GORMAN-RUPP 12D1-L48EE Application guide

OM---05465---OE01
November 13, 2002
ACEGU
THE GORMAN-RUPP COMPANY DMANSFIELD, OHIO
GORMAN-RUPP OF CANADA LIMITED DST. THOMAS, ONTARIO, CANADA Printed in U.S.A.
www.gormanrupp.com
ECopyright by the Gorman-Rupp Company
INSTALLATION, OPERATION,
AND MAINTENANCE MANUAL
WITH PARTS LIST
10 SERIES PUMP
MODEL
12D1---L48EE

The engine exhaust from this
product contains chemicals
known tothe State of Californiato
cause cancer, birth defects or
other reproductive harm.

TABLE OF CONTENTS
i
INTRODUCTION PAGE I --- 1.................................................
SAFETY - SECTION A PAGE A --- 1............................................
INSTALLAT ION --- SECTION B PAGE B --- 1....................................
Pump Dimensions PAGE B --- 1.....................................................
PREINSTALLATION INSPECTION PAGE B --- 1............................................
POSITIONING PUMP PAGE B --- 2.......................................................
Lifting PAGE B --- 2.................................................................
Mounting PAGE B --- 2.............................................................
Clearance PAGE B --- 2.............................................................
SUCTION AND DISCHARGE PIPING PAGE B --- 2.........................................
Materials PAGE B --- 2..............................................................
Line Configuration PAGE B --- 2......................................................
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 --- 3...............................................................
Suction Lines In Sumps PAGE B --- 3.................................................
Suction Line Positioning PAGE B --- 4................................................
DISCHARGE LINES PAGE B --- 4........................................................
Siphoning PAGE B --- 4.............................................................
Valves PAGE B --- 4................................................................
Bypass Lines PAGE B --- 5..........................................................
OPERATION --- SECTION C PAGE C --- 1......................................
PRIMING PAGE C --- 1.................................................................
STARTING PAGE C --- 1................................................................
OPERATION PAGE C --- 1..............................................................
Lines With a Bypass PAGE C --- 1....................................................
Lines Without a Bypass PAGE C --- 2.................................................
Leakage PAGE C --- 2..............................................................
Liquid Temperature And Overheating PAGE C --- 2.....................................
Strainer Check PAGE C --- 2.........................................................
Pump Vacuum Check PAGE C --- 2..................................................
STOPPING PAGE C --- 2................................................................
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........................................
PARTS LISTS:
Pump Model PAGE E --- 3..........................................................

TABLE OF CONTENTS
(continued)
ii
Pump End Assy PAGE E --- 5........................................................
PUMP AND SEAL DISASSEMBLY AND REASSEMBLY PAGE E --- 6.........................
Suction Check Valve Disassembly PAGE E --- 6........................................
Back Cover Removal PAGE E --- 6...................................................
Pump Casing Removal PAGE E --- 6.................................................
Impeller Removal PAGE E --- 7......................................................
Seal Removal and Disassembly PAGE E --- 7..........................................
Seal Reassembly and Installation PAGE E --- 7........................................
Impeller Installation And Adjustment PAGE E --- 8......................................
Pump Casing Installation PAGE E --- 9................................................
Back Cover Installation PAGE E --- 9.................................................
Suction Check Valve Installation PAGE E --- 9.........................................
Final Pump Assembly PAGE E --- 9..................................................
LUBRICATION PAGE E --- 9.............................................................
Seal Assembly PAGE E --- 9.........................................................
Engine PAGE E --- 9................................................................

10 SERIES OM--05465
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.
This Installation, Operation, and Maintenance
manual is designed to help you achieve the best
performance and longest life from your Gorman-
Rupp pump.
This pump is a 10 Series, semi-open impeller, self-
priming centrifugal model with a suction check
valve. It is close-coupled to a four cycle, air cooled
Yanmardieselengine,modelL48EE-DP.Thepump
is designed for handling most non-volatile, non-
flammable liquids containing specified entrained
solids. The basic material of construction for
wetted parts is gray iron with ductile iron impeller
and steel wearing parts.
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
write:
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]
As described on the following page, this manual
willalert personnel toknown procedures which re-
quire specialattention, to those which could dam-
age equipment, and to those which could be dan-
gerous topersonnel. However,this manualcannot
possibly anticipate and provide detailed precau-
tions for every situation that might occur during
maintenanceoftheunit.Therefore,itistherespon-
sibilityof the owner/maintenance personnel to en-
sure that only safe, established maintenance pro-
ceduresareused,andthat anyproceduresnotad-
dressedinthismanualareperformedonlyafteres-
tablishingthat neitherpersonalsafetynorpumpin-
tegrity are compromised by such practices.
The following are used to alert maintenance per-
sonnel to procedureswhich require specialatten-
tion,tothosewhichcoulddamage 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
result in minor personal injury or product
or property damage. These instructions
describe the requirements and the possi-
ble damage which couldresult from failure
to follow the procedure.
NOTE
Instructions to aid in installation, operation, and
maintenance or which clarify a procedure.

10 SERIES OM--05465
PAGE A -- 1SAFETY
SAFETY - SECTION A
Thisinformationappliesto10Seriesen-
gine driven pumps. Refer to the manual
accompanying the engine before at-
tempting to begin operation.
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 pro-
vide detailed instructions and precau-
tions for each specific application or for
every situation that might occur during
maintenance of the unit. Therefore, it is
the responsibility of the owner, installer
and/or maintenance personnel to en-
sure that applications and/or mainte-
nance procedures notaddressed inthis
manual are performed only after estab-
lishing that neither personal safety nor
pump integrity are compromised by
such applications or procedures.
Beforeattemptingtoopenorservicethe
pump:
1. Familiarize yourself with this man-
ual.
2. Shut down the engine and take
precautions 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 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.
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.
Afterthepumphasbeen installed,make
certain that the pump and all piping or
hose connections are tight, properly
supportedandsecurebeforeoperation.
Do not operate the pump against a
closeddischarge valveforlongperiods
oftime.Ifoperatedagainstacloseddis-
charge valve, pump components will
deteriorate, and the liquid could come
to a boil, build pressure, and cause the
pump casing to rupture or explode.
Overheated pumps can cause severe
burnsandinjuries.Ifoverheatingofthe
pump occurs:
1. Stop the pump immediately.

10 SERIESOM--05465
PAGE A -- 2 SAFETY
2. Ventilate the area.
3. Allowthepumpcompletelytocool.
4. Check the temperature before
opening any covers, plates,
gauges, or plugs.
5. Vent the pump slowly and cau-
tiously.
6. Refertoinstructionsinthismanual
before restarting the pump.
Do not remove plates, covers, gauges,
pipe plugs, or fittings from an over-
heatedpump. Vaporpressure within the
pump can cause parts being disen-
gaged to be ejected withgreat force.Al-
low the pump to cool before servicing.
Do not operate an internal combustion
engine in an explosive atmosphere.
When operating internal combustion
engines in an enclosed area, make cer-
tain that exhaust fumes are piped to the
outside. These fumes contain carbon
monoxide, a deadly gas that is color-
less, 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.Alwaysusethe correcttypeoffuel.
Never tamper with the governor to gain
more power. The governor establishes
safe operating limits that should not be
exceeded. The maximum continuous
operating speed for this pump is 3600
RPM.

10 SERIES OM--05465
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 installed ina 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 Sec-
tion E, Page 1).
Forfurtherassistance,contact yourGorman-Rupp
distributor or the Gorman-Rupp Company.
Pump Dimensions
SeeFigure1fortheapproximatephysicaldimen-
sionsofthispump.
OUTLINE DRAWING
Figure 1. Pump Model 12D1-L48EE
PREINSTALLATION INSPECTION
The pump assemblywas inspectedand tested be-
fore shipment from the factory. Before installation,
inspect the pump for damage whichmay have oc-
curred during shipment. Check as follows:
a. Inspect the pump and engine 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-

OM--05465 10 SERIES
PAGE B -- 2 INSTALLATION
ing, check for loose hardware at mating sur-
faces.
c. Carefully read all tags, decals, and markings
onthepumpassembly,andperformallduties
indicated.
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 engine have been stored for
more than 12 months, some of the compo-
nents or lubricants may have exceeded their
maximumshelflife.Thesemustbeinspected
or replaced to ensure maximum pump serv-
ice.
f. Therubbermounting kit anddischargeelbow
(see the Parts List, pages E-3 and E-5) were
shipped loose with the pump. Refer to Figure
1, page E-2 and install the parts as shown.
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.
POSITIONING PUMP
Lifting
Thispumpisdesignedtobelightweightandporta-
ble.The pump isprotectedbythe wrap-aroundroll
cage, which also serves as a two-man carry han-
dle. The total pump weight is approximately 108
pounds (49 kg), not including accessories or en-
gine fuel. Customer installed equipment such as
suction hose with foot valve must be removed be-
fore attempting to lift.
Mounting
Locatethepumpinanaccessibleplaceascloseas
practical tothe 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.
If the pump has been mounted on a moveable
base,makecertainthebaseisstationarybysetting
the brake and blocking the wheels beforeattempt-
ing to operate the pump.
To ensure sufficient lubrication and fuel supply to
the engine, do not position the pump and engine
more than 15_off horizontal for continuous opera-
tion. The pump and engine may be positioned up
to 30_off horizontal for intermittent operation
only;however,theenginemanufacturershouldbe
consulted for continuous operation at angles
greater than 15_.
Clearance
When positioning the pump, allow a minimum
clearance of 18 inches (457,2 mm) in front of the
backcovertopermitremovalof thecover andeasy
access to the pump interior.
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 notes
onPageE-1tobesureyouroverallapplicational-
lows 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
compatiblewiththeliquidbeingpumped.Ifhoseis
used in suction lines, it must be the rigid-wall, rein-
forced type toprevent 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-
tiallyincreasefrictionloss.Ifelbowsarenecessary,
use the long-radius type to minimize friction loss.

10 SERIES OM--05465
PAGE B -- 3INSTALLATION
Connections to Pump
Before tightening a connecting flange, align it ex-
actly with the pump port. Never pulla 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
linesareused,theyshouldhaveadequatesupport
to secure them when filled with liquid and under
pressure.
Gauges
Most pumps are drilled and tapped for installing
dischargepressureandvacuumsuctiongauges.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 pumpmay result in erratic
readings.
SUCTION LINES
Toavoidairpocketswhichcouldaffectpumpprim-
ing, the suction line must be as short and direct as
possible.Whenoperationinvolvesasuctionlift,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.
The maximum vertical suction lift for this pump is
25 ft. (7,6 m). It is not designed to be operated at a
higher lift.
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.
This pump isdesigned tohandle up to1-3/16inch
(30 mm) diameter spherical solids.
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 distanceequal to1-1/2times 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 the inflow andthe
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-

OM--05465 10 SERIES
PAGE B -- 4 INSTALLATION
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
criticalto efficient pump operation. Figure 2 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).
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
If a throttling valve is desired in the discharge line,
useavalveaslargeasthelargestpipetominimize
friction losses. Never install a throttling valve in a
suction line.
A check valve in the discharge line is normallyrec-
ommended, but it is not necessary in low dis-
charge head applications.
Withhighdischargeheads,itisrecommendedthat
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.
Iftheapplicationinvolvesa highdischarge
head, gradually close the discharge
throttling valve before stopping the pump.

10 SERIES OM--05465
PAGE B -- 5INSTALLATION
Bypass Lines
If a system check valve is used due to high dis-
charge head, it may be necessary to vent trapped
air from the top of the pump during the priming
process. This maybe accomplishedby installinga
bypass line from the top of the pump, back to the
sourceofliquid.Theendofthebypasslinemustbe
submerged.Thelinemustbelargeenoughtopre-
vent clogging, but not so large as to affect pump
discharge capacity.

OM--05465
10 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.
This pump is designed to pump 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.
Never tamper with the governor to gain
more power. The governor establishes
safe operating limits that should not be
exceeded. The maximum continuous
operating speed for this pump is 3600
RPM.
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).
This pump is self-priming, but the pump should
never be operated unless there is liquid in the
pump casing.
Never operate this pump unless there is
liquid in the pump casing. The pump will
not prime when dry. Extended operationof
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. Thepumphasnotbeenusedforaconsider-
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 un-
der pressure could cause injury to per-
sonnel.
Tofill the 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
Consult the operations manual furnished with the
engine.
OPERATION
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,

OM--05465 10 SERIES
OPERATIONPAGE C -- 2
open the discharge throttlingvalve. 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
engine. Priming is indicated by a positive reading
on the discharge pressure gauge or by a quieter
operation. The pump may not prime immediately
because the suction line must first fill with liquid. If
the pump fails to prime within five minutes, 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.
Leakage
No leakage should be visible at pump mating sur-
faces, or at pump connections or fittings. Keep all
lineconnectionsandfittingstightto maintainmaxi-
mum pump efficiency.
Liquid Temperature And Overheating
The maximum liquid temperature for this pump is
110_F(43_C). Donot applyit ata higheroperating
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 and allow it to cool before servicing it. Refill
the pump casing with cool liquid.
Do not remove plates, covers, gauges,
pipe plugs, or fittings from an over-
heatedpump. Vaporpressure within the
pump can cause parts being disen-
gaged to be ejected withgreat force.Al-
low the pump to cool before servicing.
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
shouldalsobecheckedifpumpflowratebeginsto
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, liquidpressuremust belimited to50% ofthe
maximum permissible operating pressure shown
on the pump performance curve. (See Section E,
Page 1.)
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.
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.

OM--05465
10 SERIES
OPERATION PAGE C -- 3
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
After stopping the pump, remove the spark plug
wire to ensure that the pump will remain inopera-
tive.
Cold Weather Preservation
In below freezing conditions, drain the pump to
preventdamagefromfreezing. Also,cleanoutany
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.

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.
Leakingor worn seal or pumpgasket. Check pump vacuum. Replace
leakingorwornsealorgasket.
Lining of suction hose collapsed. Replace suction hose.
Air leak in suction line. Correct leak.
Suction check valve or foot valve
clogged or binding. Clean valve.
Not enough liquid in casing. Add liquid to casing. See PRIMING.
Suction check valve contaminated or
damaged. Clean or replace check valve.
OM--0546510 SERIES
TROUBLESHOOTING PAGE D -- 1
TROUBLESHOOTING --- SECTION D
Review all SAFETY information in Section A.
Beforeattempting toopenorservice the
pump:
1. Familiarizeyourselfwiththismanual.
2. Shut down the engine and discon-
nect the spark plug wire to ensure
that the pump will remain inopera-
tive.
3. Allow the pump to completely cool if
overheated.
4. Check the temperature before open-
ing any covers, plates, or plugs.
5. Close the suction and discharge
valves.
6. Vent the pumpslowly and cautiously.
7. Drain the pump.

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE
PUMP REQUIRES
TOO MUCH
POWER
PUMP CLOGS
FREQUENTLY
Free impeller of debris.Impeller clogged.
Discharge head too low.
Dilute if possible.Liquid solution too thick.
Adjust discharge valve.
Open discharge valve fully to in-
crease flow rate, and run engine at
maximum governed speed.
Discharge flow too slow.
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.
Secure mounting hardware.Pump or drive not securely mounted.
Locate and eliminate source of air
bubble.
Pumping entrained air.
Strainer clogged. Check strainer and clean if neces-
sary.
Suction check valve or foot valve
clogged or binding. Clean valve.
Leakingor worn seal or pumpgasket. Check pump vacuum. Replace
leakingorwornsealorgasket.
Pump speed too slow. Check engine output; consult en-
gine operation manual.
Pump speed too high. Check engine output.
Suction lift or discharge head too high. Check piping installation and install
bypass line if needed. See INSTAL-
LATION.
Discharge line clogged or restricted;
hose kinked. Check discharge lines; straighten hose.
Impeller clogged or damaged. Cleanout debris; replacedamaged
parts.
Air leak in suction line. Correct leak.
Lining of suction hose collapsed. Replace suction hose.
Suction intake not submerged at
proper level or sump too small. Check installation and correct submergence as needed.
Impellerorotherwearingpartsworn
or damaged. Replace worn or damaged parts. Check that impeller is properly
centered and rotates freely.
OM--05465 10 SERIES
TROUBLESHOOTINGPAGE D -- 2

OM--0546510 SERIES
TROUBLESHOOTING PAGE D -- 3
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
providegeneralrecommendationsandpracticesforpreventivemaintenance.Regardlessoftheapplication
however, following a routine preventive maintenance schedule will help assure trouble-free performance
and long life from your Gorman-Rupp pump. For specific questions concerning your application, contact
your Gorman-Rupp distributor or the Gorman-Rupp Company.
Recordkeepingisanessentialcomponentofagoodpreventivemaintenanceprogram.Changesinsuction
and discharge gauge readings (if so equipped) between regularly scheduled inspections can indicate
problems that can be corrected before system damage or catastrophic failure occurs. The appearance of
wearing parts should alsobe documented at each inspection for comparison as well. Also, if records indi-
catethatacertainpart(suchastheseal)failsatapproximatelythesamedutycycle,thepartcanbechecked
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 inspections should be performed at the intervals shown on the
chart below. Critical applications should be inspected more frequently.
General Condition (Temperature, Unusual
Noises or Vibrations, Cracks, Leaks,
Loose Hardware, Etc.) I
Pump Performance (Gauges, Speed, Flow) I
Bearing Lubrication I R
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 (Seal 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
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.
Preventive Maintenance Schedule
Item Daily Weekly Monthly Semi-
Annually Annually
Service Interval*

10 SERIES OM--05465
MAINTENANCE & REPAIR PAGE E -- 1
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 12D1--L48EE
Based on 70_F(21_C) clear water at sea level
with minimumsuction lift.Since pumpinstallations
areseldomidentical,yourperformancemaybedif-
ferent due to such factors as viscosity, specific
gravity, elevation, temperature, and impeller trim.
If your pump serial number is followed by an “N”,
your pump is NOT astandardproductionmodel.
Contact the Gorman-Rupp Company to verifyper-
formance or part numbers.
Never tamper with the governor to gain
more power. The governor establishes
safe operating limits that should not be
exceeded. The maximum continuous
operating speed for this pump is 3600
RPM.

10SERIESOM--05465
MAINTENANCE & REPAIRPAGE E -- 2
SECTION DRAWING
Figure 1. Pump Model 12D1-L48EE