GORMAN-RUPP SELF-PRIMING CENTRIFUGAL PUMPS Operating instructions

PUBLICATION NUMBER OM--04760
December 2, 1998
Rev. A 11-20-03
THE GORMAN-RUPP COMPANY DMANSFIELD, OHIO
GORMAN-RUPP OF CANADA LIMITED DST. THOMAS, ONTARIO, CANADA Printed in U.S.A.
eCopyright by the Gorman-Rupp Company
SELF-PRIMING
CENTRIFUGAL PUMPS

OM--04760 SELF-PRIMING CENTRIFUGAL PUMPS
PAGE I -- 1
INTRODUCTION
INTRODUCTION
Thank You for purchasing a Gorman-Rupp Self-
Priming Centrifugal Pump. Read this manual
carefully to learn how to safely install and operate
yourpump.Failuretodosocouldresultinpersonal
injury or damage to the pump.
A set of three manuals accompanies your pump.
Each set consists of three parts; the Installation/
Operation Manual contains essential information
on installing and operating the pumps. However,
since pump installations are seldom identical,
some of the information only summarizes general
recommendations and practices required to in-
spect, position, and arrange the pump and piping.
The Parts List Manual provides performance
curve(s), a pump model cross-section drawing,
and parts list for your pump.
The Maintenance and Repair Manual provides
troubleshooting and maintenance instructions re-
quiredto properlydiagnose operationalproblems,
and to service the pump components.
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
neitheroperatorsafetynorpumpintegrityarecom-
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
which are not covered in this manual orin 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
or:
Gorman-Rupp of Canada Limited
70 Burwell Road
St. Thomas, Ontario N5P 3R7
CONTENTS
SAFETY -- SECTION A
INSTALLATION -- SECTION B
GENERAL INFORMATION PAGE B --- 1.....................................................
PREINSTALLATION INSPECTION PAGE B --- 1...............................................
POSITIONING PUMP PAGE B --- 1..........................................................
SUCTION AND DISCHARGE PIPING PAGE B --- 2............................................
AUTOMATIC AIR RELEASE VALVE PAGE B --- 5..............................................
ALIGNMENT PAGE B --- 7.................................................................
ELECTRICAL CONNECTIONS PAGE B --- 9..................................................
OPERATION -- SECTION C
PRIMING PAGE C --- 1....................................................................
STARTING PAGE C --- 1...................................................................
OPERATION PAGE C --- 2.................................................................
STOPPING PAGE C --- 3...................................................................
BEARING TEMPERATURE CHECK PAGE C --- 4.............................................
LUBRICATION PAGE C --- 4................................................................

OM--04760SELF-PRIMING CENTRIFUGAL PUMPS
PAGE I -- 2 INTRODUCTION
RECORDING MODEL AND
SERIAL NUMBERS
Please record the pump model and serial number
in the spaces provided below. Your Gorman-Rupp
distributorneedsthisinformationwhenyourequire
parts or service.
Pump Model:
Serial Number:
WARRANTY INFORMATION
The warranty provided with your pump is part of
Gorman-Rupp’s support program for customers
who operate and maintain their equipment as de-
scribed in this and the other accompanying litera-
ture. Please note that should the equipment be
abused or modified to change its performance be-
yond the original factory specifications, the war-
ranty will become void and any claim will be de-
nied.
The following are used to alert personnel to procedures which require special attention, to those which
could damage equipment, and to those which could be dangerous to personnel:
Immediate hazards which WILL resultin
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.
HazardsorunsafepracticeswhichCOULD
resultinminorpersonalinjuryorproductor
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.

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
PAGE A -- 1SAFETY
SAFETY - SECTION A
This information applies to G-R Self-
Priming Centrifugal pumps. These
pumps are available as basic, pedestal-
mounted models or as close-coupled
models driven by either an electric mo-
tor, gasoline or diesel engine. Refer to
the manual accompanying the power
sourcebeforeattempting to beginoper-
ation.
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,thismanualcannotpossiblyantici-
pate and provide detailed instructions
and precautions for every situation that
might occur during maintenance of the
unit.Therefore,it isthe responsibilityof
the owner/maintenance personnel to
ensurethatonlysafe, 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
pump integrity are compromised by
such practices.
In addition to this manual, see the sepa-
rate literature covering maintenance
andrepair,pumpparts,and anyoptional
equipment shipped with the pump.
Beforeattemptingtoopenorservicethe
pump:
1. Familiarize yourself with this man-
ual.
2. Disconnect or shut down the pow-
er source and take necessary pre-
cautions 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.
Do not attempt to pump any liquids the
pump has not been designed for, and
which may damage the pump or endan-
ger personnel as a result of pump fail-
ure. Consult the factory to determine
compatibilitybetweenthepumpandliq-
uid.
Use lifting and moving equipment in
good repair and with adequate capacity
to prevent injuries to personnel or dam-
age to equipment. Suction and dis-
charge hoses and piping must be re-
moved from the pump before lifting.
After the pump has been positioned,
make certain that the pump and all pip-
ing orhose connections are tight, prop-
erly supported and secure before oper-
ation.
Do not operate the pump against a
closed discharge valve for long periods
oftime.Ifoperatedagainstacloseddis-
charge valve, pump components will
deteriorate, and the liquid could come

SELF-PRIMING CENTRIFUAL PUMPSOM--04760
PAGE A -- 2 SAFETY
to a boil, build pressure, and cause the
pump casing to rupture or explode.
Do not remove plates, covers, gauges,
pipe plugs, or fittings from an over-
heatedpump. Vaporpressure withinthe
pump can cause parts being disen-
gaged to be ejected withgreat force. Al-
low the pump to cool before servicing.
Thesepumpsmaybeusedtohandle
productswhichifoverheatedcouldpro-
duce dangerous fumes. Use extreme
caution when venting the pump, or
whenremovingcovers,plates,plugs,or
fittings.
Neverrunthispumpbackwards.Becer-
tain that rotation is correct before fully
engaging the pump.
If the pump is used to pump materials
which could cause serious illness or in-
jury through direct exposure or emitted
fumes, wear protective clothing, such
asrubbergloves,facemask,andrubber
apron, as necessary before disassem-
bling the pump or piping.
Do not operate the pump without
shields and/or guards in place over the
drive shafts, belts, and/or couplings, or
other rotating parts. Exposed rotating
parts can catch clothing, fingers, or
tools, causing severe injury to person-
nel.
If the pump is powered by an electric
motor, do not operate a non-explosion
proof motor in an explosive atmo-
sphere. An explosion, which may cause
severe personal injury or death, could
result. Install, connect and operate the
motor in accordance with the National
Electric Code and all local codes. If
there is a conflict between the instruc-
tions in the manual accompanying the
unit and the National Electric Code or
applicable local code, the National or
Local code shall take precedence. All
electrical equipment supplied with the
pump conforms to applicable federal
regulations and national codes in effect
on the date of manufacture.
If the pump is electric motor driven, the
electrical power used to operate this
pump is high enough to cause injury or
death. Obtainthe servicesof aqualified
electrician to troubleshoot, test and/or
service the electrical components of
this pump.
If the pump is powered by an internal
combustion engine, do not operate in
anexplosiveatmosphere.Whenoperat-
ing internal combustion engines in an
enclosed area, make certain that ex-
haust fumes are piped to the outside.
These fumescontain carbon monoxide,
a deadly gas that is colorless, tasteless,
and odorless.

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
PAGE A -- 3SAFETY
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.Alwaysusethecorrecttypeoffuel.
Never tamper with the engine governor
to gain more power. The governor esta-
blishessafeoperating limitsthatshould
not be exceeded. The maximum contin-
uous operating speed for the pump is
shownontheperformancecurve(see
the Parts List Manual).
Ifthepumpispoweredbyanengine,the
engine exhaust from this product con-
tains chemicals known to the State of
California to cause cancer,birthdefects
or other reproductive harm.
Pumps and related equipment must be in-
stalled and operated according to all na-
tional, local and industry standards.

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
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
staticliftapplicationwhere thepump ispositioned
above the free level of liquid to be pumped.
If installedin 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,
besuretolimittheincomingpressureto50%ofthe
maximum permissible operating pressure as
shown on the pump performance curve (see Parts
List Manual). If the pump is fitted with a Gorman-
Rupp double grease lubricated seal, the maxi-
mum incoming pressure must be reduced to 10
p.s.i.
Forfurtherassistance,contact yourGorman-Rupp
distributor or the Gorman-Rupp Company.
PREINSTALLATION INSPECTION
The pump assemblywas inspectedand testedbe-
fore shipment from the factory. Before installation,
inspect the pump for damage whichmay haveoc-
curred during shipment. Check as follows:
a. Inspect the pump and power source (if so
equipped) 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 tags, decals, and markings
onthepumpassembly,andperformallduties
indicated. Note that the pump shaft rotatesin
the required direction.
d. Check levels and lubricate as necessary. Re-
fer to LUBRICATION in the MAINTENANCE
AND REPAIR section of this manual and any
other literature accompanying the unit and
perform 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.
Battery Installation
If the pump is engine driven, the engine battery is
not included with the unit unless otherwise speci-
fied on the pump order. See the battery tag in-
cluded with the battery box assembly for battery
specifications. Refer to information accompanying
thebatteryand/orelectrolytesolutionforactivation
and charging instructions.
Before installingthebattery,cleanthepositiveand
negative cable connectors, and the battery termi-
nals. Secure the battery by tightening the hold-
down brackets. The terminals and clamps maybe
coated with petroleum jelly to retard corrosion.
Connect and tighten the positive cable first, then
thenegativecable.
POSITIONING PUMP
Lifting
Use lifting equipment with a capacity of at least 5
times the weight of the pump, not including the
weight of accessories, wheel kit or optional equip-
ment. Customer installed equipment such as suc-
tionanddischargepipingmustberemovedbefore
attempting to lift.

OM--04760 SELF-PRIMING CENTRIFUGAL PUMPS
PAGE B -- 2 INSTALLATION

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
PAGE B -- 3INSTALLATION
slopes down to the pump at any point along the
suction run, air pockets will be created.
Fittings
Suction lines should bethe 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 ofthe 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
touseit;anysphericalsolidswhichpassthrougha
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.
RefertotheSpecificationData sheet forthespheri-
calsolidshandlingcapabilityofyour specificpump
model.
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 distanceequalto 1-1/2 times thediame-
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 carryair 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-
tioninlet, installa bafflebetween theinflow 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,
theflowpathsmayinteract,reducingtheefficiency
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 1 shows
recommended minimum submergence vs. veloc-
ity.
NOTE
The pipe submergence required may be reduced
by installing a standard pipe increaser fitting at the
end of thesuction 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).

OM--04760 SELF-PRIMING CENTRIFUGAL PUMPS
PAGE B -- 4 INSTALLATION

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
PAGE B -- 5INSTALLATION
minimize the chance of plugging.
Inlow discharge head applications (less than30
feet or 9 meters), it is recommended that the by-
pass line be run back to the wet well, and located 6
inches below the water level or cut-off point of the
low level pump. In some installations, this bypass
line may be terminated with a six-to-eight foot
length of11/4inch I.D.smooth-borehose;airand
liquid vented during the priming process will then
agitate the hose and break up any solids,grease,
or other substances likely to cause clogging.
A bypass line that is returned to a wet well
must be secured against being drawn into
the pump suction inlet.
It is also recommended that pipe unions be in-
stalled at each 90_elbow in a bypass line to ease
disassembly and maintenance.
In high discharge head applications (more than
30 feet), an excessive amount of liquid may be by-
passed and forced back to the wet well under the
full working pressure of the pump; this will reduce
overallpumpingefficiency.Therefore, itisrecom-
mended that a Gorman-Rupp Automatic Air Re-
lease Valve be installed in the bypass line.
Gorman-Rupp Automatic Air Release Valves are
reliable, and require minimum maintenance. See
AUTOMATICAIR RELEASE VALVEin this section
for installation and theory of operation of the Auto-
matic Air Release Valve. Consult your Gorman-
Rupp distributor, or contact the Gorman-Rupp
CompanyforselectionofanAutomaticAirRelease
Valve to fit your application.
Iftheinstallationinvolvesafloodedsuctionsuchas
abelow-groundliftstation,apipeunionandmanu-
alshut-offvalvemaybe installedin thebleed lineto
allowserviceofthevalvewithoutshuttingdownthe
station, and to eliminate the possibility of flooding.
If a manual shut-off valve is installed anywhere in
theair release piping, it mustbeafull-openingball
type valve to prevent plugging by solids.
If a manual shut-off valve is installed in
a bypass line, it must not be left closed
duringoperation.Aclosedmanualshut-
off valve may cause a pump which has
lost prime to continue to operate with-
out reaching prime, causing dangerous
overheating and possible explosive
rupture of the pump casing. Personnel
could be severely injured.
Allow an over-heated pump to cool be-
fore servicing.Do not remove plates,
covers,gauges,orfittingsfrom anover-
heated pump. Liquid within the pump
can reachboiling temperatures, andva-
porpressure withinthe pump cancause
parts being disengaged to be ejected
with great force. After the pump cools,
drain the liquid from the pump by re-
moving the casing drain plug. Use cau-
tion when removing the plug to prevent
injury to personnel from hot liquid.
AUTOMATIC AIR RELEASE VALVE
When properly installed and correctly adjusted to
the specific hydraulic operating conditions of the
application, the Gorman-Rupp Automatic Air Re-
leaseValvewillpermitairtoescapethroughtheby-
pass line, and then close automatically when the
pump is fully primed and pumping at full capacity.
Theory of Operation
Figures 2 and 3 show a cross-sectional view of the
AutomaticAir Release Valve, and a corresponding
description of operation.

OM--04760 SELF-PRIMING CENTRIFUGAL PUMPS
PAGE B -- 6 INSTALLATION
Figure2.ValveinOpenPosition
Duringthe priming cycle,air fromthe pump casing
flowsthroughthebypassline,andpassesthrough
theAirReleaseValvetothewetwell(Figure2).
Figure 3. Valve in Closed Position
When the pump is fully primed, pressure resulting
from flow against the valve diaphragm com-
presses the spring and closes the valve (Figure 3).
The valve will remain closed, reducing the bypass
of liquid to 1 to 5 gallons (3.8 to 19 liters) per min-
ute, until the pump loses its prime or stops.
Some leakage (1to 5gallonsor3.8to19
liters per minute) will occur when the
valve is fullyclosed. Be sure the bypass
line is directed back to the wet well or
tank to prevent hazardous spills.
Whenthepumpshutsdown,thespringreturnsthe
diaphragm to its original position. Any solids that
mayhave accumulatedin the diaphragmchamber
settle to the bottom and are flushedout duringthe
next priming cycle.
NOTE
The valve will remain open if the pump does not
reach its designed capacity or head. Valve closing
pressureis dependentupon the discharge head of
the pump at full capacity. The range of the valve
closing pressure is established by the tension rate
ofthespringasorderedfromthefactory.Valveclos-
ing pressure can be further adjusted to the exact
system requirements by moving the spring retain-
ing pin up or down the plunger rod to increase or
decrease tension on the spring. Contact your Gor-
man-Rupp distributor or the Gorman-Rupp Com-
pany for information about an Automatic Air Re-
lease Valve for your specific application.
Air Release Valve Installation
The Automatic Air Release Valve must be inde-
pendently mounted in a horizontal position and
connected to the discharge line of the self-priming
centrifugal pump (see Figure 4).
NOTE
IftheAirReleaseValveistobeinstalledonastaged
pump application, contact the factory for specific
installation instructions.

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
PAGE B -- 7INSTALLATION

OM--04760 SELF-PRIMING CENTRIFUGAL PUMPS
PAGE B -- 8 INSTALLATION
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
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.
Mostcouplings requirea specificgap or clearance
between the drivingand the driven shafts. Refer to
the coupling manufacturer’s service literature.
Alignspiderinserttypecouplingsbyusingcalipers
to measure the dimensions on the circumference
of the outer ends of the coupling hub every 90 de-
grees. The coupling is in alignment when the hub
ends are the same distance apart at all points (see
Figure 5).
Figure 5. Aligning Spider-Type Couplings
Align non-spider type couplings by using a feeler
gaugeortapergaugebetweenthecouplinghalves
every 90 degrees. The coupling is in alignment
whenthehubsarethesamedistanceapartatall
points (see Figure 6).
Figure 6. Aligning Non-Spider Type Couplings
Checkparalleladjustmentbylayingastraightedge
across both coupling rims at the top, bottom, and
side. When the straightedge rests evenly on both
halves of the coupling, the coupling is inhorizontal
parallel alignment. If the coupling is misaligned,
use a feeler gauge between the coupling and the
straightedge to measure the amount of misalign-
ment.
V-Belt Drives
When using V-belt drives, the power source and
the pump must be parallel. Use a straightedge
alongthesidesofthepulleystoensurethatthepul-
leys are properly aligned (see Figure 7). In drive
systemsusingtwoormorebelts,makecertainthat
the belts are a matched set; unmatched sets will
cause accelerated belt wear.
MISALIGNED:
SHAFTS
NOT P
A
R
A
LLEL
MISALIGNED:
SHAFTS
NOT IN LINE
ALIGNED: SHAFTS
PARALLEL AND
SHE
A
V
ES IN LINE
Figure 7. Alignment of V-Belt Driven Pumps
Tightenthebeltsinaccordancewiththebeltmanu-
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.

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
PAGE B -- 9INSTALLATION
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.
ELECTRICAL CONNECTIONS
Ifthepumpisdrivenbyanelectricmotor, check
that the electrical service available matches the
motor requirements stamped on the motor name-
plate before connecting a motor to the incoming
power. Check that the motor speed meets pump
specifications.
Ifrotationisincorrectonathree-phasemotor,have
a qualified electrician interchange any two of the
three phase wires to change direction.If rotationis
incorrect on a single-phase motor, consult the lit-
eraturesuppliedwith the motorfor specificinstruc-
tions.
Theelectricalpowerusedtooperatethe
pump is high enough to cause injury or
death. Obtainthe servicesof aqualified
electrician to make all electrical con-
nections.
If the pump is powered by an electric
motor, do not operate a non-explosion
proof motor in an explosive atmo-
sphere. An explosion, which may cause
severe personal injury or death, could
result. Install, connect and operate the
motor in accordance with the National
Electric Code and all local codes. If
there is a conflict between the instruc-
tions in the manual accompanying the
unit and the National Electric Code or
applicable local code, the National or
Local code shall take precedence. All
electrical equipment supplied with the
pump conforms to applicable federal
regulations and national codes in effect
on the date of manufacture.

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
OPERATION PAGE C -- 1
OPERATION --- SECTION C
Review all SAFETY information in Section A.
Follow the instructions on all tags, labels and de-
cals attached to the pump.
Do not attempt to pump any liquids the
pump has not been designed for, and
which may damage the pump or endan-
ger personnel as a result of pump fail-
ure.
Pump speed and operating conditions
must be within the performance range
shownonthecurveinPartsListsmanual.
Refer to the pump Specification Data Sheet or the
accompanying Parts List Manual for the specific
performance for your pump.
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 the MAINTENANCE
AND REPAIR manual).
Thepumpisself-priming,butitshouldneverbeop-
erated unless there is liquid in the pump casing.
Neveroperatethepumpunlessthereisliq-
uid in the pump casing. The pump will not
prime when dry. Extended operation of a
dry pump will destroy the seal assembly.
Add liquid to the pump casing when:
1. The pump is being put into service for the
first time.
2. Thepumphas notbeenusedforaconsider-
able length of time.
3. The liquid in the pump casing has evapo-
rated.
Once the pump casing has been filled, the pump
will prime and reprime as necessary.
After filling the pump casing, reinstall
and tighten the fill plug. Do not attempt
to operate the pump unless all connect-
ing piping is securely installed. Other-
wise, liquid in the pump forced out
under pressure could cause injury to
personnel.
To fillthe pump, remove the pump casing fillcover
or fill plug in the top of the casing, and add clean
liquid until the casing is filled. Replace the fill cover
or fill plug before operating the pump.
STARTING
Startingprocedureswillvaryslightlydependingon
the pump application, type of priming device, and
type of drive. Consult the operations manual fur-
nished with the power source.
Rotation
The correct direction of pump rotation is indicated
by an arrow on the pump body or accompanying
decals. Ifthepump is operated inthe wrong direc-
tion, the impeller could become loosened from the
shaft and seriously damage the pump.
The pump must operate inthe direction in-
dicated by the arrow on the pump, or ac-

SELF-PRIMING CENTRIFUGAL PUMPSOM--04760
OPERATIONPAGE C -- 2
companying decals. Reverse rotation
could loosen the impeller and seriously
damage the pump.
If the pump is driven by an electric motor, consult
the operating manualfurnished withthe motorbe-
fore attempting to start the motor.
Ifrotationisincorrectonathree-phasemotor,have
a qualified electrician interchange any two of the
three phase wires to change direction.If rotationis
incorrect on a single-phase motor, consult the lit-
eraturesuppliedwith the motorfor specificinstruc-
tions.
OPERATION
Pumpspeedandoperatingpointsmustbe
within the continuous performance range
shownonthepumpcurve.(SeetheParts
List Manual accompanying the pump.)
Lines With a Bypass
Close the discharge throttling valve (if so
equipped) so that the pump will not have to prime
against the weight of the liquid in the discharge
line. Air from the suction line will be discharged
throughthebypasslinebacktothewetwellduring
the priming cycle. When the pump is fully primed
andliquidisflowingsteadilyfromthebypassline,
open the discharge throttling valve. Liquid will then
continue to circulate through the bypass line while
the pump is in operation.
Lines Without a Bypass
Open all valves in the discharge line and start the
power source. Priming is indicated by a positive
reading on the discharge pressure gauge or by a
quieter operation. Thepump may not prime imme-
diately because the suction line must first fill with
liquid. Ifthe pump fails toprimewithin fiveminutes,
stop it and check the suction line for leaks.
Afterthepumphasbeenprimed,partiallyclosethe
discharge line throttling valve in order to fill the line
slowly and guard against excessive shock pres-
sure which could damage pipe ends, gaskets,
sprinkler heads, and any other fixtures connected
to the line. When the discharge line is completely
filled,adjustthethrottlingvalvetothe requiredflow
rate.
Do not operate the pump against a
closed discharge throttling valve for
long periods of time.Ifoperatedagainst
a closed discharge throttling valve,
pump components will deteriorate, and
the liquid could come to a boil, build
pressure,andcausethe pumpcasingto
rupture or explode.
Leakage
No leakage should be visible at pump mating sur-
faces, or at pump connections or fittings. Keep all
lineconnectionsandfittingstighttomaintainmaxi-
mum pump efficiency.
Liquid Temperature And Overheating
Refer to the Specification Data sheet for the maxi-
mum liquid temperature for your specific pump.
Do not apply the pump at a higher operating tem-
perature.
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 and allow it to cool before servicing it. Refill
the pump casing with cool liquid.
Allow an over-heated pump to com-
pletely cool before servicing.Do not re-
move plates, covers, gauges, orfittings
from an over-heated pump. Liquid with-
in the pump can reach boiling tempera-
tures, and vapor pressure within the
pump can cause parts being disen-
gaged to be ejected withgreatforce.Af-

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
OPERATION PAGE C -- 3
ter the pump cools, drainthe liquidfrom
the pump by removing the casing drain
plug. Use caution when removing the
plug to prevent injury to personnel from
hot liquid.
If overheating does occur, stop the pump immedi-
ately and allow it to cool before servicing it. Ap-
proach any overheated pump cautiously.
As asafeguard against rupture orexplosion dueto
heat, some pumps are equipped with a pressure
relief valve which will open if vapor pressure within
the pump casing reaches a critical point. It is rec-
ommended thatthe pressure relief valve assembly
be replaced at each overhaul, or any time the
pump casing overheats and activates the valve.
Never replace this valve with a substitute which
hasnotbeenspecifiedorprovidedbytheGorman-
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
shouldalsobechecked ifpumpflowratebeginsto
drop. If a vacuum suction gauge has been in-
stalled, monitor and record the 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
onthepumpperformancecurve.If thepumpisfit-
ted with a Gorman-Rupp double grease lubri-
cated seal, the maximum incoming pressure
must be reduced to 10 p.s.i.
Pump Vacuum Check
Withthepumpinoperative,installavacuumgauge
in the system, using pipe dope on the threads.
Block the suction line andstart the pump. At oper-
ating speed the pump should pull a vacuum of 20
inches (508 mm) or more of mercury. If it does not,
check for airleaks inthe seal, gasket, ordischarge
valve.
Openthesuctionline,andreadthevacuumgauge
with the pump primed and at operation speed.
Shut off the pump. The vacuumgauge reading will
immediately drop proportionate to static suction
lift,andshouldthenstabilize.Ifthevacuumreading
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.
Operational Checks
Checkthepumpforproperoperationwhenitisfirst
started and periodically thereafter toidentify minor
problems.
Check the pump for unusual noises or excessive
vibration while it is operating. If noise or vibration is
excessive, stop the pump and refer to Trouble-
shooting in the Maintenance And Repair Manual
for possible causes.
To avoid serious damage to the pump,
check for unusual noises or excessive vi-
bration while the pump is running. If noise
or vibration is excessive, stop operation
andrefertothetroubleshootingchartinthe
Maintenance and Repair 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.
On engine driven pumps, reduce the throttle
speedslowlyandallowtheenginetoidlebrieflybe-
fore stopping.
Iftheapplication involvesa highdischarge
head, gradually close the discharge
throttling valve before stopping the pump.

SELF-PRIMING CENTRIFUGAL PUMPSOM--04760
OPERATIONPAGE C -- 4
After stopping the pump, lock out or disconnect
the power source to ensure that the pump will re-
main inoperative.
Cold Weather Preservation
In below freezing conditions, drain the pump to
prevent damage from freezing. Also, clean outany
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. Toprevent
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.
BEARING TEMPERATURE CHECK
Bearings normallyrun at higher than ambient tem-
peratures because of heat generated by friction.
Temperatures up to 160_F(71_C) are considered
normalforbearings,andtheycanoperatesafelyto
at least 180_F(82_C).
Checkingbearingtemperaturesbyhandisinaccu-
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 temperature is a
warning that the bearings are at thepoint offailing
to operate properly. Make certain that the bearing
lubricant is of the proper viscosity and at the cor-
rect level(see LUBRICATION in the Maintenance
And Repair manual). 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.
LUBRICATION
Do not remove plates, covers, gauges,
pipe plugs or fittings from an over-
heatedpump. Vaporpressure withinthe
pump can cause parts being disen-
gaged to be ejected withgreat force. Al-
low the pump to completely cool before
servicing.
On a new pump, check the oil level inthe seal and
bearing cavities before initial startup, after the first
two weeks of operation, and every month thereaf-
ter.
Before installing or removing the lubrication plug,
always clean the area around the plug to prevent
contamination.
Self Lubricated Seal Assembly
The self lubricated seal assembly is lubricated by
themediumbeingpumped,orbyaflowoffreshliq-
uid from an external source. Flushing liquid may
be taken from the pump discharge and supplied
through auxiliary piping.
When handling abrasive or tacky liquids, supply
fresh lubricating liquid from an external source. Be
sure the liquid supplied to the seal is compatible
with the liquid being pumped, and that its flow is
controlled to prevent dilution. Consult the factory if
flushing is required.
OilLubricatedSealAssembly
Before starting the pump, remove the vented plug
and fill the seal cavity with SAE No. 30 non-deter-
gent oil. Clean and reinstall the vented plug. Refer
to the Maintenance And Repair Manual for the
seal cavity oil capacity.
Grease Lubricated Seal Assembly
Fill the automatic grease cup through the grease
fitting with No. 2 lithium base grease until grease
escapes from the relief hole. Turn the grease cup
arm counterclockwise until it is at the top of the

SELF-PRIMING CENTRIFUGAL PUMPS OM--04760
OPERATION PAGE C -- 5
stem; this will release the spring to apply greaseto
the seal.
Oil Lubricated Bearings
Bearing housings are fully lubricated when
shipped from the factory. Check the oil level regu-
larlyandmaintainitatthedesiredlevel.Whenlubri-
cation is required, add SAE No. 30 non-detergent
oil. Do not over-lubricate. Over-lubrication can
cause the bearings to over-heat, resulting in pre-
mature bearing failure.
Under normal conditions, drain the bearing hous-
ingonce eachyear andrefillwithclean oil.Change
theoilmorefrequentlyifthepumpisoperatedcon-
tinuously or installed in an environment with rapid
temperature change.
Monitor the condition of the bearing lubri-
cant regularly for evidence ofrust ormois-
ture condensation. This is especially im-
portant in areas where variable hot and
cold temperatures are common.
Forcoldweatheroperation,consultthefactoryora
lubricant supplier for the recommended grade of
oil.
Grease Lubricated Bearings
Bearing housings are fully lubricated when
shippedfromthefactory.Undernormalconditions,
add No. 0 lithium base grease from a grease gun
through the grease fitting after each 250 hours of
operation or once each month, whichever comes
first. Do not over-lubricate. Over-lubrication can
cause the bearings to over-heat, resulting in pre-
mature bearing failure.
If there is noprovision inthe bearingcavity todrain
orflushthe lubricant,the pump and bearinghous-
ingmustbedisassembledtocompletelycleanand
maintain this cavity.
Under normal conditions, change the grease after
each 5000hours of operation,or at 12 monthinter-
vals, whichever comes first. Change the grease
more frequently if the pump is operated continu-
ouslyor installedin an environment wherevariable
hot and cold temperatures are common.
Refer to the Maintenance And Repair Manual for
grease capacity of the bearing housing for the
pump.
Forcoldweatheroperation,consultthefactoryora
lubricant supplier for the recommended grade of
lubricant.
Power Source
Consult the literature supplied with the power
source, or contact your local power source repre-
sentative.