of turbine discharge with guide vane opening for head range to be
         encountered in service
       relation of runaway speed to guide vane opening for at least three net heads (design,
         minimum and maximum)
       fluctuations in spiral case pressure, draft tube pressure, and shaft torque and draft tube
         natural frequencies as a function of water flow with and without air admission
       air admission pressures and flow rates
       transient flow analysis and determination of pressure rise due to load rejection and
         design pressure for scroll case etc.
TM-1.13 Data Required with Bid Price
1        The Contractor shall submit with its Bid the following:




                                              TM-1.5
                                     TM-1 Turbine

    detailed list of scope of work including specified and recommended spare parts, tools,
      tackle, installation and testing devices
    general arrangement drawings of the proposed turbine features
    brief description of all major components of the turbine including construction and
      materials as well as details of any deviations from the specifications
    turbine performance curves, cavitation coefficient curves, Hill chart showing guide
      vane openings
    turbine installation procedure and requirements
    completed Technical Schedules
    identify the prototype unit listed in TS-1, which most closely resembles the turbine
      offered in the Bid, describing the head, speed, rated output, servomotor pressure, and
      any deviations from the design that will be required for the machine offered in the
      Bid
    information on any subcontractors that the Contractor proposes to use for any major
      castings or weldments shall be stated.
2      The Contractor shall include any other drawings, catalogs, descriptions and
photographs necessary to present a clear picture of the type and class of equipment being
supplied.
TM-1.14 Speed
1      The preferred speed of the unit is 300 rpm. Rotation must be clockwise when viewed
from above. This speed and rotation matches the existing two units.
2       The Contractor shall guarantee that the runaway speed of the turbine at the maximum
specified head shall not exceed that stated in the Bid.
TM-1.15 Efficiency Guarantee
1       The turbine shall be designed for best efficiency at the design rated net head. Bids
shall include guaranteed efficiencies for the turbine operating at the design rated net head for
80%, 90% and 100% rated output.
2     A single weighted average efficiency shall be guaranteed for the turbine and shall be
computed as follows:
                             % Rated Output
                             80     90    100
Weighting Factor             1      2     7
The weighted average efficiency shall be:


 Efficiency x Weighting Factor
                       10

The weighted average efficiency shall not be less than 91%.
3      The actual guaranteed weighted average efficiency shall be calculated using the head
as measured at the piezometer taps on the spiral case inlet pipe.



                                            TM-1.6
                                     TM-1 Turbine

4     Field tests shall be performed in accordance with IEC Publication No. 60041, Field
Acceptance Tests of Hydraulic Turbines.
TM-1.16 Cavitation Guarantees
1       Evaluation of cavitational pitting will be generally in accordance with the
International Electrotechnical Commission (IEC) Publication 60609 but shall also observe
the following specific requirements.
2      The unit distributor centerline shall be set equal to the setting of the existing units 1
and 3.
3       Under the above conditions and with the specified tailwater levels, the material loss
(due to cavitation only) shall neither impair the strength of the runner nor exceed the amounts
of cavitation pitting damage estimated from the lower line on the graphs in Appendix A of
IEC 60609. The material loss shall be determined for an 8000-h period of accumulated
operation from the date that a Taking-Over Certificate is issued for the unit, or 24 months of
commercial operation, whichever comes first, or from the date of completion of cavitation
repairs or alterations as required by this Specification
4      The Contractor shall guarantee that material lost due to cavitation pitting damage
during the guarantee period shall not exceed 2 kg per runner and 1 kg for all other parts
combined (guide vanes, bottom ring, discharge ring, draft tube liner).
5        In addition, the Contractor shall guarantee that there shall be no single continuous
area of 200 cm2 or more on the turbine where the metal thickness is reduced, due to cavitation
pitting, by an average of more than 4 mm.
6      Contractor‟s guarantee against cavitation pitting shall be based on the following
conditions of operation:
7      The operation of the unit at an output greater than the maximum normal output, as
given in the Technical Schedules, will not exceed 100 hours accumulated during the
guarantee period.
8      The operation of the generating unit at a partial output less than the normal minimum
turbine discharge given in the Technical Schedules, and including operation at speed-no-
load, will not exceed 500 hours accumulated during the guarantee period.
9      The tailwater levels during turbine operation will not be less than that stated in TM-
1.10. The maximum normal output at various net heads and tailwater levels shall be as stated
by the Contractor in the Technical Schedules.
10      In an effort to allow early determination and to limit the amount of cavitation pitting
damage, at the Employer‟s discretion, an inspection of the turbine may be arranged after
between 1000 and 3000 hours of accumulated operation from the time the unit was placed in
service. Contractor shall provide the services of a competent engineer for these inspections.
The results of the inspection shall be reviewed with the Employer. The Contractor may, after
consultation with the Employer, waive its presence at this inspection.
11     At the end of the guarantee period, the Contractor and the Employer shall also jointly
inspect and measure any cavitation damage, unless waived in writing by the Employer. If
excessive cavitation occurs, the Contractor shall immediately, unless otherwise approved by


                                            TM-1.7
                                      TM-1 Turbine

the Employer, reshape and resurface the cavitated areas by grinding, polishing, building up
by welding or other approved means, to remedy the cause insofar as possible, and propose
and implement corrective action to mitigate future pitting damage. Cavitation repairs shall be
at the expense of the Contractor. If the damage does not impair the strength of the runner or
other parts, the Employer may require the cavitation pitting repairs to be delayed as long as
ten months.
Wear due to erosion by suspended matter in the water or corrosion caused by chemical
composition of the water are not intended to be covered by the cavitation guarantee.
12      If the turbine fails to meet the above guarantee, the Contractor shall repair all pitted
areas in a satisfactory manner by welding. The final repaired surfaces shall have stainless
steel weld, having a minimum finished thickness of 3 mm. The Contractor shall also make
the necessary alterations to remove the cause or causes of this pitting or shall replace the
runner with one which is satisfactory. Contractor shall undertake all repairs at a time
convenient to the Employer and will undertake the repair work on a two 10-hours shifts per
day, seven-days per week basis unless otherwise agreed by the Employer. For the purpose of
repair, the Employer will unwater the unit, remove the turbine covers and provide
compressed air and electric power free of charge to the Contractor; the Contractor shall
provide all necessary tools, materials and labor. The Employer will assume responsibility for
loss of capacity and generation during these outages, but the Contractor shall take all steps to
complete the repair work in a minimum time period. If the removal of the causes of this
pitting requires dismantling and shipping of the runner or any of the parts, the Contractor
shall be responsible for all costs incurred. Subsequent to repair, the turbine will be subject to
the above cavitation guarantee for another period of 8000 operating hours. Notwithstanding
the provisions of the Defects Liability Period specified in the General Conditions, the
guarantee will be renewed each time the turbine fails to meet the guarantee. If the turbine
runner fails to meet the cavitation pitting guarantee after repairs have been effected three
times, the Contractor shall replace the runner completely with a new runner of an improved
design and shall bear all costs of runner replacement.
TM-1.17 Spiral Case
1      The case shall be of the spiral or volute type built from steel plate by welding, and
sectionalized as necessary for handling and shipment. Design and fabrication shall be in
accordance with ASME Boiler and Pressure Vessel Code, Section VIII, Division I. The
design shall be such that hydraulic losses are minimized. The casing shall be designed for the
maximum internal working pressure determined by the Contractor and accepted by the
Engineer (see TM- 1.41). Under this design pressure, the maximum stress, computed in
accordance with the Foppl formula, as follows, shall not exceed the stress recommended in
the ASME Boiler and Pressure Vessel Code, Section VIII, Division I:
f pr x (R a)
     et     2a

where
R = radius from vertical centerline of unit to vertical centerline of spiral case section under
     consideration (mm)



                                            TM-1.8
                                     TM-1 Turbine

a = inside radius from vertical centerline of unit to point on spiral case section under
    consideration (mm)
r = inside radius of spiral case section under consideration (mm)
t = thickness of material at point under consideration (mm)
p = maximum internal design pressure (MPa)
e = joint efficiency as given in the ASME Boiler and Pressure Vessel Code,
Section VIII, Division I, Unfired Pressure Vessels
f=   stress in material at point under consideration (MPa).
The circumferential joints shall be designed to give a strength equivalent to that of the
longitudinal joints of corresponding sections. A corrosion allowance of 2 mm thickness shall
be added.
2      Field joints shall be made by welding. Spiral case inlet end shall match downstream
coupling connecting extension piece downstream of inlet valve.
3       A watertight manhole shall be provided in the spiral case and an adequate saddle
provided to compensate for the metal removed from the casing for the manhole opening. The
clear manhole opening shall be 750 mm wide by 900 mm high. The manhole door shall have
rounded corners and be hinged to open inward. The surfaces of the door and frame shall be
contoured and ground so that when closed the inside surface of the manhole door is flush
with the inside surface of the spiral case. The hinges shall be of rugged design and provided
with an adjustment to accurately align the door. A test cock or valve and nipple shall be
installed in the spiral casing located immediately below the manhole.
4      Stainless steel bolts not less than 25 mm in dia and an endless gasket of 3-mm thick
Garlock red rubber, or equivalent, shall be provided to prevent leakage.
5       Stainless steel piezometer taps shall be provided on the casing for the purpose of
conducting performance tests. Each tap shall be designed to prevent stresses, caused by
concrete embedment or movement between the liner and the embedding concrete, from
fracturing the piezometer piping. Spiral case pressure gauge and index test piping is covered
under TM-4. Embedment in a resilient mastic is a preferred method. Embedment details shall
be acceptable to the Engineer. Any stress relief method that requires welding to the spiral
case will not be accepted. The following taps shall be provided.
        Four piezometer taps equally spaced around the spiral case inlet pipe on diameters
          at 45° to the vertical, at a location determined by the Contractor subject to
          acceptance by the Engineer, for measuring net head.
        Four Winter-Kennedy piezometer taps (one or more of which may be provided on
          the top ring of the stay ring) at locations to be determined by the Contractor
          subject to acceptance by the Engineer.
6       All lugs, jacks, foundation bolts, anchors, tie rods and turnbuckles, bracing, etc,
necessary to facilitate assembly and prevent distortion during pressure testing and concreting
shall be supplied by the Contractor. The casing plates shall be formed so that field joint gaps
and misalignments do not exceed 3 mm. The accuracy of the platework shall be proven in the
shop and all bracing, clips, dowels, etc, properly fitted before disassembly and shipment.




                                           TM-1.9
                                      TM-1 Turbine

Each casing shall be shop-assembled to its mating stay ring. All sections shall be properly
match-marked before disassembly.
7       Unless materials of spiral case dictate otherwise, all longitudinal joints in the spiral
case and stay ring shall be shop welded where possible. Shop-welded spiral case sections
shall be stress relieved in a furnace at a temperature between 600°C and 650°C if required by
ASME code. The Contractor shall provide copies of the certified time-temperature record for
furnace stress relieving. Various sections shall be shop welded or cast to form pieces as large
as shipping clearances will permit. All welds on or adjoining the spiral case shall be subject
to 100% radiographic (RT) inspection, per TG-12. Where radiography is not suitable, other
weld inspection procedures shall be submitted to the Engineer for review during spiral case
design.
8       After all field welding of the spiral case has been completed and before the spiral
casing is concreted in, the Contractor shall remove all extraneous lugs, brackets, etc, attached
to the spiral case and shall grind flush any irregularities or protuberances left on the surface
of the spiral case.
9      Spiral case may be embedded in concrete while under internal hydrostatic pressure or
provided with additional temporary internal bracing, tie-rods, etc. If not embedded, the
Contractor‟s design shall allow for expansion of the spiral case when in service by provision
of a compressible material at the interface with the concrete.
10     After the concrete encasement is cured, the Contractor shall remove all internal
bracing and grind flush any irregularities on the surface.
11      Special precautions shall be taken to prevent cracking in the spiral case plates
adjacent to the stay ring bolting flange faces due to the discontinuity in the stay ring acting as
a "stress raiser".
12      One saddle flange outlet connection, complete with heavy removable stainless steel
grill or grating and studs and nuts, shall be provided for draining the casing. The size and
location of this connection shall suit the existing embedded piping.
13     The spiral case shall be fitted with a gage pressure indicating transducer and
transmitter at the distributor centerline elevation. This shall give a 4-20 mA signal over a
range 0 to 100 m head.
14    Wetted surfaces of the spiral case shall be painted to system 1, TG 14, exposed
nonwetted surfaces to system 4, TG-14.
TM-1.18 Stay Ring
1      The stay ring shall be of welded plate steel or cast welded construction, heat treated
before final machining to relieve locked-up casting or fabrication stresses and sectionalized
as necessary for handling and shipment. It shall consist of upper and lower rings, rigidly held
together by stay vanes which guide the water to the guide vanes. For fabricated stay ring with
shrouded plate design, the vanes shall protrude through the upper and lower rings and shall
be welded with full penetration welds. For fabricated stay rings with parallel plate design, the
stay vanes shall be welded to the flat plates with full penetration welds. The stay ring vanes
shall be designed and shaped to direct the water flow with a minimum head loss and to
eliminate vibrations.


                                            TM-1.10
                                     TM-1 Turbine

2       Machined flanges shall be provided for bolted connections between the stay ring and
the head cover, between the stay ring and the bottom ring or discharge ring. The pit liner
shall be welded directly to the stay ring.
3      The surfaces of the stay ring and the welded joints in contact with water shall be
ground to a smooth finish as specified.
4       Concrete placement under the stay ring shall be made using preinstalled concrete
tubing with small holes in the stay ring for venting, visual inspection of concrete filling and
final grouting. Air vent holes shall be provided through the webs in isolated pockets. All
holes shall be provided with closure plugs. The Contractor shall submit its concreting and
grouting procedure to the Engineer for review.
5       The design shall be such that the runner, head cover and guide vanes can be lifted
vertically for dismantling without having to dismantle anything below the head cover.
6      The stay ring shall be designed to support all loads superimposed upon it by the
concrete, hydraulic conditions during hydrostatic testing and operation of the turbine,
including the loads due to the generator and rotating turbine parts with the spiral case empty.
The stay ring shall also be designed to withstand the forces transmitted to it from the spiral
case under the maximum internal design pressure without the stresses exceeding the normal
permissible values specified herein.
7      The lower and upper rings of the stay ring shall be designed to transmit the loads to
the concrete with a bearing pressure not exceeding 4.0 MPa. The trailing edges of the stay
vanes shall be shaped to minimize vortex formation.
8       The Contractor shall perform a complete stress analysis of the stay ring and identify
the most severely stressed areas according to the requirements of the ASME Code. Particular
attention shall be paid in calculating the maximum bending stresses at the vane to shroud (or
parallel plate) and spiral case to shroud (or parallel plate) junctions. The calculated stresses
shall not exceed those permitted by the ASME Code. The calculations shall be made
assuming no support from the surrounding concrete. The method of computing stresses shall
be described in the Bid.
9       Plate steel for a fabricated stay ring shall be in accordance with ASTM A516, Grade
70, normalized. The Z- or through-thickness direction properties of the plate used for upper
and lower rings of a parallel plate design shall meet the requirements of ASTM A770 for
resistance to lamellar tearing. In addition to the tensile and bend test requirements of the
material specification, representative samples of the plate steel shall be impact tested
according to the requirements specified in TG-7.
10     Parallel plates, if used in a welded stay ring, shall be examined by ultrasonic testing
(UT) at and in the vicinity of the welds to the stay vanes and the spiral case plates.
11      Welding and inspection of the stay ring shall be in accordance with requirements of
the specifications in TG. The welds shall be ground to a smooth finish. All other areas of the
stay ring in contact with water shall have a surface finish of 12.5 m . The stay rings shall be
stress relieved before machining.
12      All butt welds and welds to spiral case plate shall be examined by 100% radiographic
testing (RT) and stay vane to shroud welds shall be examined by UT. All welds shall also be


                                           TM-1.11
                                     TM-1 Turbine

checked by dye penetrant testing (PT) or magnetic particle testing (MT). Any defects
discovered shall be repaired in accordance with TG.
13      The wetted surfaces of the stay ring shall be painted according to TG-14 paint system
No. 1, exposed nonwetted surfaces to TG-14, system 4.
TM-1.19 Hydrostatic Pressure Test
A hydrostatic pressure test of the spiral case and stay ring is not required unless the
Contractor elects to embed the spiral case under pressure, in which case the Contractor shall
submit details of the procedure for acceptance by the Engineer.
TM-1.20 Head Cover
1      The head cover shall be of fabricated steel plate. All butt welds shall be full
penetration and all welds shall be furnace stress-relieved. The head cover shall be of a heavy
construction, adequately ribbed and shaped so as to give rigid support to the guide bearing,
the operating ring and the bearings for the upper stems of the guide vanes. It shall be bolted
and dowelled to a flange on the stay ring and along radial joints.
2      All major stress carrying welds shall be full penetration. Radial ribs of the head cover
may be fillet welded. The underside of the head cover shall be designed to minimize friction
and eddy losses between the head cover and the runner, and the space between shall be
adequately drained to relieve water pressure and to minimize hydraulic thrust and leakage
(see TM-1.31).
3      Deflection of the head cover shall be small enough to prevent rubbing of the guide
vanes and binding of the guide vane stems. The method of computing deflections shall be
described in the Bid.
4      The head cover assembly shall have a machined seat for the turbine guide bearing,
guide vane regulating ring, shaft gland, guide vanes and any other equipment. The part of the
head cover which constitutes the guide bearing support structure shall be so designed as to
provide rigid support. A retaining ring or pads shall be furnished to prevent any lifting
tendency of the guide vane operating ring.
5       The guide seat for the guide vane operating ring shall be provided with a renewable
self-lubricated liner accurately machined so as to ensure minimum lost motion and friction in
the operation of the guide vane operating ring. Operating ring bearings shall be self-
lubricated.
6      At least four inspection holes shall be provided in the head cover to permit inspection
and check on clearances of the runner crown seals. The inspection holes shall have gasketed
covers bolted to the head cover.
7       Two self-lubricated bearings and a water seal with gland and V type packing shall be
provided for each of the upper guide vane stems. Suitable drains shall be provided for any
leaking water from the seals so that water cannot collect in the spaces between the ribs. All
bolts and nuts for the seals shall be of stainless steel. The lower surface of the head cover
shall be accurately machined to provide a Class A surface to the water passage at the
entrance to the runner as specified in TG-9. A wearing surface of stainless steel overlay or
removable stainless steel plates, attached with suitable stainless steel bolts and dowels, shall


                                           TM-1.12
                                     TM-1 Turbine

be provided on the lower face of the head cover above the guide vanes, extending radially
inward to the entrance of the runner. Raised lands shall be provided so that the leakage
through the closed guide vanes is a minimum, while providing adequate clearance for the
guide vanes in the open position when the head cover is pressurized.
8       A renewable stainless steel seal ring, accurately machined to form a water seal with
the runner crown and shaped to reduce leakage, shall be secured with suitable stainless steel
bolts and dowels to the head cover. Any hydrostatic pressure buildup behind the seal ring
shall be relieved through built-in pressure relief holes. Leakage of water through the seal
shall be directed to the draft tube without building up pressure under the head cover. A price
reduction for substitution of a fixed seal ring may be offered.
9       A minimum of three piezometer connections shall be provided on the head cover
piped to a common manifold equipped with suitable valves and a pressure gauge. These
connections shall be arranged so that radial variations of water pressure under the head cover
can be measured. The pressure gauge shall be mounted on the turbine pit wall. All piping for
this system shall be stainless steel.
10      Walkways around the head cover and turbine bearing shall be provided with gratings
or suitable protected openings to facilitate visual inspections of equipment located below the
walkways.
11     An adequate number of eye bolts shall be supplied to lift the head cover. The head
cover shall be designed to pass through the generator stator in one piece during erection and
dismantling and with the runner and shaft in place. Suitable opening(s) shall be provided in
the head cover for maintenance of the shaft seal without removal of the head cover.
12     Plate steel for a fabricated head cover shall be in accordance with ASTM A516,
Grade 60 or 70.
13     For welding purposes, the head cover shall be considered as a pressure vessel.
14    All butt welds shall be examined by 100% ultrasonic (UT) or radiographic (RT)
methods. All other welds shall be fully examined by dye penetrant (PT) or magnetic particle
(MT) methods.
15      The head cover shall be painted according to TG-14. Paint system No. 1 shall be used
for wetted surfaces. Other exposed surfaces shall be painted with paint system No. 4.
TM-1.21 Turbine Aeration
1       An automatic turbo vent air valve of 150 mm minimum dia piping shall be provided
for admission of air through an opening in the head cover or through the generator shaft to
the runner cone, to permit smooth operation of the unit. The outlet end of the air vent pipe
shall terminate as close to the center of the runner cone as possible. The intake end of the
pipe shall terminate at the upstream wall of the powerhouse. The valve shall act as a check
valve or shall be provided with a separate check valve to prevent reverse flow. An additional
check valve shall be provided to ensure additional security against reverse flow. The opening
of the valve shall be adjustable to allow control of the air flow to the draft tube. A
padlockable isolating valve shall be provided so that repairs can be made on the air valve
without shutdown of the unit.



                                          TM-1.13
                                      TM-1 Turbine

2       If aeration of the turbine is provided through the center of the shaft, an air head shall
be provided by the Contractor on top of the generator. The air head shall be connected by the
Contractor-supplied piping to the air vent valve. The Contractor shall coordinate the design
of the air head and piping with the generator supplier.
3       The air vent valve shall have means of automatic adjustment for opening and closing
at various guide vane positions and for altering the rate of closing. The air valve and piping
shall be large enough to permit rapid air entry at atmospheric pressure and without noise
levels exceeding 85 dBA.
4        In a straight section of the turbo vent piping, the Contractor shall install a pitot tube
head located at the center of the pipe and adequately supported. The pitot tube will be located
at least six diameters downstream and at least 2 dia upstream from any flow disturbance such
as an elbow or a valve. The pitot tube shall be connected to a calibrated gauge mounted on
the turbine pit wall. The velocity head measured by the pitot tube shall be converted into air
flow in the pipe. The gauge readings shall read flow in cubic meters per second.
Alternatively, the Contractor may install a commercially available air flow measurement
device such as `Annubar' in the turbo vent piping.
5      The design of the turbo vent outlet and runner cone shall ensure that the unit will
draw sufficient air, at atmospheric pressure, under critical operating conditions to ensure
hydraulic stability.
TM-1.22 Bottom Ring
1       The bottom ring shall be made from cast steel or welding plate steel, sectionalized as
necessary for handling, shipment and removal. If the ring is of welded design, all butt welds
shall be full penetration and all welds shall be stress relieved before machining.
2       The bottom ring shall be of heavy, rugged construction, and all necessary anchors and
adjusting screws shall be provided. Bronze self-lubricating bushings shall be provided for the
lower stems of the guide vanes. The bushings shall be an interference fit in the bottom ring
and shall be locked in place.
3       A wearing surface of stainless steel overlay or removable stainless steel plates,
attached with suitable stainless steel bolts and dowels, shall be provided on the upper face of
the bottom ring below the guide vanes, extending radially inward to the entrance of the
runner. Raised lands shall be provided so that leakage through the closed guide vanes is a
minimum, while providing adequate clearance for the guide vanes in the open position when
the unit is pressurized.
4       A renewable stainless steel seal ring, accurately machined to form a water seal with
the runner, shall be secured with suitable stainless steel bolts and dowels to the bottom ring.
The seal ring shall be designed to minimize leakage. Any hydrostatic pressure buildup behind
the seal ring shall be relieved by built-in pressure relief holes. A price reduction for
substitution of a fixed seal ring may be offered.
5      Wetted surfaces of the bottom ring shall be painted to system 1, TG 14.




                                            TM-1.14
                                      TM-1 Turbine

TM-1.23 Discharge Ring
1        The discharge ring shall be of cast steel or plate steel, sectionalized as necessary to
facilitate shipment and handling. If the discharge ring is of welded plate steel, all butt welds
shall be full penetration, and all welds shall be stress relieved before machining. It shall be of
heavy section and adequately ribbed externally to secure proper anchorage to the concrete
and to prevent distortion. Where Contractor‟s design indicates that cavitation may occur at
the discharge ring, stainless steel overlay or removable facings shall be provided.
2       The discharge ring shall have a flange at the top for bolting to the bottom ring or stay
ring. The lower end shall have either a flange for bolted connection or an extension for
welded connection to the draft tube liner. The necessary foundation bolts shall be supplied
for anchoring the discharge ring to the concrete, and adjusting jacks with steel bearing plates
shall be furnished to facilitate leveling during installation. Suitable grout holes with plugs
shall be provided in the discharge ring, as required, for concreting and grouting.
3      The lower end of the discharge ring or, alternatively, the draft tube liner flange shall
be machined to form a ledge for support of the runner and turbine shaft when disconnected
from the generator.
4      Wetted carbon steel surfaces of the discharge ring shall be painted to system 1,
TG-14.
TM-1.24 Draft Tube Liner
1       The draft tube liner shall be of plate steel having a minimum thickness of 12 mm and
shall be adequately ribbed and stiffened to prevent distortion. The top of the liner shall be
machined true to level and diameter for bolting or field welding to the discharge ring. It shall
extend to a point 1 m beyond the tip of the central pier nose, and include a steel nose
covering 1 m long anchored to the pier. If the Contractor‟s design require a longer liner
extent, the Contractor shall provide separate pricing for the additional length required. The
Contractor is responsible for ensuring a smooth transition from the termination of the liner to
the existing concrete draft tube, including grouting, concreting, formwork, preparatory
treatment of existing concrete, embedded steel, anchors, etc. The first 0.5 m of the liner
below the runner band shall be faced with or constructed from stainless steel conforming to
ASTM A743 Grade CA 6NM.
2       A watertight and airtight manhole door, having a clear opening not less than 750 mm
wide by 900 mm high, complete with studs and nuts, shall be provided in the draft tube liner
in a location determined in consultation with the Engineer. The manhole door shall have
rounded corners, hinged to open outward into the access passageway. The hinges shall be of
rugged design and provided with an adjustment to align the door. Stainless steel bolts not less
than 24 mm in dia, and an endless gasket of 3 mm Garlock red rubber or approved equivalent
shall be provided to prevent leakage during pressure surges. Stainless steel jacking bolts shall
be provided. The inside surface of the door shall be contoured and ground flush with the
inside of the draft tube liner. A test cock which provides a clear bore in the open position for
rodding shall be installed in the draft tube liner below the door. A draft tube pressure and
vacuum gauge connection shall also be furnished in the liner. A 300 mm dia flanged pipe
connection shall be provided below the door for draining the draft tube.



                                            TM-1.15
                                       TM-1 Turbine

3      The liner shall be completely assembled and matchmarked in the shop with all ribs
accurately fitted. To facilitate field installation, the liner shall be shipped in as few pieces as
shipping limitations will allow.
4       A sufficient number of leveling screws, jacks, turnbuckles and hold-down bolts shall
be provided to permit centering, leveling and securely holding the liner, both vertically and
laterally, during assembly and while concrete is being placed. Suitably spaced grout holes
shall be provided to facilitate final lowpressure grouting of the liner after shrinkage of the
embedding pour has taken place. Suitable plugs shall be installed in the grout holes and
ground flush after grouting is completed.
5      Wetted surfaces of the liner shall be painted to system 1, TG-14, nonwetted exposed
surfaces to system 4, TG-14.
TM-1.25 Draft Tube
The draft tube is of the elbow type. The Contractor shall be responsible for reviewing the
existing draft tube substructure concrete outline with regard to design and details which
could affect the performance of the new unit. Removal of the existing bulkhead is specified
elsewhere in these specifications.
TM-1.26 Runner
Design and Construction
1       The runner shall be a fabricated one piece runner made from plate with stainless steel
blades and band. Plate steel blades shall be appropriately contoured by machining, to ensure
high turbine efficiency. The runner crown may be stainless steel or carbon steel, with a
stainless steel surface at the head cover seal.
2       A fabricated stainless steel runner cone shall be bolted to the underside of the crown.
All bolting shall be stainless steel.
3      Materials for runner construction shall be as follows:
        Runner blades, band ASTM A487/A743 CA 6NM
        Runner crown CA 6NM (as above) or ASTM A516M, Gr 485
4      Mill Certificates shall be provided to the Engineer for the turbine runner blades,
crown and band, coupling bolts, runner cone and wearing rings.
5      The runner shall be connected to the shaft by through-bolts with nuts and locking
devices. The coupling bolt holes in the runner shall be line reamed with the runner and shaft
assembled. The fit of the bolts shall be in accordance with the minimum values shown in the
most recent issue of ANSI/IEEE 810. The connection shall be designed for tightening and
holding from above, as required for incremental assembly.
6      The contour of the runner blades shall be accurate and shall be finished so that the
vane profile precisely conforms to the design within the tolerances set out in IEC Publication
60193, except as otherwise specified herein. The blades shall be evenly and symmetrically
spaced. Before shipment, Contractor shall submit proof that the finished runner contours and
shape agree with the design requirements.




                                            TM-1.16
                                     TM-1 Turbine

7       If a fabricated runner is used, all welds shall be full penetration and furnace stress
relieved. The Contractor shall provide copies of the certified timetemperature record for
furnace stress relieving. During stress relief, the weldment shall be adequately supported in
the furnace to prevent distortion due to its own weight. After stress relief, the welds shall be
chipped or ground to the correct contour, and shall be magnetic particle inspected.
8       The joint preparation between the blades and the crown and band shall be double
grooved to ensure complete penetration through the full thickness and length of the joint. At
the joints near the entrance and discharge edge of the blades the weld root area shall be
gouged to sound metal by suitable means after sufficient weld metal has been deposited from
the first side. The gouged area shall be magnetic particle inspected prior to depositing any
weld metal on the second side of the joint. The length of weld root to be gouged at each
entrance and discharge edge shall not be less than 15% of the blade length.
9       All welding shall be visually inspected frequently for cracks and other defects. After
the final weld is completed and the surface ground smooth to the final surface, the welded
joint shall be fully inspected by magnetic particle method. In addition, the welds at each
entrance and discharge edge of the blades shall be inspected by ultrasonic methods over a
distance of at least 15% of the blade length. Any defects shall be chipped or gouged to
expose sound metal prior to any subsequent welding. The reweld area shall be inspected
during welding and after completion as required for the original weld.
10      The welding filler metal or electrodes used shall be of a grade suitable for the
material being welded, and shall be suitable for all position welding. No welding electrode
larger than 3/8 in. diameter shall be used. When welding the blades, a jig fixture shall be used
to ensure proper position and spacing of the runner blades.
11      The blade positions shall be checked several times during welding to assure that the
proper position is maintained. Care shall be exercised during the welding operations, to
minimize distortion by employing adequate bracing, intermittent skip welding around the
runner, and avoiding excessive localized heating.
12      During welding operations, the runner shall be positioned so that insofar as practical
all welds are made in approximately the down-hand position.
13    Peening may be used to control distortion and for relieving localized stresses;
however, the first and last layer of deposited weld metal shall not be peened.
14      Prior to assembling the runner for welding, all accessible water passage surfaces shall
be finish machined and/or ground to the correct contour, except in those areas that, due to the
manufacturing procedure, must be finished following the completion of all welding. Any
irregularities which might be conducive to pitting shall be corrected by welding and grinding.
15     After machining and finishing, the run outs on the band and crown sealing surfaces,
the coupling face and location recess shall be measured and recorded. These records shall be
made available to the Engineer on request.
16      The runner seal rings shall be renewable and of a weldable grade of stainless steel.
Special attention shall be given to the reliability and anti-galling characteristics of the
rotating and stationary rings which shall be given securely fastened in place using stainless
steel bolts and dowels.



                                           TM-1.17
                                     TM-1 Turbine

17      Contractor shall prepare and submit to the Engineer for acceptance a detailed
fabrication procedure for the runner before starting fabrication. The fabrication procedure
shall include details of welding, peening, preheating, nondestructive testing requirements and
stress relieving.
18    The runner shall be designed to withstand safely the stresses due to operating at
runaway speed under conditions of maximum head with no load on the generator.
19     The runner shall be designed to support its own weight and the weight of the turbine
shaft when disconnected from the generator shaft with the runner resting on a shoulder of the
discharge ring or draft tube liner flange.
20      The radial clearances between the runner and stationary seal rings shall be as small as
possible, consistent with safe operation and with the clearances required in the turbine and
generator guide bearings. Provision shall be made for vertical movement of the runner and
shafts to allow for adjusting and dismantling the generator thrust bearing and for clearing the
generator shaft coupling spigot.
21     Provision shall be made to permit aeration of the draft tube through the runner crown
should operating experience show this to be necessary or desirable.
22      For Contractor‟s information, the existing Units 1 and 3 runners were manufactured
by Allis Chalmers with a discharge diameter of 79 in. and 15 blades and for a rated head of
215 ft.
Runner Profile and Surface Finish
1      The quality control for the runner, as outlined below, is based on the guidelines given
in the Electric Power Research Institute Report EPRI AP 4719 dated August 1986. The
surface profile classes are defined in TG 9.
2       The Contractor shall fabricate and maintain accurate templates of durable material to
check blade profile during runner manufacture and on completion, prior to shipment. The
templates shall be mounted in such a way that their shapes are not disturbed during use. A
complete set of templates shall be provided to the Employer at the time of shipment of the
runner.
3        The Contractor, before manufacturing begins, shall prepare a written inspection plan
of steps to be taken to ensure homology from the design to the final manufactured runner.
The plan shall be submitted to the Engineer for review. The plan shall specify the acceptance
criteria (i.e., tolerances) and shall include sketches showing locations of measurements with
sample record sheets for tabulating the results of any inspection. The results of the homology
checks shall be documented in reports submitted to the Engineer as runner manufacturing
progresses.
4     The surface profile classes (TG-9) shall, as a minimum, be applied in the following
manner.
Area Class
Suction Side of Blade
       -   leading edge extending 0.06 D* toward trailing edge A
       -   trailing edge extending 0.1 D toward leading edge A


                                          TM-1.18
                                         TM-1 Turbine

       -    from band one third blade length toward crown A
       -    remainder of suction surface B
Pressure Side of Blade
       -    leading edge extending 0.06 D toward trailing edge A
       -    from band one third of blade length toward crown A
       -    remainder of pressure surface B
Crown and Band
       -    fillet areas Same as adjacent
blade surface
       -    Remainder B
       *D = runner discharge diameter.
5      The maximum deviation in blade profile shall meet IEC 60193.
6      The Contractor shall establish more restrictive controls than those specified above if
he considers this necessary to suit design and operating conditions and ensure all guarantees
are met.
7      The Contractor's engineer responsible for the runner hydraulic design shall inspect the
runner at various stages of manufacture, and shall certify in writing that the manufacturing
process is such that the specified tolerance for hydraulic design will be achieved. Copies of
the written certification shall be submitted to the Engineer. This certification shall be
provided at the following stages.
          Blade pattern;
          After blade forming;
          After machining of first blade is complete;
          After fit up of four to six blades;
          After final machining.
Balancing of Runner
1      The runner shall be accurately balanced statically and dynamically in the shop to
meet balance quality G6.3 of the ISO Standard 1940 at normal operating speed.
2      The hydraulic unbalance of the runner shall be within 1.5% of the average vent
opening. The hydraulic unbalance shall be calculated by vectorially adding the average
discharge vent openings for each of the blades. The final vent measurements shall be made in
the shop after all welding and grinding work on the runner is completed.
TM-1.27 Shaft
1       The turbine shaft shall be made of forged carbon steel, properly heat treated in
accordance with TG-7. It shall be provided with integrally forged coupling flanges top and
bottom for connecting to the generator shaft and to the runner hub, respectively. It shall be of
ample size to operate at any speed up to the full runaway speed without detrimental vibration
or distortion and to operate at maximum output without exceeding normal design stress.
2      The Contractor may propose a hollow fabricated shaft design if it can be proven that
such a design does in fact meet the requirements of the specification. All drawings and


                                            TM-1.19
                                     TM-1 Turbine

welding procedures for this alternative design shall be submitted to the Engineer for review
before manufacture commences.
3       The turbine shaft shall be accurately machined all over and polished where exposed
to view from the guide bearing journal, up to and including the coupling and the coupling
guard to a surface finish of 3.2 ìm. All welded parts of the shaft shall be coated in accordance
with System 1 of TG-14 to prevent corrosion and corrosion cracking. The guide bearing
journal and the shaft seal sleeve shall be polished to give a finish not to exceed 0.4 ìm Ra (Ra
= roughness average as defined in ANSI/ASME B46.1).
4      The shaft shall be hollow bored to a diameter of at least 150 mm throughout its entire
length and shall have a finish of approximately 3.2 ìm. The Contractor shall perform a
borescope inspection of the shaft material.
5       The shaft shall be provided with a boss to form the journal at the bearing and a boss
to support a wear-resistant sleeve at the shaft seal. The sleeve shall be made in two halves,
removable and renewable and securely fastened to the shaft. After assembly on the shaft, the
sleeve shall be accurately machined and polished. The sleeve shall be made of AISI 410
stainless steel or approved equivalent. Effective means shall be adopted for the prevention of
corrosion of the shaft underneath the sleeve. Suitable oil baffles and water deflectors shall be
provided between the main guide bearing and the shaft seal.
6       The amount of shaft runout shall be checked by rotating the finished turbine shaft in a
lathe or aligning device in the Contractor's shop. The amount of runout shall not exceed the
tolerances recommended for turbine shafts in NEMA Standards for Vertical Hydraulic
Turbine Generator Shaft Runout Tolerances MG 5.1. Two bands shall be marked on the shaft
for use with reference plugs for alignment. The bands shall be concentric with the shaft and
polished to a finish of 0.4 ìm Ra. The turbine generator shaft coupling shall be designed in
accordance with ANSI/IEEE 810. The lower shaft coupling to the runner shall be
dimensioned so far as is practicable in accordance with ANSI/IEEE 810 standards.
7       Immediately above the bearing housing, a circumferential line shall be inscribed on
the shaft, and an adjustable pointer shall be mounted on the bearing housing opposite this line
to indicate if any axial movement of the shaft occurs, and to permit realignment after thrust
bearing dismantling.
8      The outer cylindrical surface of the flanges shall be marked with `H' to show the high
spot on the face of coupling.
9       The Contractor shall finish the recess of the female half coupling of the generator
shaft to standard tolerance.
10      The Contractor shall be responsible for the final reaming of the coupling bolt holes
and coupling up and aligning of the turbine and generator shaft in the field, including use of
steel drilling template and pin gauge for the coupling. The Contractor shall furnish the
coupling bolts for coupling the shafts together, as well as the nut guard on the turbine side of
the coupling.
11      The field alignment procedure for shaft and bearings shall be accepted by the
Engineer prior to the start of assembly. The publication "Hydroelectric Turbine-Generator
Units Guide for Erection Tolerances and Shaft Alignment", published by the Canadian
Electrical Association, 1990, is recommended as a basis for the assembly procedure. Under


                                           TM-1.20
                                     TM-1 Turbine

the conditions of rotational test, the runouts at the turbine bearing shall not exceed 0.02
mm/m length of shaft between the generator thrust bearing and the turbine guide bearing.
12     In operation of the assembled turbine and generator
        static runouts at the turbine guide bearing shall not exceed half the amount of the
          total bearing clearance across the diameter
        vibration shall not be excessive relative to best modern practice for similar units.

TM-1.28 Guide Bearing
1       The turbine guide bearing shall be of the babbitted oil-lubricated type preferably self-
cooled and shall be self-lubricating oil flow design. The bearing shall be self-pumping for oil
circulation and shall be designed and constructed to be free from oil throwing or from
emission of oil vapor.
2       A segmented pad type bearing is preferred with individual adjustment of the position
of the pads and of the alignment. It shall be as near to the runner as possible, consistent with
convenient access to the shaft water seal. The bearing arrangement shall permit axial
movement of the shaft.
3       The bearing reservoir shall have removable top cover plates to prevent dirt or foreign
matter from entering the bearing. The bearing shall be made of cast steel or welded plate
steel of heavy construction. The bearing shall be rigidly supported on the turbine head cover.
Irrespective of the material used, the bearing shall be stress relieved between the rough and
finished machining operations.
4      The bearing shall be split vertically into two or more sections to facilitate dismantling
and the mating sections shall be dowelled securely. The design of the bearing and oil
reservoir shall permit their inspection, adjustment or removal without disturbing the head
cover or major dismantling of other parts of the turbine. The bearing design shall be such that
no water shall enter the lubricating system via the shaft seal and there shall be no loss of oil
by leakage past the lower oil shedder or by overflow from any part of the oil system under
any condition of normal operation within the range of headwater and tailwater elevations
from speed-no-load to full load.
5      The unmachined internal portions of the bearing and the inside of the oil reservoir
shall be sandblasted, blown clean and painted with an oil resistant enamel applied as
described in TG-14, Paint System 2.
6       Babbitt shall be in accordance with the specification outlined in TG 7. The babbitt
lining shall be securely anchored or bonded to the shell and shall be accurately bored and
shall be suitably grooved for oil circulation. The lining shall be fitted and scraped where
required to eliminate high spots.
7      The bearing shall be of adequate design to operate under all starting, running and
stopping conditions met in normal operation, fault conditions, commissioning and
maintenance.
8        Suitable lifting eyes and backing out studs shall be provided for use in removing and
installing the bearing.



                                           TM-1.21
                                      TM-1 Turbine

9       If cooling of the lubricating oil is necessary, a water cooled heat exchanger, 120%
capacity, shall be provided, designed for immersion in the oil reservoir. The cooler shall be
the straight through design made of stainless steel. All connections shall be made outside of
the oil reservoir. These shall be arranged such that water from a leaking connection cannot
drip into either the bearing or the oil reservoir. A water-in-oil sensor shall be provided with
alarm light on the turbine and generator gauge panel.
10     Cooling water will be available at a temperature and quality to be determined by
Contractor at the site. See also TM-4.12. If further filtration is required, the Contractor shall
provide all necessary equipment, controls and instrumentation.
11     The bearing shall be capable of operating without damage
          continuously at any speed up to full rated speed
          for 30 minutes at runaway speed
          for 15 minutes at rated speed without cooling water or oil circulation
          for 5 minutes at runaway speed without cooling water or oil circulation
12      The Contractor shall be responsible for making the connection to and supplying all
piping inside the turbine pit, including the necessary tees for the main shaft seal and bearing
supplies. All piping shall be provided with a sufficient number of Victaulic couplings to
permit ease of removal.
13      The lubricating oil system shall have sufficient capacity to supply the required
amount of oil to the turbine guide bearing, and the oil reservoir shall have sufficient capacity
to hold all the oil in the entire bearing system, and to provide cool oil to the bearing under all
conditions of load. The bearing design shall prevent the leakage of oil down along the shaft
and shall provide for returning oil from the bearing to the reservoir. Piping for filling the
bearing and reservoir shall be separate from the drain piping.
14     The Contractor shall also supply and install the following indicating and protection
devices for the guide bearing:
        two dial type temperature controllers to indicate the hottest part of the bearing.
          Each controller shall have two sets of separately adjustable contacts suitable for
          operating alarm and tripping circuits at 220 V dc. The temperature controllers
          shall be mounted by the Contractor on the governor actuator cubicle (see TM-2)
        two resistance temperature detectors (platinum, 100-ohm, three-wire, double
          element) one for the bearing and one for the oil so that both the bearing and oil
          temperatures may be indicated and recorded at a remote location
        one turbine bearing water flow transducer 4 to 20 mA with direct reading
          instrument (if required)
        one solenoid valve on cooling water supply line, failsafe type, energize to close,
          suitable for 220 V dc operation
        one direct visual indicator of the bearing oil level marked in litres and high-, low-
          level and trip adjustable alarm contacts with 220 V dc contact rating.
15     All thermometer bulbs and detectors shall be installed in dry wells.




                                            TM-1.22
                                      TM-1 Turbine

16      Turbine bearing oil lubrication system shall be designed to provide sufficient oil
circulation and cooling for all starting, running and stopping conditions met in normal
operation, fault conditions, commissioning and maintenance.
17      Temperature in the bearing pads shall not exceed 60¢ª C at the maximum cooling
water temperature.
TM-1.29 Lubricating Oil
Type of oil is specified in TG-17.
TM-1.30 Shaft Water Seal
1       A water seal shall be provided below the bearing which shall prevent the leakage of
water along the shaft. The shaft seal shall be arranged for water lubrication. Two or more
connections for water shall be provided, evenly spaced on the periphery to admit a supply of
clean water at a pressure sufficient to exclude foreign matter from the seal. Any leakage
water from the seal shall be removed by drains. The seal shall be so arranged that it may be
serviced without disturbing the bearing or unwatering the draft tube. For its base bid the
Contractor shall include a packing type seal similar to the existing seal on Units 1,3 which
consists of a packing box located in the head cover below the turbine guide bearing oil pot. It
is supported on the head cover and is adjustable by tightening a gland that compresses the
sealing elements. The sealing elements are two groups of square, flexible lead impregnated
cord separated by a bronze Hring, which is used as a chamber into which water is admitted to
lubricate the packing. For Unit 2, the sealing elements shall employ PTFE or similar rather
than lead. The Contractor shall provide the change in pricing for substitution of the packing
type seal with a self-aligning, balanced split face type seal. The seal shall be self-
compensating for wear, with seal water injected directly between the mating faces and all
wetted surfaces of corrosion resistant materials. All fasteners shall be stainless steel. Wearing
faces shall incorporate a wear indicator.
2       A secondary sealing device shall be provided below the main seal to allow the
packing to be serviced. This device shall be interlocked with the unit automatic starting
system to prevent start-up when in use. This secondary sealing device shall prevent leakage
along the shaft when the turbine is stationary and subjected to tailwater pressure and shall be
inflated by compressed air. The Contractor is advised that service air is available for this
purpose. The Contractor shall supply and install the necessary pressure reducing station and
all associated piping.
3        Suitable devices, such as lifting bolts and backing-out studs, shall be provided to
facilitate installing and removing shaft seal parts.
4       Water for the shaft seal shall be cooling water drawn from the same source as that for
the guide bearing.
5      A shaft water seal flow transducer 4 to 20 mA with direct reading instrument shall be
provided in the water supply piping to the seal. A 150 mm duplex pressure gauge shall be
provided for indicating the pressure beneath the seal and in the supply line.
6      The Contractor shall provide the necessary water filtration equipment, piping and
valves, including pressure reducing valves, piping and fittings within the turbine pit
terminated by Victaulic couplings, unions or flanges at the connection to embedded piping.


                                           TM-1.23
                                     TM-1 Turbine

Filtration shall remove particles larger than 25 ìm and shall be provided with automatic
backwash equipment with controls, and shall be sized to ensure continuous maintenance-free
water supply to the shaft seal. Piping shall be provided with a sufficient number of Victaulic
couplings or unions to permit ease of removal. All piping and fittings shall be stainless steel.
7       All bolts, nuts, screws and hardware used in connection with the shaft water seal shall
be of stainless steel.
8      The shaft seal housing shall be made of steel with corrosion resistant surfaces where
required to ensure proper operation and easy maintenance of the whole assembly.
TM-1.31 Guide Vanes and Operating Mechanism
1        The turbine shall be equipped with one set of stainless steel guide vanes. The Bidder
shall submit a base Bid using cast construction but may offer fabricated construction as an
alternate. The Bidder may also submit an alternate of carbon steel construction with stainless
steel overlay. The guide vanes shall be uniform in shape and their cross sections shall be such
as to direct properly and accelerate gradually the water entering the runner with a minimum
of friction and hydraulic disturbance. The guide vanes shall have a self-closing tendency over
the greater part of their operating range.
2     The number of guide vanes and the number of runner vanes shall be coordinated in a
manner to ensure that the turbine will operate without objectionable vibrations.
3       The guide vane material shall be cast stainless steel in accordance with ASTM A743,
Grade CA 6NM. Each casting shall be fully examined by MT and UT at the stem to guide
vane fillets.
4       If of welded design, the billets for the stems shall be ordered sufficiently large to
permit the guide vane stems to clean up during machining without first having to weld up
scarf marks left by the steel mill. Each side of each guide vane shall be formed of one plate
for the purpose of maintaining a uniform contour and reducing friction. Fabrication details
shall be accepted by the Engineer before the alternate welded design will be accepted.
5       The guide vanes shall be accurately machined and ground to a smooth finish and even
surface. The tips and contact surfaces shall be machined to template in such a fashion as to
provide for uniform contact when in the closed position. All guide vanes shall be
interchangeable. At least one guide vane shall be drilled through to provide a drainage hole
(see TM-1.20).
6       The guide vanes shall be carefully fitted along the line of contact during shop
assembly within 0 mm to 0.05 mm maximum clearance to ensure minimal leakage when they
are closed against headwater pressure.
7      Each guide vane shall be provided with self-lubricated guide bearings in the bottom
ring and head cover. The intermediate stem bushing shall be provided with V-type packing.
8       Each upper guide vane stem shall be provided with a self-lubricated thrust bearing or
collar. Positive means shall be provided to permit the vertical clearance of the guide vanes to
be adjusted from above the head cover. Wear washers are not acceptable.
9     Guide vanes, stems, links and operating rings shall be designed to produce a
minimum of lost motion and friction. The guide vanes shall be connected through couplings,


                                           TM-1.24
                                     TM-1 Turbine

links and levers to the guide vane regulating ring. The link pins shall be of the eccentric type
with at least 6 mm eccentricity to facilitate adjustment. During tower assembly and before
dowelling of the guide vane stems, the eccentric pins shall be set in such a way that all of the
6 mm adjustment is available to the Employer for future adjustment. The design shall be such
that repairs and replacements can be easily and quickly made with minimum dismantling of
the turbines.
10      The guide vane regulating ring shall be made of cast steel or welded steel plate with
all welds full penetration and stress relieved. The guide vane regulating ring and guide vane
mechanism shall be so designed as to remain undisturbed when dismantling and replacing the
main guide bearing and accessories.
11      The guide vane operating mechanism shall be of ample strength and power to operate
the guide vanes and to withstand the maximum load that can be imposed on it by the most
severe operating conditions. All parts having relative contact in motion shall be provided
with self-lubricated bushings.
12      A suitable shear pin or breaking link shall be provided between each guide vane stem
and the regulating ring and shall be strong enough to withstand the maximum normal
operating forces, but which will break or release in the event of excessive forces acting in
either the opening or closing direction and will protect the rest of the mechanism from
damage in case one or more of the guide vanes become blocked.
13      Stops shall be provided to limit the angle of movement of the guide vane stem levers
in case of breaking of the shear pin or link so that interference of the loose guide vane with
operation of the other guide vanes will be prevented.
14      As a precaution against damage when a guide vane is free to rotate due to breakage of
a shear pin or link, the guide vane levers shall be restrained from excessive movement by
means of a friction device located on the guide vane stem which provides a restraining force
between the guide vane coupling and lever. The friction device shall be designed to resist
independent movement of the guide vane for the maximum hydraulic torque at any guide
vane position. The friction device mechanism on each guide vane shall be tested during
installation to ensure performance as designed. The Bidder shall offer a price reduction for
deletion of the friction device.
15     A manually adjustable stop shall be incorporated, with which the motion of each
guide vane in the opening direction can be positively limited.
16      An alarm feature shall be provided so that a circuit shall be broken in the event that
any one of the shear pins fails. Connectors shall be provided at each shear pin to facilitate
repair of the alarm circuit in the event of failure. The alarm circuit shall be protected from
damage by flexible or rigid conduit where appropriate. It shall be terminated at a junction
box on the wall of the turbine pit for connection to external circuits. Each replacement shear
pin included in spare parts inventory shall be wired ready to connect into the alarm circuit.
17     Exposed surfaces of the operating ring shall be painted to system 4, TG-14.
TM-1.32 Servomotors
1     The turbine shall be provided with two oil pressure operated double-acting hydraulic
servomotors having a combined capacity sufficient to supply the maximum force necessary


                                           TM-1.25
                                      TM-1 Turbine

to operate and hold closed the guide vanes, under maximum operating head, at the minimum
oil pressure. The servomotors shall be designed for the maximum allowable working
pressure of the governor system.
2        The servomotors shall be rigidly supported from the stay ring on pedestals or from the
pit liner and shall be capable of moving the guide vanes from a completely closed position to
a fully open position in one stroke and vice versa. The servomotors shall be recessed into the
pit liner so that the head cover can be removed without disturbing the servomotor cylinders.
3       The servomotor cylinders shall be made of cast steel or welded steel plate. Welds
shall be full penetration and stress relieved.
4       The servomotor piston rod shall be provided with self-lubricating bushings. The
piston rod shall be arranged for adjustment of stroke. The piston rod shall be coated with
hard industrial chromium of not less than 0.3 mm thickness or suitable ceramic. The
connecting rod pins shall be hardened and ground. Cushioning shall be provided over the last
10% of stroke in each direction.
5       The inner surface of the cylinder shall be bored to a uniform diameter and shall have
a surface of 1.6 ìm Ra or better to allow the piston to traverse freely and smoothly and to
reduce oil leakage past the piston to a minimum. Chevron type packing shall be used to
prevent oil leakage from the cylinder past the piston rod. The piston connecting rod shall be
of forged steel of uniform diameter. Each piston shall be fitted with not less than three piston
rings, suitably shaped to give close contact and uniform pressure on the cylinder walls. The
servomotor cylinders shall be provided with flanges for connecting oil piping. Connections
for pressure gauges shall be provided at each end of each cylinder. An air vent and a drain
cock shall be provided on each servomotor for air release and oil draining. Outlet of each
shall be provided with a plug.
6       The servomotor cylinder shall be designed and located so that the force for moving
the turbine guide vanes shall be divided approximately equally between the two cylinders
and shall be applied in substantially equal magnitude to opposite sides of the guide vane
regulating ring and tangentially to the ring.
7       Provision shall be made for adequate field alignment of the servomotors using
leveling or dutchmen plates supplied by the Contractor. The servomotor flange shall be
dowelled in the field to its mounting flange.
8       A manual locking device of a simple construction to permit locking the guide vanes
in either the open or closed position and capable of withstanding safely the full operating
force of the servomotors shall be provided at the servomotors. The device shall be such that it
can be easily engaged and disengaged by one man. Electrical contact switches suitable for
indication for 220 V dc system shall be provided to indicate guide vane lock in the fully open
and fully closed positions. An additional contact for unit start interlock shall be provided. All
contacts shall be wired to terminal blocks in the turbine terminal box.
9       Bypass connections, equipped with orifices and/or adjustable needle valves, with a
secure means of locking the adjustment, shall be provided on the servomotors to retard the
rate of closure of the guide vanes slightly below speedno- load to the fully closed position.
The bypass connections shall be fitted with check valves to prevent sluggish movement on
opening the guide vanes from the fully closed position.


                                           TM-1.26
                                       TM-1 Turbine

10      A suitable pointer and scale, graduated in tenths with subdivisions, shall be provided
at the servomotors to indicate the percent stroke of the servomotor and guide vane angle in
degrees from the closed position. The scale shall be calibrated in the field and marked
`closed' at one end of the scale and `opened' at the other end.
11     Each servomotor shall be fitted with a stroke limiter which is capable of manual
adjustment. Means for positively locking the adjustment shall be provided.
12    The servomotors shall be painted on the outside as described in TG 14, Painting
System No. 4.
13     Servomotors shall be pressure tested according to TG-18.
TM-1.33 Turbine Pit Liner, Walkways, Platforms and Stairways
1       A pit liner of heavy steel plate, with servomotor pockets, shall be provided. It shall be
made in sections with bolted or welded connections as necessary for shipment. The bottom
shall be prepared for welding to the stay ring with full penetration welds or provided with a
flange machined and drilled for dowelling and bolting to the stay ring. The vertical pit liner
plate wall shall not be less than 16 mm thick, except in the section containing the two
servomotors which shall be not less than 20 mm thick. The liner shall be adequately ribbed
and substantially anchored to the surrounding concrete in order that forces may be
transmitted from the structure above the casing through to the stay ring without appreciable
distortion of the pit liner. Suitable provision shall be made for the support of the servomotor
cylinders and for the transmission of servomotor reaction forces through the pit liner to the
surrounding concrete. Additional pit liner anchors shall be provided by the Contractor in the
vicinity of the servomotor mountings to ensure adequate support.
2       The sections of the pit liner containing the servomotor pockets shall be thermally
stress relieved and the surfaces of the servomotor support plates shall be machined after
stress relieving.
3       The top of the pit liner shall be provided with a drain channel and take-off pipe(s) of
sufficient dimensions to handle all water leaking through the concrete around the pit liner.
All leakage water shall be piped to the existing drainage sump. Contractor shall provide
additional embedded piping if required.
4      The pit liner shall extend a minimum of 3 m above the centerline of the distributor.
5       Maintenance, operation and inspection walkways and platforms, complete with floor
plates or gratings, stairs and handrails, shall be furnished in the turbine pit to provide
convenient and safe access to all operating equipment and points of inspection and
lubrication. In addition, walkways, platforms and stairs shall be designed to provide access
not less in scope and space provision than that existing for Units 1 to 3. Minimum width of
walkways, stairs and platforms shall be 600 mm clear space. Ladder access shall only be
permitted at the Engineer's discretion to points requiring infrequent access. The design of the
floor plates, gratings, stairs and handrails shall facilitate easy removal to permit free access to
the turbine. All walkways and platforms shall have 50 mm high kickplates.
6      Platforms and walkways shall be designed for live loads not less than those specified
in TC-1, except as noted. The platform around the shaft shall be designed to support the
weight of the turbine guide bearing.


                                            TM-1.27
                                     TM-1 Turbine

7       Walkways, platforms, stairs, handrails, kickplates and exposed surfaces of the pit
liner shall be painted to system 4, TG 14.
TM-1.34 Drains
Adequate provision for drainage of turbine pit leakage water shall be provided, together with
piping to interconnect with the holes passing through the stay vanes. Necessary piping and
valving shall be provided to permit complete drainage of the spiral case, including new
embedded piping if required.
TM-1.35 Not Used
TM-1.36 Service Air Compressors
The station has service and brake air. This system should have adequate capacity for Unit 2,
on the basis that the requirements are similar to those of Units 1 and 3. The Contractor shall
be responsible to connect up to those systems and verify the adequacy of same. Any
additional requirements shall be identified and provided by the Contractor, subject to
acceptance by the Engineer.
TM-1.37 Electrical
1      The Contractor shall supply all the necessary switches, contactors, magnetic starters
and relays with the turbine electrical auxiliaries according to this subsection and other
sections of the specifications.
2       All electrical items supplied by the Contractor shall comply with the appropriate
section of the ANSI, NEMA and EEMAC standards. The arrangement and layout of
electrical items shall be subject to acceptance by the Engineer. The Contractor shall provide
and install terminal boxes in locations which will be accepted by the Engineer, and shall
provide and install all wiring and conduit from his electrical components to these terminal
boxes. All electrical wiring and conduit within the turbine pit, including wiring for pressure
and flow switches, temperature relays, and thermometer alarms, shall be supplied by the
Contractor, and shall terminate at terminal blocks in the turbine terminal box located in the
turbine pit and supplied by the Contractor. All wiring shall be stranded wire, insulated with
600-V oilproof insulation.
3      Refer also to TG-10 for other electrical requirements.
TM-1.38 Not Used
TM-1.39 Installation Equipment, Wrenches, Tools and Fixtures
1       The Contractor shall supply all tools required for normal maintenance and repair for
each item of the work including one complete set of case hardened open-end wrenches to fit
all nuts and bolts on the turbine.
2       Each tool shall be new and marked with its size and/or purpose. All tools shall be
suitably arranged in lockable tool boxes, except where otherwise specified. A list of the tools
contained, stamped on an attached metal tab, shall be included.
3      The Contractor shall provide all slings and special lifting attachments for the
equipment.



                                          TM-1.28
                                     TM-1 Turbine

4      In addition to the above, the Contractor shall furnish
        tools and devices for installation, dismantling and adjustment of shaft seal
          components
        tools and devices for installation and maintenance of turbine guide bearing
        tools for other auxiliary equipment provided.
All large tools and wrenches shall be new, and insofar as practicable, be mounted on a
suitable board arranged for wall mounting and provided with means for ready identification.
5      All tools in their boxes together with all other tools, devices, slings, lifting
attachments, etc, provided by the Contractor, all in good order, shall be handed over to the
Employer at the time of issue of the Taking Over Certificate.
TM-1.40 Contractor’s Design Calculations and Data
1       The Contractor shall submit, for acceptance by the Engineer, copies of all its detailed
calculations. Calculations shall be of sufficient detail to show all design parameters,
references, material specifications, allowable stresses supported by references, etc, and shall
be submitted in conjunction with the Contractor's drawings.
2      In particular, calculations shall be submitted regarding
        structural analysis of stay ring, spiral case, head cover and bottom ring, draft tube
          and pit liners, for deflection and stress as appropriate
        structural analysis of runner
        interaction of governor and pressure regulator to confirm timing and linkage
          arrangement
        speed and pressure rise on load rejection using turbine guide vane flow,
          recognizing nonlinearities in the guide vane linkage
        pressure rise on full load rejection simultaneously on Units 1, 2 and 3, taking into
          account actual operating parameters of Units 1 and 3, to ensure that the design
          pressure is not exceeded
        structural analysis of hollow cone valve including adequacy of support vanes to
          prevent vibration
        compressed air systems
        pressure oil system
        natural frequencies of the unit (torsion, vertical)
        avoidance of resonance between draft tube surge frequencies and natural
          frequency of all rotating parts
        no load and system governor gain settings recommended by the Contractor
        shaft whirling speed, recognizing all bearing support stiffnesses and generator
          field (unbalanced magnetic pull).
3       The Contractor shall also provide other calculations as required by the Engineer for
his review and acceptance of the Contractor's design.




                                           TM-1.29
                                      TM-1 Turbine

TM-1.41 Pressure Regulator
1      A hydraulically balanced pressure-type, pressure regulator shall be provided,
complete with hollow cone valve, energy absorber, discharge liner, piping, controls, access
hatches at different floors to the valve chamber and anchor bolts.
2      The regulator shall operate as a pressure relief in conjunction with the governor and
turbine to limit water hammer pressure rise caused by rapid closure of the turbine guide
vanes. Allowable pressure rise is set by the design of the existing penstock and shall not
exceed 10% during simultaneous full load rejection of all 3 units. The Contractor shall
confirm this limitation by examination of existing drawings and design data and shall
perform calculations of pressure rise for Engineer‟s review and acceptance. The results of a
turbine index test performed on Unit 3 in 1975 are attached in Appendix A for the
Contractor‟s information.
3       The performance and operating characteristics of the pressure regulator shall equal or
exceed that of the existing pressure regulators for Units 1 and 3. The entire regulator
mechanism, including the linkage connection to the turbine, shall be designed to withstand
safely all normal operating loads; including full load rejection on three (3) units; and also any
abnormal loading that may be imposed due to failure of control components or loss of control
pressure.
4       The regulator shall have a discharge capacity of not less than 100% of the turbine
discharge capacity under maximum turbine output with the guide vanes at full open position,
so that when operating on “water saving”, full or part load rejection by the turbine will be
followed immediately by no less quantity of water discharged through the regulator than was
rejected by the turbine. In addition, with the regulator flow adjusted to have a discharge
capacity equal to 100% or more of the maximum turbine discharge, the discharge through the
regulator during load rejection shall be not less than the turbine discharge reduction at all
guide vane openings throughout the stroke for the head range specified.
5      With the regulator set at “water saving”, the normal guide vane closing shall not
cause any opening of the regulator.
6       The regulator shall be designed to open completely in the minimum time that the
governor is capable of making a full-closing stroke. With minimum time setting, the
governor full or part closing stroke from any guide vane position shall not cause a penstock
pressure rise in excess of 10% of the maximum static head or a speed rise in excess of 45%,
to be confirmed by the Contractor‟s design. In order to reduce the force exerted by the
governor mechanism to operate the regulator, hydraulic balance shall be incorporated in the
design.
7       The mechanism shall be designed so that the regulator will remain closed with the
spiral case empty and during and after the filling process without manipulation of auxiliary
devices. Also, it shall be designed so that it can be opened or closed by a single manual
device when the spiral case is empty.
8      The regulator operating mechanism shall be provided with a solid connection to the
turbine guide vanes operating ring. The connection shall be sufficiently strong to stall the
servomotors, should the regulator stick and fail to open and shall retard the closing action of
the servomotors to a time interval not less than the set closing time of the regulator when


                                           TM-1.30
                                     TM-1 Turbine

operating “water saving”. The connection to the regulator shall include an adjustable length
operating lever and rock-shaft and an adjustable length operating rod, to permit varying the
stroke and discharge capacity of the regulator with respect to the turbine. The hydraulic
system shall use oil from the governor oil system.
9       The pressure regulator, energy absorber and discharge liner shall be capable of
continuous operating under all conditions without objectionable noise, vibration or excessive
cavitation. The continuous period of operation at full capacity, during which time no
maintenance will be required, shall be stated in the Bid.
10     The body and energy absorber shall be either cast steel, normalized and tempered; or
steel weldment, properly stress-relieved, or a combination of both.
11     The regulator inlet shall be connected directly to the spiral case without an
intermediate valve and shall be attached in a manner to minimize hydraulic disturbances. The
nozzle entrance to the pressure regulator shall be adequately mechanically reinforced on the
outside. Vanes will not be permitted inside the water passage.
12     Removable and renewable stainless steel seat rings shall be provided on the main
plunger and body.
Parts of the regulator which may be subjected to heavy cavitating action, especially around
the discharge throat area, shall be lined with or made from stainless steel.
13      Air-vent pipes shall be provided to admit sufficient air to the regulator discharge
areas for smooth continuous operation. The separate vent pipes shall be not less than 300 mm
pipe size and shall extend from the regulator to the tailrace wall of the powerhouse with
screened intakes above the flood line.
14      The discharge chamber shall have a water tight removable hatch for convenient
access to the discharge chamber and for removal of the pressure regulator valve. A test cock
shall be provided at the proper elevation to determine if the water level in discharge liner is
below the hatch.
15      The discharge liner for the regulator and energy absorber shall extend from the
regulator to the tailrace gate. It shall be designed to minimize erosion in the tailrace. A
common tailrace gate slot will be used for one draft tube gate and the pressure regulator
tailrace gate. The liner shall be designed to withstand the dynamic and vibration forces
imposed on it under all operating conditions. The construction requirement for the turbine
draft tube, including anchoring requirements, drain connections, etc. shall apply to the
regulator discharge liner.
16      The pressure regulator valve shall be pressure tested in the Contractor‟s shop at 150%
of the maximum operating pressure.
17      All parts of the pressure-regulator installation, that require bleeding of air after the
spiral case or penstock is dewatered, shall be provided with suitable automatic air valves of a
design accepted by the Engineer.
18     The regulator shall be designed to operate “water-saving” with the closing time
adjustable to suit penstock conditions.




                                           TM-1.31
                                       TM-1 Turbine

19     The design of the control shall prevent hunting of the regulator under all operating
conditions.
20     The entire control system shall be designed “fall safe” i.e., failure of any component,
including loss of control pressure, shall not impose dangerous stresses or endanger the
regulator or turbine and penstock in any way.
21     Regulator position indicator shall have white background and black numerals and
scale markings, and shall be mounted for convenient visibility. The position indicator shall
be graduated in tenths of regulator opening.
22     Limit switches shall be provided for regulator fully closed, regulator fully open.
23    Pressure gauge shall be provided to indicate dashpot oil pressure. The gauge shall be
conveniently visible.
24      All necessary gauges, valves, relays, pressure and limit switches gaskets, piping,
indicating lights, nameplates etc. shall be provided for a complete and operable pressure-
regulator installation.
25       Bolted and gasketted inspection covers or hatches shall be provided as required to
facilitate inspection and maintenance.
TM-1.42 Inspection and Tests
General
1       All equipment shall be subject to inspection and testing by the Contractor as specified
herein and in TG-18.
2       The Contractor shall furnish certified copies of all test results, the results of each test
shall be recorded in the form of test certificates or reports.
Type Tests
3      Type tests may be offered by the Contractor, as specified in TG-18, provided the
Contractor gives evidence to the Engineer as to the similarity of the equipment tested and the
Contract equipment.
Shop Tests
4      The equipment shall be subjected to shop tests as specified in GC 13 and in
accordance with the latest issue of the applicable standards.
5      In addition, the Contractor shall perform the following shop tests:
(a) Material Tests
Material tests shall be as specified in TG-18.
(b) Hydrostatic Tests
Hydrostatic tests shall be as specified in TG-18.
(c) Shop Tests
Shop tests as specified in TM-1.



                                            TM-1.32
                                      TM-1 Turbine

Field Tests
6      The Contractor shall carry out field inspections and tests as specified in GC-14 and in
accordance with the latest issue of the applicable standards.
7       In addition, the Contractor shall perform the following field tests. Complete tests shall
be made at the site to determine the performance and operating characteristics of the
complete unit and to determine whether or not the guarantees have been met. Tests on the
turbine shall include the following:
        alignment and rotation checks in the dry
        mechanical run, including an overspeed test that trips the overspeed switch and, if
          requested by the Engineer, to full runaway speed for one minute
        governor operation
        guide vane timing tests
        measurement of shaft run-out over complete range of speeds and loads
        guide-bearing temperature tests
        proving of interlocks and indications
        load and overload tests
        load rejection tests (25%, 50%, 75%, and 100% output)
        investigation of any objectionable vibrations, pressure or power surges or noise
          under any operating condition
        guide vane servomotor pressure differential tests over complete range of load
        index tests
        other tests as required by the Engineer.
           The index tests shall be performed to determine relative performance of the unit
           to compare the unit performance curve with the guarantees and to verify the
           power guarantees.
           The index tests shall be performed in accordance with the IEC Publication No.
           60041, "International Code for the Field Acceptance Tests of Hydraulic
           Turbines", including the latest issue of the draft chapter on index tests. The
           Contractor shall calculate prototype performance based on the peak efficiency
           predicted from the model test data.
        All necessary instrumentation and equipment for the commissioning tests shall be
          provided by the Contractor unless otherwise specified in this Specification.
Output Guarantee Test
8       The Contractor shall carry out a test to confirm that output guarantees of the turbine
as stated in the contract document have been met.
Efficiency Guarantee Tests
9       Testing to verify the turbine efficiencies shall be done by the Contractor prior to
issuing the Taking Over Certificate.
10     Tests shall be carried out in accordance with IEC Publication 60041.




                                           TM-1.33
                                     TM-1 Turbine

11      A minimum of 10 operating points over the flow range shall be measured for the
selected net head. Multiple testing of individual test points may be carried out, as determined
by the Contractor, in which case, results for this test point shall be averaged for guarantee
evaluation purposes.
12      The net head shall be measured between the piezometer ring downstream from the
inlet valve and the tailwater level.
13     The output from the unit shall be measured at the generator current transformer and
generator losses added to arrive at turbine outputs.
14     For purpose of evaluation of performance guarantees, the efficiency test results shall
be considered as correct without any tolerance for accuracy or error.




                                          TM-1.34
                        TM-1 Turbine

Appendix A
Unit 3 Turbine Index Test




                            TM-1.35
                                         TM-2 Governors
                                        Table of Contents

TM-2    Governors ...........................................................................………….........TM-2.1
  TM-2.1 Purpose and Function ..................................................…………..........TM-2.1
  TM-2.2 Drawings ....................................................................…………..........TM-2.1
  TM-2.3 Standards and Codes ....................................................…………….......TM-2.1
  TM-2.4 Ratings and Performance ...........................................…………….........TM-2.2
  TM-2.5 Quantities and Descriptions .......................................…………….........TM-2.3
  TM-2.6 Guide Vane Position Feedback ...................................……………........TM-2.4
  TM-2.7 Scheme of Control, Indication and Annunciation .......……………........TM-2.4
  TM-2.8 Controls and Instruments ...........................................……………........TM-2.7
  TM-2.9 Speed Sensing ...........................................................……………........TM-2.11
  TM-2.10 Speed Switches .........................................................………….........TM-2.11
  TM-2.11 Emergency Shutdown Device ....................................…………........TM-2.12
  TM-2.12 Governor Electronic Equipment .................................…………........TM-2.12
  TM-2.13 Stability .......................................................................………….......TM-2.15
  TM-2.14 Electrical Power Supply ..............................................……………......TM-2.15
  TM-2.15 Governor Oil Pumps .....................................................…………......TM-2.17
  TM-2.16 Pressure Tank ................................................................……………....TM-2.18
  TM-2.17 Sump Tank ....................................................................…………......TM-2.19
  TM-2.18 Piping, Valves and Controls .........................................……………....TM-2.20
  TM-2.19 Installation Equipment, Wrenches, Tools and Fixtures ……………...TM-2.20
  TM-2.20 Contractor‟s Design Calculations .....................................………..…TM-2.21
  TM-2.21 Inspection and Tests .........................................................…………..TM-2.21
  TM-2.22 Spare Parts .......................................................................…………...TM-2.21
  TM-2.23 Governor Air Compressor ................................................………….TM-2.22
  TM-2.24 Conversion of Units 1 and 3 Governors to Digital Control ..................TM-2.22




                                                   TM-2.i
                                   TM-2 Governors

Kajakai Hydroelectric Project
Addition of Unit 2
Technical Specification
TM-2 Governors
TM-2.1 Purpose and Function
1      This section describes the governor equipment to be supplied for Unit 2 and the
requirements for the conversion of Units 1 and 3 governors to digital control. The existing
services in the powerhouse are described, and the connections that will be required for the
new governing equipment are defined.
2       The governor shall be a digital electronic type, microprocessor-based, programmable
and electro-hydraulic. It shall be complete with speed sensing elements, mechanical and
electronic restoring mechanisms, pressure system, oil piping, shutdown solenoid, oil pressure
and level failure relays, guide vane limit position switches, speed switches, mechanical guide
vane limit control assembly, brake valve and all parts and accessories required to constitute a
completely automatic assembly for regulating the speed and controlling the guide vanes of
the turbine with which it is to be used.
3      The governors shall operate a pressure regulator connected to the turbine scroll case.
Refer to TM-1.41 for Unit 2 pressure regulator specifications and requirements imposed on
governor.
4       Layout of the governor and actuator cubicles, the pumps and tanks shall be similar to
existing units and shall be accepted by the Engineer.
5     It is the intent of these specifications that the new and converted governors shall be
complete with all necessary devices for completely automatic and local manual control, and
shutdown.
6       The new governor and parts used for the converted governors shall be of a proven
design with an established history of satisfactory operation in hydroelectric generating
stations. Components shall be of a class which will provide long-term and safe operation.
7      Prior to proceeding with detail design of the new and converted governors, the
Contractor shall submit a Design Memorandum to the Engineer for review. The Design
Memorandum shall outline the rating, performance, control, instrumentation, alarm features,
operating sequence, etc, including a detailed listing of local and remote devices to be
supplied. The Design Memorandum shall take account of the existing controls and
instrumentation (Contractor check in field) and define any changes to this specification
required.
TM-2.2 Drawings
The accompanying drawings form part of this specification.
TM-2.3 Standards and Codes
1      The equipment shall comply with the requirements of the latest revisions of the
following standards, where applicable.


                                           TM-2.1
                                    TM-2 Governors

       IEEE 125            Recommended Practice for Preparation of Equipment
                           Specifications for Speed-Governing of Hydraulic Turbines
                           Intended to Drive Electric Generators
       ASME B31.1          Power Piping Code
       ASME PTC29          Speed Governing Systems for Hydraulic Turbine-Generator Units
       IEC 308             International Code for Testing of Speed Governing Systems for
                           Hydraulic Turbines
2     Unless otherwise stipulated in this section of the specification, the equipment shall
comply with the requirements and the latest revisions of the applicable standards as listed in
TG-3.
3       If this specification conflicts in any way with any of the standards and codes so listed,
the more stringent requirement shall govern. However, the Contractor shall bring these
conflicts to the Engineer‟s attention to permit discussion at least 4 weeks prior to finalization
of Contractor‟s design.
TM-2.4 Ratings and Performance
1       The rating of the governor shall be not less than the torque capacity of the
servomotors for operation of the turbine guide vanes. The governor shall be capable of
supplying sufficient oil to the servomotors to operate the turbine guide vanes to give an
effective time of 12 seconds for a complete closing or opening stroke with the recommended
minimum oil pressure and under the maximum net head on the turbine. The minimum
governor time shall be determined by the Contractor to ensure that the design pressure of
spiral casing is not exceeded under the worst pressure rise of a three-unit load rejection.
Calculations for this shall be submitted as specified. The velocity of the oil in the pipes shall
not exceed 4 m/s at the maximum rate of guide vane movement.
2     The nominal operating pressure of the governor hydraulic system shall not exceed
4800 kPa. The maximum system operating pressure shall not be more than 1.1 times the
nominal operating pressure.
3      The speed deadband at rated speed shall not exceed 0.02%.
4      The dead time shall not exceed 0.20 s for a step load change of 10% of the rated
capacity of the turbine or for step speed change of 1% of the rated speed of the turbine.
5       Speed Stability Index – When the generating unit is operating independently and
under steady state load demand, the magnitude of the envelope of the speed variations caused
by the governor shall not exceed 0.3% with the unit operating at 5% speed droop.
6       Power Stability Index – When the generating unit is operating in parallel with other
generators and under steady state load demand, the magnitude of the envelope of the load
variation caused by the governor shall not exceed 0.4% with the unit operating at 5% speed
droop or regulation.
7      Load Rejection - Following rejection to zero load from any load, the speed
(subsequent to the initial overspeed deviation) shall be returned to the set point, with no more
than one underspeed deviation (not to exceed 5%) and one overspeed deviation (not to
exceed 5%) of rated speed.



                                            TM-2.2
                                    TM-2 Governors

8       Load Change on Isolated Load – When rejecting or accepting an isolated load, the
governor shall provide a suitably damped speed control defined by the response of the unit to
a step-change (increase or decrease) of the load, such that the second speed deviation shall be
attenuated to less than 20% at the first speed deviation.
9      Transient Immunity – System and individual components shall be free from false
operation or failure for all magnitudes of transients that can occur in the control circuitry and
power supplies external to the governor cubicle speed signal generator. Good design practice
in accordance with IEEE 125 shall be used (including, but not limited to, shielded cables,
surge suppression on all inductive devices such as solenoids and relays).
10   Ambient Temperature – The governor shall be capable of continuous operation at a
maximum ambient temperature of 40°C.
11      The governor performance shall be based on the following system characteristics
        -   water starting time
        -   effect of surges in the intake water passages and in the tailrace (to be determined
            by Contractor)
        -   pressure regulator characteristics
        -   generator stored energy constant
        -   system frequency varying between 95% and 105% of rated frequency; and turbine
            operating singly or in combination with other units over full range of head and
            flow.
TM-2.5 Quantities and Descriptions
1      The Contractor shall design, supply and install turbine speed governing equipment for
Unit 2 consisting of the following.
Quantity     Description
2            Governor oil pumps including motor, drive and controls
1            Governor oil jockey pump including motor, drive and controls
1            Pressure tank including valves, gauges, switches, etc
1            Sump tank including valves, gauges, switches, etc
2            Governor air compressors including motors, drives and controls
1 Lot        Electronic speed sensing elements, speed switches, position sensors, feedback
             devices
1            Governor cubicle including all wiring, valves, instrumentation, controls and
             electrical devices
1            Actuator cubicle including actuator and control assemblies, valves, wiring,
             instrumentation controls and electrical devices
1 Lot        Instrumentation and electrical devices for remote mounting
1 Lot        Software for governor system
1 Lot        Equipment interconnections
1 Lot        Shop and field tests
2       This work includes:
        -   all interconnecting piping and wiring including couplings, valves, flanges, filters,
            junction boxes, electrical enclosures


                                            TM-2.3
                                   TM-2 Governors

       -   piping and electrical termination and tie-ins to existing/new facilities
       -   all instruments control and safety devices
       -   all anchors, turnbuckles, fixtures, machine pads, jacks and foundation bolts for
           field alignment and installation
       -   all painting materials and test equipment for field painting and touch-up
       -   all special tools and devices for handling, assembly, installation, erection,
           dismantling at site
       -   all equipment, tools, instruments and devices for conducting field tests
       -   all welding materials and equipment for site welding
       -   any other item not specified above but necessary to complete the manufacture,
           assembly, machining, erection, commissioning and testing
       -   oil for the first filling of the hydraulic system.
3      The Contractor shall assume responsibility for
       -   field checking of the location and dimensions of all structures, equipment, piping
           or other services that may affect its work
       -   field checking of all its connections to, or interfacing with, existing structures,
           equipment, piping or other services.
       -   quality of all materials and workmanship supplied by the Contractor entering into
           the completed work
       -   rigid adherence to the dimensions of parts as shown on drawings
       -   governor characteristics guaranteed in the Contract
       -   satisfactory performance of the entire work under all specified operating
           conditions without signs of undue strain and without breakdown, cracking,
           damage or deterioration of any of the parts due to faulty or unsuitable material,
           design, workmanship, handling, storage, transportation, assembly or erection
           procedure
       -   stable operation of the entire work during opening and closing of the guide vanes
           under all turbine operating conditions.
4       The Contractor shall also convert the existing governor at Units 1 and 3 to digital
control.
TM-2.6 Guide Vane Position Feedback
A displacement non-contact type transducer shall be provided to measure servomotor stroke
and thus the guide vane position. The output from the transducer shall be used in the closed
loop speed controller, and to operate guide vane position indicators.
TM-2.7 Scheme of Control, Indication and Annunciation
1      The Contractor shall provide controls and instrumentation for the purposes of
commissioning and normal operations. Manual operation shall be from the actuator cubicle,
and normal control from the control room, or the governor cubicle. The governor design shall
include speed control, power control, gate limit control and manual control modes. All mode
changes shall be made with bumpless transfer.
2      The scheme of distribution of controls between the cubicles and control room
described in the following lists represents the Engineer‟s level of requirements. The



                                           TM-2.4
                                   TM-2 Governors

Contractor may, subject to the Engineer‟s acceptance, offer a scheme differing in some
details.
(a) Actuator Cubicle
All actuator and control assemblies shall be enclosed in a metal cubicle(s) of rigid
construction and neat appearance, which shall be dust-proof and properly ventilated. All
gauges, indicating, and control devices shall be mounted on the front panel of the actuator
cubicle in a symmetrical, convenient and functional manner. Inspection doors shall be
provided on all exposed sides and on top for access to the actuator equipment, and these
doors shall be fitted with handles and latches. Instruments within the cubicle shall be readily
accessible for adjustment and maintenance through the inspection doors.
Wiring within the actuator cubicle and small piping shall be neatly arranged and brought to
terminal blocks in approved locations. All incoming wiring and control cables shall enter the
cubicle from below the actuator cubicle.
The following devices shall be provided for use during commissioning and manual operation
of the unit.
Indicating Instruments
       -   tachometer
       -   guide vane position and guide vane limit
       -   generator load meter, MW
       -   governor system oil pressure
       -   spiral casing pressure gauge
       -   turbine guide bearing temperature indicators (2)
       -   generator guide and thrust bearing temperature indicators (4).
Controls
       -   initiate startup and shutdown
       -   guide vane limit (raise/lower)
       -   generator friction brake solenoid control switch "On", "Off"
       -   "Manual" (guide vane limit control)/"Automatic" (feedback) control selector,
           momentary contact
       -   emergency shutdown (manual valve)
       -   oil pumps controls, including lead-lag echelon controls and selection of
           "Manual"/"Off"/ "Automatic"
       -   inlet valve trip
       -   local/remote selection (to suppress any control action from the control room or
           locally depending on position, maintained position switch with indication)
       -   actuator lock release, momentary contact.
Indicating Lights
       -   governor guide vane limit (manual)/feedback (auto) selection
       -   actuator lock "on"
       -   shutdown solenoid apply/release
       -   oil pressure system warning lights for low oil pressure, low oil level, water in oil,
           oil filter pressure drop out of limits


                                            TM-2.5
                                   TM-2 Governors

       -    oil pressure system shutdown condition, extreme low oil level, extreme low
            pressure.
It is not acceptable for any fluid (oil, water) lines to enter the portion of the cubicle
containing electrical equipment.
(b) Governor Cubicle
The electronic section of the governor shall be housed in a separate cubicle. The cubicle shall
contain redundant dual processors, with watchdog checking so that a faulty processor can be
identified and power transferred to the remaining good processor. The cubicle racks shall be
accessible from the front of the cubicle after opening the cubicle door. The controls and
adjustments shall be accessible when the cubicle door is open.
The cubicle shall be located on the main floor in a similar position to the cubicles for units 1
and 3. It shall be provided with built-in air conditioning to maintain temperature and
humidity levels inside the cubicle at least 10% less than the maximum specified by
manufacturers of all components within the cubicle at an external temperature of 40°C and
relative humidity of 70%. At least the following facilities for indication and adjustments shall
be provided. Adjustment and display using a keyboard and display screen is acceptable.
       -   tachometer, indication at all times
       -   load, megawatt indication at all times
       -   load, megawatt setting, indication
       -   permanent speed droop, indication and adjustment
       -   speed control loop gains (Proportional, Integral, Derivative), for
load/off-load settings, indication and adjustment
       -   derivative gain time constant, indication and adjustment
       -   governor gain (automatic/no-load), indication and adjustment
       -   load set control time constant, indication and adjustment
       -   load feedback time constant, indication and adjustment
       -   watchdog monitor status indication
       -   deadband, indication and adjustment
       -   start position guide vane limiter (5 position)
       -   guide vane position indication
       -   guide vane limit, indication
       -   speed setpoint
       -   load setpoint
       -   governor loading rates, megawatt per second, four steps, indication and
           adjustment.
The following indicating lamps shall be provided. These shall be visible at all times.
       -   governor remote (control room) mode "on"
       -   unit breaker "close"
       -   governor auto control "on"
       -   load ramp rate, 4 lamps
       -   actuator lock "on"
       -   speed sensor failure
       -   power supply failure (primary power, backup power)


                                            TM-2.6
                                   TM-2 Governors

       -   alarm from oil pressure system
       -   guide vane feedback system failure, one lamp each for mechanical, electronic
       -   mechanical overspeed system tripped
       -   creep detection alarm
The following terminals for external alarm shall be provided in the cubicle:
       -   actuator lock on
       -   speed sensor failure
       -   governor gain selection (no-load/system)
       -   watchdog monitor status
       -   power supply transfer to "back-up"
       -   power supplies failure
       -   oil pressure system alarm/failure
       -   guide vane feedback system failure
       -   mechanical overspeed device tripped
Speed signal contacts are listed in TM-2-10. Speed switches are to be separated from the
governor, and will have a separate power supply and speed transducer. They may be used for
redundant checks before applying brakes, excitation or main breaker closure.
(c) Control Room
The following devices shall be mounted on the main control bench board in the control room
of the power station.
Indicating Instruments
       -   tachometer reading in revolutions per minute
       -   guide vane position and guide vane limit (analog display, not selsyn type)
       -   load set point (megawatts), digital indication, 0 – 120% of rated.
Controls
       -   startup; normal, partial and emergency shutdown
       -   mechanical guide vane limit (raise/lower contacts)
       -   load set control (raise/lower contacts)
       -   generator friction brake (on/off maintained contact, action may be inhibited by
           sequence controller)
       -   generation ramping rate selection (4 rates selectable, 4 momentary contacts).
Indicating Lights
       -   generator friction brake "on"
       -   generation ramping rate selection, one of four lights to indicate rate selected
       -   fault, alarm and ready status (one indicator for each of the three conditions)
       -   diagnostic messages for incomplete start or shutdown sequences or other
           conditions
       -   local/remote control mode selected.
TM-2.8 Controls and Instruments
The following describes the intended functioning and special requirements of the controls
and indicators.


                                            TM-2.7
                                    TM-2 Governors

(a) Manual Guide Vane Position and Guide Vane Limit
The mechanical guide vane limit device shall limit the degree of guide vane opening at any
position within the full range of guide vane travel. The limit shall be adjustable at all times
from the actuator cubicle, and from the operator's control panel when remote control is
selected at the actuator cubicle. The actual position of the guide vane limit shall be displayed
at both locations at all times.
When on manual control and the actuator lock is not applied, the unit shall open the guide
vane to the limit regardless of speed as sensed by the normal speed sensor. When on
automatic control, the guide vane position shall be determined by normal governor action
based on unit or system speed, droop setting and load setting. Guide vane position shall not
exceed the limit in either manual or automatic control.
The mechanical guide vane limit device shall be electric motor driven with direct hand
control at the actuator cubicle. The device shall be provided with three position controlled
switches. One of these shall be used to deenergize the drive motor in the opening direction at
the full guide vane position. One shall be used to de-energize the drive motor in the close
direction at the closed position. The third switch shall be used to deenergize the motor in the
close direction at a guide vane position approximately equal to the speed-no-load guide vane
opening. In the event of a protective shutdown condition, the mechanical guide vane limit
device shall shut the unit down by setting the limit device to zero for protection backup
operation.
The guide vane limit drive motor shall have provision for changing the speed of operation in
the range of 5% of guide vane full opening per second to 10% of guide vane full opening per
second.
(b) Partial Shutdown (speed-no-load) Device
An electronic partial shutdown device shall be provided which limits the guide vane opening
to slightly above synchronous speed, whenever the unit is off line.
An electronic start position guide vane limit shall be provided. It shall include a five position
selector switch to provide five different guide vane openings to compensate for variation in
headwater elevation
(c) Speed Adjustment Control and Indication
Speed control shall be located at the control room. The speed setting will be used when the
unit is off-line and may be adjusted for commissioning or testing purposes. The automatic
synchronizer (or the control room operator) will adjust the speed setting to bring the unit into
synchronism. Speed adjustment will be raised up or lowered in response to contact closure by
the synchronizer or operator action. The speed adjustment shall be implemented through an
electronic operated speed-adjusting device. After the unit is synchronized, the speed setting
shall be automatically returned to the nominal synchronous speed setting. Speed adjustment
range shall be 85% to 110% of rated speed with a granularity of 0.01%.
(d) Load Set Point Adjustment Control and Indication
Load adjustment control shall be from the governor cubicle and the control room using
raise/lower adjustment devices. A selector switch with four maintained contact positions
shall also be provided to allow selection of a ramp rate (0.1 MW/s, 0.2 MW/s, 0.3 MW/s, 0.4


                                            TM-2.8
                                    TM-2 Governors

MW/s, to be confirmed by Contractor), with indicating lamps to confirm rate selection. Load
set point adjustment will be implemented by program in the controller.
Power control shall be automatically selected after synchronizing and breaker closure.
Optimum governor gains shall be preselected for network operation and shall be applied as
soon as power control is effective. When operating on power control, the speed feedback
loop shall remain fully functional and shall use the synchronous speed (automatically reset to
synchronous after synchronizing) as the reference. When operating on power control, the
operator will set the desired power output, but the actual response shall be biased (depending
on speed droop or regulation) if network frequency deviates from the nominal synchronous
frequency. When operating on manual control, the power control set point shall be
automatically adjusted to suit the actual output so that transfer from manual to power control
can be done with no significant interruption or change in output.
(e) Permanent Speed Droop/Load Regulation
Permanent speed droop shall be adjustable and indicated at the governor cubicle only. The
speed droop adjustment range shall be 0 to 10% and shall be adjustable when the unit is
operating on the system.
(f) Guide Vane Control
It shall be possible to operate in guide vane opening control mode from the governor cubicle
and the control room, by changing the feedback signal from load control to guide vane
control through a selector switch in the governor cubicle.
(g) Manual Control
Manual control is required for testing and commissioning, and to permit the unit to remain
on-line while emergency repairs are carried out on the governor electronics.
It shall be permissible to select manual control when the unit is on-line, either by operator
action or as a result of protective action. The guide vanes will remain in the same position
(see actuator lock description), i.e., the position at the time of changeover, until the operator
releases the actuator lock. The operator may adjust the guide vane limit to the actual guide
vane position before releasing the lock to prevent a sudden change in load. The unit shall be
protected from runaway by the manual guide vane limit device, the shut-down solenoid and
the mechanical overspeed shutdown device when running on manual control. Manual control
shall be selected automatically on speed sensor failure, or on failure of the electronics of the
primary speed control loop. All equipment needed for manual control shall be independent of
power and speed control so that manual control can be used when other control modes are
shut down, deenergized or inoperative.
(h) Governor Gain Parameters
The governor shall normally select gain parameters depending on whether the unit is on line
or off line. Detection of unit on-line or off- line shall be through a load sensing device.
(i) Mechanical Guide Vane Position Switches
A switch assembly operated by the servomotor position transducer or restoring system shall
be provided. Each contact shall be adjustable to open or to close at any point from closed




                                            TM-2.9
                                   TM-2 Governors

position to full guide vane opening. These switches shall be included in the control scheme as
specified.
Contacts shall be electrically separate, ungrounded and suitable for 220 V dc operation.
(j) Generator Friction Brake Control
A solenoid operated air brake valve for controlling the operation of the generator air brakes
shall be supplied and mounted in the actuator cubicle. The air valve shall contain provision
for emergency hand operation. It shall be possible to secure the valve in the open position so
that the brakes are maintained on for maintenance purposes.
A control switch shall be provided in the control room. The control switch shall have `on' and
`off' positions. The switch shall be provided with spring return from the `on' position.
The following devices shall also be supplied:
       -   a pressure switch in the air line connection to the generator brake with contacts to
           open as an interlock to prevent unit start-up when brakes are applied
       -   a pressure switch on the air supply line to the brake air valve to energize an alarm
           circuit on low air pressure
       -   pressure gauges for indicating the air pressure in the air supply line to the brake
           air valve and also in the line to the generator brake.
(k) Tachometer
An electrically operated tachometer shall be supplied to indicate the speed of the turbine in
revolutions per minute. The synchronous speed shall be clearly marked and shall be at the
mid-scale point with the pointer in a vertical position. Tachometer output signal, 4 to 20 mA,
shall be provided for the speed indicator on the control desk in the control room.
(l) Oil Pressure Gauge
An electrically operated pressure gauge shall be mounted at the governor cubicle to indicate
the pressure in the governor oil pressure system. The gauge shall be graduated in MPa.
(m) Governor Guide Vane Velocity (Time) Adjustment
The actuator shall be equipped with means to adjust the opening and closing rates of the
guide vanes independently between a minimum of 12 seconds (TM-2.4) and a maximum of
24 seconds, and with a secure means of locking these adjustments.
The above rates are defined by the time required for a complete servomotor stroke at a
uniform rate. The guide vane servomotor shall be fitted with a cushioning device to control
closing rate for the final part of guide vane closure.
(n) Actuator Lock
A device shall be provided that causes the turbine guide vanes to lock in the current guide
vane position. This device shall be automatically applied when the governor is transferred to
manual (guide vane limit) control. The lock shall be effective until released by the operator,
or the unit is returned to automatic control. The actuator lock shall not prevent the unit from
closing under guide vane limit control or in response to any protective initiated shutdown.




                                           TM-2.10
                                   TM-2 Governors

(o) Spiral Case Pressure Gauge
An electrically operated panel meter shall be mounted at the actuator cubicle to indicate
spiral case pressure. The pressure transmitter shall be 4- to 20-mA output.
The meter shall be calibrated in meters of water and indicate a range of 0 to 150 m.
(p) Cabinet Lights and Power Receptacles
Vapor-proof lighting fixtures inside the cubicle and to illuminate operating devices and
instruments and the outside of the actuator cubicle shall be provided. The lights shall provide
adequate levels of illumination for operation and maintenance work and shall be operated by
an on/off switch for the outside lighting and an auto-matic switch for the inside lighting when
the cubicle door is opened.
One convenience power receptacle shall be provided inside the actuator cubicle and the
governor cubicle.
Lighting and power receptacles shall be wired separately from the governor supply and shall
operate from the 220-V, single-phase, 50-Hz, ac supply system.
TM-2.9 Speed Sensing
1      The speed sensing element of the governor shall receive its speed signal from an
independent speed signal generator using an inductive proximity sensing transducer, or
approved equivalent, which shall be furnished as part of the governor equipment. The use of
generator frequency as a speed signal is not permitted.
2      The speed signal generator shall be directly connected to the generator shaft, capable
of absorbing normal generator shaft movements and shall be electrically isolated from its
supports and from the generator shaft. The speed signal generator shall be designed to safely
withstand the maximum runaway speed of the turbine.
3      Speed sensors and associated power supply shall be duplicated to the speed control
loop digital controller. One set of equipment shall be dedicated to speed switches described
in TM-2-10.
TM-2.10 Speed Switches
1       A minimum of eight electrical speed switches shall be provided in the governor
cubicle. Each switch module shall be complete with an auxiliary relay having four
electrically separate contacts (2 NO and 2 NC). Contacts shall be field convertible, shall be
suitable for 220-V dc operation and shall be wired to a terminal block in the cubicle.
2      These switches shall be mechanical type and will be used as follows.
Overspeed Protection
To cause unit shutdown through the shutdown solenoid and the protection circuits,
       -   switch to close at and above 130% of rated speed.
First Stage Alarm
To cause the unit to be brought to speed-no-load through the mechanical gate limit,
       -   switch to close at and above 115% of rated speed.


                                          TM-2.11
                                    TM-2 Governors

Excitation and Synchronizing
To operate the generator excitation, field flashing and trip the generator breaker,
        -   switch to close at and above 90% of rated speed
        -   switch to close at and below 90% of rated speed.
Generator Oil Lift Pump
To operate thrust bearing oil lift pump,
        -   switch to close at and below 90% of rated speed.
Generator Brakes
Two switches to operate the generator brakes,
        -   the dynamic brake switch shall close at and below 50% of rated speed
        -   the friction brake switch shall close at and below 20% of rated speed.
Spare
        -   One spare switch shall be provided (installed).
Creep Detector
A rotational creep detector shall be provided and shall operate a relay to initiate a signal
should the unit begin to creep after being brought to rest. The relay shall be made active by
the governor sequence controller and a creep indication shall be given if motion is detected at
any time when the unit should be at a standstill. Operation of the relay shall also start the
high pressure oil pump for the thrust bearing. The creep detector shall also indicate zero unit
speed.
TM-2.11 Emergency Shutdown Device
1       A mechanical-hydraulic emergency shutdown device shall be designed and supplied
by the Contractor. The device shall be mounted below the generator on the main turbine shaft
to operate automatically at 10% above the maximum speed rise on full load rejection. The
device shall be adjustable, with a seal applied to indicate if the original setting has been
changed. It shall be capable of manual initiation for verification of operation. A manual reset
shall be provided. A means of confirming adjustment shall be provided, for example a spring
balance to measure the force required to trip the device when the unit is not rotating.
2       Operation of the device shall activate a hydraulic valve to act directly on the supply
oil pressure to the pilot servomotor of the guide vane relay valve, closing the guide vanes
irrespective of any other electrical signals or the action of other protective devices. The valve
shall operate without any electrical power supply.
3      An auxiliary contact device shall be provided for control and annunciation purposes.
The contacts shall be wired to the governor cubicle.
TM-2.12 Governor Electronic Equipment
1      All electronic equipment such as amplifiers and logic circuits shall be of solid state
design using industrial or military grade discrete transistors or integrated circuits, bearing




                                           TM-2.12
                                      TM-2 Governors

JEDEC or EIA registered device numbers. All components shall be suitable for long-term
operation at temperatures between 0°C and 70°C.
2       The governor system shall be immune from false operation or failure from high
voltage, high frequency transients (such as radio transmitters) that may be induced in the
control circuitry and power supplies internal and external to the governor system. Special
precautions shall be taken to limit exposure of sensitive governor electronic circuits
connected to remote equipment. These circuits shall be isolated by means of solid state
optical couplers.
3      All inductive devices, such as relay solenoids shall be provided with suppression
devices to limit surge voltages that may be generated when the coil circuits are interrupted.
The governing system shall be designed and tested for surge withstand capability in
accordance with ANSI/IEEE Standard C37.90.1 - Relays-Surge Withstand Capability (SWC)
Test.
4      The governor shall be a 3-term proportional, integral and derivative type. Each of the
terms shall be adjustable independent of the others.
5       A dual range of regulation parameters shall be provided, so that a set of gains that is
best suited for no-load and system operation may be selected. This selection shall be made
automatically depending on on/off load status. The range normally used for no-load
operation shall be applied if this control is activated. The following minimum adjustment
ranges shall be provided.
Adjustment Range
                                        Off Line        On Line     Granularity
        Integral Gain (K1)              0.01 – 1        0.01 – 10   0.001
        Proportional Gain (KP)          0–4             0 – 20      0.01
        Derivative Gain (KD)            0–1             0–5         0.01
6       All adjustments shall be calibrated so that the dial settings can be related to the
idealized governor equation
       y = e (KI / D + KP + KD·D)
where
     y = guide vane position
     e = error signal
     D = differential operator, d/dt
The error signal shall be obtained from speed and load setting
        e = R (Lset - Lact) + (Nset - Nact)
where
     R = permanent speed droop setting
     L = load (or guide vane position before main breaker closure)
     n = speed
     set = subscript indicating dial setting
     act = subscript indicating actual value.



                                              TM-2.13
                                    TM-2 Governors

7       A first order lag or filter shall be used in the load or guide vane feedback path, and
also in the derivative path, so that these filters affect only the load feedback and derivative of
the error signal respectively. The time constant of each filter shall be adjustable in the range
0 to 1.0 s.
8       A rapid load response set feature shall be supplied. The preferred method of
achieving this is to apply the load set signal to both the guide vane feedback summing point,
and to the final summing point for the P, I and D paths. The load set error signal should be
filtered before the final summing point. The time constant of this filter should be adjustable
in the range 0 to 20.0 s. The load set shall be adjusted by a raise/lower contact. The load set
shall respond by ramping up or down at a rate which is selectable by the operator. This
arrangement shall be implemented in software by the digital controller used for closed loop
control.
9       A deadband feature shall be provided which shall have the affect of suppressing
governor response to frequency variations within an adjustable frequency band. This feature
shall be active only when the unit is on-line and shall be automatically selected depending on
main breaker status. The adjustment range shall be 0.0 to + 0.5 Hz.
10      The digital controller for the primary speed control loop shall be programmed and
equipped to give a watchdog function. If this feature detects that the digital controller is not
functioning, then the governor shall revert to manual control. This condition shall be
indicated at the governor cubicle. The digital controller will attempt to restart automatically.
11 The minimum requirements for the digital controller are:
       -   The non-volatile memory shall be at least 20% larger than required for operation
           and storage at time of shipment.
       -   The system (including revisions) shall be programmable from local input via a
           laptop computer.
       -   Programming from a LAN shall not be possible. However, downloading of
           control levels and gate limits shall be possible.
       -   The status of any I/O signal shall be selected to be displayed on the HMI screen.
       -   A redundant microprocessor control unit shall be supplied which, in case of
           failure of the primary unit, shall assume control of the unit without interrupting
           operations.
       -   The redundant control unit shall also be equipped with a watchdog function
           which, in case of failure of the redundant unit, shall revert to manual hardware
           mode.
       -   The Central Processor Unit (CPU) shall be a 32-bit design with a multiprocessor
           capability.
       -   Two RS 232 C serial ports with a capability of running at speeds of at least 9600
           baud shall be provided, one of these ports will be connected and used to
           communicate with a SCADA system located in the control room. The software to
           be provided shall report on the start-up sequence and on any events occurring
           during normal operations. Provide interface software for use on a Windows XP
           based portable computer through RS-232 ports.
       -   Non-volatile electrically reprogrammable (EPROM) memory shall be used for the
           operating system and the normally executed control program. The functional


                                            TM-2.14
                                  TM-2 Governors

           requirement is that the controller shall recover automatically from an electronic
           fault in the CPU without requiring assistance from permanently installed magnetic
           disc or tape storage devices. The system shall revert to manual control while the
           digital controller resumes normal control. All operator-selected and time-
           dependent variables required for a restart of the processor shall be maintained in
           nonvolatile static memory.
       -   Adequate facilities are to be provided to permit the Employer to maintain and
           modify the control system to meet future needs. Facilities to be provided must
           include configuration aids, parameter adjustment aids and diagnostic aids. Menu-
           driven or block type programming aids are preferred. Any programming language
           to be used will be subject to approval by the Engineer. The Contractor shall be
           responsible for the correct operation of all software to the satisfaction of the
           Employer before acceptance of the unit.
       -   Major process variables (gate, load feedback, guide vane position) in analog form
           shall be converted with a minimum 12-bit resolution.
       -   The speed signal shall be brought to the governor cubicle in digital (i.e., pulse
           train) format. Precision shall be ƒp0.01%.
       -   The design shall be fail-safe and redundant as required to give high reliability.
TM-2.13 Stability
1       The governor system shall be capable of controlling, in a stable manner, the speed of
the turbine at all power outputs between zero and maximum power outputs when the unit is
operating in parallel with other generators.
2      The range of conditions covered by stability requirements includes sustained
conditions, load rejection, and sudden load changes, both large and small.
3      Following rejection to zero of any load within the capability of the governed unit,
speed shall be returned to the speed reference.
TM-2.14 Electrical Power Supply
1      Primary power supply to the electronic portion of the governor shall be from the 220
V dc station battery. The Contractor shall provide duplicate internal power supplies from the
220 V dc source.
2       Provision shall be made to remove power from portions of the electronic controls to
permit limited servicing of components while the unit is on line and under manual control.
3      Contacts shall be provided to alarm when the internal power supply has transferred to
the back-up power supply, and separate contacts shall be provided to indicate power failure
causing shutdown.
TM-2.15 Governor Oil Pumps
1       The governor system shall be provided with two main motor-driven oil pumps, each
having a capacity per minute of not less than 1.5 times the total oil volume of the guide vane
servomotors, and one continuous running jockey pump having a capacity at least 20% in
excess of the expected steady state regulation and leakage in the governor system. The relief
valve for each pump shall be set to pass full delivery at 110% of operating pressure.



                                          TM-2.15
                                   TM-2 Governors

2      Each main pump shall be of adequate capacity to supply the oil required for normal
governing of the unit plus the requirements of the inlet valve and pressure regulator. It shall
be possible to run either main pump continuously so that it discharges to the sump or to the
pressure tank without overheating the oil.
3      A suitable oil strainer shall be fitted in the suction line of each pump, and each
discharge line shall have a filter with differential pressure switch and alarm.
4       Each pump shall be of the screw type, mounted separately from the sump tank and
shall be self-priming under all conditions. Gear type pumps are not acceptable for the main
pumps. The pump bases shall be provided with a drip pan or drip lip with plugged drain to
collect oil leakage. Control switches and indicator lamps shall be mounted on the front panel
of the actuator cubicle.
5       Each pump shall be directly connected to a 380-V, three-phase, 50 Hz, squirrel-cage
low-starting current, induction type motor designed for full voltage across the line starting,
and conforming to the standards of IEC, or approved equal. The motor shall have ball or
roller bearings and shall have closed conduit terminal boxes and windings with moisture- and
oil-resistant insulation. The windings shall be braced for line start application. The capacity
and torque shall be suitable for the pump requirements. The motors and electrical equipment
shall be as specified in TG 10.
6       Automatic pressure-operated motor controls shall be furnished with the pumping unit,
which shall start the main pumps on a lead/lag sequence when the oil pressure in the pressure
tank drops to a predetermined point and which shall stop the pumps when the oil pressure
rises to a predetermined point. The jockey pump motor shall be suitable for continuous
operation.
7      The starting control equipment shall be arranged so as to start the motor and permit it
to reach full speed before the pump loads and to unload the pump before the motor is
disconnected from the power supply. Combination heavyduty magnetic starters with unfused
disconnecting switches and ambient temperature compensated thermal overloads, single-
phasing and undervoltage protection housed in enclosure as specified in TG-10 and complete
with external overload manual reset button shall be furnished by the Contractor and shall be
mounted on or adjacent to the pump units. Each starter shall be equipped with two auxiliary
contacts, one normally open and one normally closed.
8       A 380/220-V control transformer shall be provided within each magnetic starter
enclosure, of suitable size for control of the starter and supply to the starter accessories.
Suitable terminal blocks with marking strips shall be provided in accessible places for the
control wiring. All control equipment shall be suitable for operation from the 220-V control
transformers. The control equipment shall include a timer, adjustable from 0 to 60 s which
shall prevent simultaneous closing of the starters when the power supply is removed and then
restored.
9        The two main oil pumps shall be arranged with echelon controls to be operated either
independently or together, with one pump used for normal operation and the other arranged
to start with a drop in oil pressure. A manual control switch shall be provided to select one of
the two pumps as the lead pump. An indicator light shall show which pump is lead pump. An
alarm shall be provided to indicate continuous running of the lag pump over an adjustable



                                           TM-2.16
                                    TM-2 Governors

period of time. An oil pressure operated unloader valve shall be provided, of sufficient
capacity to pass the full delivery of the pump with enough margin to prevent activating the
safety relief valve. The unloader valve shall be operated from the pressure tank pressure by a
pilot line, complete with isolating valves and filters or by pressure switch and shall be
equipped with `snap' action pilot valves. Hand operated valve shall be provided to permit
isolating pumps from the oil pressure system and its removal for repairs without losing oil
pressure. All valves and mechanisms shall be accurately set and tested in the shop before
delivery.
10     Each governor pump shall be provided with an adjustable temperature switch with
two electrically separate contacts suitable for operation at 220 V dc located in the pump
suction side for high governor oil temperature alarm.
TM-2.16 Pressure Tank
1       The governor shall be provided with a pressure accumulator tank of welded
construction, which shall be constructed in accordance with the requirements of the latest
issue of the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. The pressure
tank shall have a total volume of at least 25 times the total volume of the gate servomotor
cylinders of the turbine plus the requirements of the inlet valve and pressure regulator, and
shall be designed for a pressure at least 10% above the actual maximum system operating
pressure. When starting at low oil level and at corresponding tank pressure, volume must
permit at least one and one half full closures of the governor servomotor, plus any turbine
pressure regulator oil requirement, without assistance from pumps. When operating between
high pressure (pump cut-out pressure) and low pressure (pump cut-in pressure) the tank shall
deliver at least 2.5 times the volume of the servomotor without assistance from the pumps. At
nominal operating pressure the oil shall occupy one quarter the total volume of the tank, the
other threequarters being occupied by air.
2       The pressure tank shall be equipped with a pressure gauge, a safety relief valve, air
blow-off valve and at least two oil-level sight gauges. The safety relief valve shall be set to
open at the maximum system operating pressure. The sight gauges shall be long enough to
overlap the high and low oil levels by at least 150 mm and shall be of the armored flat glass
transparent type with manual shutoff and ball check valves for shutting off air and oil
discharge from the pressure tank in the event of breakage of the sight gauge. The safety relief
valve and air blowoff valve shall be designed to relieve the air to atmosphere in a manner not
injurious to personnel or equipment in the vicinity of the tank.
3       The pressure tank shall be provided with an automatic air admission system to
maintain a proper proportion of the air cushion volume. The Contractor shall supply all
necessary piping, fittings, filters, moisture separators, solenoidcontrolled valves, pressure and
level switches required for this system. Solenoids shall be suitable for operation at 220 V dc.
4       An adequate manhole, not less than 500-mm diameter, with a suitable oilresistant
gasket shall be provided. The tank shall be painted as set forth in TG-14 painting system No.
2 on the inside and painting system No. 4 for the outside and steel piping. Prior to shipping,
all threaded openings shall be closed with standard pipe plugs. Flanged openings shall be
protected with wooden covers bolted in position and sealed with grease and waterproof tape.




                                           TM-2.17
                                   TM-2 Governors

5      All connections to the pressure tank, with the exception of air supply, air blow-offs
and the upper gauge connections, shall be made below the low oil level and shall be designed
to prevent foaming. Drain valves shall be provided to drain the pressure tank into the sump
tank for cleaning or repairs. A drip pan or lip shall be provided to collect oil leakage, with
plugged drain connection.
6       The pressure tank shall be provided with a float valve assembly to prevent air
admission into the governor piping system under conditions of low oil level. Alternately an
internal check valve and anti-sloshing baffles may be provided to prevent accidental closure
of the internal check valve during a seismic event.
7      Pressure switches shall be heavy duty, easily adjustable, drift-free and of suitable
ranges. In addition to pressure switches required for echelon control, the following pressure
switches shall be provided and connected to the pressure tank.
       -   For a low governor oil pressure alarm to the control room annunciator and
           automatic unit control, contacts to close on low pressure.
       -   For an extreme low pressure trip (unit lockout relay), contacts to open on extreme
           low governor oil pressure and simultaneously contacts to close on extreme low
           pressure.
       -   For the automatic air admission system, contacts to open at governor oil operating
           pressure.
8      The following "Magnetrol" or approved equivalent liquid level devices shall be
provided and mounted externally with piping, valves, and unions to permit their removal
without interrupting turbine operation
       -   high oil level for alarm purposes, one contact to close
       -   high oil level for automatic air admission, one contact to close
       -   low oil level for alarm purposes, one contact to close
       -   low oil level for unit shutdown, one contact to close
       -   extreme low oil level, two contacts to close.
All contacts shall be adjustable, ungrounded, electrically separate and suitable for 220 V dc
operation.
9       All pressure and level switches shall be provided with individual shut-off and bleed
valves.
10    The oil supply used to pilot control functions shall be provided with trim filter with
manual transfer on line. Dirty filter indicators and alarm circuits shall be provided.
TM-2.17 Sump Tank
1       The governor system shall be supplied with a steel sump tank of sufficient capacity to
hold at least 10% more than the total quantity of oil in the entire system for supplying oil to
the governor, inlet valve and pressure regulator. The sump tank shall be provided with a
breather with air filter and a manhole with a suitable oil-resistant gasket for access to the
interior of the tank.
2      Suitable oil level and temperature gauges shall be provided.




                                           TM-2.18
                                   TM-2 Governors

3       The tank shall also have suitable connections for filling and draining the tank and
connections for an oil purifier. The oil purifier connections shall consist of two 38 mm pipe
outlets and valves, one located near the bottom on one side and the other near the top on the
opposite side. If required by Contractor‟s design to meet the specified requirements for
continuous reliable operation, a recirculation pump with valved dual filters with 5 µm filter
elements shall be provided. Filter pressure drop switches with alarm lights on the governor
cubicle shall be provided. A vertical filter screen or basket with magnets shall be arranged to
divide the sump tank into `clean' and `dirty' oil compartments. All filters and strainers shall
be readily removable for cleaning and permit continued operation of the pressure oil system
(on-line servicing). The outlets of all oil pipes to the sump shall be below the low oil level.
4      Deaeration baffles shall be provided between oil return lines and suction line of the
oil pumps. Any components that require adjustments shall not be located inside the sump
tank.
5      Low-level and high- level switches shall be provided, suitable for 220 V dc, which
will operate alarms whenever the oil level reaches the preset levels.
6     A water-in-oil detector shall be provided and connected to an alarm in the control
room and to the governor sequence controller.
7       The tank shall be provided with a drip lip or drip pan with plugged drain to collect
any oil leakage.
8      The interior surfaces of the sump tank shall be painted in accordance with TG-14
coating system No. 2, the exterior to system 4, TG-14.
9       The maximum oil temperature shall not exceed 65oC. If necessary, oil coolers shall be
provided. Design of oil coolers, if required, shall be as specified in TM-1-28. An oil
temperature indicator shall be provided. An alarm shall be provided for high temperature and
a unit shutdown contact for extreme high temperature.
TM-2.18 Piping, Valves and Controls
1       The Contractor shall furnish and install all interconnecting piping between oil pumps,
sump tank, pressure tank, servomotors, cubicle, inlet valve and pressure regulator, together
with all necessary pipe supports and valves. The entire piping system shall be in accordance
with the requirements of TG-11, except as noted.
2      All hydraulic piping shall be designed to limit the oil velocity in the pipe to less than
4.5 m/s when operating at the maximum speed of the servomotor, except for pump suction
lines which shall have a velocity of no more than 2 m/s, and relief valve discharge lines
which shall have a velocity of no more than 7 m/s.
3      Governor oil pressure system shall have isolation valves adjacent to the pressure tank,
the governor cubicle and sump and in the supply lines to servomotors, inlet valve and
pressure regulator.
4      To minimize oil spills, all valves and flanged connections (the number of which
should be minimized) shall be located, as far as practical, over drip pans or drip lips included
with the tanks or pumps.




                                           TM-2.19
                                    TM-2 Governors

5       Governor system isolation valves shall be lockable and shall have position indicating
limit switches for full open and full closed, which shall be included in the start permissives.
6       Governor system oil pressure piping system shall be capable of depressurizing the
governor cabinet and supply lines to each servomotor, inlet valve and pressure regulator
without depressurizing the pressure tank. The piping system shall be capable of “block and
bleed” isolation of pressure source(s) to allow for safe maintenance isolation.
7       All proportional valves shall have dual filters with suitable mesh to ensure
satisfactory operation of the valves.
8       The oil supply system controls shall be mounted on the sump tank or in a free-
standing cubicle for installation close to the oil supply system. The electrical controls shall be
protected from oil mist and vapours. Redundant dual microprocessors shall be used to control
pump start-up and lead-lag sequence, detection of out of limits for oil level and pressure,
high temperature and other fault conditions
TM-2.19 Installation Equipment, Wrenches, Tools and Fixtures
1      One complete set of case-hardened wrenches, special tools and special lifting
attachments, which may be necessary or convenient for assembling, dismantling and
maintaining the governor, shall be furnished.
2       Each tool shall be new and marked with its size and/or purpose. All tools shall be
suitably arranged in lockable tool boxes, except where otherwise specified. A list of the tools
contained, stamped on an attached metal tab, shall be included.
3       All large tools and wrenches shall be new, and insofar as practicable, be mounted on
a suitable board arranged for wall mounting and provided with means for ready
identification.
4      All tools in their boxes together with all other tools, devices, slings, lifting
attachments, etc, provided by the Contractor, all in good order, shall be handed over to the
Employer at the time of issue of the Taking Over Certificate.
TM-2.20 Contractor’s Design Calculations
1       The Contractor shall submit, for approval by the Engineer, copies of all its detailed
calculations. Calculations shall be of sufficient detail to show all design parameters,
references, material specifications, allowable stresses supported by references, etc, and shall
be submitted in conjunction with the Contractor's drawings.
2      In particular, calculations shall be submitted regarding:
        Governor timing
        Oil flows, pressures and volumes for governor operation alone and simultaneous
           with the inlet valve and/or pressure regulator
        Oil velocity in piping
        Speed stability, deadband and dead time
        Alarms and shutdown settings.
           Calculations shall be provided for each operating scenario.




                                            TM-2.20
                                    TM-2 Governors

3      The Contractor shall also provide other calculations as required by the Engineer for
his approval of the Contractor's design.
TM-2.21 Inspection and Tests
1       All equipment shall be subject to inspection and testing by the Contractor as specified
and in accordance with TG-18.
2       The Contractor shall furnish certified copies of all test results, the results of each test
shall be recorded in the form of test certificates or reports as specified.
Type Tests
3      Type tests may be offered by the Contractor, as specified in TG-18, provided the
Contractor gives evidence to the Engineer as to the similarity of the equipment tested and the
Contract equipment.
Shop Tests
4      The equipment shall be subjected to shop tests in accordance with the latest issue of
the applicable standards.
5      In addition, the Contractor shall perform the following shop tests:
(a) Material Tests
Material tests shall be as specified in TG-18.
(b) Hydrostatic Tests
Hydrostatic tests shall be as specified in TG-18.
(c) Shop Tests
Shop tests as specified in TM-2.
6       The equipment shall be functionally tested insofar as practicable in the Contractor's
plant, to test operation of all circuits and devices, and to optimize performance.
Field Tests
7       The Contractor shall carry out field inspections and tests in accordance with the latest
issue of the applicable standards.
8       Complete tests shall be performed on site by the Contractor to check the sequence of
operation and to optimize performance of each item of equipment during all normal and
abnormal operating conditions mentioned specifically or implied in this specification. The
tests shall prove that all specified requirements have been met.
9      Other tests on governing equipment are part of turbine tests (see TM-1).
TM-2.22 Spare Parts
The Contractor shall supply specified spare parts, special tools and devices as detailed in the
Commercial Schedules and shall supply recommended spare parts for 2 years operation.
Spare parts for field testing and acceptance trials shall be provided by the Contractor. All
spare parts shall be identical electrically and mechanically to the corresponding parts in the



                                            TM-2.21
                                    TM-2 Governors

equipment, and shall be suitably packed and clearly marked ready for long-term storage
indoors.
TM-2.23 Governor Air Compressor
Contractor shall supply two air compressors (operating and standby), air-cooled, each having
minimum 100% capacity and an operating pressure of at least 150 kPa above the maximum
oil operating pressure. All accessories, including automatic echelon control equipment,
piping, air receivers with 300-L minimum capacity, flexible connectors, air filters, safety
valves and gauges shall be included. The compressors shall be equipped with unloading
devices for starting unloaded and idling. Intake filter and silencer shall be provided. Pressure
switches shall be provided for low- and high-pressure alarms. The compressors shall be
mounted on vibration-absorbing pads.
The Contractor may offer optional pricing for an automatic nitrogen recharging system as an
alternative to air compressors. The system shall be complete with 12 months supply of
nitrogen in the form of cylinders in the powerhouse, with at least 2 cylinders (1 operating, 1
standby) connected to the piping feeding the pressure tank. The system shall include all
necessary pressure regulators; relief, isolation and control valves; instrumentation and
controls; piping, tubing, wiring; control panel with lights and alarms; wheeled steel hand cart
for transfer of nitrogen cylinders.
TM-2.24 Conversion of Units 1 and 3 Governors to Digital Control
1      The Contractor shall provide all necessary field investigation, design, manufacture,
shop or field modifications or repairs, installation, testing, commissioning and guarantees to
convert the existing governors to digital control.
2       It is the Contractor‟s responsibility to determine the best method to carry out the
conversion to achieve optimum operability, maintainability, reliability and functionality of
the modified governors while ensuring minimum disturbance to operation of the turbine
generator units. The performance of the converted governors and the new governor for Unit 2
shall be the same as far as possible and their control functions shall be compatible so that
when all 3 units are operating the governor controls work harmoniously together.
3      The Contractor shall coordinate its work with the rehabilitation work being carried
out on Units 1 and 3 to minimize disturbance to the rehabilitation work.
4       It is the Contractor‟s responsibility to initiate discussions with the contractor for the
rehabilitation work to determine the scheduling of the Contractor‟s work.
5       The Contractor shall supply all necessary parts, material, panels, devices, wiring,
piping, brackets, clips, etc as required to complete the work. The Contractor‟s scope of work
includes replacement of any existing parts, devices, etc where they are not suitable for use in
the digital governor.
6      The Contractor shall apply protective coatings in accordance with TG-14, systems 2,
3 or 4 as applicable, including painting of parts of equipment, devices or panels affected by
modifications and including all touch-up painting.
7        Work by the Contractor, including parts, material, devices, wiring, piping etc shall be
at least equivalent in quality to the Work carried out by the Contractor on Unit 2. The scope,


                                           TM-2.22
                                   TM-2 Governors

flexibility and degree of control and functionality of all controls provided by the converted
governors shall not be less than that afforded by the governor before conversion nor less than
that afforded by the new governor on Unit 2, except that attributable to limitations inherent in
the governor before conversion.
8       The Contractor shall prepare a detailed description of the proposed conversion,
including marked-up copies of existing drawings and data, and submit to the Engineer for
acceptance. The submission shall identify all parts to be modified or repaired and the nature
of the modifications/repairs, all parts to be replaced and the reasons why, and all new parts to
be added with manufacturer‟s specifications on the parts. A functional description of the
control scheme shall be provided.
9      Where feasible, all new controls shall be installed in the existing governor cubicles.
Where not feasible the Contractor shall provide a new panel suitable in terms of size, shape
and arrangement of controls for mounting adjacent to the existing cubicle. If a PLC is
supplied it shall be housed in a separate panel.
10     For all electrical equipment, instrumentation or devices requiring air conditioned
enclosures and supplied for the conversion, the Contractor shall provide all necessary air
conditioning equipment.
11     The Contractor shall provide all software necessary for the controls supplied,
including software manuals and training of the Employer‟s staff in use of the software. The
Contractor shall perform all programming necessary for putting the converted governors
back in service, including that necessary to integrate it with other software resulting either
from this Contract or from the rehabilitation work on Units 1 and 3.
12      The Bidder shall provide optional pricing for replacement of Units 1 and 3 existing
low pressure hydraulic equipment (2.4 MPa operating pressure) with equipment to match that
used on Unit 2 operating at 4.8 MPa. Pricing shall include removal of existing hydraulic
equipment, design, manufacture, delivery, installation, testing, commissioning, training and       1
guarantee of new hydraulic equipment, including all modifications to existing equipment,
structures, linkages, devices, controls, instrumentation, wiring, piping to accommodate the
new equipment, and provision of all drawings and manuals. Governor air for Units 1 and 3
shall be supplied from the same system as Unit 2 and include a third 100% capacity standby
compressor with all necessary modifications to piping, valves, controls etc.




1          Per contract negotiations



                                           TM-2.23
                                          TM-3 Inlet Valve
                                         Table of Contents
TM-3 Inlet Valve

Table of Contents
TM-3    Inlet Valve .........................................................................…………..........TM-3.1
  TM-3.1 Purpose and Function .................................................……………….....TM-3.1
  TM-3.2 Drawings ..................................................................………………......TM-3.1
  TM-3.3 Standards and Codes ..................................................…………….........TM-3.1
  TM-3.4 Quantities and Descriptions ........................................…………...…....TM-3.1
  TM-3.5 Spare Parts ..................................................................…………....…....TM-3.3
  TM-3.6 Operation and Control of Equipment ........................………………......TM-3.3
  TM-3.7 Shop Assembly ..........................................................…………….........TM-3.3
  TM-3.8 Hydraulic Conditions .................................................…………….........TM-3.3
  TM-3.9 Operating Conditions ................................................……………........TM-3.3
  TM-3.10 Data Required With Bid price ......................................………….........TM-3.4
  TM-3.11 Design and Construction ..............................................………….........TM-3.4
  TM-3.12 Design Criteria ............................................................……….…..........TM-3.5
  TM-3.13 Head Loss Guarantee ...................................................…………….......TM-3.6
  TM-3.14 Valve Body ..............................................................………………........TM-3.6
  TM-3.15 Valve Disc, Shaft and Seal .........................................…………….......TM-3.6
  TM-3.16 Valve Bearings ..........................................................…………..….......TM-3.7
  TM-3.17 Bypass Assembly ........................................................…………..….....TM-3.7
  TM-3.18 Transition ....................................................................……………....TM-3.7
  TM-3.19 Flexible Couplings ......................................................……………....TM-3.8
  TM-3.20 Valve Operating Mechanism .......................................……….……....TM-3.8
  TM-3.21 Materials ....................................................................…….………........TM-3.9
  TM-3.22 Controls .......................................................................…..………….....TM-3.9
  TM-3.23 Not Used .....................................................................…….………....TM-3.10
  TM-3.24 Not Used .....................................................................…………….......TM-3.10
  TM-3.25 Not Used ....................................................................……………........TM-3.10
  TM-3.26 Not Used ....................................................................……………........TM-3.10
  TM-3.27 Piping and Valves ......................................................……………........TM-3.10
  TM-3.28 Control Cubicle ..........................................................…………….......TM-3.10
  TM-3.29 Electrical ....................................................................………….........TM-3.11
  TM-3.30 Installation Equipment, Wrenches, Tools and Fixtures ………..…... TM-3.11
  TM-3.31 Contractor‟s Design Calculations .....................................……………TM-3.11
  TM-3.32 Inspection and Tests               ....................................................………........TM-3.12




                                                    TM-3.i
                                    TM-3 Inlet Valve

Kajakai Hydroelectric Project
Contract KR-02
Addition of Unit 2
Technical Specification
TM-3 Inlet Valve
TM-3.1 Purpose and Function
1       The inlet valve to be supplied under this specification is to be installed in an existing
turbine bay to complete the three-unit powerhouse. It must be constructed to suit the existing
water passages and powerhouse layout.
2       The inlet valve will be used to isolate unit 2 turbine from the penstock independently
of units 1 and 3.
TM-3.2 Drawings
The accompanying drawings form part of this specification.
TM-3.3 Standards and Codes
1      The equipment shall comply with the requirements of the latest revision of the
following standards where applicable. ASME Boiler and Pressure Vessel Code, Section VIII,
Division I
2     Unless otherwise stipulated in this section of the specification, the equipment shall
comply with the requirements and the latest revisions of the applicable standards as listed in
TG-3.
3       If this specification conflicts in any way with any of the specified standards or codes,
the more stringent requirement shall govern. However, the Contractor shall bring these
conflicts to the Engineer‟s attention to permit discussion at least 4 weeks prior to finalization
of Contractor‟s design.
TM-3.4 Quantities and Descriptions
1       The Contractor shall supply one inlet valve assembly consisting of the following.

Quantity    Description
1           Valve body assembly, including body, disc and shaft, together with bearings,
            adjustable seal and appurtenances
1           Hydraulic operating mechanism, including cylinders, necessary mechanical
            linkages, support steel, baseplates and embedded anchors.
1           Counterweight mechanism, including weight assembly and lever arm
1           Control system, including electrohydraulic control, sensing and indicating
            devices, control piping, and devices for local and remote indication and control
1           Bypass assembly with piping, motor or hydraulic-operated flow control valve,
            manual isolating valves, and control equipment
1 lot       Access platforms complete with ladders and guardrails



                                            TM-3.1
                                    TM-3 Inlet Valve

Quantity     Description
1 set        Upstream and downstream transition sections including downstream extension
             piece
2            Flexible type couplings downstream from the inlet valve
2 sets       Flange coupling bolt assemblies, if required by Contractor‟s design
1 or more    Automatic air vent valve(s) on the downstream side of the valve with all controls
             and discharge piping for venting during water filling of the turbine
1            300-mm saddle flange outlet on the upstream side of the valve at the lowest
             level, piping and plug valve for drainage of the penstock
1 Lot        Additional features and accessories as specified or required, including anchor
             bolts, nuts, washers, suitable lifting devices and support structure
1 Lot        Shop and field tests
2       This work includes
        -   all interconnecting piping and wiring including couplings, valves, flanges,
            junction boxes, electrical enclosures
        -   piping and electrical terminations and tie-ins to existing facilities
        -   all instruments, control and safety devices
        -   all anchors, turnbuckles, fixtures, machine pads, jacks and foundation bolts for
            field alignment and installation
        -   all painting materials and test equipment for field painting and touch-up
        -   all equipment, tools, instruments and devices for conducting field tests
        -   all special tools and devices for handling, assembling, installation, erection,
            dismantling at site
        -   all welding materials and equipment for site welding
        -   any other item not specified above but necessary to complete the manufacture,
            assembly, machining, erection, commissioning and testing.
3       The Contractor shall assume responsibility for
        -   field checking of the location and dimensions of all structures, equipment, piping
            or other services that may affect its work
        -   field checking of all its connections to, or interfacing with, existing structures,
            equipment, piping or other services
        -   quality of all materials and workmanship supplied by the Contractor entering into
            the completed work
        -   rigid adherence to the dimensions of parts as shown on drawings
        -   strength of all parts of the inlet valve when subject to the most adverse load
            conditions
        -   maximum head losses guaranteed in Contract
        -   satisfactory performance of the entire work under all specified operating
            conditions without signs of undue strain and without breakdown, cracking,
            damage or deterioration of any of the parts due to faulty or unsuitable material,
            design, workmanship, handling, storage, transportation, assembly or erection
            procedure
        -   freedom from excessive pitting of any part of the valve under the specified
            operating conditions in accordance with the Contractor's guarantee


                                            TM-3.2
                                    TM-3 Inlet Valve

       -   freedom from abnormal vibration under the specified operating conditions
       -   stable operation of the entire work during opening and closing of the valve.
TM-3.5 Spare Parts
The Contractor shall supply specified spare parts, special tools and devices as detailed in the
Commercial Schedules and shall supply recommended spare parts for 2 years operation.
Spare parts for field testing and acceptance trials shall be provided by the contractor. All
spare parts shall be identical electrically and mechanically to the corresponding parts in the
equipment, and shall be suitably packed and clearly marked ready for long-term storage
indoors.
TM-3.6 Operation and Control of Equipment
The inlet valve will be operated locally as well as from the powerhouse control room. The
Contractor shall provide all equipment, apparatus and devices to achieve the specified
methods of local and remote operation indication and control.
TM-3.7 Shop Assembly
1       All equipment, fabrications and structures covered by the specifications shall be fully
assembled in the Contractor's shop for inspection by the Engineer. All necessary adjustments
shall be made in the shop to achieve the specified tolerances.
2      Prior to dismantling, each assembly shall be permanently and clearly matchmarked in
the shop to facilitate site erection. Dismantling shall be done only to the point required for
shipping. In particular, there shall be minimum disconnection of electrical wiring.
3       The Contractor shall complete the application of protective coatings in its shop as
specified in TG-14.
TM-3.8 Hydraulic Conditions
1     The general arrangement of the intake, water passages, turbine inlet valve and
powerhouse is as shown on the drawings.
2      The inlet valve shall be designed for the hydraulic conditions as follows.
(a) Headwater Levels
       -   Maximum (post spillway gate inst.) 1045.0 m
       -   Normal (present) 1033.5 m
       -   Minimum 1012.0 m
(b) Inlet Valve
       -   Centerline elevation 962.0 m
       -   Diameter of penstock stub 3.3 m
       -   Maximum pressure at centerline of To be determined by valve, including water
           hammer Contractor, see TM-1
TM-3.9 Operating Conditions
1       The inlet valve will be closed to shut off water to the unit in case of turbine shutdown,
and to permit unwatering of the turbine for inspection.


                                            TM-3.3
                                   TM-3 Inlet Valve

2      Under emergency conditions, the valve shall be capable of closing against maximum
turbine flows and maximum operating head. The valve closure characteristics must be
designed so that the pressure rise in the penstock during valve closure against design flow
does not exceed the maximum pressure, including waterhammer.
TM-3.10 Data Required With Bid price
1      The Contractor shall submit with its Bid the following:
       -   detailed list of scope of supply, including spare parts, tools, installation and
           testing devices
       -   arrangement drawings of the inlet valve
       -   brief description of all major components of the valve, including construction and
           details of any deviation from the specifications
       -   valve installation procedure and requirements
       -   schematic diagram of hydraulic control system
       -   completed technical data sheets
       -   list of material specifications, mechanical/chemical properties and design stresses,
           supported by references
       -   information on any subcontractors that the Contractor proposes to use for any
           major castings or weldments.
2      The Bidder shall include any other drawings, catalogs, descriptions and photographs
necessary to present a clear picture of the type and class of equipment to be supplied.
TM-3.11 Design and Construction
1       The inlet valve shall be horizontal shaft butterfly biplane type. The valve shall be
suitable for installation in the existing valve chamber within the space available. The valve
body and the disc shall be so proportioned and sized that, when fully open, there will be
minimum obstruction to flow of water. All parts of the valve body and disc shall be designed
for the maximum pressure including water hammer in accordance with ASME Boiler and
Pressure Vessel Code, Section VIII, Division 1.
2       The design of the valve body and transition sections shall be such as to adequately
resist the hydraulic forces acting directly on the body and transition sections, and those
resulting from the thrust of the disc when in a closed position. The body shall be properly
ribbed circumferentially to ensure sufficient rigidity to minimize deformation. It is the
Contractor‟s responsibility to ensure that all hydraulic thrusts, including transients, are
transmitted to existing concrete within the load capacity of the concrete.
3       The valve shall be designed and fabricated in subassemblies to facilitate field
installation and removal of the several valve elements and operating mechanisms from the
valve chamber. The largest piece of the valve shall satisfy all transportation limitations for
size and weight.
4      Opening of the valve shall be by the action of hydraulic cylinders and closing by the
counterweight mechanism. Oil for the hydraulic cylinders shall be supplied from the
governor oil system.




                                           TM-3.4
                                   TM-3 Inlet Valve

TM-3.12 Design Criteria
1      The valve and appurtenances shall be designed and located such that its assembly and
disassembly can be carried out with the existing powerhouse EOT crane.
2      The valve and appurtenances shall be capable of closing against the maximum head,
including water hammer, starting from an initial discharge equal to the maximum turbine
discharge under full guide vane generation or full guide vane runaway conditions. Normal
working stresses shall not be exceeded in any parts of the valve under these conditions.
3      The valve shall be designed to operate and seal properly during all operating
conditions, including penstock filling, normal pressures and during water hammer transients.
4       Opening time shall not be greater than 2.0 minutes. The closing time shall be not less
than 1.5 minutes and not more than 3 minutes. The rate of movement shall be retarded near
the end position for both open and closing strokes. Adjustment shall be provided to slow the
final 10% of the closing stroke, so that this final movement can be set to occur in a time
varying from 20 seconds to 40 seconds. Restrictive orifices shall be provided to limit the
valve closing time to a minimum of 1 minute in case of rupture of a hydraulic line. All above
times are subject to confirmation by Contractor‟s design and acceptance of Contractor‟s
design by Engineer.
5       The valve will normally be opened only after pressure equalization across the disc. A
differential pressure switch shall be provided in the control circuit to prevent the valve
opening if the differential pressure is above 10 m water column.
6       In normal service, the inlet valve will be maintained fully open by the oil pressure in
the hydraulic operator and not a mechanical latch. Mechanical latches shall be provided for
maintenance purposes to allow the disc to be secured in either the full open or full closed
position. The latches shall be designed and constructed to safely resist the maximum force
that may be developed by the servomotors. The latches shall be supplied with key operated
locks to prevent unauthorized latching or unlatching.
7      Fluid velocities in the piping of the oil hydraulic system shall be limited to 4.5 m/s.
The operating pressure for the hydraulic system shall be determined from the governor oil
system operating pressure.
8      The operating cylinders shall be sized to open the valve with minimum system oil
pressure and to retard closing under the most adverse hydraulic torque on the valve disc due
to emergency closure at maximum turbine discharge without exceeding the cylinder design
pressure.
9      All parts subject to water pressure including surge, or oil pressure, shall be designed
in accordance with the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1.
10     A 2-mm corrosion allowance shall be added to the extension piece, transition sections
and the valve body.
11     No significant foundation settlement is anticipated in the powerhouse.




                                           TM-3.5
                                    TM-3 Inlet Valve

TM-3.13 Head Loss Guarantee
The Contractor shall design the inlet valve, transition and extension pieces to achieve
minimum head losses. Head loss coefficient for the water passage from the inlet end of the
upstream transition piece to the outlet end of the downstream extension piece shall not
exceed 0.1 when the flow through the valve is equal to the flow through the turbine at 100%
rated output. The head losses shall be guaranteed and measured in the field between upstream
piezometer taps in the penstock and downstream piezometer taps in the spiral casing inlet.
TM-3.14 Valve Body
1       The valve body shall be of normalized cast steel or stress-relieved welded steel, and
shall have a stainless steel sealing seat to receive the seal. The valve body shall be machine
finished where required for matching parts and drilled to receive the shaft bearings. The body
shall be flanged on both ends, and the flanges shall be faced, shop drilled and spot faced. The
drilling shall match the drilling of the companion flanges for the transition sections. Bolting
shall be in accordance with ASTM A193 and A194.
2       Integral pads shall be provided on the valve body for transmitting the vertical load to
the concrete foundation. Suitable beams and anchor plates and bolts for securing the valve in
position shall be provided. These shall be designed to resist any forces from the valve
operating cylinders. The body and transition sections shall be so arranged that no weight or
vertical thrust from the valve, transition section or contained water is applied to the penstock.
The support pads shall be of a type to permit free and adequate movement in the upstream
and downstream directions of the valve during opening or closing.
3      The design of supports and foundations for the valve shall be by the Contractor
conforming to these requirements.
4      External exposed carbon steel surfaces of the valve body shall be painted with paint
system No. 4 according to TG-14.
TM-3.15 Valve Disc, Shaft and Seal
1       The disc shall be made of normalized cast steel or stress-relieved welded steel, and
shall be so designed and constructed as to produce a minimum of hydraulic loss. The disc
edges shall be shaped to minimize vibrations that may be caused by vortex shedding. All
surfaces of the disc in contact with water shall be smooth and free from hollows, depressions,
cracks or projections.
2      The seal shall be of synthetic polymer. The disc shall be of sufficiently rigid
construction, and the disc and sealing surfaces shall be designed for all hydraulic conditions
including the condition with the unit dewatered downstream of the inlet valve.
3       The seal adjustment shall be accomplished either in the seal retaining elements or in
the seal seating element from the downstream side of the valve. Alternative seal designs that
do not require seal adjustment will be considered if satisfactory experience can be
demonstrated with the seal design.
4      The seal retainers and seal fasteners shall be of suitable stainless or highalloy steel.
The seal shall be designed and constructed of such materials that they will provide maximum



                                            TM-3.6
                                   TM-3 Inlet Valve

tightness, maximum resistance to erosion by silt, minimum maintenance, and convenient
adjustment and replacement.
TM-3.16 Valve Bearings
The bearings shall be self-lubricated type. A packing type of seal, complete with gland, shall
be provided at the outer end of each bearing to prevent the release of penstock water to the
exterior of the valve.
TM-3.17 Bypass Assembly`
1       The bypass assembly shall include one motor or hydraulic pressure operated flow
control valve, minimum size 75 mm, with auxiliary manual operating mechanism, two
manual gate valves, and necessary piping flanges, fittings, bolts and gaskets. The manual
valves shall be located downstream and upstream of the motor/hydraulic operated valve. The
piping in the bypass system shall be 100-mm dia or larger. The design and materials shall be
such that cavitation and erosion damage will be avoided under all specified operating
conditions.
2      The Contractor shall provide one or more Victaulic couplings in the bypass line
       -   to facilitate installation of the bypass
       -   to allow relative movement of the connection points of the bypass to the main
           water passage, if the Contractor's design requires the downstream connection
           point to be downstream of the extension piece inlet.
3       The sequence of operation of the bypass valve in relation to the main valve shall be as
follows. The manual valves are normally open. To start watering the unit, the bypass valve
will open and allow the spiral case to fill and pressurize to reservoir level. The automatic air
vent valve will vent the air until the water level reaches the top of the spiral case. When the
pressure across the butterfly valve is less than 5 m water column, it will start to open. The
bypass valve will start to close 60 s after the butterfly valve starts to open. The bypass valve
is not used in the main valve closure sequence.
4      Access platforms complete with floor plates or grating, kickplates, handrails and
ladders shall be furnished to provide safe and convenient access to the bypass valves and
other parts which may require inspection or maintenance. Platforms shall be designed to
provide access not less in scope and space provision than that existing for Units 1 and 3.
Minimum platform width shall be 600 mm clear space. Platforms shall be designed for live
loads not less than those specified in TC-1.
5      External exposed surfaces of carbon steel piping, valves and supports shall be painted
with system 4 according to TG-14.
TM-3.18 Transition
1       The Contractor shall supply and install transition sections and extension piece to
connect to the existing penstock and to the spiral case inlet. For removal of existing penstock
bulkhead and connection of transition piece see TI-3. The Contractor shall be responsible for
fitting the transition pieces and extension piece to suit the spiral case and the existing
penstock. Transition sections shall be complete with flanged ends for bolting to the inlet
valve.


                                            TM-3.7
                                    TM-3 Inlet Valve

2      All shop butt welds in the transition sections and extension piece shall be subject to
100% radiographic (RT) or ultrasonic (UT) examination by the Contractor. All other shop
welds shall be fully examined by dye penetrant (PT) or magnetic particle (MT) by the
Contractor. Any field welds shall be examined 100% RT by the Contractor.
3      The Contractor shall supply and install four upstream piezometer taps just upstream
from the field joint between the upstream transition piece and the existing penstock.
4       The Contractor shall supply and install cooling water supply and drain connections in
the upstream transition section. Cooling water supply connections shall be located within
+ 90º from the top of the transition.
5       One or more automatic air release valves shall be provided to adequately and safely
vent air from the high point of the transition section or extension piece while filling the
turbine water passages via the inlet valve bypass. The location of this valve(s) may be in the
transition section or extension piece downstream from the inlet valve. Exhaust air from the
valves shall be piped to discharge to a safe location as agreed with the Engineer.
6       External exposed carbon steel surfaces shall be painted with system 4 of TG-14.
Internal surfaces shall be painted with system 1, TG-14.
TM-3.19 Flexible Couplings
1       If required by Contractor‟s design to accommodate valve movement relative to the
scroll case during operation, two flexible couplings shall be provided on the downstream side
of the valve. One coupling shall connect the downstream transition section to the extension
piece. The second coupling shall connect the extension piece to the spiral case inlet. The
flexible couplings shall be gasketed, sleeve type, with diameter to properly fit the pieces
which it connects. Each coupling shall consist of one steel ring, of thickness and length as
required, one steel follower, one rubber-compounded, wedge-section gasket, and sufficient
number of bolts to properly compress the gasket.
2       The finished ring and follower shall be a true circular section, free from irregularities,
flat spots or surface defects. The follower shall be of sufficient strength to accommodate the
number of bolts necessary to obtain adequate gasket pressure without excessive distortion.
The shape of the follower shall be of such a design as to provide positive confinement of the
gasket. The flexible couplings of the inlet valve shall be designed so that the valve assembly
can be removed from its position without dismantling.
3     The design of the couplings shall provide adequate gap to accommodate any
movements of the valve relative to the fixed spiral case inlet. Those portions of the coupling
assembly over which sliding motion will occur shall be protected with stainless steel overlay.
4      Carbon steel surfaces of the couplings shall be painted with system 1 according to
TG-14.
TM-3.20 Valve Operating Mechanism
1       The operating mechanism shall consist of two hydraulic cylinders, one at each end of
the valve disc shaft and counterweights. The valve shall be held open by hydraulic pressure
in the cylinders only. All pilot and control valves, limit switches and interlocks necessary for
the operation of the main valve and bypass valve shall be provided.


                                            TM-3.8
                                   TM-3 Inlet Valve

2       The cylinders shall be fabricated from welded plate or seamless pipe. Cylinder welds
shall be fully penetrated and stress relieved. Flanges shall be of forged steel and shall be
provided with suitable gaskets or seal rings designed to remain oiltight at maximum
pressures. The rod-end flanges shall contain a bronze bushing with chevron packing. The
cylinder bores shall be honed to a 1.6 ìm Ra (Ra = roughness average per ASME B46.1)
finish. The pistons shall be of cast steel, and shall be supplied with approved type packing
and with metal piston rings suitable for the required oil pressure service. The rods shall be
straight and true, and shall be of forged steel coated with minimum 0.3 mm thick hard
industrial chromium or with a suitable ceramic. Each connecting rod shall be attached to a
lever which shall be keyed to the main valve shaft.
3       Restrictive flow orifices shall be integral with the cylinder and not exposed to
separation from the cylinder under action of external accidental physical abuse.
4       Connections for pressure gauges shall be provided at each end of each cylinder. An
air vent and a drain cock shall be provided on each cylinder for air release and oil draining.
5       The counterweights shall be sized to provide net closing torque on the disc under all
possible operating conditions and shall be fabricated of steel or cast iron. The Contractor
shall incorporate suitable margins of safety in its determination of closing torque. Limit
switches shall be provided to electrically indicate the open and closed positions of the inlet
valve at the local control station and the powerhouse control room. A stainless steel
mechanical position indicator shall be provided, mounted on the inlet valve body to show the
position of the disc from full open to full closed.
6      Access platforms complete with floor plates or grating, kickplates, handrails and
ladders shall be furnished to provide safe and convenient access to the hydraulic cylinders,
mechanical latches and other parts which may require inspection or maintenance. Other
requirements shall be as specified in TM-3-17.
7      Exposed external carbon steel surfaces of cylinders, valves and steel piping shall be
painted with system 4 according to TG-14.
TM-3.21 Materials
Materials used in construction of the valve shall satisfy the requirements of TG-7.
TM-3.22 Controls
1      All electric and hydraulic controls required for the complete operation of the inlet
valve and bypass valve are to be provided under this contract.
2       On a signal to open, oil shall be directed through a flow control valve to the inlet
valve hydraulic cylinder. On a signal to close, the oil shall be directed through a flow control
valve to the governor oil sump. The control device shall limit the rate of closure of the inlet
valve through dashpot action of the hydraulic cylinder.
3        The power system for the controls shall be drawn from the station dc bus and include
duplicate internal power supplies. The inlet valve controls shall be failsafe, such that failure
of critical components or both internal power supplies will initiate valve closure.




                                            TM-3.9
                                   TM-3 Inlet Valve

TM-3.23 Not Used
TM-3.24 Not Used
TM-3.25 Not Used
TM-3.26 Not Used
TM-3.27 Piping and Valves
The Contractor shall furnish all interconnecting piping between inlet valve and governor oil
system and between inlet valve and local control cubicle, together with all necessary supports
and valves. Piping shall be in accordance with TG-11.
TM-3.28 Control Cubicle
(a) General
A control cubicle shall be furnished for the inlet valve, suitable for mounting in the vicinity
of the inlet valve. The panel shall be so arranged that it comprises a completely assembled
unit, including control equipment for inlet valve cylinders and bypass valve, complete with
gauges, pressure switches and operating signals.
(b) Construction
The control cubicle shall be a self-supporting, freestanding assembly with steel frame and
fully enclosed by a steel sheet, providing a dust- and vermin-proof enclosure. The steel sheet
shall be at least 3 mm thick, specially selected for smoothness and straightness, and free from
surface flaws. Where necessary, additional frame members shall be provided so that all
console sections are sufficiently rigid to assure proper functioning of the devices mounted
thereon, and to adequately sustain the loads imposed in service. A door or readily removable
section shall afford access to the interior.
(c) Equipment
All parts in the cubicle shall be mounted in one compartment, and the electrical equipment,
such as switches and controls, including pressure switches and control valves, mounted in
another compartment. Special care shall be taken to arrange the electrical equipment so that
an oil leak will not foul the wiring or electrical equipment. An anticondensation heater with
thermostat shall be provided to reduce humidity in electrical control equipment to acceptable
levels.
(d) Operating Controls and Indication
The following controls and indications shall be provided as a minimum in the control
cubicle, with provision for remote control and indication through the PLC/SCADA system
for the inlet valve items.
       -   a red light for each governor pump operating
       -   low/high governor sump tank oil level alarm
       -   a flashing red light for the inlet valve to indicate the opening sequence which
           remains on when inlet valve is open
       -   a flashing green light for the inlet valve to indicate the closing sequence which
           remains on when inlet valve is closed


                                           TM-3.10
                                    TM-3 Inlet Valve

       -   a red light for the inlet valve to indicate the bypasss valve is not in the closed
           position
       -   a red light for the inlet valve to indicate that the differential pressure across the
           valve disc is greater than acceptable for opening the main disc
       -   low/high governor pressure tank oil level alarm
       -   a governor hydraulic system trouble alarm
       -   a manually operated switch located in the control room to allow the operator to
           override all controls and initiate an emergency close sequence.
TM-3.29 Electrical
1       All equipment shall be shipped completely wired, except that wiring shall not be
installed where it would be disturbed by or for shipment, and shall be arranged for
connection to the power supply. Where wiring cannot be properly mounted within
assemblies, it shall be placed in conduit.
2       All electric wiring within the electrical enclosures shall be neatly arranged and
brought to terminal blocks in approved locations. All incoming wiring and control cables
shall enter the cubicle from above. The wire and equipment used for control circuit wiring
shall be in accordance with TG 10.
TM-3.30 Installation Equipment, Wrenches, Tools and Fixtures
1       The Contractor shall provide all special erection tools and handling equipment for the
installation and maintenance of the work. Installation equipment shall be of the type not
normally available and shall be specially manufactured for use with the equipment; it shall
include, but not be limited to, the following:
       -   valve body and disc removal devices, wire rope slings, shackles, lifting brackets,
           etc, with suitable connections for adaption to the existing overhead crane
       -   any special devices or equipment that may be required or may be useful in
           assembling or dismantling any part of the equipment, each marked with its
           purpose.
2       All large tools and wrenches shall be new, and insofar as practicable, be mounted on
a suitable board arranged for wall mounting and provided with means for ready
identification.
3       All tools, devices, slings, lifting attachments, etc, all in good order, shall be handed
over to the Employer at the time of issue of the Taking Over Certificate.
TM-3.31 Contractor’s Design Calculations
1       The Contractor shall submit, for review and acceptance by the Engineer, copies of all
its detailed calculations. Calculations shall be of sufficient detail to show all design
parameters, references, material specifications, allowable stresses supported by references,
etc, and shall be submitted in conjunction with the Contractor‟s drawings.
2      In particular, calculations shall be submitted regarding
       -   head loss at rated conditions, based on turbine design data
       -   analysis of all loading conditions for stresses in the valve components including
           detailed calculations for the biplane assembly


                                            TM-3.11
                                     TM-3 Inlet Valve

       -   calculations of the foundation loads, including thrust from the hydraulic
           servomotors for anchor design
       -   calculation of hydraulic forces and torque on the valve, disc and body during
           opening and closing of the valve for different positions of the valve including
           servomotor(s)
       -   sizing of the hydraulic operating system, including oil flows, pressures and
           volumes for each operating scenario
       -   calculations of sizing of the bypass valve
       -   calculations of closing time at various discharges through the valve
       -   calculations of penstock pressure transients during emergency closure, including
           maximum pressure developed at the inlet valve.
       The valve disc forms an important pressure boundary and detail calculations will be
       required for this complex shape.
3 The Contractor shall also provide other calculations as required by the Engineer for his
review of the Contractor‟s design.
TM-3.32 Inspection and Tests
General
1       All equipment shall be subject to inspection and testing by the Contractor as specified
herein and in TG-18.
2       The Contractor shall furnish certified copies of all test results, the results of each test
shall be recorded in the form of test certificates or reports as specified.
Type Tests
3      Type tests may be offered by the Contractor, as specified in TG-18, provided the
Contractor gives evidence to the Engineer as to the similarity of the equipment tested and the
Contract equipment.
Shop Tests
4      The equipment shall be subjected to shop tests as specified in GC 13 and in
accordance with the latest issue of the applicable standards.
5      In addition, the Contractor shall provide the following shop tests:
(a) Material Tests
Material tests shall be as specified in TG-18.
(b) Hydrostatic Tests
Hydrostatic tests shall be done on the valve and the bypass valve as specified in TG-18. Tests
shall be conducted with two pressure heads to confirm the integrity of the valve body and one
pressure head to confirm the valve seals of the downstream side.
(c) Shop Tests
Shop tests as specified in TM-3.




                                            TM-3.12
                                   TM-3 Inlet Valve

Field Tests
6      The Contractor shall carry out field inspections and tests as specified in GC-14 and in
accordance with the latest issue of the applicable standards.
7      In addition, the Contractor shall perform the following field tests.
       -   Complete tests shall be made at the site to determine the performance and
           operating characteristics of the complete unit and to determine whether or not the
           guarantees have been met. Tests on the inlet valve shall include the following:
       -   alignment checks on valve foundations and flexible couplings in the dry
       -   operational tests in the dry
       -   leakage test with valve closed
       -   proving of interlocks and indications
       -   operational tests in the dry and wet
       -   investigation of any objectionable vibrations, pressure surges or noise under any
           operating condition
       -   servomotor pressure differential tests over complete stroke
       -   emergency closure test with unit at full load
       -   other tests as required by the Engineer.
All necessary instrumentation and equipment for the tests shall be provided by the
Contractor.
Efficiency Head Loss Guarantee Test
8       Testing to verify the head loss across the inlet valve shall be done by the Contractor
prior to issuing the Taking-over Certificate.
9      Tests shall be carried out in accordance with IEC Publication 41, where applicable for
pressure measurements.
10      The head loss across the inlet valve shall be measured between the piezometer ring
upstream from the inlet valve and the piezometer ring downstream from the inlet valve in the
spiral case inlet section.




                                           TM-3.13
                       TM-4 Auxiliary Mechanical Systems
                               Table of Contents
TM-4    Auxiliary Mechanical Systems ………………………………………….TM-4.1
  TM-4-1 Purpose and Function ...........................................…………………....TM-4.1
  TM-4-2 Drawings .......................................................................……………....TM-4.1
  TM-4-3 Standards and Codes ............................................………………….....TM-4.1
  TM-4-4 Equipment Supplied by the Contractor ..……………………………..TM-4.1
  TM-4-5 Control and Auxiliary Power Supplies ………………..………………..TM-4.2
  TM-4-6 Electrical Equipment ..................................……………………….........TM-4.2
  TM-4-7 Painting ....................................................................………………........TM-4.2
  TM-4-8 Nameplates ............................................................……………….......TM-4.2
  TM-4-9 Quantities and Descriptions ......................………………………........TM-4.2
  TM-4-10 Spare Parts ............................................................………………….......TM-4.3
  TM-4-11 Drainage and Unwatering Systems ..........…………………………....TM-4.3
  TM-4-12 Cooling Water System ......................................…………………….....TM-4.4
  TM-4-13 Generator Fire Detection and Carbon Dioxide (CO2) Prot System ……TM-4.5
  TM-4-14 Generator Step-up Transformers Fire Detection and Prot System ……TM-4.6
  TM-4-15 Compressed Air Systems ..............................…………………………..TM-4.8
  TM-4-16 Not Used .................................................................…………………....TM-4.9
  TM-4-17 Domestic Water System ..............................……………………….......TM-4.9
  TM-4-18 Piezometer Piping .............................................……………………..TM-4.9
  TM-4-19 Inspection and Tests .......................................……………………......TM-4.10




                                                TM-4.i
                    TM-4 Auxiliary Mechanical Systems

Kajakai Hydroelectric Project
Addition of Unit 2
Technical Specifications
TM-4 – Auxiliary Mechanical Systems
TM-4-1 Purpose and Function
1       The auxiliary mechanical systems shall comprise the powerhouse mechanical systems
embedded and exposed piping and equipment necessary to integrate the works involved with
the extension of all service facilities for the addition of the third generating unit into the
existing plant.
2       The equipment shall match, as closely as possible, in design, function, arrangement
and materials, that utilized throughout the existing plant. It shall be the Contractor‟s
responsibility to review the existing systems and to design the modifications necessary to
interface all systems and equipment with the existing works.
3      All equipment furnished shall be suitable for operation under all possible local
conditions.
TM-4-2 Drawings
1      The accompanying drawings form part of the specifications.
2      The Contractor is advised that details shown on the drawings concerning existing
embedded and exposed piping should be field checked by the Contractor and that should the
design of Unit 2 auxiliary mechanical systems require modifications to embedded pipe
sleeves, piping runs, pipe sizing, valves and equipment to that presently indicated on the
drawings for the existing units, the Contractor shall be responsible for making such
modifications. This also applies to drawings which become available in the future and are
provided to the Contractor.
TM-4-3 Standards and Codes
1      Unless otherwise stipulated in the specifications, the equipment shall comply with the
requirements and the latest revisions of the applicable standards as listed in TG-3 or
elsewhere in the specification.
TM-4-4 Equipment Supplied by the Contractor
1       The systems and equipment supplied by the Contractor shall generally include, but
not be limited to, those listed herein or shown on the drawings.
2       The Contractor-supplied equipment shall meet in every respect the requirements set
forth herein and those specified by the General Technical Specifications.
3       All piping systems material, fabrication, storage, cleaning, installation and testing
shall comply with the requirements of Section TG.
4       The Contractor shall supply all necessary embedded and exposed pipe sleeves,
piping, fittings, valves, vents and supports from new and existing distribution headers and
equipment to the termination points of the embedded piping already provided at Unit 2.


                                           TM-4.1
                     TM-4 Auxiliary Mechanical Systems

5       The Contractor shall be responsible for the removal of all temporary covers, blanking
plates, blind flanges, etc, installed at the exposed termination points of the existing embedded
piping.
6       The Contractor shall identify and accept all existing exposed and embedded piping
prior to commencing its own work and shall also ensure that existing piping is clear of all
possible obstructions before making final connection to new and existing termination points.
7      The Contractor shall be responsible for removal of all temporary supports and for
providing adequate support systems during extension of existing service piping headers.
TM-4-5 Control and Auxiliary Power Supplies
All equipment supplied for the auxiliary mechanical systems shall be suitable for operation
on the control and auxiliary power supplies outlined in TG-5.
TM-4-6 Electrical Equipment
All electrical equipment associated with auxiliary mechanical systems and equipment herein
specified shall meet the requirements of TG-10.
TM-4-7 Painting
All painted surfaces shall be, so far as is practical, shop painted in accordance with the
specifications outlined in TG-14.
TM-4-8 Nameplates
All equipment shall be identified, and all nameplate wording shall be subject to the
Engineer‟s review. Nameplates shall be in accordance with the specifications outlined in TG-
13.
TM-4-9 Quantities and Descriptions
The Contractor shall supply auxiliary mechanical systems as follows:
Quantity      Description
1             Generator enclosure trench drain water collection tank with level alarm and
              drainage piping
1 Lot         Drainage and unwatering piping including fittings, gauges valves, supports,
              and tie-ins
1 Lot         Cooling water piping including fittings, gauges, valves including relief
              valves, supports and tie-ins
1 Lot         Unit 2 generator fire detection and carbon dioxide (CO2) protection system;
              including bank of CO2 cylinders (if necessary), piping, fittings, gauges,
              valves including deluge valve, switches, actuating devices, CO2 discharge
              nozzles, supports and tie-ins
1 Lot         Generator step-up transformers fire protection system; including piping,
              fittings gauges, valves including deluge valve, switches, actuating devices,
              sprinkler heads, supports and tie-ins
1 Lot         Interconnecting fire protection piping; including supplemental strainer and
              fire service booster pump (if necessary), fittings, valves, supports and tie-ins
6             Fire hose cabinets


                                            TM-4.2
                    TM-4 Auxiliary Mechanical Systems

Quantity       Description
1 Lot          Fire protection control and annunciation system including panel, devices,
               wiring and tie-ins
12             Portable hand fire extinguishers
1 Lot          Compressed air piping including fittings, gauges, valves, supports and tie-ins
1 Lot          Piezometer piping including fittings, gauges, valves including valve station,
               test station, miscellaneous steel, supports and tie-ins
TM-4-10 Spare Parts
The Contractor shall supply spare parts, special tools and devices as detailed in the
Commercial Schedules and shall supply recommended spare parts for two years operation.
Spare parts for field testing and acceptance trials shall be provided by the Contractor. All
spare parts shall be identical electrically and mechanically to the corresponding parts in the
equipment, and shall be suitably packed and clearly marked ready for long term storage
indoors.
TM-4-11 Drainage and Unwatering Systems
1       The drainage and unwatering extended piping systems shall be designed to handle
powerhouse drainage from the additional floor and equipment drains and for the unwatering
of Unit 2 penstock, turbine spiral casing and draft tube.
2      Powerhouse normal drainage trench and equipment minor leakage flows are directed
by gravity to the existing drainage sump and pumped to tailrace by drainage pumps already
provided. The Contractor is advised that existing embedded pipes for the Unit 2 drainage and
unwatering system should be field checked by the Contractor.
3      Turbine headcover and shaft seal leakage water shall be drained by gravity via the
stay vanes to a floor trench in a similar manner to the existing headcover and shaft seal
leakage drains water for Units 1 and 3.
4       The generator enclosure drainage piping shall be routed to, and connected at, the
outside wall of the generator enclosure. The Contractor shall design and supply a cooling
water leakage collection tank to monitor leakage water originating from within the generator
enclosure. The tank shall be mounted external to the generator enclosure. The tank shall be
equipped with a floatoperated, high water level alarm and tank drainage piping. Normal flow
of leakage water will be via the tank discharge piping to the generator enclosure trench
drains.
5      The Contractor shall pay particular attention in its design to minimize potential
flooding of both the turbine and the generator enclosures in the event of a break in a cooling
water supply pipe.
6     Drainage of the Unit 2 spiral casing shall be by means of a suitably valved line
downstream of the turbine inlet valve.
7      Drainage of the Unit 2 draft tube will be by means of an existing embedded line
discharging directly to the unwatering sump adjacent to Unit 1. The Contractor shall provide
a suitable isolating valve for Unit 2 draft tube drain. The Contractor shall confirm the
operation of the drainage facility in its entirety.



                                           TM-4.3
                    TM-4 Auxiliary Mechanical Systems

8       Drainage of the power tunnel, penstocks, and manifold to tailwater level is
accomplished by closing the existing intake gate and draining to tailwater through the
partially open guide vanes of one or more of the units. To fully unwater the power tunnel, it
will be then necessary to install the draft tube gates and discharge the remaining water from
the draft tube of the closed-off unit using the unwatering pumps. The Contractor shall supply
the necessary drainage manifold connecting the penstock drain at the bottom of the upstream
transition section of the turbine inlet valve to the spiral casing drain and embedded drain line
terminating at the draft tube. The drainage manifold shall be complete with all necessary
valves, piping and supports, including hose gate valves at both upstream and downstream
branch lines for purging the lines of debris.
9       Filling the draft tube, spiral casing and penstock to tailwater level will be
accomplished by gravity flow from the tailrace. Contractor shall provide a valved filling line
in the downstream drainage gallery.
10     The Contractor shall make good all existing drain openings at Unit 2, where
necessary, including replacement of grilles as required.
TM-4-12 Cooling Water System
1      It shall be the Contractor‟s responsibility to review the existing cooling water supply
system and to design the modifications necessary to interface all systems and equipment for
Unit 2 with the existing plant.
2      The equipment shall match, where possible, in design, function, arrangement and
materials that utilized in the existing plant.
3      The existing cooling water system nominally comprises piping and isolating valve
and dual strainer from connections in section of penstock upstream of inlet valve of Units 2
(penstock stub) and 3, supplying water to Units 1 and 3, respectively.
4       The Contractor shall provide a new cooling water connection for supplying water to
Unit 2, located downstream of the penstock bulkhead and upstream of the new inlet valve.
The Contractor shall provide all valves, piping, supports, embedded sleeves, controls, as
required to provide cooling water to all users on Unit 2. The new connection and adjacent
isolating gate valve shall be sized for supplying the total cooling water requirements for
Units 1 + 2 + 3 combined. Downstream of the gate valve, the pipe size shall be reduced to
that required for supplying only Unit 2 and include a Victaulic coupling prior to the reduction
for easy future changes. For Unit 2 supply, the header shall include an automatic duplex
strainer, sized for 2 x 120% of the total cooling water flow required for Unit 2, complete with
300 m filter elements, automatic backwash system with local control panels and contacts
for trouble alarm to SCADA, and backwash piping to powerhouse drainage sump. The
pressure rating of the strainer shall be not less than the turbine scroll case design pressure
multiplied by 1.25.
The Contractor shall supply additional manually operated duplex strainers at use points if
required by its design.
All strainers shall be equipped with isolating valves and bypass with lockable bypass valve.




                                            TM-4.4
                    TM-4 Auxiliary Mechanical Systems

5      All turbine and generator cooling water and service water supply and discharge
branch line connections shall be made external to the turbine/generator enclosures to
minimize leakage within the enclosures.
6      Pressure, flow control and alarm devices, except those specified herein, are covered
under the sections of the specification describing the equipment which they service.
7      All strainers, piping, valves and controls associated with the generator water and
surface air cooling shall be sized for not less than 120% total combined flow rate.
TM-4-13 Generator Fire Detection and Carbon Dioxide (CO2)
Protection System
1       It shall be the Contractor‟s responsibility to review the existing generator fire
detection and carbon dioxide (CO2) protection system and to design the modifications
necessary to interface all systems and equipment for Unit 2 with the existing plant; including
supply of additional CO2 cylinders, if necessary.
2      The existing generator fire detection and carbon dioxide (CO2) protection system for
Units 1 and 3 nominally comprises:
       -   bank of CO2 cylinders, piping, CO2 discharge nozzles
       -   discharge control regulators, manifolds, valves
       -   manual stations, electric/pneumatic actuating/release devices, thermostats
       -   smoke and/or heat sensors, fire alarm system panel.
3       Contractor shall provide sealing of the generator housing to control the leakage and
dissipation of the CO2 and ensure that all safety features are provided such as:
       -   interlocking to disable the automatic release of the CO2 whenever the generator
           housing access door is open
       -   electrical interlocking between heat sensors detecting fire in the generator and the
           generator differential relaying scheme to prevent accidental CO2 discharge
       -   portable CO2 detection kits
       -   portable breathing apparatus for the personnel.
4      The equipment for Unit 2 shall match, as closely as possible, in design, function,
arrangement and materials, as that utilized in the existing plant in order to facilitate
maintenance. If not provided in the existing installation, the Contractor shall provide a means
for weighing the CO2 cylinders to check percentage full.
5      The Contractor shall ensure that the design, manufacture, installation, and testing of
the generator fire detection and carbon dioxide (CO2) protection system for Unit 2 is done in
accordance with the following standards:
       -   Factory Mutual requirements
       -   NFPA 12 - Standards on Carbon Dioxide Extinguishing Systems
       -   NFPA 851 - Recommended Practice for Fire Protection for Hydroelectric
           Generating Plants
       -   Afghan National Standards.
6      The Contractor shall supply a new fire alarm and detection systems with a
microprocessor-based control panel complete with suitable detectors, control panel and


                                           TM-4.5
                    TM-4 Auxiliary Mechanical Systems

wiring for interlocking with generator protection system. The fire protection panel shall be
based on the “notifier” or equipment system.
7       The Contractor shall supply and install new piping, fittings, brackets, etc, located
inside the generator housing for the fire protection system. Conduit boxes and necessary
wiring to a suitable junction box shall also be supplied and installed in the hot-air stream on
the inlet side of the coolers, and above the stator winding, to mount the detectors. Quantity
and type of fire detectors and all control and wiring shall be subject to acceptance by
Engineer.
8      The fire detection and protection systems shall be complete in all respects with all
mechanical, piping and electrical materials, devices, alarms, interconnections, etc, to form
fully operable systems. All electrical and mechanical equipment, wiring, piping, etc, shall
conform to the requirements of Section TG.
9      The Contractor shall coordinate with the generator manufacturer to ensure provision
of an adequately sized system. The solenoid valve shall be operated normally by temperature
and generator differential relay operation. The Contractor shall also supply a manually
operated emergency release, isolating valve, CO2 supply pressure gauges, and annunciation
equipment.
10     Calculations of the design of the CO2 system, together with the drawings, shall be
submitted to the Engineer for review at least 30 days prior to procurement of any parts of the
system. Information shall include the following :
       -   number, size and arrangement of nozzles for the generator fire protection system
           with details
       -   number and location of all pipe supports and hangers with details
       -   type, size and location of all valves and system components
       -   number, type and location of all heat-actuated devices
       -   control panels layout
       -   electrical control schematics and wiring diagram
       -   discharge rate (kg/min/nozzle).
11     Contractor shall provide a generator fire protection control and annunciation system,
including control and annunciator panels, initiating relays, cabling, 4 dry contacts for remote
annunciation and alarms. The control panel shall installed outside the generator housing.
12     All new fire protection system equipment shall be inspected and tested in the
presence of an authorized inspector and the Engineer.
TM-4-14 Generator Step-Up Transformers Fire Detection and
Protection System
1       The Contractor shall design and provide new fire detection and protection systems for
the generator step-up transformers (TE-6). The generator step-up transformers are a set of
three (3) single-phase oil-filled 13.8 kV to 110 kV transformers located just outside the
upstream wall of the powerhouse at elevation 974.60 m. There are fire protection walls
separating each of the three transformers.
2       The step-up transformer fire detection and protection systems shall include, but not be
limited to, those items listed herein or shown on the specification drawings.


                                           TM-4.6
                    TM-4 Auxiliary Mechanical Systems

3      The transformer fire protection systems shall comprise:
       -   fire protection dry pipe deluge system for each of the three transformers,
           including pumps, branch piping, deluge valve, actuating devices, sprinkler spray
           loops, spray nozzles, emergency manual release, and isolating valve
       -   step-up transformers fire protection control and annunciation system, including
           control and annunciator panels, initiating relays, cabling, 4 dry contacts for each
           system for remote annunciation and alarms
       -   all interconnecting piping, deluge valves, isolating valves, strainers, supports, etc,
           to form a complete fire protection system.
4       The step-up transformer fire protection system water supply shall be taken from the
tailrace, including provision of booster pumps and jockey pump.
5       Pumps shall include 2 x 100% capacity booster pumps (1 operating, 1 standby),
jockey pump, complete with all piping, valves, controls, interlocks and instrumentation,
control panel. Water strainer shall be dual basket type with isolation valves for each basket,
valved (lockable) bypass, stainless steel filter elements, differential pressure gauge, switch
and alarm. Tailrace intake shall be bellmouth type and fitted with 25 mm square stainless
steel grid with bell mouth inlet sized for maximum 0.3 m/s net velocity and arranged to face
vertically down. Pump location and piping arrangement shall ensure flooded pump suction at
all specified tailwater levels. Low points shall have valved drains and suction line shall have
connection to permit backwashing.
6      The fire protection deluge valves for each of the three transformers shall be of the dry
pipe type complete with the necessary controls and activating devices. The release control
system shall automatically deluge the transformer(s) adjacent to the transformer on which the
controls have activated the system. The system shall be capable of delivering a minimum
discharge rate over the area to be protected in accordance with NFPA 15.
7      For each deluge system, the Contractor shall also supply manual test push button,
water supply isolating valve, primary valve, water supply and priming supply pressure
gauges, annunciation and unit shutdown devices including alarm and indication for „deluge
valve blocked‟.
8       The Contractor shall supply all necessary sprinkler spray loops including pipe support
structure, pipe supports, spray nozzles and associated hardware. Support structure, supports
and spray loops shall be designed to permit easy removal of a single transformer without
removal of the adjacent transformer‟s fire protection piping and supports.
9       The fire control panel shall be microprocessor based and based on the “notifier” or
equivalent system. The Contractor shall provide suitable fire/heat detectors and all associated
electrical devices, junction boxes, interlocks, wiring, conduit, supports to provide a complete
system.
10     In addition to the supply piping and deluge system for the step-up transformer, the
Contractor shall design and supply a system of piping for six (6) fire hose cabinets, to be
located at key points through the powerhouse. The system supplied by the Contractor shall
include all necessary piping, valves, supports, fire hose, hose discharge nozzles and cabinets.
11     It is the Contractor‟s responsibility to ensure the fire protection scheme implemented
meets approval of all authorities having jurisdiction.


                                            TM-4.7
                    TM-4 Auxiliary Mechanical Systems

12     Calculations of the design of the overall system and of each deluge system, together
with the drawings, shall be submitted to the Engineer at least 30 days prior to procurement of
any parts of the system. Information shall include the following:
       -   number, size and arrangement of nozzles for the step-up transformers fire
           protection system, with details
-      number and location of all pipe supports and hangers, with details
       -   size and arrangement of piping systems
       -   type, size and location of all valves and system components
       -   number, type and location of all heat-actuated devices
       -   control panels layout
       -   electrical control schematics and wiring diagrams
       -   system deluge density (L/min/m2)
       -    pressure drops, flows, velocities including determination of the most
           hydraulically remote nozzle.
13     The fire protection and detection systems shall be complete in all respects with all
mechanical, piping and electrical materials, devices, alarms, interconnections, etc, to form
fully operable systems. All electrical and mechanical equipment, wiring, piping, etc, shall
conform to the requirements of Section TG.
14      All new fire protection system equipment shall be inspected and tested in the
presence of an authorized inspector and the Engineer. Hydrostatic tests shall be in accordance
with the provisions of NFPA 13, Standards for Installation of Sprinkler Systems. Operating
tests shall be conducted in accordance with the provisions of NFPA 15, Standards for Water
Spray Fixed Systems for Fire Protection.
TM-4-15 Compressed Air Systems
1      It shall be the Contractor‟s responsibility to review the existing compressed air
system and to design the modifications necessary to interface all systems and equipment for
Unit 2 with the existing plant.
2     The equipment shall match, as closely as possible, in design, function, arrangement
and materials the equipment utilized in the existing plant.
3       The powerhouse compressed air systems shall include but not be limited to those
listed herein or shown on the specification drawings.
4      The compressed air systems shall comprise:
       -   tie-in(s) to the existing service air supply headers for service to Unit 2
       -   tie-in to the existing brake air supply header to service Unit 2
       -   branch piping, isolating globe valves, and air hose connections from the service
           air
       -   branch piping, solenoid-operated valve, and isolating globe valve from the service
           air header to the cooling water strainer automatic backwash controls
       -   branch piping and isolating valve from the brake air header to the Unit 2 generator
           brake control valve located in the actuator cubicle.




                                           TM-4.8
                     TM-4 Auxiliary Mechanical Systems

5      All pressure, flow control and alarm devices, except those specified herein, are
covered under the sections of the specifications describing the equipment which they service.
6      The Contractor shall supply all interconnecting piping between distribution headers,
branch piping and systems equipment complete with necessary pipe supports and associated
hardware.
7       The Contractor is advised that there is currently no provision for instrument quality
air and that should such air quality be required, the Contractor shall include provision in its
Bid together with details of such requirements and associated equipment, including
applicable costs. Dryers shall be of the dessicant type.
TM-4-16 Not Used
TM-4-17 Domestic Water System
It is not expected that any modifications or additions to the existing domestic water system
will be required.
TM-4-18 Piezometer Piping
1       The Contractor shall design and provide new piezometer piping systems for Unit 2.
The new piezometer piping systems shall include, but not be limited to, those items listed
herein or shown on the specification drawings.
2       The equipment shall match, as closely as possible, in design, function, arrangement
and materials, as that utilized in the existing plant. It shall be the Contractor‟s responsibility
to review the existing piezometer piping systems.
3      The piezometer piping shall be used for the purpose of conducting turbine
performance and index tests on Unit 2 as described in TM-1.
4      The piezometer piping shall comprise:
       -   embedded piping, complete with necessary adapters, from the four net head taps
           provided in the turbine spiral case inlet to the test station header
       -   embedded piping, complete with necessary adapters, from the four index test taps
           provided in the turbine spiral case to the test station header
       -   exposed piping, complete with necessary adapters, from the four inlet valve head
           loss taps (see TM-3-18) just upstream of the connection of the penstock to the
           transition section, to the test station header
       -   protective wrap and asphalt coating at all tap connections to the spiral case and
           penstock
       -   continuous protective steel angle complete with attachments to reinforcement
           steel for net head and index test piezometer piping up to the test station header
       -   one stainless steel test station header plate, complete with eight adapters, isolating
           valves and plugs, for installation in the downstream gallery (H1 - H4, S1 - S4)
       -   one stainless steel test station header plate, complete with four adapters, isolating
           valves and plugs, for installation in the inlet valve gallery (H5 - H8)
       -   test station manifold with valves.
5      The Contractor shall clearly identify each piezometer connection at the test station
header plate as follows:


                                            TM-4.9
                     TM-4 Auxiliary Mechanical Systems

       -   four spiral case net head pressure taps H-1 through H-4
       -   four spiral case index test taps S-1 through S-4
       -   four inlet valve head loss taps H-5 through H-8.
6       After installation of all piezometer piping and before placement of the spiral case
concrete, the Contractor shall, in the presence of the Engineer, pressure test, flow test and
identify each piezometer line for its intended purpose.
7       For details of the net head and index test piezometer taps provided in the turbine
spiral casing refer to TM-1-17.
TM-4-19 Inspection and Tests
General
1      All auxiliary mechanical systems shall be subject to inspection and testing by the
Contractor as specified in TG-18.
2      All auxiliary mechanical systems shall be fully tested in accordance with the pre-
commissioning operational and commissioning tests specified in TI-1 and in conjunction
with the testing of the electrical equipment.
3       The Contractor shall furnish certified copies of all test results, the results of each test
shall be recorded in the form of test certificates or reports as specified in TG-18.
4      The Contractor shall provide all necessary materials, equipment, instrumentation and
controls for all tests specified below.
Type Tests
5      Type tests may be offered by the Contractor as specified in TG-18, provided the
Contractor gives evidence to the Engineer as to the similarity of the equipment tested and the
Contract equipment.
Shop Tests
6      The equipment shall be subjected to shop tests as specified in TG-18 and in
accordance with the latest issue of the applicable standards.
7      In addition, the Contractor shall perform the following shop tests:
(a) Material Tests
Material tests shall be as specified in TG-18.
(b) Hydrostatic Tests
Hydrostatic tests shall be as specified in TG-18.
Field Tests
8      The Contractor shall carry out field inspections and tests as specified in TG-18 and in
accordance with the latest issue of the applicable standards.
9      The Contractor shall perform all necessary tests to check performance of each system
as a whole and when each system is operated in conjunction with existing systems on Units 1



                                            TM-4.10
                   TM-4 Auxiliary Mechanical Systems

and 3, for all normal and abnormal operating conditions. These tests shall prove that all
operating requirements have been met.




                                        TM-4.11

				
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Description: TM Turbine eye liner