Amarillo Chittom AirFlo
728 S. Wheeling
Tulsa, OK 74104
(918) 585-5638 FAX (918) 587-3577
web site http://www.amarillochittom.com
IM-PowerFlo01 May 2003
A NOTE ABOUT YOUR NEW FAN AND THIS MANUAL ...........
Thank you for purchasing a PowerFlo fan from Amarillo Chittom AirFlo. Your new fan
includes features and quality construction that is the result of years of research using the best
equipment and manufacturing practices available. Amarillo Chittom AirFlo is as interested as
you are in the fan exceeding your expectations of performance and life. This manual has been
developed to make installing and maintaining your new fan a simple and trouble free
PowerFlo fans represent the best performing and most cost effective aluminum fan on
the market today. As with any investment in precision equipment, proper care and some
precautions will help protect your investment for years of trouble free operation while obtaining
maximum performance. If you have any questions concerning the installation, operation or
maintenance of your new PowerFlo fan, please contact us for assistance.
1.0 Getting Ready For Installation
1.1 Parts Identification and Inspection
1.2 Pre-Installation Planning
2.0 Hub Installation
3.0 Blade Installation
4.0 Initial Operation Procedures
5.0 Periodic Maintenance
Service, Quality and Dependability For Over 40 years Page 2
1.0 Getting Ready For Installation ...
1.1 Parts Identification and Inspection
Every fan has been carefully manufactured and packaged for shipment.
Please inspect the materials to ensure that you have received all of your
shipment and that no damage has occurred during shipping. If any damage is
evident, either before or after unpacking, please notify the delivering carrier
immediately to file a damage claim.
1 Fan Blade Quantity as specified on order
2 Fan Hub 1 Per Fan
3 Air Intake Side Blade Clamp 1 Per Blade
4 Discharge Side Blade Clamp 1 Per Blade
5 Checo Split Taper Bushing 1 Per Fan
6 Bushing Attachment Bolts 3 Per Fan
7 Bushing Bolt Lock Washer 3 Per Fan
8 Blade Clamp Bolt 2 Per Blade
9 Blade Clamp Bolt Flat Washer 4 Per Blade
10 Blade Clamp Self-Locking Nut 2 Per Blade
11 Key (Generally Provided By Others) 1 Per Fan
Service, Quality and Dependability For Over 40 years Page 3
1.2 Pre-Installation Planning
The installation of your new PowerFlo fan is simple and with a little planning
can be accomplished very quickly. One person can perform the installation
provided a means of lifting the hub into position is available.
For most installations, the fan shaft key is provided with the shaft. Check to
make sure the key is available and that the shaft is clean and in good
condition. This is a good time to double check that the correct size bore has
been ordered for the fan bushing.
A list of tools is provided below for your reference. The digital protractor as
shown is the easiest and generally the most accurate for setting blade pitch. If
one is not available, you can order one through Amarillo Chittom AirFlo or you
may use a bubble protractor with 1/2 degree or finer increments that is
available through better local tool distributors. A smaller torque wrench is
shown and may be desirable for tightening the split taper bushing bolts since
excessive torque on these bolts may cause damage.
A Torque Wrench
B Box End Wrench 1 1/8 for 3/4” Bolts 3/4 for 1/2” Bolts
C Socket (Bshg Hdwe) 9/16 for 3/8” Bolts 3/4 for 1/2” Bolts
D Socket (Blade Hdwe) 1 1/16 for 3/4 Nuts 3/4 for 1/2” Nuts
E Allen Wrench 1/8 Hex for 1/4” Set Screw
F Plain Blade Screw Driver
G Precision Protractor (For blade pitch adjustment)
H Straight Edge (For blade pitch adjustment)
Service, Quality and Dependability For Over 40 years Page 4
2.0 Hub Installation ...
Drive a screwdriver into the flange of the
split taper bushing to enlarge the bore
enough to slide onto the fan shaft.
Caution - Do not drive the screw driver
into the tapered surface or damage to
this critical mating surface may occur.
The fan hub may be installed either with
the bushing away from the end of the
shaft or with the bushing towards the
end of the shaft. If the bushing goes
towards the end of the shaft, slide the
fan hub on the shaft prior to installing
the split taper bushing.
When lifting the fan hub, bolts may be
inserted into the blade clamp mounting
holes to use as a handle.
DO NOT APPLY ANTI-SIEZE
COMPOUND TO THE SHAFT OR TO
THE BUSHING BOLTS.
Slide the split taper bushing and key
onto the fan shaft until it is in the desired
location on the shaft. Remove the
screw driver from the flange allowing the
bushing to clamp down on the shaft.
Use an allen wrench to tighten the set
screw over the key just enough that the
bushing and key will not move during
mounting of the fan hub.
Slide the tapered bore of the fan hub
over the split taper bushing. Insert the
bushing bolt through the split lock
washer and drilled holes in the bushing
flange. Finger start the bolts in the hub.
Service, Quality and Dependability For Over 40 years Page 5
Using a torque wrench, tighten the three
split taper bushing bolts. The bolts
should each be tightened a little at a
time and move to the next bolt
sequentially, working up to the specified
torque for the bolt. After the bolt
reaches the specified torque, keep
going around the bolts in order checking
the torque until no further tightening is
required to remain at the specified
Do not over torque the bushing bolts or
damage may occur.
Torque 3/8” bolts to 35 ft. lbs.
Torque 1/2” bolts to 45 ft. lbs. Tighten the set screw over the key in the
split taper bushing completely so the
screw point locks into the key surface.
3.0 Blade Installation ...
The blade clamps are different for the air
intake side of the fan and the air
discharge side. The two parts can be
identified by the depth of the cut for the
blade shank shoulder. The cut is
deeper on the air discharge side to
produce a droop in the installed fan
Place one of each clamp around the
shank of the blade as shown.
Hold the blade so that the clamp with
the deeper shoulder cut is to the
discharge side of the fan and tip of the
fan blade is angled slightly towards the
air intake side of the fan.
The clamps should easily slide between
the two plates of the fan hub.
Service, Quality and Dependability For Over 40 years Page 6
Line up one of the holes in the plates
and blade clamps. Place a blade clamp
bolt through a flat washer and insert the
bolt through the hole that is lined up in
the clamps and plates. Place another
flat washer on the blade clamp bolt and
start the self-locking nut on the bolt
Caution - If the clamps do not
slide freely between the plates, Swing the blade around until the second
check to see that you do not set of holes lines up between the plates
have either two intake side and clamps. Install the second blade
clamps or two discharge side clamp bolt finger tight with a flat washer
clamps. under both the bolt head and the nut.
Recommended practice for Slide the blade shoulder firmly against
tightening bolted joints is to the clamps and tighten the blade clamp
hold the bolt head still while
bolts just enough that the blade does not
turning the nut. Therefore, it is
a good idea to make sure the slide in the clamps.
nuts are on the side of the hub
easiest to access with the Rotate the blade around the
torque wrench. If not, remove circumference of the fan ring to make
them one at a time and switch
sure there is proper tip clearance all the
them before all the blades are
installed. way around.
Installing spacer rings to If necessary because of interference
reduce the fan diameter for with the fan ring, spacer rings have
proper tip clearance will been shipped with your fan assembly to
decrease fan performance
slightly. Better fan
reduce the fan diameter. Determine
performance will be achieved if how much the blade must be moved in
the fan ring can be increased to provide proper tip clearance. Each
in size instead of reducing the spacer ring will reduce the fan radius
fan diameter. (i.e. increase tip clearance) by 1/8 inch.
A maximum of three spacer rings may
be installed on each fan blade.
To install spacer rings, loosen the single
blade installed in the hub. Slide the
blade towards the center of the hub and
snap the required number of spacer
rings over the blade shank.
Service, Quality and Dependability For Over 40 years Page 7
Pull the blade out radially so the spacer
rings are firmly “sandwiched” between
the blade shank shoulder and the back
side of the blade clamp. Tighten the
bolts enough to keep the blade in
position and rotate the blade again to
verify proper tip clearance all the way
Install the rest of the fan blades in the
hub repeating the procedure used for
the first blade.
Install the same number of spacer rings
on every fan blade. Failure to maintain
consistency in the number of spacer
rings on each blade will result in
increased vibration and stress.
For vertical applications, it might be
easier to install blades in opposite
sockets so that the weight remains
balanced as much as possible during
Mark a location on the fan ring where
each blade will be pitched. For vertical
applications this will either be at the
three o’clock or nine o’clock position,
depending on direction of rotation.
Loosen the blade clamp hardware just
enough that the blade can be rotated in
the blade clamps. Line up the trailing
edge with your reference mark you just
made on the fan ring.
At a position one inch from the blade tip,
lay a straight edge across the trailing
edge of the fan blade and the high point
of the blade airfoil. Rotate the blade in
the clamps until you get the right pitch.
Service, Quality and Dependability For Over 40 years Page 8
Caution - The blades should Torque the blade clamp hardware to 50
be adjusted in pitch until the ft. lbs for 1/2” bolts or 90 ft. lbs. for 3/4
target value is achieved plus or
inch bolts. Tighten one nut a turn or
minus 1/4 degree. Failure to
rotate each blade to the same two and move over to the other bolt for a
position for adjustment of the turn or two, switching back and forth
blade pitch can result in until the proper torque is reached and
excessive variation between maintained on both nuts.
blades. Excessive pitch
variation may result in vibration
Recheck the blade pitch at the position
and high stress levels in the
fan or surrounding equipment. one inch in from the tip to make sure it
has not changed during tightening of the
blade clamp hardware.
Repeat this process for each fan blade,
rotating them one at a time to the same
position in the fan ring and setting the
pitch on the blade.
Locate a convenient place in the fan ring
to check the tip track of the fan blades.
Place a mark in the fan ring at the
trailing edge of the fan blade parallel to
the rotation of the fan blade in the ring.
Rotate each blade to the same position
in the fan ring, mark and number the
location of the trailing edge for each
If the distance between the two outer
marks is greater than 1/2 inch, identify
Caution - Excessive tip track the blade that is different. Loosen that
may lead to high vibration blade and move the blade in the desired
levels in the fan or surrounding direction. Retorque the blade clamp
equipment. Stress in the fan hardware.
blade and hub will increase
with excessive tip track.
Recheck the pitch of the blade that tip
track adjustment was made to and
recheck the tip track of all blades.
Repeat the process as necessary.
Service, Quality and Dependability For Over 40 years Page 9
4.0 Initial Operation Procedures ...
Check to see that all hardware is tight and the fan rotates freely by hand before
starting the fan.
Make sure all guards are in place and that proper procedures are followed for
removing any lock out devices.
“Bump” the fan motor and verify the direction of fan rotation is correct.
Start the fan and watch both the fan and the fan ring as the fan comes up to
speed. If any contact or excessive movement of the fan ring is observed, shut
the fan off immediately and correct the cause of the problem. Allow the fan to
operate several minutes so the fan drive system stabilizes.
Check the fan speed and the fan motor power consumption. When checking
the power on an electric fan motor, be sure to measure the voltage and the
motor current. Checking the motor amperage only may give a false power
indication since high or low voltage affects the amperage of the motor at a
constant load condition.
Caution - Obtaining amperage and voltage readings on an electric motor may
require defeating the safety features of electrical enclosures. Please seek the
assistance of a qualified electrician and follow all applicable safety precautions.
The HP value provided in the fan specifications is the HP required at the fan
shaft to meet the specified air flow and static pressure requirements. The
motor output HP required will be higher than the specified fan HP because of
losses in the gear drive or belt drive. The actual fan HP may increase at
temperatures lower than those used for the selection and rating of the fan due
to changes in the density of the air moving through the fan.
Consult the factory if the difference between the measured HP of the motor
and the specified fan HP seems excessive. Minor adjustments in pitch to
achieve the desired fan HP are normal due to variations in equipment, fan ring
geometry and tip clearances.
Warning - Do not increase the fan operating speed above the RPM listed in the
fan specifications without first consulting the factory. Operating the fan at
excessive speeds may shorten the life of the fan significantly.
Service, Quality and Dependability For Over 40 years Page 10
5.0 Periodic Maintenance ...
Most fan failures are not sudden catastrophic degradation of the equipment
and can be prevented by regular inspection and maintenance of the fan and
fan drive system. Correcting problems before fan failures occur is more cost
effective than replacing equipment after a fan failure.
PowerFlo fans should be inspected for damage and correct hardware torque
after the first full week of operation and at intervals not greater than six
months thereafter. Be sure to follow all safety precautions including proper
lock out and tag out procedures when inspecting and performing maintenance
on your equipment.
Clean any accumulated scale or foreign matter from the fan assembly when
you perform the regular maintenance on the fan. The build up of foreign matter
on the fan increases operating stresses and may affect the life of the fan in
addition to reducing fan efficiency.
Check the fan for any cracks, dents or corrosion. Black streaks originating
from rivets are a good indicator that wear is occuring in the connections. Pay
particular attention to any areas exhibiting black streaks for cracks and
looseness of the mechanical joints. Sudden or frequent appearance of these
black oxide trails may be an indication of excessive vibration in the operating
unit or very high aerodynamically induced loads in the fan blades. Blades with
wear or damage may be replaced individually without adversely affecting fan
balance. Please consult the factory for details concerning blade replacement.
The 5052-H38 aluminum used for construction of the fan blades is a marine
alloy offering good resistance to corrosion and minor dents. Special coatings
and hardware options are available for fans operating in more aggressive
environments. Please contact the factory for information concerning suitability
of the fan and recommended options for fans operating in corrosive
Check the fan blade tips and the fan rings for any signs of wear or contact.
Check all hardware for proper torque.
Service, Quality and Dependability For Over 40 years Page 11
6.0 Warranty ...
Amarillo Chittom AirFlo warrants to the original purchaser only the material and workmanship
of its products for 24 months after delivery or 12 months after equipment is put into use,
whichever occurs first.
Amarillo Chittom AirFlo will repair or replace, at its option, and without charge, the equipment
or any part or parts thereof which shall fail due to defective material or workmanship within
said period, provided and on condition that:
1. The equipment is promptly delivered with all handling and freight charges prepaid to
Amarillo Chittom AirFlo, 728 South Wheeling, Tulsa, Oklahoma, 74104 or contact Amarillo
Chittom AirFlo at (918) 585-5638, for its inspection, repair or replacement.
2. Equipment is accompanied by a proof of purchase document when returned to Amarillo
3. All replacement parts are F.O.B., Tulsa, Oklahoma, and will be shipped freight
This warranty is limited to defects in material and workmanship, and it does not apply to
loss or damage which is the result of accident, misuse, mis-application (including operation
at “critical speeds”), resonance, improper installation, negligence, acts of god or any cause
occurring after delivery to the original purchaser.
All other warranties, expressed, implied or statutory, including warranties of fitness for a
particular purpose and of merchantability, are limited to the above period of this warranty
and are otherwise excluded from this warranty.
Amarillo Chittom AirFlo continually strives to improve the design and mechanical quality of its
products. We are not, however, obligated to install these improvements on products previously
The foregoing shall be the sole and exclusive remedy of any person, whether in contract,
tort or otherwise, and Amarillo Chittom AirFlo shall not be liable for incidental or consequential
damage or commercial loss, nor for any other loss or damage except as set forth above.
This warranty may not be extended or modified.
This warranty gives you specific legal rights and you may have other rights which vary from
state to state.
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