GORMAN-RUPP PUMPS D Series Application guide

OM-01490-04
June 17, 1987
Rev. F 07‐05‐19
GORMAN‐RUPP PUMPS
www.grpumps.com
e1987 Gorman‐Rupp Pumps Printed in U.S.A.
INSTALLATION, OPERATION,
AND MAINTENANCE MANUAL
WITH PARTS LIST
D SERIES PUMP
MODEL
3D-B

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Please record your pump model and serial number in the
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needs this information when you require parts or service.
Pump Model:
Serial Number:

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...............................................
POSITIONING PUMP PAGE B - 2..........................................................
Lifting PAGE B - 2....................................................................
Mounting PAGE B - 2................................................................
SUCTION AND DISCHARGE PIPING PAGE B - 2............................................
Materials PAGE B - 2.................................................................
Line Configuration PAGE B - 2.........................................................
Fixed, Rigid Piping PAGE B - 2........................................................
Gauges PAGE B - 3..................................................................
SUCTION LINES PAGE B - 3..............................................................
Fittings PAGE B - 4..................................................................
Strainers PAGE B - 4.................................................................
Sealing PAGE B - 4..................................................................
DISCHARGE LINES PAGE B - 4...........................................................
Siphoning PAGE B - 4................................................................
Valves PAGE B - 4...................................................................
ALIGNMENT PAGE B - 4.................................................................
ELECTRICAL CONNECTIONS PAGE B - 5..................................................
OPERATION - SECTION C PAGE C - 1.......................................
STARTING PAGE C - 1...................................................................
OPERATION PAGE C - 1.................................................................
Priming PAGE C - 1..................................................................
OPERATION CHECKS PAGE C - 1.........................................................
Gearbox Check PAGE C - 1...........................................................
Leakage Check PAGE C - 1...........................................................
Strainer Check PAGE C - 1............................................................
Accumulator Chamber Check PAGE C - 1..............................................
STOPPING PAGE C - 2...................................................................
Cold Weather Preservation PAGE C - 2.................................................
GEARBOX TEMPERATURE CHECK PAGE C - 2.............................................
TROUBLESHOOTING - SECTION D PAGE D - 1...............................
PUMP MAINTENANCE AND REPAIR ‐ SECTION E PAGE E - 1..................
STANDARD PERFORMANCE CHART PAGE E - 1...........................................
PARTS LISTS:
Pump Model PAGE E - 3.............................................................
Diaphragm Pot Assembly PAGE E - 5..................................................
Plunger Rod Assembly PAGE E - 7....................................................
Gearbox Assembly PAGE E - 9........................................................

TABLE OF CONTENTS
(continued)
ii
PUMP AND GEARBOX DISASSEMBLY AND REASSEMBLY PAGE E - 10.......................
Suction And Discharge Check Valve Removal PAGE E - 10...............................
Diaphragm Removal PAGE E - 10......................................................
Plunger Rod Removal And Disassembly PAGE E - 11....................................
Gearbox Removal And Disassembly PAGE E - 11........................................
Gearbox Reassembly And Installation PAGE E - 13......................................
Plunger Rod Reassembly And Installation PAGE E - 14...................................
Diaphragm Installation PAGE E - 15....................................................
Suction And Discharge Check Valve Installation PAGE E - 15.............................
LUBRICATION PAGE E - 15...............................................................
Plunger Rod Assembly PAGE E - 15...................................................
Gearbox PAGE E - 16................................................................

D SERIES OM-01490
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 is a D Series, positive displacement pump util
izing a single‐action diaphragm to produce a
straight‐through flow of liquid. The pump is ideally
suited to industrial and contractor's applications
since it will handle liquids ranging from clear water
to construction‐site muck. The basic material of
construction for wetted parts is aluminum, with
neoprene flap valves and diaphragm.
This manual will alert personnel to known proce
dures which require special attention, to those
which could damage equipment, and to those
which could be dangerous to personnel. However,
this manual cannot possibly anticipate and provide
detailed precautions for every situation that might
occur during maintenance of the unit. Therefore, it
is the responsibility of the owner/maintenance per
sonnel to ensure that only safe, established main
tenance procedures are used, and that any proce
dures not addressed in this manual are performed
only after establishing that neither personal safety
nor pump integrity are compromised by such prac
tices.
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]
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.

D SERIES OM-01490
PAGE A - 1WARNINGS
SAFETY‐ SECTION A
This information appllies to D Series ba
sic diaphragm pumps. Gorman‐Rupp
has no control over or particular knowl
edge of the power source which will be
used. Refer to the manual accompany
ing the power source 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. Lock out incoming power to the
power source to ensure that the
pump will remain inoperative.
3. Allow the pump to completely cool
if overheated.
4. Close the discharge valve (if
used).
5. Drain the pump.
This pump is designed to handle non‐
volatile non‐flammable liquids contain
ing specified entrained solids. Do not
attempt to pump volatile, corrosive, or
flammable liquids which may damage
the pump or endanger personnel as a
result of pump failure.
After the pump has been installed, block
the wheels and secure the pump to pre
vent creeping. Make certain that the
pump and all piping or hose connec
tions are tight, properly supported and
secure before operation.
Do not operate the pump without the ec
centric and coupling guards in place
over the rotating parts. Exposed rotat
ing parts can catch clothing, fingers, or
tools, causing severe injury to person
nel.
The gearbox provided on this pump is
designed for operation at 1750 RPM
maximum input speed. If operated at a
higher RPM, pump components may be
destroyed.
Install and operate only an explosion
proof motor in an explosive atmo
sphere. Install, connect, and operate
the motor in accordance with the Na
tional 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
the applicable local code, the National
or local code shall take precedence.

D SERIESOM-01490
PAGE A - 2 WARNINGS
Never install a positive shut‐off valve in the
discharge line; discharge restrictions will
cause excessive friction loss resulting in
overloading and destruction of pump and
drive components. It is strongly recom
mended that unless absolutely necessary,
no positive shut‐off valve be installed in the
suction line; excessive restriction will
cause incomplete filling of the diaphragm
chamber and result in shortened dia
phragm life.

D SERIES OM-01490
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.
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 3D‐B
PREINSTALLATION INSPECTION
The pump assembly was inspected and tested be
fore shipment from the factory. Before installation,
inspect the pump for damage which may have oc
curred during shipment. Check as follows:
a. Inspect the pump for cracks, dents, damaged
threads, and other obvious damage.
b. Check for and tighten loose attaching hard
ware. Since gaskets tend to shrink after dry
ing, check for loose hardware at mating sur
faces.
c. Carefully read all tags, decals, and markings
on the pump assembly, and perform all duties
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 motor have been stored for
more than 12 months, some of the compo
nents or lubricants may have exceeded their
maximum shelf life. These must be inspected
or replaced to ensure maximum pump serv
ice.

OM-01490 D SERIES
PAGE B - 2 INSTALLATION
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.
ELECTRIC MOTOR INSTALLATION
The pump is designed to be flex‐coupled to a 1750
RPM synchronous speed electric motor. The pump
base will accept either a 143T or 145T motor frame.
Be sure the motor to be used meets these specifi
cations and is compatible with the intended appli
cation.
Install and operate only an explosion
proof motor in an explosive atmo
sphere. Install, connect, and operate
the motor in accordance with the Na
tional 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
the applicable local code, the National
or local code shall take precedence.
POSITIONING PUMP
Lifting
Pump unit weights will vary depending on the
mounting and drive provided. Check the shipping
tag on the unit packaging for the actual weight, and
use lifting equipment with appropriate capacity.
Drain the pump and remove all customer‐installed
equipment such as suction and discharge hoses
or piping before attempting to lift existing, installed
units.
The pump assembly can be seriously
damaged if the cables or chains used to lift
and move the unit are improperly wrapped
around the pump.
Mounting
Locate the pump in an accessible place as close as
practical to the liquid being pumped. Level mount
ing is essential for proper operation.
The pump may have to be supported or shimmed
to provide for level operation or to eliminate vibra
tion.
After the pump has been positioned, block the
wheels and secure the pump to prevent creeping.
SUCTION AND DISCHARGE PIPING
Pump performance is adversely effected by in
creased suction lift, discharge elevation, and fric
tion losses. See Page E‐1 to be sure your overall
application allows the 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.
Never pull a line into place by tightening connec
tions at the pump. Lines near the pump must be in
dependently supported to avoid strain on the
pump which could cause excessive vibration and
increased diaphragm and gear train wear. If hose‐
type lines are used, they should have adequate
support to secure them when filled with liquid and
under pressure.

D SERIES OM-01490
PAGE B - 3INSTALLATION
Fixed, Rigid Piping
This pump is equipped with an integral suction ac
cumulator chamber which promotes an efficient
flow of liquid and acts as an air cushion against
shock. Since the air in this chamber will leak away
during pump operation, the air must be replen
ished periodically. To introduce air into the cham
ber, stop the pump and remove the suction accu
mulator plug and integral gasket; this will break
prime and allow the liquid in the chamber to drain
away through the suction line.
If the pump is mounted in a system with fixed, rigid
piping, it is recommended that a flexible connec
tion be installed at or near the suction and dis
charge ports to absorb shock which would other
wise be transmitted through the drive train and
greatly accelerate pump wear.
In a fixed piping installation, properly sized surge
suppressors must be installed in both suction and
discharge lines. If commercial surge suppressors
are not readily available, air chambers may be fab
ricated from pipe as shown in Figure 2.
AIR CHAMBERS
(18 TO 24 INCH LENGTHS OF
6 TO 8 INCH DIAMETER PIPE
WITH WELDED CAPS)
DISCHARGE
CHAMBER
DISCHARGE
FLEXIBLE JOINT FLEXIBLE JOINT
SUCTION
CHAMBER
1/2‐INCH VALVE FOR
RECHARGING AIR
CHAMBER WITH
COMPRESSED AIR
(ALSO ON DISCHARGE
CHAMBER)
SUCTION
NOTE: INSTALL AIR CHAMBERS OFF FLOW LINE TEES
TO AVOID SURFACE TURBULENCE WITHIN CHAMBERS.
Figure 2. Fixed Piping Installation
Note that the air chambers have not been installed
directly in the flow line, but have been installed off
tees to avoid turbulence within the chambers. The
air chambers are fitted with valves to permit intro
duction of small amounts of compressed air to fur
ther dampen shock; this compressed air will leak
away during operation, and should be replaced
from time to time. If the suction chamber floods,
open the suction chamber valve to break prime
and allow the liquid in chamber to drain through
the suction line.
Gauges
If discharge pressure and vacuum suction gauges
are desired, drill and tap the suction and discharge
lines not less than 18 inches (457,2 mm) from the
suction and discharge ports and install the lines.
Installation closer to the pump may result in erratic
readings.

OM-01490 D SERIES
PAGE B - 4 INSTALLATION
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.
NOTE
Maximum pump performance is realized at suction
lifts of 5 feet or less. Use the shortest possible
length of suction hose or piping; lengths of 25 feet
or longer will reduce the capacity of the pump.
It is strongly recommended that no positive shut‐
off valve be installed in the suction line; excessive
restrictions will cause incomplete filling of the dia
phragm chamber and result in short diaphragm
life.
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. The suction line
should not be restricted more than 1 inch below the
nominal suction size.
The use of pipe couplings in the suction line is not
recommended.
Strainers
If a strainer is furnished with the pump, be certain
to use it; any spherical solids which pass through a
strainer furnished with the pump will also pass
through the pump itself.
If a strainer is not furnished with the pump, but is
installed by the pump user, make certain that the
total area of the openings in the strainer is at least
three or four times the cross section of the suction
line, and that the openings will not permit passage
of solids larger than the solids handling capability
of the pump.
This pump is designed to handle up to 2‐1/4 inch
(57,2 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.
DISCHARGE LINES
The discharge line must be the same size
as, or larger than, the suction line. Never in
stall or operate the pump with a discharge
line smaller than the suction; a restricted
discharge line will cause excessive friction
loss resulting in overloading and destruc
tion of pump and drive components.
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
The pump is provided with integral suction and dis
charge check valves.
Never install a positive shut‐off valve in the
discharge line; discharge restrictions will
cause excessive friction loss resulting in
overloading and destruction of pump and
drive components. It is strongly recom

D SERIES OM-01490
PAGE B - 5INSTALLATION
mended that unless absolutely necessary,
no positive shut‐off valve be installed in the
suction line; excessive restriction will
cause incomplete filling of the diaphragm
chamber and result in shortened dia
phragm life.
ALIGNMENT
Before attempting to open or service the
pump:
1. Familiarize yourself with this man
ual.
2. Shut off incoming power to the mo
tor and lock it out to ensure that the
pump will remain inoperative.
3. Allow the pump to completely cool
if overheated.
4. Close the discharge valve (if
used).
5. Drain the pump.
It is imperative that alignment be checked
before the pump is operated.
The pump and gearbox were aligned and secured
at the factory, but fastening hardware may have
loosened during shipment. It is imperative that this
hardware and the alignment be checked after the
pump is installed and before operation. Adjust
ments may be made by loosening the securing
hardware and shifting or shimming components
as required.
This pump is designed to be driven by a flex‐
coupled electric motor.
To check coupling alignment, use a feeler gauge or
taper gauge between the coupling halves every
90_. The coupling is in alignment when the hubs
are the same distance apart at all points.
To check parallel adjustment, lay a straightedge
across both coupling halves at the top, bottom and
sides. The horizontal parallel adjustment is correct
when the straightedge rests evenly on both halves
of the coupling at all points. Use a feeler gauge be
tween the coupling to measure any misalignment.
Do not operate the pump without the ec
centric and coupling guards in place
over the rotating parts. Exposed rotat
ing parts can catch clothing, fingers, or
tools, causing severe injury to person
nel.
ELECTRICAL CONNECTIONS
Before connecting the motor to the incoming pow
er, check that the electrical service available
matches the pump motor requirements stamped
on the motor nameplate.
The pump must be operated in the direc
tion indicated by the arrow on the gearbox
and on the accompanying decals. Reverse
rotation could cause pump components to
be destroyed.
Install and operate only an explosion
proof motor in an explosive atmo
sphere. Install, connect, and operate
the motor in accordance with the Na
tional 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
the applicable local code, the National
or local code shall take precedence.

OM-01490
D 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 handle non‐
volatile non‐flammable liquids contain
ing specified entrained solids. Do not
attempt to pump volatile, corrosive, or
flammable liquids which may damage
the pump or endanger personnel as a
result of pump failure.
After the pump has been installed, block
the wheels and secure the pump to pre
vent creeping. Make certain that the
pump and all piping or hose connec
tions are tight, properly supported and
secure before operation.
Pump application will affect its performance, espe
cially discharge velocities. Consult the Gorman‐
Rupp factory for actual performance levels for the
pump.
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 components are properly lu
bricated (see LUBRICATION in MAINTENANCE
AND REPAIR).
Make certain that any positive shut‐off
valve installed in the suction line is open
before operating the pump; excessive re
striction will cause incomplete filling of the
diaphragm chamber and result in short
ened diaphragm life. No positive shut‐off
valve should be installed in the discharge
line.
STARTING
Consult the operations manual furnished with the
motor before starting the pump. Open any valves
installed in the suction line and start the pump.
Rotation
The correct direction of rotation is indicated by an
arrow on the gearbox accompanying decals. If the
pump is operated in the wrong direction, pump
components may be seriously damaged or de
stroyed since the integral check valves permit flow
in only one direction.
The pump must be operated in the direc
tion indicated by the arrow on the gearbox
and on the accompanying decals. Reverse
rotation could cause pump components to
be destroyed.
If an electric motor is used to drive the pump, re
move V‐belts, couplings, or otherwise disconnect
the pump from the motor before checking motor
rotation. Operate the motor independently while
observing the direction of the motor shaft, or cool
ing fan.
If rotation is incorrect on a three‐phase motor, have
a qualified electrician interchange any two of the
three phase wires to change direction. If rotation is
incorrect on a single‐phase motor, consult the liter
ature supplied with the motor for specific instruc
tions.
OPERATION
The pump is designed to operate at ap
proximately 60 cycles per minute through

OM-01490 D SERIES
OPERATIONPAGE C - 2
a gearbox with A 30:36:1 ratio and a 1750
RPM maximum input drive. Make certain
that the electric motor installed does not
exceed this rpm; otherwise, pump compo
nents may be destroyed.
Priming
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 the motor and
check the suction line for leaks.
OPERATION CHECKS
Gearbox Check
Check that the gearbox is properly lubricated (see
LUBRICATION in MAINTENANCE AND RE
PAIR).
Leakage Check
No leakage should be visible at pump mating sur
faces, connections or fittings. Keep all line connec
tions and fittings tight to maintain maximum pump
efficiency.
Strainer Check
If a suction strainer has been installed, check and
clean it as necessary. It should be cleaned if pump
flow begins to drop. If a vacuum suction gauge has
been installed, monitor and record the readings
regularly to detect strainer blockage.
Accumulator Chamber Check
Check periodically to ensure that there is sufficient
air in the integral suction accumulator chamber.
Replenish as required (see Fixed, Rigid Piping in
Section B for details).
STOPPING
After stopping the pump, shut off incoming power
to the motor and lock it out to ensure that the pump
will remain inoperative.
If the pump will be idle for more than a few hours, or
if it has been pumping liquids containing a large
amount of solids, flush it with clean water.
Cold Weather Preservation
The primary construction materials of this
pump are aluminum, with neoprene flap
valves and diaphragm. Do not attempt to
clean or flush this pump with any liquid
which would attack pump fittings or com
ponents. avoid cleaning with cleaning sol
vent.
In below freezing conditions, drain the water from
the pump and the lines when the pump is not in op
eration. Also, clean out any solids by flushing with a
hose.
GEARBOX TEMPERATURE CHECK
The gearbox runs higher than ambient tempera
tures because of heat generated by friction. Tem
peratures of approximately 200_F (93_C) are con
sidered normal, and can operate intermittently at
250_F (121_C).
Checking gearbox temperatures by hand is inac
curate. Place a contact‐type thermometer against
the housing and record this temperature for future
reference.
A sudden increase in gearbox temperature is a
warning that the bearings are at the point of failing.
Make certain that the bearing lubricant is of the
proper viscosity and at the correct level (see LU
BRICATION in Section E). Bearing overheating
can also be caused by shaft misalignment and/or
excessive 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 within 20 minutes or less.

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP FAILS TO
PRIME
PUMP STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE
D SERIES OM-01490
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 manual.
2. Shut off incoming power to the motor
and lock it out to ensure that the
pump will remain inoperative.
3. Allow the pump to completely cool if
overheated.
4. Close the discharge valve (if used).
5. Drain the pump.
Air leak in suction line. Correct leak.
Lining of suction hose collapsed. Replace suction hose.
Integral suction or discharge check Clean valves, check that flange nuts
valve clogged, binding, or not seating are tight.
properly.
Cracked or broken diaphragm. Replace diaphragm.
Diaphragm not securely in place. Secure diaphragm.
Strainer clogged. Check strainer and clean if necessary.
Air leak in suction line. Correct leak.
Suction intake not properly submerged. Check installation.
Lining of suction hose collapsed. Replace suction hose.
Cracked or broken diaphragm. Replace diaphragm.
Diaphragm not securely in place. Secure diaphragm.
Strainer clogged. Check strainer and clean if necessary.
Integral suction or discharge check Clean valves, check that flange nuts
valve clogged, binding, or not seating are tight.
properly.

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP REQUIRES
TOO MUCH
POWER
PUMP
CLOGS FRE
QUENTLY
EXCESSIVE NOISE
BEARINGS
RUN TOO HOT
OM-01490 D SERIES
TROUBLESHOOTINGPAGE D - 2
Liquid solution too thick. Dilute if possible.
Integral discharge check valve clogged Clean valve.
or binding.
Bearings in motor or gearbox Check bearings.
worn or binding.
Integral suction or discharge check Clean valves, check that flange nuts
valve clogged, binding, or not seating are tight.
properly.
Liquid solution too thick. Dilute if possible.
Pump, gearbox, or motor not Check and tighten mounting bolts.
securely mounted.
Gearbox or motor not properly See LUBRICATION in MAINTE‐
lubricated. NANCE AND REPAIR.
Bearing temperature is high, but within Check bearing temperature regularly
limits. to monitor any increase.
Low or incorrect lubricant. Check for proper type and level of
lubricant.
Drive misaligned. Align drive properly.

D SERIES OM-01490
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.
IN GALLONS PER MINUTE AT 60 STROKES PER MINUTE
STATIC
LIFT
IN FEET
STATIC DISCHARGE HEAD IN FEET
51015 20
578676668
10 73 64 66 62
5964606815
20 64 59 65 59
5660565625
IN LITERS PER MINUTE AT 60 STROKES PER MINUTE
STATIC DISCHARGE HEAD IN METERS
STATIC
LIFT
IN METERS 1,5 3,0 4,6 6,1
1,5 295,2 253,6 249,8 257,4
3,0 276,3 242,2 249,8 234,7
4,6 257,4 227,1 242,2 223,3
6,1 242,2 223,3 246,0 223,3
7,6 212,0 212,0 227,1 212,0
STANDARD PERFORMANCE TEST DATA FOR PUMP MODEL 3D‐B
Based on 70_F (21_C) clear water at sea level
with minimum suction lift, using 3 inch (7,62 cm)
suction hose and 4 inch (10,16 cm) non‐collapsible
discharge hose. Since pump installations are sel
dom identical, your performance may be different
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 a standard production model.
Contact the Gorman‐Rupp Company to verify per
formance or part numbers.
The pump end is designed to operate at
approximately 60 cycles per minute
through a gearbox with a 30.36:1 ratio at a
maximum input speed on 1750 RPM. Make
certain that input speed does not exceed
this RPM. Operation at higher RPM can
cause pump components to be damaged
or destroyed.

D SERIESOM-01490
MAINTENANCE & REPAIRPAGE E - 2
ILLUSTRATION
PARTS PAGE
Figure 1. Pump Model 3D‐B

ITEM
NO.
PART NAME PART
NUMBER
QTY ITEM
NO.
PART NAME PART
NUMBER
QTY
D SERIES OM-01490
MAINTENANCE & REPAIR PAGE E - 3
PARTS LIST
Pump Model 3D‐B
(From S/N 883512 Up)
If your pump serial number is followed by an “N”, your pump is NOT a standard production model. Contact
the Gorman‐Rupp Company to verify part numbers.
1 ECCENTRIC GUARD 38861-501 23200 1
2 NYLOCK CAPSCREW BT0403 15991 1
3 WASHER S157 1
4 LOCK WASHER K04 15991 1
5 LUBRICATION DECAL 38817-066 1
6 G‐R DECAL GR-03 1
7 SNAP RING 5385 1
8 TRADEMARK DECAL 38812-049 1
9 GUARD WARNING DECAL 38816-063 REF
10 GEARBOX ASSY 8981 1
11 COUPLING GUARD 34613-005 15020 1
12 GUARD WARNING DECAL 38816-063 REF
13 COUPLING HALF 24355-035 1
14 COUPLING HALF 24355-037 1
15 SPIDER 24355-262 1
16 KEY N0304 15990 1
17 U-BOLT 5495 15991 2
18 FLANGED HEX NUT 21765-314 4
19 AXLE 4607AD 15990 1
20 SPACE WASHER 5382 15991 4
21 HAIRCLIP PIN 21183-010 4
22 HEX HD CAPSCREW B0403 15991 2
23 FLAT WASHER K04 15991 2
24 FLANGED HEX NUT 21765-310 2
25 BASE 13583 24000 1
26 HEX HD CAPSCREW B0608 15991 5
27 FLANGED HEX NUT 21765-314 5
28 PLUNGER ROD ASSY 5685 1
29 DRAW BAR 5438 15990 1
30 U-BOLT 5495 15991 2
31 FLANGED HEX NUT 21765-314 4
32 SUCTION STICKER 6588AG 1
33 FLAT WASHER K08 15991 4
34 HEX NUT D08 15991 4
35 HEX HD CAPSCREW B0811 15991 4
36 DIAPHRAGM POT ASSY 46475-701 1
37 DIAPHRAGM RING 13582 13010 1
38 TIRE/WHEEL ASSY S752 2
39 DISCHARGE STICKER 6588BJ 1
40 HEX HD CAPSCREW B0604 15991 2
41 LOCKWASHER J06 15991 2
42 HEX HD CAPSCREW B0402-1/2 15991 2
43 T TYPE LOCKWASHER AK04 15991 2
44 FLAT WASHER K04 15991 2
NOT SHOWN:
STRAINER 9026D 24001 1
NAME PLATE 2613BP 13990 1
DRIVE SCREW BM#04-03 15990 4
INSTRUCTION TAG 38817-011 1
INSTRUCTION TAG 38817-031 1
OPTIONAL:
STATIONARY BASE 8283 24000 1
INDICATES PARTS RECOMMENDED FOR STOCK

D SERIESOM-01490
MAINTENANCE & REPAIRPAGE E - 4
ILLUSTRATION
Figure 2. 46475-701 Diaphragm Pot Assembly