Page 1
ACDEU
OM-06443-01
February 24, 2012
Rev. A 03‐27‐13
INSTALLATION, OPERATION,
AND MAINTENANCE MANUAL
WITH PARTS LIST
PAH SERIES PUMP
MODEL
PAH4A60C-B
THE GORMAN‐RUPP COMPANY MANSFIELD, OHIO
GORMAN‐RUPP OF CANADA LIMITED ST. THOMAS, ONTARIO, CANADA Printed in U.S.A
www.grpumps.com.
2012 The Gorman‐Rupp Company
Page 2
Register your new
Gorman‐Rupp pump online at
www.grpumps.com
Valid serial number and e‐mail address required.
RECORD YOUR PUMP MODEL AND SERIAL NUMBER
Please record your pump model and serial number in the
spaces provided below. Your Gorman‐Rupp distributor
needs this information when you require parts or service.
Pump Model:
Serial Number:
Page 3
TABLE OF CONTENTS
INTRODUCTION PAGE I - 1.................................................
SAFETY ‐ SECTION A PAGE A - 1............................................
INSTALLATION - SECTION B PAGE B - 1....................................
PREINSTALLATION INSPECTION PAGE B - 1............................................
POSITIONING PUMP PAGE B - 1.......................................................
Lifting PAGE B - 2.................................................................
Mounting PAGE B - 2.............................................................
SUCTION AND DISCHARGE PIPING PAGE B - 2.........................................
Materials PAGE B - 2..............................................................
Line Configuration PAGE B - 2......................................................
Connections to Pump PAGE B - 2..................................................
Gauges PAGE B - 2...............................................................
SUCTION LINES PAGE B - 2...........................................................
Fittings PAGE B - 2...............................................................
Strainers PAGE B - 2..............................................................
Sealing PAGE B - 3...............................................................
Suction Lines In Sumps PAGE B - 3.................................................
Suction Line Positioning PAGE B - 3................................................
DISCHARGE LINES PAGE B - 4........................................................
Siphoning PAGE B - 4.............................................................
Valves PAGE B - 4................................................................
ALIGNMENT PAGE B - 4..............................................................
Coupled Drives PAGE B - 4........................................................
Drive Belts PAGE B - 5............................................................
DRIVE BELT TENSIONING PAGE B - 5..................................................
General Rules of Tensioning PAGE B - 5.............................................
OPERATION - SECTION C PAGE C - 1......................................
PRIMING PAGE C - 1.................................................................
STARTING PAGE C - 1................................................................
Rotation PAGE C - 1..............................................................
OPERATION PAGE C - 1..............................................................
Leakage PAGE C - 1..............................................................
Liquid Temperature And Overheating PAGE C - 1.....................................
Strainer Check PAGE C - 2.........................................................
Pump Vacuum Check PAGE C - 2..................................................
STOPPING PAGE C - 3................................................................
BEARING TEMPERATURE CHECK PAGE C - 3..........................................
Cold Weather Preservation PAGE C - 3..............................................
TROUBLESHOOTING - SECTION D PAGE D - 1..............................
PREVENTIVE MAINTENANCE PAGE D - 3...............................................
PUMP MAINTENANCE AND REPAIR ‐ SECTION E PAGE E - 1.................
STANDARD PERFORMANCE CURVE PAGE E - 1........................................
i
Page 4
TABLE OF CONTENTS
(continued)
PARTS LISTS:
Pump Model PAGE E - 3..........................................................
Pump End Assembly PAGE E - 5...................................................
Priming Chamber Kit PAGE E - 6...................................................
Priming Chamber Assembly PAGE E - 7.............................................
PUMP AND SEAL DISASSEMBLY AND REASSEMBLY PAGE E - 8.........................
Priming Chamber Removal And Disassembly PAGE E - 8..............................
Discharge Check Valve Removal and Disassembly PAGE E - 9.........................
Suction Spool Removal PAGE E - 9.................................................
Pump Casing and Wear Ring Removal PAGE E - 9....................................
Impeller Removal PAGE E - 9......................................................
Seal Removal PAGE E - 10..........................................................
Pump Shaft and Bearing Removal and Disassembly PAGE E - 10........................
Bearing Cleaning And Inspection PAGE E - 11........................................
Pump Shaft and Bearing Reassembly and Installation PAGE E - 11......................
Seal Reassembly and Installation PAGE E - 13........................................
Impeller Installation PAGE E - 14.....................................................
Pump Casing and Wear Ring Installation PAGE E - 15..................................
Discharge Check Valve Assembly and Installation PAGE E - 16..........................
Priming Chamber Assembly And Installation PAGE E - 16...............................
LUBRICATION PAGE E - 16.............................................................
Seal Assembly PAGE E - 16.........................................................
Bearings PAGE E - 16..............................................................
Power Source PAGE E - 17.........................................................
ii
Page 5
PAH SERIES
OM-06443
INTRODUCTION
Thank You for purchasing a Gorman‐Rupp pump.
Read this manual carefully to learn how to safely
install and operate your pump. Failure to do so
could result in personal injury or damage to the
pump.
This pump is a PAH Series, priming‐assisted cen
trifugal model. The unit is designed for handling
non‐volatile, non‐flammable liquids containing
specified entrained solids. The basic material of
construction is ductile iron, with alloy steel shaft
and ductile iron wear ring.
This manual will alert personnel to known proce
dures which require special attention, to those
which could damage equipment, and to those
which could be dangerous to personnel. However,
because pump installations are seldom identical,
this manual cannot possibly provide detailed in
structions and precautions for every aspect of
each specific application. Therefore, it is the re
sponsibility of the owner/installer of the pump to
ensure that applications not addressed in this
manual are performed only after establishing that
neither operator safety nor pump integrity are com
promised by the installation. Pumps and related
equipment must be installed and operated ac
cording to all national, local and industry stan
dards.
The following are used to alert personnel to proce
dures which require special attention, to those
which could damage equipment, and to those
which could be dangerous to personnel:
Immediate hazards which WILL result in
severe personal injury or death. These
instructions describe the procedure re
quired and the injury which will result
from failure to follow the procedure.
Hazards or unsafe practices which
COULD result in severe personal injury
or death. These instructions describe
the procedure required and the injury
which could result from failure to follow
the procedure.
If there are any questions regarding the pump
which are not covered in this manual or in other lit
erature accompanying the unit, please contact
your Gorman‐Rupp distributor or the Gorman‐
Rupp Company:
The Gorman‐Rupp Company
P.O. Box 1217
Mansfield, Ohio 44901-1217
Phone: (419) 755-1011
or:
Gorman‐Rupp of Canada Limited
70 Burwell Road
St. Thomas, Ontario N5P 3R7
Phone: (519) 631-2870
Hazards or unsafe practices which COULD
result in minor personal injury or product or
property damage. These instructions de
scribe the requirements and the possible
damage which could result from failure to
follow the procedure.
NOTE
Instructions to aid in installation, operation, and
maintenance or which clarify a procedure.
PAGE I - 1INTRODUCTION
Page 6
Page 7
PAH SERIES
SAFETY ‐ SECTION A
This information applies to Prime Aire
Series basic pumps. Gorman‐Rupp has
no control over or particular knowledge
of the power source which will be used.
Refer to the manual accompanying the
power source before attempting to be
gin operation.
Because pump installations are seldom
identical, this manual cannot possibly
provide detailed instructions and pre
cautions for each specific application.
Therefore, it is the owner/installer's re
sponsibility to ensure that applications
not addressed in this manual are per
formed only after establishing that nei
ther operator safety nor pump integrity
are compromised by the installation.
OM-06443
sive, or flammable liquids which may
damage the pump or endanger person
nel as a result of pump failure.
Use lifting and moving equipment in
good repair and with adequate capacity
to prevent injuries to personnel or dam
age to equipment. Attach lifting equip
ment to the lifting device fitted to the
pump. If chains or cable are wrapped
around the pump to lift it, make certain
that they are positioned so as not to
damage the pump, and so that the load
will be balanced. The bail is intended for
use in lifting the pump assembly only.
Suction and discharge hoses and pip
ing must be removed from the pump be
fore lifting.
Before attempting to open or service the
pump:
1. Familiarize yourself with this man
ual.
2. Disconnect or lock out the power
source to ensure that the pump will
remain inoperative.
3. Allow the pump to completely cool
if overheated.
4. Check the temperature and make
sure the pump is cool before open
ing any covers, plates, or plugs.
5. Close the suction and discharge
valves.
6. Vent the pump slowly and cau
tiously.
7. Drain the pump.
After the pump has been installed, make
certain that the pump and all piping or
hose connections are tight, properly
supported and secure before operation.
Do not operate the pump against a
closed discharge valve. If operated
against a closed discharge valve, pump
components will deteriorate, and the
liquid could come to a boil, build pres
sure, and cause the pump casing to rup
ture or explode. Momentary closure of a
discharge valve is acceptable only
when required for startup or shutdown
procedures.
This pump is designed to handle most
non‐volatile, non‐flammable liquids
containing specified entrained solids.
Do not attempt to pump volatile, corro
Do not operate the pump without the
PAGE A - 1SAFETY
Page 8
guards in place over the rotating parts.
Exposed rotating parts can catch cloth
ing, fingers, or tools, causing severe in
jury to personnel.
Do not remove plates, covers, gauges,
pipe plugs, or fittings from an over
heated pump. Vapor pressure within the
pump can cause parts being disen
gaged to be ejected with great force. Al
low the pump to cool completely before
servicing.
PAH SERIESOM-06443
This pump may be used to handle mate
rials which could cause illness through
direct exposure or emitted fumes. Wear
adequate protective clothing when
working on the pump or piping.
Pumps and related equipment must be in
stalled and operated according to all na
tional, local and industry standards.
PAGE A - 2 SAFETY
Page 9
INSTALLATION - SECTION B
Review all SAFETY information in Section A.
Since pump installations are seldom identical, this
section offers only general recommendations and
practices required to inspect, position, and ar
range the pump and piping.
Most of the information pertains to a standard
static lift application where the pump is posi
tioned above the free level of liquid to be pumped.
If installed in a flooded suction application where
the liquid is supplied to the pump under pressure,
some of the information such as mounting, line
configuration, and priming must be tailored to the
specific application. Since the pressure supplied
to the pump is critical to performance and safety,
be sure to limit the incoming pressure to 50% of
the maximum permissible operating pressure as
shown on the pump performance curve.
For further assistance, contact your Gorman‐Rupp
distributor or the Gorman‐Rupp Company.
OM-06443PAH SERIES
Only operate this pump in the direction in
dicated by the arrow on the pump body
and on the accompanying decal. Refer to
ROTATION in OPERATION, Section C.
d. Check levels and lubricate as necessary. Re
fer to LUBRICATION in the MAINTENANCE
AND REPAIR section of this manual and per
form duties as instructed.
e. If the pump and power source have been
stored for more than 12 months, some of the
components or lubricants may have ex
ceeded their maximum shelf life. These must
be inspected or replaced to ensure maxi
mum pump service.
If the maximum shelf life has been exceeded, or if
anything appears to be abnormal, contact your
Gorman‐Rupp distributor or the factory to deter
mine the repair or updating policy. Do not put the
pump into service until appropriate action has
been taken.
PREINSTALLATION INSPECTION
The pump assembly was inspected and tested be
fore shipment from the factory. Before installation,
inspect the pump for damage which may have oc
curred during shipment. Check as follows:
a. Inspect the pump for cracks, dents, damaged
threads, and other obvious damage.
b. Check for and tighten loose attaching hard
ware. Since gaskets tend to shrink after dry
ing, check for loose hardware at mating sur
faces.
c. Carefully read all warnings and cautions con
tained in this manual or affixed to the pump,
and perform all duties indicated. Note the di
rection of rotation indicated on the pump.
Check that the pump shaft rotates counter
clockwise when facing the impeller.
POSITIONING PUMP
Lifting
Pump unit weights will vary depending on the
mounting and drive provided. Check the shipping
tag on the unit packaging for the actual weight, and
use lifting equipment with appropriate capacity.
Drain the pump and remove all customer‐installed
equipment such as suction and discharge hoses
or piping before attempting to lift existing, installed
units.
The pump assembly can be seriously
damaged if the cables or chains used to lift
and move the unit are improperly wrapped
around the pump.
PAGE B - 1INSTALLATION
Page 10
OM-06443 PAH SERIES
Mounting
Locate the pump in an accessible place as close as
practical to the liquid being pumped. Level mount
ing is essential for proper operation.
The pump may have to be supported or shimmed
to provide for level operation or to eliminate vibra
tion.
SUCTION AND DISCHARGE PIPING
Pump performance is adversely effected by in
creased suction lift, discharge elevation, and fric
tion losses. See the performance curve and oper
ating range shown on Page E‐1 to be sure your
overall application allows pump to operate within
the safe operation range.
Materials
to secure them when filled with liquid and under
pressure.
Gauges
Most pumps are drilled and tapped for installing
discharge pressure and vacuum suction gauges. If
these gauges are desired for pumps that are not
tapped, drill and tap the suction and discharge
lines not less than 18 inches (457,2 mm) from the
suction and discharge ports and install the lines.
Installation closer to the pump may result in erratic
readings.
SUCTION LINES
To avoid air pockets which could affect pump prim
ing, the suction line must be as short and direct as
possible. When operation involves a suction lift, the
line must always slope upward to the pump from
the source of the liquid being pumped; if the line
slopes down to the pump at any point along the
suction run, air pockets will be created.
Either pipe or hose maybe used for suction and
discharge lines; however, the materials must be
compatible with the liquid being pumped. If hose is
used in suction lines, it must be the rigid‐wall, rein
forced type to prevent collapse under suction. Us
ing piping couplings in suction lines is not recom
mended.
Line Configuration
Keep suction and discharge lines as straight as
possible to minimize friction losses. Make mini
mum use of elbows and fittings, which substan
tially increase friction loss. If elbows are necessary,
use the long‐radius type to minimize friction loss.
Connections to Pump
Before tightening a connecting flange, align it ex
actly with the pump port. Never pull a pipe line into
place by tightening the flange bolts and/or cou
plings.
Lines near the pump must be independently sup
ported to avoid strain on the pump which could
cause excessive vibration, decreased bearing life,
and increased shaft and seal wear. If hose‐type
lines are used, they should have adequate support
Fittings
Suction lines should be the same size as the pump
inlet. If reducers are used in suction lines, they
should be the eccentric type, and should be in
stalled with the flat part of the reducers uppermost
to avoid creating air pockets. Valves are not nor
mally used in suction lines, but if a valve is used,
install it with the stem horizontal to avoid air pock
ets.
Strainers
If a strainer is furnished with the pump, be certain
to use it; any spherical solids which pass through a
strainer furnished with the pump will also pass
through the pump itself.
If a strainer is not furnished with the pump, but is
installed by the pump user, make certain that the
total area of the openings in the strainer is at least
three or four times the cross section of the suction
line, and that the openings will not permit passage
of solids larger than the solids handling capability
of the pump.
This pump is designed to handle up to 3‐inch (76,2
mm) diameter spherical solids.
PAGE B - 2 INSTALLATION
Page 11
OM-06443PAH SERIES
Sealing
Since even a slight leak will affect priming, head,
and capacity, especially when operating with a
high suction lift, all connections in the suction line
should be sealed with pipe dope to ensure an air
tight seal. Follow the sealant manufacturer's rec
ommendations when selecting and applying the
pipe dope. The pipe dope should be compatible
with the liquid being pumped.
Suction Lines In Sumps
If a single suction line is installed in a sump, it
should be positioned away from the wall of the
sump at a distance equal to 1 1/2 times the diame
ter of the suction line.
If there is a liquid flow from an open pipe into the
sump, the flow should be kept away from the suc
tion inlet because the inflow will carry air down into
the sump, and air entering the suction line will re
duce pump efficiency.
If it is necessary to position inflow close to the suc
tion inlet, install a baffle between the inflow and the
suction inlet at a distance 1 1/2 times the diameter
of the suction pipe. The baffle will allow entrained
air to escape from the liquid before it is drawn into
the suction inlet.
If two suction lines are installed in a single sump,
the flow paths may interact, reducing the efficiency
of one or both pumps. To avoid this, position the
suction inlets so that they are separated by a dis
tance equal to at least 3 times the diameter of the
suction pipe.
Suction Line Positioning
The depth of submergence of the suction line is
critical to efficient pump operation.
recommended minimum submergence vs. veloc
ity.
Figure 2 shows
NOTE
The pipe submergence required may be reduced
by installing a standard pipe increaser fitting at the
end of the suction line. The larger opening size will
reduce the inlet velocity. Calculate the required
submergence using the following formula based
on the increased opening size (area or diameter).
Figure 1. Recommended Minimum Suction Line Submergence vs. Velocity
PAGE B - 3INSTALLATION
Page 12
OM-06443 PAH SERIES
DISCHARGE LINES
Siphoning
Do not terminate the discharge line at a level lower
than that of the liquid being pumped unless a si
phon breaker is used in the line. Otherwise, a si
phoning action causing damage to the pump
could result.
Valves
This pump is designed with a check valve in the
discharge line.
If a throttling valve is desired in the discharge line,
use a valve as large as the largest pipe to minimize
friction losses. Never install a throttling valve in a
suction line.
With high discharge heads, it is recommended that
a throttling valve and a system check valve be in
stalled in the discharge line to protect the pump
from excessive shock pressure and reverse rota
tion when it is stopped.
When mounted at the Gorman‐Rupp factory, driver
and pump are aligned before shipment. Misalign
ment will occur in transit and handling. Pumps
must be checked and realigned before operation.
Before checking alignment, tighten the foundation
bolts. The pump casing feet and/or pedestal feet,
and the driver mounting bolts should also be tightly
secured.
When checking alignment, disconnect
the power source to ensure that the
pump will remain inoperative.
Adjusting the alignment in one direction
may alter the alignment in another direc
tion. check each procedure after altering
alignment.
Coupled Drives
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
ALIGNMENT
The alignment of the pump and its power source is
critical for trouble‐free mechanical operation. In
either a flexible coupling or V‐belt driven system,
the driver and pump must be mounted so that their
shafts are aligned with and parallel to each other. It
is imperative that alignment be checked after the
pump and piping are installed, and before opera
tion.
NOTE
Check Rotation, Section C, before final alignment
of the pump.
When using couplings, the axis of the power
source must be aligned to the axis of the pump
shaft in both the horizontal and vertical planes.
Most couplings require a specific gap or clearance
between the driving and the driven shafts. Refer to
the coupling manufacturer's service literature.
Align spider insert type couplings by using calipers
to measure the dimensions on the circumference
of the outer ends of the coupling hub every 90.
The coupling is in alignment when the hub ends
are the same distance apart at all points (see Fig
ure 2).
Figure 2. Aligning Spider‐Type Couplings
PAGE B - 4 INSTALLATION
Page 13
OM-06443PAH SERIES
Figure 3. Aligning Non‐Spider Type Couplings
Align non‐spider type couplings by using a feeler
gauge or taper gauge between the coupling halves
every 90. The coupling is in alignment when the
hubs are the same distance apart at all points (see
Figure 3).
Check parallel adjustment by laying a straightedge
across both coupling rims at the top, bottom, and
side. When the straightedge rests evenly on both
halves of the coupling, the coupling is in horizontal
parallel alignment. If the coupling is misaligned,
use a feeler gauge between the coupling and the
straightedge to measure the amount of misalign
ment.
MISALIGNED:
SHAFTS
NOT PARALLEL
MISALIGNED:
SHAFTS
NOT IN LINE
ALIGNED: SHAFTS
PARALLEL AND
SHEAVES IN LINE
Figure 4. Alignment of V‐Belt Driven Pumps
Tighten the belts in accordance with the belt manu
facturer's instructions. If the belts are too loose,
they will slip; if the belts are too tight, there will be
excessive power loss and possible bearing failure.
Select pulleys that will match the proper speed ra
tio; overspeeding the pump may damage both
pump and power source.
Do not operate the pump without the
guard in place over the rotating parts.
exposed rotating parts can catch cloth
ing, fingers, or tools, causing severe in
jury to personnel.
DRIVE BELT TENSIONING
General Rules of Tensioning
Drive Belts
When using drive belts, the power source and the
pump must be parallel. Use a straightedge along
the sides of the pulleys to ensure that the pulleys
are properly aligned (see Figure 4). In drive sys
tems using two or more belts, make certain that the
belts are a matched set; unmatched sets will cause
accelerated belt wear.
For new drive belts, check the tension after 5, 20
and 50 hours of operation and re‐tension as re
quired (see the following procedure for measuring
belt tension). Thereafter, check and re‐tension if re
quired monthly or at 500 hour intervals, whichever
comes first.
Ideal drive belt tension is the lowest tension at
which the belt will not slip under peak load condi
tions. Do not over‐tension drive belts. Over‐ten
sioning will shorten both drive belt and bearing life.
Under‐tensioning will cause belt slippage. Always
keep belts free from dirt, grease, oil and other for
eign material which may cause slippage.
PAGE B - 5INSTALLATION
Page 14
PAH SERIES
OM-06443
OPERATION - SECTION C
Review all SAFETY information in Section A.
Follow the instructions on all tags, labels and
decals attached to the pump.
This pump is designed to handle liquids
containing large entrained solids and
slurries. Do not attempt to pump vola
tile, corrosive, or flammable liquids
which may damage the pump or endan
ger personnel as a result of pump fail
ure.
Pump speed and operating condition
points must be within the continuous per
formance range shown on the perfor
mance curve in Section E on page E-1.
Rotation
The correct direction of pump rotation is counter
clockwise when facing the impeller. The pump
could be damaged and performance adversely af
fected by incorrect rotation. If pump performance
is not within the specified limits (see the curve on
page E‐1), check the direction of power source ro
tation before further troubleshooting.
If an electric motor is used to drive the pump, re
move V‐belts, couplings, or otherwise disconnect
the pump from the motor before checking motor
rotation. Operate the motor independently while
observing the direction of the motor shaft, or cool
ing fan.
If rotation is incorrect on a three‐phase motor, have
a qualified electrician interchange any two of the
three phase wires to change direction. If rotation is
incorrect on a single‐phase motor, consult the liter
ature supplied with the motor for specific instruc
tions.
Priming
PRIMING
Install the pump and piping as described in IN
STALLATION. Make sure that the piping connec
tions are tight, and that the pump is securely
mounted. Check that the pump is properly lubri
cated (see LUBRICATION in MAINTENANCE
AND REPAIR).
The pump will begin to prime upon startup. The air
in the suction line will be discharged from the educ
tor discharge line. Complete priming is indicated
by a positive discharge pressure reading.
If full priming is not achieved, the discharge check
valve may be malfunctioning. If this occurs, shut
down the pump and consult Maintenance and
Repair, Section E for further details.
STARTING
Consult the operations manual furnished with the
power source.
The pump will begin to prime upon startup. The air
in the suction line will be discharged from the educ
tor discharge line. Complete priming is indicated
by a positive discharge pressure reading.
If full priming is not achieved, the discharge check
valve may be malfunctioning. If this occurs, shut
down the pump and consult the separate Mainte
nance and Repair manual for further details.
OPERATION
Leakage
Once the pump is fully primed, no leakage should
be visible at pump mating surfaces, or at pump
connections or fittings. Keep all line connections
and fittings tight to maintain maximum pump effi
ciency.
Liquid Temperature And Overheating
The maximum liquid temperature for this pump is
160 F (71C). Do not apply it at a higher operating
temperature.
OPERATION PAGE C - 1
Page 15
OM-06443 PAH SERIES
Overheating can occur if operated with the valves
in the suction or discharge lines closed. Operating
against closed valves could bring the liquid to a
boil, build pressure, and cause the pump to rup
ture or explode. If overheating occurs, stop the
pump immediately and allow it to completely cool
before servicing it. Approach any over‐heated
pump cautiously.
Allow an over‐heated pump to com
pletely cool before servicing. Do not re
move plates, covers, gauges, or fittings
from an overheated pump. Liquid within
the pump can reach boiling tempera
tures, and vapor pressure within the
pump can cause parts being disen
gaged to be ejected with great force. Af
ter the pump cools, drain the liquid from
the pump by removing the casing drain
plug. Use caution when removing the
plug to prevent injury to personnel from
hot liquid.
Never introduce air or steam pressure into the
pump casing or piping to remove a blockage. This
could result in personal injury or damage to the
equipment. If backflushing is absolutely neces
sary, liquid pressure must be limited to 50% of the
maximum permissible operating pressure shown
on the pump performance curve.
Pump Vacuum Check
With the pump inoperative, install a vacuum gauge
in the system, using pipe dope on the threads.
Block the suction line and start the pump. At oper
ating speed the pump should pull a vacuum of 20
inches (508,0 mm) or more of mercury. If it does
not, check for air leaks in the seal, gasket, or dis
charge valve.
Open the suction line, and read the vacuum gauge
with the pump primed and at operation speed.
Shut off the pump. The vacuum gauge reading will
immediately drop proportionate to static suction
lift, and should then stabilize. If the vacuum reading
falls off rapidly after stabilization, an air leak exists.
Before checking for the source of the leak, check
the point of installation of the vacuum gauge.
As a safeguard against rupture or explosion due to
heat, this pump is equipped with a pressure relief
valve which will open if vapor pressure within the
pump casing reaches a critical point. If over‐heat
ing does occur, stop the pump immediately and al
low it to cool before servicing it. Approach any
over‐heated pump cautiously. It is recom
mended that the pressure relief valve assembly be
replaced at each overhaul, or any time the pump
casing over‐heats and activates the valve. Never
replace this valve with a substitute which has not
been specified or provided by the Gorman‐Rupp
Company.
Strainer Check
If a suction strainer has been shipped with the
pump or installed by the user, check the strainer
regularly, and clean it as necessary. The strainer
should also be checked if pump flow rate begins to
drop. Monitor and record the vacuum suction
gauge readings regularly to detect strainer block
age.
STOPPING
Never halt the flow of liquid suddenly. If the liquid
being pumped is stopped abruptly, damaging
shock waves can be transmitted to the pump and
piping system. Close all connecting valves slowly.
On engine driven pumps, reduce the throttle
speed slowly and allow the engine to idle briefly be
fore stopping.
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
Do not operate the pump against a
closed discharge throttling valve for
long periods of time. If operated against
OPERATIONPAGE C - 2
Page 16
PAH SERIES
OM-06443
a closed discharge throttling valve,
pump components will deteriorate, and
the liquid could come to a boil, build
pressure, and cause the pump casing to
rupture or explode.
After stopping the pump, switch off the engine igni
tion and remove the key to ensure that the pump
will remain inoperative.
PERIODIC CHECKS
Seal Cavity And Bearing Lubrication
Both the seal and bearing cavities were fully lubri
cated at the factory. Check the lubrication levels
before startup, and regularly thereafter as indi
cated in Section E, Maintenance and Repair.
When lubrication is required, use only SAE No. 30
non‐detergent oil.
Bearing Temperature Check
to operate properly. Make certain that the bearing
lubricant is of the proper viscosity and at the cor
rect level (see LUBRICATION in Section E, Main
tenance and Repair). Bearing overheating can
also be caused by shaft misalignment and/or ex
cessive vibration.
When pumps are first started, the bearings may
seem to run at temperatures above normal. Con
tinued operation should bring the temperatures
down to normal levels.
Air Compressor
The air compressor was lubricated for test at the
factory. However, always check the lubrication lev
el before startup.
Consult the manual accompanying the air com
pressor and preform all duties and checks as indi
cated.
COLD WEATHER PRESERVATION
Bearings normally run at higher than ambient tem
peratures because of heat generated by friction.
Temperatures up to 160F (71C) are considered
normal for bearings, and they can operate safely to
at least 180F (82C).
Checking bearing temperatures by hand is inaccu
rate. Bearing temperatures can be measured ac
curately by placing a contact‐type thermometer
against the housing. Record this temperature for
future reference.
A sudden increase in bearing temperatures is a
warning that the bearings are at the point of failing
In below freezing conditions, drain the pump to
prevent damage from freezing. Also, clean out any
solids by flushing with a hose. Operate the pump
for approximately one minute; this will remove any
remaining liquid that could freeze the pump rotat
ing parts. If the pump will be idle for more than a
few hours, or if it has been pumping liquids con
taining a large amount of solids, drain the pump,
and flush it thoroughly with clean water. To prevent
large solids from clogging the drain port and pre
venting the pump from completely draining, insert
a rod or stiff wire in the drain port, and agitate the
liquid during the draining process. Clean out any
remaining solids by flushing with a hose.
OPERATION PAGE C - 3
Page 17
Page 18
PAH SERIES
TROUBLESHOOTING - SECTION D
Review all SAFETY information in Section A.
Before attempting to open or service the
pump:
1. Familiarize yourself with this manual.
2. Lock out or disconnect the power
source to ensure that the pump will
remain inoperative.
3. Allow the pump to completely cool if
overheated.
4. Check the temperature and make
sure pump is cool before opening
any covers, plates, or plugs.
5. Close the suction and discharge
valves.
6. Vent the pump slowly and cautiously.
7. Drain the pump.
OM-06443
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP FAILS TO
PRIME
PUMP STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE
Discharge check valve contami
nated, damaged, or unable to seat.
Air leak in suction line. Correct leak.
Lining of suction hose collapsed. Replace suction hose.
Leaking or worn seal or pump gasket. Check pump vacuum. Replace
Suction lift or discharge head too high. Check piping installation and install
Air compressor damaged or belts bro
ken.
Strainer clogged. Check strainer and clean if neces
Eductor clogged. Check and clean eductor.
Air leak in suction line. Correct leak.
Lining of suction hose collapsed. Replace suction hose.
Leaking or worn seal or pump gasket. Check pump vacuum. Replace
Clean or replace check valve.
leaking or worn seal or gasket.
bypass line if needed. See INSTAL
LATION.
Check and repair/replace.
sary.
leaking or worn seal or gasket.
TROUBLESHOOTING PAGE D - 1
Page 19
OM-06443
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PAH SERIES
PUMP STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE (cont.)
PUMP REQUIRES
TOO MUCH
POWER
Strainer clogged.
Discharge check valve clogged.
Suction intake not submerged at
proper level or sump too small.
Impeller or other wearing parts worn
or damaged.
Suction lift too high.
Pump speed too slow. Check driver output; consult driver
Belt or flexible coupling broken. Check and replace as necessary.
Pump speed too high. Check driver output.
Extreme ambient temperature. Reduce pump output.
Discharge head too low.
Fuel filter clogged. Check & replace often in extreme
Check strainer and clean if neces
sary.
Check and clean check valve.
Check installation and correct
submergence as needed.
Replace worn or damaged parts.
Check that impeller is properly
centered and rotates freely.
Free impeller of debris.Impeller clogged.
Measure lift w/vacuum gauge. Re
duce lift and/or friction losses in
suction line.
operation manual.
Adjust discharge valve.
operating conditions.
PUMP CLOGS
FREQUENTLY
EXCESSIVE NOISE
Dilute if possible.Liquid solution too thick.
Check and replace as required.Fuel contaminated.
Pump or jack shaft bearing(s) frozen. Disassemble, check and replace
bearing(s) as required..
Discharge flow too slow.
Suction check valve or foot valve
clogged or binding.
Liquid solution too thick.
Cavitation in pump. Reduce suction lift and/or friction
Pumping entrained air.
Impeller clogged or damaged.
Open discharge valve fully to in
crease flow rate, and run engine at
maximum governed speed.
Clean valve.
Dilute if possible.
losses in suction line. Record vac
uum and pressure gauge readings
and consult local representative or
factory.
Locate and eliminate source of air
bubble.
Secure mounting hardware.Pump or drive not securely mounted.
Clean out debris; replace damaged
parts.
TROUBLESHOOTINGPAGE D - 2
Page 20
PAH SERIES
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
OM-06443
BEARINGS RUN
TOO HOT
Bearing temperature is high, but
within limits.
Low or incorrect lubricant.
Suction and discharge lines not prop
erly supported.
Excessive tension on drive belt.
PREVENTIVE MAINTENANCE
Since pump applications are seldom identical, and
pump wear is directly affected by such things as
the abrasive qualities, pressure and temperature
of the liquid being pumped, this section is intended
only to provide general recommendations and
practices for preventive maintenance. Regardless
of the application however, following a routine pre
ventive maintenance schedule will help assure
trouble‐free performance and long life from your
Gorman‐Rupp pump. For specific questions con
cerning your application, contact your Gorman‐
Rupp distributor or the Gorman‐Rupp Company.
Record keeping is an essential component of a
good preventive maintenance program. Changes
in suction and discharge gauge readings (if so
Check bearing temperature regu
larly to monitor any increase.
Check for proper type and level of
lubricant.
Check piping installation for proper
support.
Align drive properly.Drive misaligned.
Check belt tension. Adjust as
required.
equipped) between regularly scheduled inspec
tions can indicate problems that can be corrected
before system damage or catastrophic failure oc
curs. The appearance of wearing parts should also
be documented at each inspection for comparison
as well. Also, if records indicate that a certain part
(such as the seal) fails at approximately the same
duty cycle, the part can be checked and replaced
before failure occurs, reducing unscheduled down
time.
For new applications, a first inspection of wearing
parts at 250 hours will give insight into the wear rate
for your particular application. Subsequent inspec
tions should be performed at the intervals shown
on the chart below. Critical applications should be
inspected more frequently.
TROUBLESHOOTING PAGE D - 3
Page 21
OM-06443
PAH SERIES
Preventive Maintenance Schedule
Service Interval*
Item
General Condition (Temperature, Unusual
Noises or Vibrations, Cracks, Leaks,
Loose Hardware, Etc.) I
Pump Performance (Gauges, Speed, Flow) I
Bearing Lubrication I
Seal Lubrication (And Packing Adjustment,
If So Equipped) I R
V‐Belts (If So Equipped) I
Air Release Valve Plunger Rod (If So Equipped) I C
Front Impeller Clearance (Wear Plate) I
Rear Impeller Clearance (Back Plate) I
Check Valve I
Pressure Relief Valve (If So Equipped) C
Pump and Driver Alignment I
Shaft Deflection I
Bearings I
Bearing Housing I
Piping I
Driver Lubrication - See Mfgr's Literature
Daily Weekly Monthly Semi‐
Annually
Annually
Legend:
I = Inspect, Clean, Adjust, Repair or Replace as Necessary
C = Clean
R = Replace
* Service interval based on an intermittent duty cycle equal to approximately 4000 hours annually.
Adjust schedule as required for lower or higher duty cycles or extreme operating conditions.
TROUBLESHOOTINGPAGE D - 4
Page 22
PAH SERIES
OM-06443
PUMP MAINTENANCE AND REPAIR - SECTION E
MAINTENANCE AND REPAIR OF THE WEARING PARTS OF THE PUMP WILL MAINTAIN PEAK
OPERATING PERFORMANCE.
STANDARD PERFORMANCE FOR PUMP MODEL PAH4A60C-B
Based on 70F (21C) clear water at sea level
with minimum suction lift. Since pump installations
are seldom identical, your performance may be dif
ferent due to such factors as viscosity, specific
gravity, elevation, temperature, and impeller trim.
Contact the Gorman‐Rupp Company to verify per
formance or part numbers.
Pump speed and operating condition
If your pump serial number is followed by an “N”,
your pump is NOT a standard production model.
MAINTENANCE & REPAIR PAGE E - 1
points must be within the continuous per
formance range shown on the curve.
Page 23
OM-06443 PAH SERIES
PARTS PAGE
ILLUSTRATION
AIR COMPRESSOR PIPING
PRIMING CHAMBER PIPING
Figure 1. Pump Model PAH4A60C-B
MAINTENANCE & REPAIRPAGE E - 2
Page 24
PAH SERIES
PARTS LIST
Pump Model PAH4A60C-B
(From S/N 1512753 Up)
ITEM
PART NAME PART
NO.
1 64P60C-(SAE 3/11.5) 46133-307 --- 1
2 SPACER 31141-034 15000 4
3 LOCK WASHER J04 15991 4
4 HEX HEAD CAP SCREW B0405 15991 4
5 FLAT WASHER K06 15991 8
6 SPROCKET 24271-008 --- 1
7 BUSHING 24131-564 --- 1
8 SYNCHRONOUS BELT 24186-008 --- 1
9 LOCK WASHER J06 15991 4
10 HEX HEAD CAP SCREW B0610 15991 4
11 BELT GUARD ASSY 42351-489 24150 1
12 AIR COMPRESSOR ASSY 46181-909 --- 1
13 STUD C1213 15991 8
14 GASKET 25113-036 --- 1
15 PRIMING CHAMBER KIT 48275-005 --- 1
16 LOCK WASHER J12 15991 8
17 HEX NUT D12 15991 8
18 SUCTION SPOOL 38644-814 10000 1
19 GASKET 25113-034 --- 1
20 BLIND FLANGE ASSY 42111-358 --- 1
21 LOCK WASHER J10 15991 8
22 HEX HEAD CAP SCREW B1007 15991 8
23 CHECK VALVE KIT 48274-003 --- 1
-CHECK VALVE 26642-124 --- 1
-FLAPPER 26688-005 --- 1
NUMBER
MAT'L
CODE
QTY ITEM
NO.
24 1/2” I.D. X 41” LG HOSE 18513-113 --- 1
25 HOSE BARB FTG 26523-047 --- 1
26 CONNECTOR S1598 --- 1
27 1/2” I.D. X 24” LG HOSE 18513-113 --- 1
28 HOSE CLAMP 26518-666 --- 1
29 HOSE BARB FITTING 26523-446 --- 2
30 1/2” CHECK VALVE 26641-092 --- 1
31 HOSE BARB FITTING 26523-387 --- 1
32 HOSE CLAMP 26518-642 --- 1
33 3/8” I.D. X 24” LG HOSE 18513-302 --- 1
34
NOT SHOWN:
OM-06443
PART NAME PART
NUMBER
-COVER O‐RING 25152-366 --- 1
-FLANGE GASKET 25113-034 --- 1
SHAFT KEY N1012 15990 1
WARNING DECAL 2613FE --- 1
G‐R DECAL GR-06 --- 1
PRIME AIRE PLUS DECAL 38812-099 --- 1
WARNING PLATE 2613EV 13990 1
DISCHARGE STICKER 6588BJ --- 1
OIL LEVEL DECAL 38816-123 --- 1
LUBE DECAL 11421A --- 1
NAME PLATE 38818-156 13000 1
DRIVE SCREW BM#04-03 17000 4
SUCTION STICKER 6588AG --- 1
STRAINER 7823A 24000 1
MAT'L
CODE
QTY
INDICATES PARTS RECOMMENDED FOR STOCK
MAINTENANCE & REPAIR PAGE E - 3
Page 25
OM-06443 PAH SERIES
ILLUSTRATION
Figure 2. 46133-307 Pump Assembly
MAINTENANCE & REPAIRPAGE E - 4
Page 26
PAH SERIES
OM-06443
PARTS LIST
46133-307 Pump End Assembly
ITEM
NO.
1 PUMP CASING SEE NOTE BELOW 1
2 WEAR RING 38691-363 11010 1
3 SUCTION HEAD O‐RING 25152-383 --- 2
3A PUMP CASING O‐RING 25152-383 --- 2
4 PIPE PLUG P04 15079 1
5 PIPE PLUG P08 15079 3
6 STUD C1211 15991 8
7 LOCK WASHER J12 15991 8
8 HEX NUT D12 15991 8
9 REPAIR ROTATING ASSEMBLY 44163-514 --- 1
10 STUD C1213 15991 4
11 ADJUSTING SCREW 31871-070 1500G 4
12 LOCK COLLAR 38115-551 15001 4
13 BACK COVER NUT 31871-073 15000 4
14 HEX HEAD CAP SCREW B0804 15991 4
15 LOCK WASHER J08 15991 4
16 SUCTION HEAD 38246-613 10000 1
INCLUDED W/REPAIR PUMP CASING ASSY 46474-908 --- 1
PART NAME
PART
NUMBER
MAT'L
CODE
QTY
INDICATES PARTS RECOMMENDED FOR STOCK
MAINTENANCE & REPAIR PAGE E - 5
Page 27
OM-06443 PAH SERIES
ILLUSTRATION
Figure 3. 44163-514 Repair Rotating Assembly
MAINTENANCE & REPAIRPAGE E - 6
Page 28
PAH SERIES
OM-06443
ARTS LIST
44163-514 Repair Rotating Assembly
ITEM
NO.
1 IMPELLER 38621-733 11010 1
2 SOCKET HEAD CAP SCREW BD1006 15991 1
3 IMPELLER WASHER 31167-038 17000 1
4 ROLL PIN S2197 --- 1
5 SHIM SET 48261-033 --- 1
6 MECH SEAL 25285-822 --- 1
7 SHAFT SLEEVE 31163-022 17000 1
8 O‐RING 25152-150 --- 1
9 SEAL PLATE 38272-533 10000 1
10 BEARING CAVITY SIGHT GAUGE S1471 --- 2
10A SEAL CAVITY SIGHT GAUGE S1471 --- 2
11 REDUCER PIPE BUSHING AP1202 15079 1
12 LIP SEAL 25227-856 --- 2
13 SEAL CAVITY AIR VENT S1530 --- 2
13A BEARING CAVITY AIR VENT S1530 --- 1
14 GASKET 38683-665 18000 1
15 LOCK WASHER J10 15991 14
16 HEX HEAD CAP SCREW B1007 15991 14
17 DRIVE FLANGE GASKET 38683-664 18000 1
18 PEDESTAL 38257-210 10000 1
19 PIPE PLUG P12 15079 3
19A BEARING CAVITY DRAIN PLUG P12 15079 1
19B SEAL CAVITY DRAIN PLUG P12 15079 1
20 OIL SEAL 25258-845 --- 1
21 DRIVE FLANGE 38545-015 10000 1
22 BEARING LOCKNUT 23962-015 --- 1
23 BEARING LOCK WASHER 23962-515 --- 1
24 BALL BEARING 23422-417 --- 1
25 IMPELLER SHAFT 38512-526 16000 1
26 KEY N0806 15990 1
27 ROLLER BEARING 23535-001 --- 1
28 KEY N1012 15990 1
NOT SHOWN:
PART NAME
PUMP CASING O‐RING 25152-383 --- 1
SHIPPING PLUG 11495B 15079 2
INSTRUCTION TAG 6588U --- 1
PART
NUMBER
MAT'L
CODE
QTY
INDICATES PARTS RECOMMENDED FOR STOCK
MAINTENANCE & REPAIR PAGE E - 7
Page 29
OM-06443 PAH SERIES
ILLUSTRATION
Figure 4. 48275-005 Priming Chamber Kit
ITEM
NO.
1 PRIMING CHAMBER ASSY 46112-709 --- 1
2 PIPE BUSHING AP1608 11999 1
3 STREET ELBOW RS08 11999 1
4 BALL VALVE 26631-052 --- 1
5 STUD C0809 15991 4
6 HEX NUT D08 15991 4
7 LOCK WASHER J08 15991 4
8 GASKET 38687-053 19060 1
9 BAFFLE 31113-011 17000 1
INDICATES PARTS RECOMMENDED FOR STOCK
PART NAME
PART
NUMBER
MAT'L
CODE
MAINTENANCE & REPAIRPAGE E - 8
QTY
Page 30
PAH SERIES
OM-06443
ILLUSTRATION
Figure 5. 46112-709 Priming Chamber Assembly
PARTS LIST
ITEM
NO.
1 PRIMING VALVE 26664-007 --- 1
2 HEX HD CAPSCREW B0806 15991 8
3 LOCKWASHER J08 15991 8
4 PRIMING VALVE GASKET 38683-657 19060 1
5 PRIMING CHAMBER 38343-020 10000 1
6 STRAINER ASSY 46641-222 17000 1
INDICATES PARTS RECOMMENDED FOR STOCK
MAINTENANCE & REPAIR PAGE E - 9
PART NAME
-ORIFICE BUTTON 26688-021 --- 1
PART
NUMBER
MAT'L
CODE
QTY
Page 31
OM-06443 PAH SERIES
ILLUSTRATION
Figure 6. 46181-909 Air Compressor Assembly
ITEM
NO.
1 MACH SCREW X#10-02 15991 4
2 HEX NUT D#10 15991 4
3 LOCK WASHER J#10 15991 4
4 FLAT WASHER K#10 15991 4
5 AIR COMPRESSOR COVER 38354-043 15120 1
6 AIR COMPRESSOR 26813-111 --- 1
7 PIPE CAP V06 15079 1
8 PIPE NIPPLE T0616 15079 1
9 90° ADAPTER 25412-003 --- 1
10 PULLEY ASSEMBLY 44112-004 --- 1
11 AIR COMPRESSOR KNOB 38429-501 19220 1
12 SERVICE TEE US08 11999 1
13 REDUCER PIPE BUSHING AP0806 15079 1
14 VENTURI 26817-002 --- 1
15 PIPE COUPLING AE08 15079 1
16 PIPE ELBOW R08 11999 1
17 PRESSURE RELIEF VALVE 26662-028 --- 1
PART NAME
PART
NUMBER
MAT'L
CODE
MAINTENANCE & REPAIRPAGE E - 10
QTY
Page 32
PAH SERIES
OM-06443
PUMP AND SEAL DISASSEMBLY AND REASSEMBLY
Review all SAFETY information in Section A.
Follow the instructions on all tags, label and de
cals attached to the pump.
This pump requires little service due to its rugged,
minimum‐maintenance design. However, if it be
comes necessary to inspect or replace the wearing
parts, follow these instructions which are keyed to
the illustrations (see Figures 1 through 6) and the
corresponding parts lists. Instructions for the air
compressor are covered separately in specific liter
ature available from the manufacturer.
Some pump service functions may be performed
without separating the pump end assembly from
the engine. However, the priming chamber (15,
Figure 1) and discharge check valve assembly (23,
Figure 1) must be removed to service most pump
components. The following instructions assume
complete disassembly of the pump is required.
Before attempting to service the pump, lock out or
disconnect the power source and take precautions
to ensure that it will remain inoperative. Close all
valves in the suction and discharge lines and drain
the pump casing by removing the lowermost pipe
plug (5, Figure 2). Clean and reinstall the pipe plug.
pump integrity are compromised by
such practices.
Before attempting to open or service the
pump:
1. Familiarize yourself with this man
ual.
2. Lock out or disconnect the power
source to ensure that the pump will
remain inoperative.
3. Allow the pump to completely cool
if overheated.
4. Check the temperature and make
sure it is cool before opening any
covers, plates, gauges, or plugs.
5. Close the suction and discharge
valves.
6. Vent the pump slowly and cau
tiously.
7. Drain the pump.
Use only replacement parts provided or
approved by Gorman‐Rupp. Use of non‐
authorized parts may result in damage to
the equipment and/or injury to personnel
and will invalidate the warranty.
This manual will alert personnel to
known procedures which require spe
cial attention, to those which could
damage equipment, and to those which
could be dangerous to personnel. How
ever, this manual cannot possibly antici
pate and provide detailed instructions
and precautions for every situation that
might occur during maintenance of the
Priming Chamber Removal And Disassembly
(Figure 4)
Disconnect both the suction piping and the air dis
charge tubing from the priming chamber assembly
(1). Support the priming chamber assembly using
a sling and a suitable lifting device. Remove the
hardware (6 and 7) and separate the priming
chamber assembly, gasket (8) and baffle (9) from
the pump assembly.
unit. Therefore, it is the responsibility of
the owner/maintenance personnel to
ensure that only safe, established main
tenance procedures are used, and that
any procedures not addressed in this
manual are performed only after estab
lishing that neither personal safety nor
MAINTENANCE & REPAIR PAGE E - 11
(Figure 5)
Remove the hardware (2 and 3) securing the prim
ing valve (1) to the priming chamber (5). Carefully
lift the valve components from the priming cham
ber. Remove the gasket (4) and clean the mating
surfaces.
Page 33
PAH SERIESOM-06443
If the priming valve float is stuck or the strainer (6) is
clogged, it can usually be cleaned without further
disassembly.
The only serviceable part of the priming valve is the
orifice button (not shown). If liquid continues to by
pass through the priming chamber after adjusting
the orifice button (see Priming Chamber Reas
sembly and Installation for adjustment), the but
ton may require replacement. To replace the orifice
button, remove one of the “e‐clips” from the pivot
pin closest to the orifice button and remove the piv
ot pin. This will allow the linkage to be raised high
enough to access the orifice button.
Remove the hex nut and lock washer securing the
orifice button to the linkage bar and unscrew the
orifice button from the linkage bar.
Discharge Check Valve Removal and
Disassembly
(Figure 1)
Support the discharge check valve assembly (23)
using a sling and a suitable lifting device. Remove
the hardware (not shown) and separate the dis
charge check valve assembly and gasket (not
shown) from the pump assembly (1).
The flapper and cover O‐ring are the only service
able parts of the check valve. If the flapper requires
replacement, remove the hardware securing the
cover. Separate the cover and O‐ring and remove
the flapper.
screws (11) to press the suction head out of the
pump casing.
Remove and discard the O‐ring (3).
Inspect the wear ring and, if replacement is re
quired, install two 5/8-11 UNC‐2B capscrews (not
supplied) in the tapped holes in the suction head
and use the screws to press the wear ring out of the
suction head.
Pump Casing Removal
(Figure 2)
If the impeller (1, Figure 3) is to be removed, the im
peller screw (2, Figure 3) must be removed before
removing the pump casing (1). With the discharge
check valve removed, insert a soft metal bar or rod
through the discharge port to block impeller rota
tion.
Use an impact wrench with a hex key to loosen the
impeller capscrew, then remove the capscrew,
washer (3, Figure 3) and roll pin (4, Figure 3). Re
move the metal bar or rod blocking impeller rota
tion.
Support the pump casing (1) using a suitable hoist
and sling. Disengage the hardware (7 and 8) se
curing the pump casing to the rotating assembly
(9). Use the hoist and sling to pull the pump casing
straight away from the rotating assembly. Use cau
tion to ensure that the pump casing does not fall
onto and damage the impeller.
Remove and discard the pump casing O‐ring (3A).
Suction Head and Wear Ring Removal
(Figure 2)
The wear ring (2) is easily accessible and may be
serviced by removing the suction head (16). Before
attempting to service the pump, remove the lower
most pipe plug (5) from the pump casing drain the
pump. Clean and reinstall the drain plug.
It is not necessary to remove the suction spool (18,
Figure 1) from the suction head unless replace
ment of the spool, gasket (14, Figure 1) or suction
head is required. To remove the suction head, re
move the back cover nuts (13) and two diagonally
opposing locking collars (12). Use the adjusting
Removing Air Compressor
(Figure 1)
Further disassembly of the pump requires remov
ing the air compressor assembly (12) from the ro
tating assembly (9, Figure 2).
Disengage the hardware (3, 4 and 5) and remove
the belt guard assembly (11).
Remove the hardware (5, 9 and 10) securing the air
compressor assembly (12) to the mounting flange
(20, Figure 3). Use a pry bar to raise the air com
pressor high enough to remove the spacers (2).
Remove the belt (8) from the air compressor drive
pulley (not shown).
MAINTENANCE & REPAIRPAGE E - 12
Page 34
PAH SERIES
OM-06443
Disconnect all hoses and fittings from the air com
pressor and use a suitable hoist and sling to re
move the air compressor assembly.
Draining Oil From Seal Cavity
(Figure 3)
If any further disassembly is to be performed on the
pump, the seal oil cavity must be drained to pre
vent the oil in the seal cavity from escaping as the
impeller is removed.
Position a clean container under the seal cavity
drain plug (19B). Remove the plug and drain the oil
from the seal cavity into the container. For shorter
drain time, remove the vented plug (13). Clean and
reinstall the drain plug and vent plug. Inspect the
oil for water, dirt or a cloudy condition which could
indicate seal failure.
Impeller Removal
Seal Removal
(Figures 3 and 7)
Remove the spring centering washer and seal
spring. Slide the shaft sleeve (7) and rotating por
tion of the seal off the shaft as a unit.
Apply oil to the shaft sleeve and work it up under
the rubber bellows. Slide the rotating portion of the
seal off the shaft sleeve. Remove the shaft sleeve
O‐ring (8).
Use a pair of stiff wires with hooked ends to remove
the stationary element and O‐ring from the seal
plate bore.
An alternate method of removing the stationary
seal components is to remove the hardware (15
and 16) and separate the seal plate and gasket
(14) from the pedestal (18). Position the seal plate
on a flat surface with the impeller side down. Use a
wooden dowel or other suitable tool to press on the
back side of the stationary element until the ele
ment and its O‐ring can be removed.
(Figure 3)
With the pump casing removed, use a suitable
three‐jawed puller to remove the impeller (1) and
key (26) from the shaft (25). Use caution when re
moving the impeller; tension on the shaft seal
spring will be released as the impeller is removed.
NOTE
An alternate method of removing the impeller is to
insert a pair of wedges 180_ apart between the im
peller and seal plate (9). Tap the wedges evenly in
an alternating pattern to “walk” the impeller off the
shaft.
Remove the impeller adjusting shims (5); tie and
tag the shims, or measure and record their thick
ness for ease of reassembly.
Inspect the impeller and replace if cracked or badly
worn.
Separating Rotating Assembly From Power
Source
(Figure 1)
Further disassembly requires separating the rotat
ing assembly from the power source. Remove the
coupling securing the rotating assembly to the
power source. Remove the belt (8).
Remove any hardware securing the pedestal (18,
Figure 3) to the base. Use a suitable hoist and sling
to move the rotating assembly to a clean, well‐
equipped workshop for further disassembly.
Remove the capscrews from the center of the
bushing (7). Reinstall the capscrews in the tapped
holes in the bushing and tighten them in an alter
nating pattern until the bushing is “jacked” out of
the sheave (6). Slide the bushing and sheave off
the shaft. Remove the key (28, Figure 3).
Shaft and Bearing Removal and Disassembly
(Figure 3)
If no further disassembly is required, refer to Seal
Installation.
MAINTENANCE & REPAIR PAGE E - 13
When the pump is properly operated and main
tained, the bearing housing should not require dis
Page 35
PAH SERIESOM-06443
assembly. Disassemble the shaft and bearings
only when there is evidence of wear or damage.
Shaft and bearing disassembly in the field
is not recommended. These operations
should be performed only in a properly
equipped shop by qualified personnel.
Remove the bearing housing drain plug (19A) and
drain the lubricant. Clean and reinstall the drain
plug.
Disengage the hardware (15 and 16) and remove
the mounting flange (21), gasket (17) and oil seal
(20). Use a suitably sized dowel to press the oil seal
from the mounting flange.
Place a block of wood against the impeller end of
the shaft (25) and tap the shaft and assembled
bearings (24 and 27) from the bearing housing.
Press the oil seal (20) from the bearing housing.
precautions printed on solvent contain
ers.
Clean the bearings thoroughly in fresh cleaning
solvent. Dry the bearings with filtered compressed
air and coat with light oil.
Bearings must be kept free of all dirt and
foreign material. Failure to do so will great
ly shorten bearing life. Do not spin dry
bearings. This may scratch the balls or
races and cause premature bearing fail
ure.
Rotate the bearings by hand to check for rough
ness or binding and inspect the bearing balls. If ro
tation is rough or the bearing balls are discolored,
replace the bearings.
The bearing tolerances provide a tight press fit
onto the shaft and a snug slip fit into the bearing
housing. Replace the bearings, shaft, or bearing
housing if the proper bearing fit is not achieved.
After removing the shaft and bearings, clean and
inspect the bearings in place as follows.
To prevent damage during removal from
the shaft, it is recommended that bearings
be cleaned and inspected in place. It is
strongly recommended that the bearings
be replaced any time the shaft and bear
ings are removed.
Clean the bearing housing, shaft and all compo
nent parts (except the bearings) with a soft cloth
soaked in cleaning solvent. Inspect the parts for
wear or damage and replace as necessary.
If bearing replacement is required, straighten the
tab on the bearing lock washer (23). Use a spanner
wrench to remove the bearing lock nut (22). Re
move the bearing lock washer.
Use a bearing puller to remove the inboard and
outboard bearings from the shaft.
Shaft and Bearing Reassembly and Installation
(Figure 3)
Inspect the shaft (25) for distortion, nicks or
scratches, or for thread damage on the impeller
end. Dress small nicks and burrs with a fine file or
emery cloth. Replace the shaft if defective.
Clean and inspect the bearings as indicated in
Shaft And Bearing Removal And Disassembly.
Most cleaning solvents are toxic and
flammable. Use them only in a well ven
tilated area free from excessive heat,
sparks, and flame. Read and follow all
To prevent damage during removal from
the shaft, it is recommended that bearings
be cleaned and inspected in place. It is
strongly recommended that the bearings
MAINTENANCE & REPAIRPAGE E - 14
Page 36
PAH SERIES
be replaced any time the shaft and bear
ings are removed.
OM-06443
The bearings may be heated to ease installation.
An induction heater, hot oil bath, electric oven, or
hot plate may be used to heat the bearings. Bear
ings should never be heated with a direct flame or
directly on a hot plate.
NOTE
If a hot oil bath is used to heat the bearings, both the
oil and the container must be absolutely clean. If
the oil has been previously used, it must be thor
oughly filtered.
NOTE
Position the outboard bearing (24) on the shaft with
the retaining ring on the bearing O.D. toward the
drive end of the shaft. The inboard bearing (27) is
equipped with a flange ring that is shipped loose
with the bearing. Install the flange ring on the shaft
prior to heating and installing the bearings.
Heat the bearings to a uniform temperature no
higher than 250F (120C), and slide the bearings
onto the shaft, one at a time, until they are fully
seated against the shaft shoulders. This should be
done quickly, in one continuous motion, to prevent
the bearings from cooling and sticking on the shaft.
After the bearings have been installed and allowed
to cool, check to ensure that they have not moved
during cooling. If movement has occurred, use a
suitably sized sleeve and a press to reposition the
bearings against the shaft shoulders.
It is recommended that a new bearing lock
washer (23) be installed any time the shaft
and bearings are disassembled. Re‐use of
an old lock washer may create a pre‐load
condition on the bearing, resulting in pre
mature bearing failure.
Install the bearing lockwasher (23) and screw the
bearing locknut (22) onto the shaft until tight.
Torque the bearing lock nut to (150 ft. lbs. (20,8 m.
kg.). After torquing, locate the tab on the lock
washer that aligns with a slot in the lock nut and
bend the tab over into the slot.
Apply a light coating of oil to the lip of the inboard oil
seal (12) and press it into the pedestal bore with the
lip positioned as shown in Figure 3. Press the oil
seal into the pedestal until the face is just flush
with the machined surface on the pedestal.
It is recommended that a sleeve be positioned
against the inboard oil seal to prevent the lip of the
oil seal from rolling as the shaft and bearings are
installed in the pedestal. The O.D. of the sleeve
should be just smaller than the bearing housing
bore, while the I.D. of the sleeve should be just larg
er than the O.D. of the lip seal area of the shaft.
With the lip seal sleeve in place, lubricate the lip
seal area of the shaft and slide the shaft and as
sembled bearings into the bearing housing until
the retaining ring on the outboard bearing seats
against the pedestal. Remove the lip seal sleeve.
When installing the shaft and bearings into
If heating the bearings is not practical, use a suit
ably sized sleeve and an arbor (or hydraulic) press
to install the bearings on the shaft.
When installing the bearings onto the
shaft, never press or hit against the outer
race, balls, rollers or cage. Press only on
the inner race.
MAINTENANCE & REPAIR PAGE E - 15
the bearing bore, push against the outer
race. Never hit the balls, rollers or cages.
Apply a light coating of oil to the lip of the outboard
oil seal (12) and press it into the pedestal with the
lip positioned as shown in Figure 3. The face of the
oil seal should be just flush with the outer face of
the bearing cap.
Apply a light coating of oil to the lip of the oil seal
(20) and press it into the drive flange (21) with the
lip positioned as shown in Figure 3. The oil seal
should be centered in the flange bore.
Page 37
PAH SERIESOM-06443
Install the gasket (17) and slide the assembled
drive flange and oil seal over the impeller shaft. Use
caution not to cut or roll the lip of the oil seal (20) on
the shaft keyway. Secure the drive flange to the
pedestal with the hardware (15 and 16). Torque the
capscrews (16) to 41 ft. lbs. (5,7 m. kg.).
Lubricate the bearings as indicated in LUBRICA
TION at the end of this section.
Securing Rotating Assembly to Power Source
(Figure 1)
Install the key (34) in the shaft keyway, making sure
to leave room in the keyway for the drive key (28,
Figure 3). Install the bushing (7) and sprocket (6)
on the shaft to the dimension shown in Figure 7.
compressor and the mounting flange. Secure the
compressor to the mounting flange with the hard
ware (5, 9 and 10). Reinstall the guard (11) and se
cure it with the hardware (3, 4 and 5).
Reinstall the drive coupling on the impeller shaft.
Using a suitable lifting device, position the pedes
tal assembly on the base and secure it with the pre
viously removed hardware. Align the coupling as
described in Installation, Section B.
Seal Reassembly and Installation
(Figures 3 and 8)
Most cleaning solvents are toxic and
flammable. Use them only in a well ven
tilated area free from excessive heat,
sparks, and flame. Read and follow all
precautions printed on solvent contain
ers.
Figure 7. Drive Sprocket Positioning
Secure the bushing and sheave to the shaft by
torqueing the bushing screws to 15 ft. lbs. (180 in.
lbs. or 2,1 m. kg.). Install the belt (8) over the
sprocket and up through the slot in the mounting
flange (20, Figure 3).
Use a suitable hoist and sling to position the air
compressor assembly (12) on the mounting
flange. Slide the belt (8) over the air compressor
sprocket. Use a pry bar to raise the compressor
high enough to install the spacers (2) between the
Clean the seal cavity and shaft with a cloth soaked
in fresh cleaning solvent. Inspect the stationary
seat bore in the seal plate for dirt, nicks and burrs,
and remove any that exist. The stationary seat bore
must be completely clean before installing the
seal.
A new seal assembly should be installed
any time the old seal is removed from the
pump. Wear patterns on the finished faces
cannot be realigned during reassembly.
Reusing an old seal could result in prema
ture failure.
To ease installation of the seal, lubricate the shaft
sleeve O‐ring and the stationary element O‐ring
with a very small amount of light lubricating oil.
See Figure 8 for seal part identification.
MAINTENANCE & REPAIRPAGE E - 16
Page 38
PAH SERIES
OM-06443
SPRING
IMPELLER
SHAFT
KEY
IMPELLER
SHAFT
SPRING
CENTERING
WASHER
RETAINER
IMPELLER
SHIMS
BELLOWS
ROTATING
ELEMENT
SEAL PLATE
O‐RING
SLEEVE
O‐RING
SHAFT
SLEEVE
STATIONARY
ELEMENT
Figure 8. Seal Assembly
This seal is not designed for operation at
temperatures above 160F (71C). Do not
use at higher operating temperatures.
If the seal plate was removed, install the seal plate
gasket (14). Position the seal plate over the shaft
and secure it to the bearing housing with the hard
ware (15 and 16).
Press the stationary element and its O‐ring into the
seal plate until fully seated in the seal plate bore. A
push tube cut from a length of plastic pipe would
aid this process. The I.D. of the tube should be
slightly larger than the O.D. of the shaft sleeve (7).
Install the shaft sleeve O‐ring (8) in the groove in
the I.D. of the sleeve. Lubricate the O‐ring and the
O.D. of the shaft sleeve with “P-80 Emulsion” or
water. Do not use oil or any substitute lubricant
other than water.
Slide the rotating subassembly (consisting of the
rotating element, retainer and bellows) onto the
sleeve until the rotating element is just flush with
the chamfered end of the sleeve. Slide the shaft
sleeve and rotating subassembly onto the shaft
until the seal faces contact and the shaft sleeve
seats against the shoulder on the impeller shaft.
Install the seal spring and spring centering washer.
Lubricate the seal assembly as indicated in
LUBRICATION, after the impeller has been in
stalled.
Impeller Installation And Adjustment
(Figure 3)
Inspect the impeller (1) and replace it if cracked or
badly worn.
Install the same thickness of adjusting shims (5) as
previously installed. Install the impeller key (26) in
the shaft keyway. Align the keyway in the impeller
with the shaft key and press the impeller onto the
shaft until fully seated.
A clearance of .025 to .040 inch (0,64 to 1,02 mm)
between the impeller and the seal plate is neces
sary for maximum pump efficiency. Measure this
clearance and add or remove impeller adjusting
shims as required.
MAINTENANCE & REPAIR PAGE E - 17
Page 39
PAH SERIESOM-06443
Apply `Loctite Retaining Compound No. 242' or
equivalent to the threads of the impeller capscrew
(2). Install the roll pin (4) in the hole in the impeller.
Position the impeller washer over the end of the im
peller shaft so the hole in the washer aligns with the
roll pin. Block impeller rotation as described in Im
peller Removal and torque the impeller capscrew
to 180 ft. lbs. (24,9 m. kg.).
Pump Casing Installation
(Figure 2)
Lubricate the O‐ring (3) with light grease and install
it in the groove in the O.D. of the seal plate. Install a
lifting eye in the uppermost hole in the pump cas
ing (1) for the pipe plug (5). Be sure to screw the
lifting eye tightly into the hole as far as it will go. At
tach a suitable lifting device to the lifting eye and
use the lifting device to position the pump casing
over the rotating assembly. Install the hardware (7
and 8) on the studs (6) and use the hardware to ful
ly seat the pump casing against the seal plate (9,
Figure 3).
casing until the wear ring just touches the impeller
when the shaft is turned. Tighten the back cover
nuts evenly to avoid binding.
With the wear ring just touching the impeller, turn
the two free adjusting screws until they engage the
pump casing. Position the locking collars over the
adjusting screws so the holes in the collars for the
locking screws align approximately with the holes
in the suction head.
Loosen the back cover nuts used to press the
suction head into the pump casing one full turn.
Pull the collars off the adjusting screws, index them
three detents counterclockwise, and reinstall the
collars on the adjusting screws. Use the collars to
turn the adjusting screws clockwise until the holes
in the locking collars realign with the tapped screw
holes in the back cover plate. Secure the locking
collars to the back cover plate with the hardware
(14 and 15). Install the two remaining hand knobs
snugly against the adjusting screws.
Suction Head and Wear Ring Installation and
Adjustment
(Figure 2)
If the wear ring (2) was removed, position the re
placement wear ring in the suction head (16) and
use an arbor (or hydraulic) press to press it into the
suction head until fully seated.
Install the O‐ring (3) in the groove in the O.D. of the
suction head and lubricate it with light grease.
Position the suction head over the studs (10).
The clearance between the wear ring and the im
peller is adjusted using the four back cover nuts
(13) and locking collars (12). There are 18 detents
on the I.D. of each locking collar. Indexing the col
lars one detent on the adjusting screws represents
approximately .005 inch (0,13 mm) of wear plate
clearance. The recommended clearance between
the wear ring and the impeller is .008 to .015 inch
(0,2 to 0,4 mm).
Screw the four adjusting screws (11) into the
tapped holes in the back cover plate until they are
just flush with the machined surface on the back
side of the cover plate.
Use two back cover nuts on diagonally opposing
studs (10) to press the suction head into the pump
Remove the first two back cover nuts from their
studs. Turn the adjusting screws clockwise until
they engage the pump casing. Install the locking
collars and hardware (14 and 15). Reinstall the
back cover nuts.
Be sure the wear ring does not scrape against the
impeller when the shaft is turned.
After the face clearance has been set, tighten the
hardware securing the rotating assembly to the
pump casing.
Discharge Check Valve Reassembly And
Installation
(Figure 1)
If the discharge check valve (23) was disas
sembled to replace the flapper or cover O‐ring,
position the flapper in the valve body and check to
ensure free movement.
Install the valve cover O‐ring and secure the cover
to the body with the previously removed hardware.
Apply a small amount of light grease to the dis
charge flange gasket to hold it in place and posi
tion it against the pump casing flange. Support the
discharge check valve assembly using a sling and
a suitable lifting device. Using the previously re
MAINTENANCE & REPAIRPAGE E - 18
Page 40
PAH SERIES
OM-06443
moved hardware, secure the discharge check
valve assembly and flange gasket to the pump as
sembly (1).
Priming Chamber Assembly And Installation
(Figure 5)
Clean and inspect the components of the priming
valve (1). Inspect the linkage and ensure the orifice
button (not shown) squarely engages the valve
seat. Replace the orifice button if required (see
Priming Chamber Removal and Disassembly
for orifice button removal).
If the orifice button was removed, screw the new
orifice button into the linkage bar until fully seated.
Align the hole in the linkage bar with the holes in the
bracket and reinstall the pivot pin. Secure the pivot
pin with the previously removed “e‐clip”.
Adjust the orifice button seating as necessary by
screwing the orifice button into or out of the linkage
bar. Proper adjustment is achieved when the ori
fice button fully seats against the orifice before the
linkage bar on the float bottoms against the
threads on the orifice button. When adjustment is
complete, install and tighten the lock washer and
hex nut securing the orifice button.
Install the strainer (6) and priming valve gasket (4).
Lower the float into the priming chamber (5) and
secure the priming valve with the previously re
moved hardware (2 and 3).
ounces (5 liters) of SAE No. 30 non‐detergent oil to
the center of the sight gauge (10A). Clean and rein
stall the vented plug. Check the oil level regularly
and maintain it at the middle of the sight gauge.
Bearings
(Figure 3)
The bearing housing was fully lubricated when
shipped from the factory. Check the oil level regu
larly through the sight gauge (10) and maintain it at
the midpoint of the gauge. When lubrication is re
quired, remove the air vent (13A) and add SAE No.
30 non‐detergent oil through the opening. When
lubricating a dry (overhauled) intermediate, fill the
bearing cavity with approximately 50 ounces (1,5
liters). Clean and reinstall the air vent. Do not over‐
lubricate. Over‐lubrication can cause the bearings
to over‐heat, resulting in premature bearing failure.
NOTE
The white reflector in the sight gauge must be posi
tioned horizontally to provide proper drainage.
Under normal conditions, drain the bearing hous
ing once each year and refill with clean oil. Change
the oil more frequently if the pump is operated con
tinuously or installed in an environment with rapid
temperature change.
(Figure 4)
Install the baffle (9) and gasket (8) on the suction
spool (18, Figure 1) and use a sling and suitable lift
ing device to position the priming chamber assem
bly on the suction spool. Secure the priming cham
ber assembly with the hardware (6 and 7).
Reconnect the suction piping to the hopper spool
and the air discharge tubing to the priming cham
ber assembly.
Monitor the condition of the bearing lubri
cant regularly for evidence of rust or mois
ture condensation. This is especially im
portant in areas where variable hot and
cold temperatures are common.
For cold weather operation, consult the factory or a
lubricant supplier for the recommended grade of
oil.
LUBRICATION
Seal Assembly
(Figure 3)
Before starting the pump, remove the air vent (13)
and fill the seal cavity with approximately 170
MAINTENANCE & REPAIR PAGE E - 19
Power Source
Consult the literature supplied with the power
source, or contact your local power source repre
sentative.
Page 41
For U.S. and International Warranty Information,
Please Visit www.grpumps.com/warranty
or call:
U.S.: 419-755-1280
International: +1-419-755-1352
For Canadian Warranty Information,
Please Visit www.grcanada.com/warranty
or call:
519-631-2870
THE GORMAN‐RUPP COMPANY MANSFIELD, OHIO
GORMAN‐RUPP OF CANADA LIMITED ST. THOMAS, ONTARIO, CANADA
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