GORMAN-RUPP PUMPS PAH Series Application guide

OM-06451-01
February 17, 2012
Rev. F 09‐15‐16
GORMAN‐RUPP PUMPS
www.grpumps.com
2012 Gorman‐Rupp Pumps Printed in U.S.A.
INSTALLATION, OPERATION,
AND MAINTENANCE MANUAL
WITH PARTS LIST
PAH SERIESPUMP
MODEL
PAH6B60-6068H

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Gorman‐Rupp pump online at
www.grpumps.com
Valid serial number and e‐mail address required.
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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:
The engine exhaust from this
product contains chemicals
known to the State of California to
cause cancer, birth defects or
other reproductive harm.

TABLE OF CONTENTS
i
INTRODUCTION PAGE I - 1.................................................
SAFETY ‐ SECTION A PAGE A - 1............................................
INSTALLATION - SECTION B PAGE B - 1....................................
Pump Dimensions PAGE B - 1.....................................................
PREINSTALLATION INSPECTION PAGE B - 1............................................
Battery Installation PAGE B - 2.....................................................
POSITIONING PUMP PAGE B - 2.......................................................
Lifting PAGE B - 2.................................................................
Mounting PAGE B - 2.............................................................
SUCTION AND DISCHARGE PIPING PAGE B - 3.........................................
Materials PAGE B - 3..............................................................
Line Configuration PAGE B - 3......................................................
Connections to Pump PAGE B - 3..................................................
Gauges PAGE B - 3...............................................................
SUCTION LINES PAGE B - 3...........................................................
Fittings PAGE B - 3...............................................................
Strainers PAGE B - 3..............................................................
Sealing PAGE B - 4...............................................................
Suction Lines In Sumps PAGE B - 4.................................................
Suction Line Positioning PAGE B - 4................................................
DISCHARGE LINES PAGE B - 5........................................................
Siphoning PAGE B - 5.............................................................
Valves PAGE B - 5................................................................
ALIGNMENT PAGE B - 5..............................................................
AUTO‐START PAGE B - 5.............................................................
Float Switch Installation PAGE B - 6.................................................
OPERATION - SECTION C PAGE C - 1......................................
OPERATION PAGE C - 1..............................................................
PRIMING PAGE C - 1.................................................................
STARTING PAGE C - 1................................................................
Manual Starting PAGE C - 1........................................................
Automatic Starting PAGE C - 2.....................................................
Priming PAGE C - 2...............................................................
ROUTINE OPERATION PAGE C - 3.....................................................
OPERATION IN EXTREME HEAT PAGE C - 3............................................
OPERATIONAL CHECKS PAGE C - 3...................................................
Leakage PAGE C - 3..............................................................
Pump Vacuum Check PAGE C - 3..................................................
Liquid Temperature And Overheating PAGE C - 3.....................................
Strainer Check PAGE C - 4.........................................................

TABLE OF CONTENTS
(continued)
ii
STOPPING PAGE C - 4................................................................
Manual Stopping PAGE C - 4.......................................................
Automatic Stopping PAGE C - 4....................................................
Safety Shutdown System PAGE C - 4...............................................
PERIODIC CHECKS PAGE C - 5.......................................................
Seal Cavity and Bearing Lubrication PAGE C - 5......................................
Bearing Temperature Check PAGE C - 5.............................................
Engine Fuel Filter PAGE C - 5......................................................
Engine Oil PAGE C - 5.............................................................
Air Compressor PAGE C - 5........................................................
Air Compressor Drive Belt PAGE C - 5...............................................
COLD WEATHER PRESERVATION PAGE C - 5...........................................
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........................................
PARTS LISTS:
Pump Model PAGE E - 3..........................................................
Power Unit Kit PAGE E - 5.........................................................
Pump Assembly PAGE E - 7.......................................................
Pump End Assembly PAGE E - 9...................................................
Repair Rotating Assembly PAGE E - 11...............................................
Priming Chamber Kit PAGE E - 12...................................................
Priming Chamber Assembly PAGE E - 13.............................................
Drive Assembly PAGE E - 14........................................................
PUMP AND SEAL DISASSEMBLY AND REASSEMBLY PAGE E - 15.........................
Priming Chamber Removal And Disassembly PAGE C - 15..............................
Discharge Check Valve Removal and Disassembly PAGE C - 16.........................
Separating Pump And Drive Assembly From Engine PAGE C - 16........................
Draining Oil From Seal Cavity PAGE C - 17............................................
Loosening Impeller PAGE C - 17.....................................................
Pump Casing And Wear Plate Removal PAGE C - 17...................................
Impeller Removal PAGE C - 18......................................................
Seal Removal PAGE C - 18..........................................................
Shaft and Bearing Removal and Disassembly PAGE C - 18.............................
Shaft and Bearing Reassembly and Installation PAGE C - 19............................
Securing Bearing Housing And Drive Assembly To Engine PAGE C - 20..................
Seal Reassembly and Installation PAGE C - 21........................................
Impeller Installation And Adjustment PAGE C - 24......................................
Pump Casing And Wear Plate Installation PAGE C - 24.................................
Discharge Check Valve Reassembly And Installation PAGE C - 24.......................
Priming Chamber Assembly And Installation PAGE C - 24...............................
LUBRICATION PAGE C - 25.............................................................
Seal Assembly PAGE C - 25.........................................................
Bearings PAGE C - 25..............................................................
Engine PAGE C - 25................................................................

PAH SERIES OM-06451
PAGE I - 1INTRODUCTION
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.
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.
If there are any questions regarding the pump or
its application which are not covered in this man
ual or in other literature accompanying this 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: [phone]
or:
Gorman‐Rupp of Canada Limited
70 Burwell Road
St. Thomas, Ontario N5P 3R7
Phone: [phone]
For information or technical assistance on the
power source, contact the power source manufac
turer's local dealer or representative.
HAZARD AND INSTRUCTION
DEFINITIONS
The following are used to alert maintenance per
sonnel to procedures which require special atten
tion, 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.
Hazards or unsafe practices which COULD
result in minor personal injury or product
or property damage. These instructions
describe the requirements and the possi
ble damage which could result from failure
to follow the procedure.
NOTE
Instructions to aid in installation, operation, and
maintenance or which clarify a procedure.

PAH SERIES OM-06451
PAGE A - 1SAFETY
SAFETY ‐ SECTION A
This information applies to Prime Airer
Series engine driven pumps. Refer to
the manual accompanying the engine
before attempting to begin 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.
Before attempting to open or service the
pump:
1. Familiarize yourself with this man
ual.
2. Shut down the engine and discon
nect the positive battery cable 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.
This pump is equipped with an automat
ic starting system, and is subject to au
tomatic restart. Keep hands and cloth
ing away from the unit to prevent injury
during automatic operation. Disconnect
the positive battery cable before per
forming any maintenance. Failure to do
so may result in serious personal injury.
Do not attempt to disengage any part of
an overheated pump unit. Vapor pres
sure within the pump casing can eject
these parts with great force when they
are disengaged. Allow the pump to
completely cool before servicing it.
This pump is designed to handle most
non‐volatile, non‐flammable liquids
containing specified entrained solids.
Do not attempt to pump volatile, corro
sive, or flammable liquids which may
damage the pump or endanger person
nel as a result of pump failure.
Death or serious personal injury and
damage to the pump or components
can occur if proper lifting procedures
are not observed. Make certain that
hoists, chains, slings or cables are in
good working condition and of suffi
cient capacity and that they are posi
tioned so that loads will be balanced
and the pump or components will not be
damaged when lifting. Suction and dis
charge hoses and piping must be re
moved from the pump before lifting. Lift
the pump or component only as high as
necessary and keep personnel away
from suspended objects.
After the pump has been installed, make
certain that the pump and all piping or

PAH SERIESOM-06451
PAGE A - 2 SAFETY
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.
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.
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.
Do not operate the pump without guards
in place over the rotating parts. Ex
posed rotating parts can catch clothing,
fingers or tools, causing severe injury to
personnel.
Make sure the pump is level. Lower jack
stands and chock the wheels, if so
equipped. Use caution when positioning
the skid‐mounted unit to prevent damage
to the fuel tank.
Do not operate an internal combustion
engine in an explosive atmosphere.
When operating an internal combustion
engine in an enclosed area, make sure
exhaust fumes are piped to the outside.
These fumes contain carbon monoxide,
a deadly gas that is colorless, tasteless
and odorless.
Fuel used by internal combustion en
gines presents an extreme explosion
and fire hazard. Make certain that all
fuel lines are securely connected and
free of leaks. Never refuel a hot or run
ning engine. Avoid overfilling the fuel
tank. Always use the correct type of fuel.
Never tamper with the governor to gain
more power. The governor establishes
safe operating limits that should not be
exceeded. Refer to the performance
curve on page E-1 for the maximum
continuous operating speed for this
pump.

PAH SERIES OM-06451
PAGE B - 1INSTALLATION
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 positioned
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.
Pump Dimensions
See Figure 1 for the approximate physical dimen
sions of this pump.
OUTLINE DRAWING
Figure 1. Pump Model PAH6B60-6068H
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.

OM-06451 PAH SERIES
PAGE B - 2 INSTALLATION
c. Carefully read all tags, decals, and markings
on the pump assembly, and perform all duties
indicated. Note that the pump shaft rotates in
the required direction.
Only operate this pump in the direction in
dicated by the arrow on the pump body
and on the accompanying decal. Other
wise, the impeller could become loosened
from the shaft and seriously damage the
pump.
d. Check levels and lubricate as necessary. Re
fer to LUBRICATION in the Maintenance and
Repair Manual and perform duties as in
structed.
e. If the pump has been stored for more than 12
months, some of the components or lubri
cants may have exceeded their maximum
shelf life. These must be inspected or re
placed to ensure maximum 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.
Battery Installation
Unless otherwise specified on the pump order, the
engine battery is not included with engine driven
units.
Refer to the information accompanying the battery
and/or electrolyte solution for activation and charg
ing instructions.
Before installing the battery, clean the positive and
negative cable connectors, and the battery termi
nals. Secure the battery by tightening the
holddown brackets. The terminals and clamps
may be coated with petroleum jelly to retard corro
sion. Connect and tighten the positive cable first,
then the negative cable.
POSITIONING PUMP
Death or serious personal injury and
damage to the pump or components
can occur if proper lifting procedures
are not observed. Make certain that
hoists, chains, slings or cables are in
good working condition and of suffi
cient capacity and that they are posi
tioned so that loads will be balanced
and the pump or components will not be
damaged when lifting. Suction and dis
charge hoses and piping must be re
moved from the pump before lifting. Lift
the pump or component only as high as
necessary and keep personnel away
from suspended objects.
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.
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 and eliminate vibration.
For engine driven units, the pump must be posi
tioned as level as possible to ensure sufficient lubri
cation and fuel supply to the engine.
If the pump has been mounted on a moveable
base, make certain the base is stationary by setting
the brake and blocking the wheels before attempt
ing to operate the pump.

PAH SERIES OM-06451
PAGE B - 3INSTALLATION
If the pump has been mounted on a mov
able base, do not attempt to operate the
pump unless the unit is level. Be sure
the leveling stands are positioned on a
solid surface, and the wheels are
chocked.
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
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
to secure them when filled with liquid and under
pressure.
Gauges
The pump is drilled and tapped for installing dis
charge pressure and vacuum suction gauges. It is
recommended that gauges be installed to monitor
pump performance. Seal the gauge threads with
pipe dope to ensure an airtight seal. Follow the
sealant manufacturer's recommendations when
selecting and applying the pipe dope. The pipe
dope should be compatible with the liquid being
pumped.
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.
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
Be certain to use the strainer furnished with the
pump; any spherical solids which pass through the
strainer will also pass through the pump itself.
If a strainer not furnished with the pump 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 11/16 inch
(17,5 mm) diameter spherical solids.

OM-06451 PAH SERIES
PAGE B - 4 INSTALLATION
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. Figure 2
shows recommended minimum submergence vs.
velocity.
Although not recommended, the vacuum assisted
priming feature allows the pump to be operated
temporarily in a “slurping” application with varying
water levels.
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).

PAH SERIES OM-06451
PAGE B - 5INSTALLATION
Figure 2. Recommended Minimum Suction Line Submergence vs. Velocity
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 be installed in the discharge line
to protect the pump from excessive shock pres
sure and reverse rotation when it is stopped.
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
ALIGNMENT
The alignment of the pump, air compressor and
engine is critical for trouble‐free mechanical opera
tion. See Section E, Securing Intermediate And
Drive Assembly To Engine in MAINTENANCE
AND REPAIR, for details.
AUTO‐START
The standard pump is equipped with an auto‐start
control system which allows the pump to start and
stop as the liquid level in the wet well or sump rises
and falls.
Refer to the information which follows for installa
tion details for the liquid level sensing system pro
vided with your pump.

OM-06451 PAH SERIES
PAGE B - 6 INSTALLATION
Float Switch Installation
The Float Switch autostart system employs either a
single or double float switch, where a bulb raises or
lowers (floats) with the liquid level, thus activating
an enclosed miniature switch. The floats are
equipped with a socket type connector that plugs
into a matching receptacle on the auto‐start control
box.
Standard floats are equipped with 50 feet (15,2 m)
of cable.
When installing the floats, note the following:
a. Be sure to provide sufficient room in the wet
well or sump so that floats do not get ob
structed or drawn into the suction line. If a flex
ible suction hose is used, it may be extended
to lay along the bottom of the wet well or sump
and the float can be attached to the hose
above the point where it bends along the bot
tom. Direct the suction line toward the flow,
and the float(s) away from the flow. If a stand
pipe is available, attach the float switch cable
to the standpipe in the sump at the approxi
mate desired liquid level.
b. In a single float system, the cable can be teth
ered to the suction line or standpipe approxi
mately 6 inches (152 mm) above the float.
This setting allows approximately 9 inches
(229 mm) of liquid rise between pump start/
stop. The start/stop interval may be increased
by extending the float end of the cable. The
liquid level in the sump will increase approxi
mately 8 inches (203 mm) between start/stop
intervals for every 6 inches (152 mm) of cable
increase.
c. If a double float switch system is used, posi
tion the “Start” float at the desired high water
level in the sump, and the “Stop” float at the
desired low water level in the pump.
d. Refer to Figure 3 for additional float switch
data.
OPERATING
RANGE
(See Table Below)
CABLE
TETHER
POINT
OFF
(Emptying)
ON
(Filling)
ON
(Emptying)
OFF
(Filling)
1.25” Pipe
(Not Furnished)
ENGINE
CONTROL
BOX
1.0
(0.3)
APPROXIMATE FREE CORD LENGTH IN FT. (M)
0.5
(.15)
1.0
(0.3)
1.5
(.46)
2.0
(0.6)
2.5
(.76)
3.0
(0.9)
2.0
(0.6)
3.0
(0.9)
4.0
(1.2)
Figure 3. Float Switch Data

OM-06451
PAH SERIES
OPERATION PAGE C - 1
OPERATION - SECTION C
Review all SAFETY information in Section A.
Follow the instructions on all tags, labels and
decals attached to the pump.
Do not operate an internal combustion
engine in an explosive atmosphere.
When operating an internal combustion
engine in an enclosed area, make sure
exhaust fumes are piped to the outside.
These fumes contain carbon monoxide,
a deadly gas that is colorless, tasteless
and odorless.
OPERATION
This pump is designed to handle most
non‐volatile, non‐flammable liquids
containing specified entrained solids
and corrosives. Do not attempt to pump
volatile, 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.
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
Check the fuel level and oil levels in the engine, air
compressor, pump bearings and seal housing.
Make sure the pump is level. Lower the jack stands
and chock the wheels, if so equipped.
Make sure the pump is level. Lower jack
stands and chock the wheels, if so
equipped. Use caution when positioning
the skid‐mounted unit to prevent damage
to the fuel tank.
This pump is equipped with automatic
liquid level controls, and is subject to
automatic restart. Keep hands and
clothing away from the unit to prevent
injury during automatic operation. Dis
connect the positive battery cable be
fore performing any maintenance. Fail
ure to do so may result in serious per
sonal injury.
Consult the engine operations manual before at
tempting to start the unit.
Manual Starting
On initial start‐up, set the engine speed at the half‐
throttle position. Turn the key switch on the control

OM-06451 PAH SERIES
OPERATIONPAGE C - 2
box to the “MANUAL” position, then press and hold
the “ENTER” button until the engine starts.
Pump speed and operating condition
points must be within the continuous per
formance range shown on the curve on
Page E‐1.
Automatic Starting
With the float system installed, follow the proce
dures outlined for manual starting and adjust the
throttle to the desired flow rate. Turn the key switch
to “OFF”, then move it to the “AUTO” position.
The pump will start automatically when the liquid
level in the sump or wet well increases and the
float(s) rise to the “on” position. An alarm will sound
and the control box will begin a countdown display
before the unit starts. When the liquid is sufficiently
pumped down, the unit will automatically shut
down.
The unit can be stopped while in the “AUTO” mode
by moving the key switch to the “OFF” position.
NOTE
If the key switch is moved to the “OFF” position
while in the “AUTO” mode, the engine will stop.
However, the auto‐start process will continue as
soon as the key switch is moved back to the “AUTO”
position.
The control panel is equipped with high oil temper
ature, low oil pressure, engine overspeed and en
gine overcrank safety shutdowns. If any of these
problems occur, the engine will not start. When the
problem is corrected, turn the key switch to the
“OFF” position to reset the control.
Priming
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.
Routine Operation
Do not operate an internal combustion
engine in an explosive atmosphere.
When operating an internal combustion
engine in an enclosed area, make sure
exhaust fumes are piped to the outside.
These fumes contain carbon monoxide,
a deadly gas that is colorless, tasteless
and odorless.
Adjust the engine speed to achieve the desired
output. Do not exceed the factory set engine speed
and system operating pressure. Do not operate
below the recommended operating speed (if appli
cable).
Never tamper with the governor to gain
more power. The governor establishes
safe operating limits that should not be
exceeded. Refer to the performance
curve on page E-1 for the maximum
continuous operating speed for this
pump.
Operation In Extreme Heat
The safety shutdown system will automatically
stop the unit if engine operating temperature ex
ceeds design limits. If engine over‐temperature
shutdown occurs, allow the unit to cool before re
starting.
If engine overheating continues, check the engine
lubricant level and viscosity. Consult the engine
operation manual for the recommended lubricant
for operation in extreme heat.
If the unit is being operated in the automatic mode,
adjust the float(s) to allow shorter run and longer
cooling periods, if possible.

OM-06451
PAH SERIES
OPERATION PAGE C - 3
This pump is equipped with automatic
liquid level controls, and is subject to
automatic restart. Keep hands and
clothing away from the unit to prevent
injury during automatic operation. Dis
connect the battery before performing
any maintenance. Failure to do so may
result in serious personal injury.
OPERATIONAL CHECKS
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.
Pump Vacuum Check
Read the vacuum gauge with the pump primed
and at operation speed. Shut off the pump. The
vacuum gauge reading will immediately drop pro
portionate to static suction lift, and should then sta
bilize. 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 installa
tion of the vacuum gauge.
Liquid Temperature And Overheating
The maximum liquid temperature for this pump is
160F (71C). Do not apply it at a higher operating
temperature.
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.
Strainer Check
Check the strainer regularly, and clean it as neces
sary. 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 blockage.
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.
STOPPING
Manual 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.
In the manual mode, reduce the throttle speed
slowly, and allow the engine to idle briefly before
switching the engine key switch to `OFF'.
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.

OM-06451 PAH SERIES
OPERATIONPAGE C - 4
After stopping the pump, switch off the engine igni
tion and remove the key to ensure that the pump
will remain inoperative.
Automatic Stopping
In the automatic mode, the pump will stop when
the liquid in the wet well or sump lowers and acti
vates the “Off” float switch(s). The pump will restart
automatically when the liquid rises and activates
the “On” float switch(s).
Safety Shutdown System
The unit is equipped with a safety system to auto
matically shut down the engine under certain con
ditions. The engine will automatically shut down:
1. If the engine exceeds its safe operating tem
perature.
2. If the engine oil pressure drops below design
limits.
3. If the engine fails to start within a pre‐set peri
od of time.
4. If the engine speed exceeds the safe operat
ing range.
5. If the engine fan belt breaks.
Lights on the control panel will indicate which of the
safety features has caused the engine to shut
down.
Should any of the safety features cause the engine
to shut down, the cause must be determined and
corrected before putting the unit back into service.
The engine will not restart until the key switch has
been returned to the `OFF' position for at least 10
seconds.
All safety shutdown features are pre‐set at the fac
tory for optimum performance and safety; do not
attempt to adjust these settings.
Never disconnect any of the safety shut
down features; this will void the warran
ty and could result in serious damage to
the unit and/or injury to personnel. Safe
ty shutdown features are pre‐set at the
factory; do not attempt to adjust any of
the settings. Determine the cause of
shutdown before putting the unit back
into service. Consult the factory for ad
ditional information.
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
Bearings normally run at higher than ambient tem
peratures because of heat generated by friction.
Temperatures up to 160F (71C) are considered
normal for bearings, and they can operate safely to
at least 180F (82C).
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
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.
Engine Fuel Filter
Consult the manual accompanying the engine,
and change the fuel filter periodically as indicated.
If operated under extremely dusty and/or humid

OM-06451
PAH SERIES
OPERATION PAGE C - 5
conditions, change the filter more frequently. Irreg
ular performance and loss of power usually indi
cate a dirty fuel filter.
Engine Oil
The engine was lubricated for test at the factory.
However, always check the lubrication level before
startup.
Consult the manual accompanying the engine,
and change the oil filter periodically as indicated. If
operated under extremely dusty conditions,
change the filter more frequently.
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
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.

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP FAILS TO
PRIME
Strainer clogged. Check strainer and clean if neces
sary.
Suction lift or discharge head too high. Check piping installation and install
bypass line if needed. See INSTAL
LATION.
Leaking or worn seal or pump gasket. Check pump vacuum. Replace
leaking or worn seal or gasket.
Lining of suction hose collapsed. Replace suction hose.
Air leak in suction line. Correct leak.
Discharge check valve contami
nated, damaged, or unable to seat.
Clean or replace check valve.
PUMP STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE
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
leaking or worn seal or gasket.
Air compressor damaged or belts bro
ken.
Check and repair/replace.
Eductor clogged. Check and clean eductor.
PAH SERIES OM-06451
TROUBLESHOOTING PAGE D - 1
TROUBLESHOOTING - SECTION D
Review all SAFETY information in Section A.
Before attempting to open or service the
pump:
1. Familiarize yourself with this man
ual.
2. Shut down the engine and discon
nect the positive battery cable to
ensure that the pump will remain
inoperative.
3. Allow the pump to completely cool
if overheated.
4. Check the temperature before
opening any covers, plates, or
plugs.
5. Close the suction and discharge
valves.
6. Vent the pump slowly and cau
tiously.
7. Drain the pump.
This pump is equipped with an automat
ic starting system, and is subject to au
tomatic restart. Keep hands and cloth
ing away from the unit to prevent injury
during automatic operation. Disconnect
the positive battery cable before per
forming any maintenance. Failure to do
so may result in serious personal injury.

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE (cont.)
PUMP REQUIRES
TOO MUCH
POWER
PUMP CLOGS
FREQUENTLY
Impeller or other wearing parts worn
or damaged.
Free impeller of debris.Impeller clogged.
Replace worn or damaged parts.
Check that impeller is properly
centered and rotates freely.
Discharge head too high.
Measure lift w/vacuum gauge. Re
duce lift and/or friction losses in
suction line.
Suction lift too high.
Install bypass line.
Pump speed too slow. Check engine output; consult en
gine operation manual.
Pump speed too high. Check engine output.
Discharge head too low.
Dilute if possible.Liquid solution too thick.
Adjust discharge valve.
Pump or jack shaft bearing(s) frozen. Disassemble, check and replace
bearing(s) as required..
Liquid solution too thick.
Open discharge valve fully to in
crease flow rate, and run engine at
maximum governed speed.
Discharge flow too slow.
Dilute if possible.
Suction check valve or foot valve
clogged or binding.
Clean valve.
Suction intake not submerged at
proper level or sump too small.
Check installation and correct
submergence as needed.
EXCESSIVE NOISE Cavitation in pump. Reduce suction lift and/or friction
losses in suction line. Record vac
uum and pressure gauge readings
and consult local representative or
factory.
Clean out debris; replace damaged
parts.
Impeller clogged or damaged.
Secure mounting hardware.Pump or drive not securely mounted.
Locate and eliminate source of air
bubble.
Pumping entrained air.
Discharge check valve clogged. Check and clean check valve.
Strainer clogged. Check strainer and clean if neces
sary.
Belt or flexible coupling broken. Check and replace as necessary.
Extreme ambient temperature. Reduce pump output.
Fuel filter clogged. Check & replace often in extreme
operating conditions.
Check and replace as required.Fuel contaminated.
OM-06451 PAH SERIES
TROUBLESHOOTINGPAGE D - 2