GORMAN-RUPP PUMPS GMS1 1/2 User manual

OM-07468-05
September 1, 2022
GORMAN‐RUPP PUMPS
www.grpumps.com
2022 Gorman‐Rupp Pumps Printed in U.S.A.
INSTALLATION, OPERATION,
AND MAINTENANCE MANUAL
ROTARY GEAR PUMP
MODELS
GMS SERIES PUMPS
GMS1 1/2GH3-B /S2

Register your new
Gorman‐Rupp pump online at
www.grpumps.com
Valid serial number and e‐mail address required.
RECORD YOUR PUMP MODEL AND SERIAL NUMBER
Please record your pump model and serial number in the
spaces provided below. Your Gorman‐Rupp distributor
needs this information when you require parts or service.
Pump Model:
Serial Number:

TABLE OF CONTENTS
i
INTRODUCTION PAGE I - 1...................................................
SAFETY - SECTION A PAGE A - 1............................................
INSTALLATION - SECTION B PAGE B - 1.....................................
PUMP MODEL DESIGNATION PAGE B-1..................................................
PREINSTALLATION INSPECTION PAGE B-2................................................
STORAGE PAGE B-2....................................................................
Flushing PAGE B-2..................................................................
PUMP INSTALLATION PAGE B-3..........................................................
Lifting PAGE B-3.....................................................................
Positioning The Pump PAGE B-3......................................................
Mounting PAGE B-3.................................................................
Piping PAGE B-3....................................................................
Strainers PAGE B-4..................................................................
Gauges PAGE B-4...................................................................
Sealing PAGE B-4...................................................................
Valves PAGE B-4....................................................................
Barrier Liquids for Optional Double Lipseal PAGE B-4....................................
ALIGNMENT PAGE B-4..................................................................
Coupled Drives PAGE B-4............................................................
V‐Belt Drives PAGE B-5...............................................................
V‐BELT TENSIONING PAGE B-5..........................................................
General Rules of Tensioning PAGE B-5.................................................
Tension Measurement PAGE B-6......................................................
ELECTRICAL CONNECTIONS PAGE B-7...................................................
OPERATION - SECTION C PAGE C - 1.......................................
PUMP OPERATION PAGE C-1............................................................
PRE‐OPERATION PAGE C-1..............................................................
Before Starting The Pump PAGE C-1...................................................
Checking Pump Rotation PAGE C-1...................................................
STARTING PAGE C-1....................................................................
OPERATION PAGE C-2..................................................................
Liquid Temperature PAGE C-2.........................................................
Overheating PAGE C-2...............................................................
Checking Gauges PAGE C-2..........................................................
Strainer Check PAGE C-2.............................................................
Leakage PAGE C-2..................................................................
PRESSURE RELIEF VALVE ADJUSTMENT PAGE C-3........................................
Cracking Pressure PAGE C-3.........................................................
Complete By‐Pass Pressure PAGE C-3.................................................
STOPPING PAGE C-3....................................................................
TROUBLESHOOTING - SECTION D PAGE D - 1...............................
TROUBLESHOOTING WITH GAUGES PAGE D-1............................................
TROUBLESHOOTING CHART PAGE D-2...................................................
PREVENTIVE MAINTENANCE PAGE D-3...................................................

TABLE OF CONTENTS
(continued)
ii
PUMP MAINTENANCE AND REPAIR - SECTION E PAGE E - 1.................
PARTS KEY:
Typical GMS D, G, J And N Pump Models PAGE E-3.....................................
Typical GMS R Pump Model PAGE E-5.................................................
PUMP DISASSEMBLY PAGE E-6..........................................................
Preparing for Disassembly PAGE E-7..................................................
Pressure Relief Valve (10) PAGE E-7...................................................
Foot Bracket Kit (08) PAGE E-7........................................................
Head/Idler Kit (01/02) PAGE E-7.......................................................
Gland Removal (04N) PAGE E-7.......................................................
Backhead Removal (06) PAGE E-8....................................................
Rotor/Shaft Removal (03) PAGE E-8...................................................
Seal Removal (05) PAGE E-8..........................................................
Housing Assembly (04) PAGE E-8.....................................................
PUMP REASSEMBLY PAGE E-8..........................................................
Cleaning and Inspection PAGE E-8....................................................
Bushing Preparation PAGE E-9........................................................
Housing Assembly (04) PAGE E-9.....................................................
Backhead Kit (06) PAGE E-9..........................................................
Rotor/Shaft Assembly (03) PAGE E-9..................................................
Head/Idler Kit (01/02) PAGE E-10......................................................
Seal Installation (05) PAGE E-10.......................................................
Gland Installation (04N) PAGE E-10....................................................
Foot Bracket Kit (08) PAGE E-10.......................................................
SETTING END CLEARANCE PAGE E-10...................................................
RELIEF VALVE DISASSEMBLY PAGE E-11.................................................
RELIEF VALVE REASSEMBLY PAGE E-12..................................................
Relief Valve (10) Installation PAGE E-13................................................
SEAL APPENDIX - SECTION F PAGE F-1.....................................
Standard Friction Drive And Optional 60A And 61J Mech. Seals PAGE F-1......................
Lip Seal Option 65A PAGE F-3............................................................
Positive Drive (Option 60D) Seal PAGE F-5..................................................
Standard Packing Seal (Option 65) PAGE F-7...............................................
O‐RING APPENDIX - SECTION G PAGE G-1..................................
JACKETED HEAD/BACKHEAD APPENDIX - SECTION H ………………….PAGE H-1
Inlet and Outlet Location …… .PAGE H-1...................................................

OM-04386GMS SERIES
PAGE I-1INTRODUCTION
INTRODUCTION
Thank You for purchasing a Gorman‐Rupp Rotary
Gear Pump. This manual is designed to help you
achieve the best performance and longest life from
your Gorman‐Rupp Rotary Gear pump. Read this
manual carefully to learn how to safely install, op
erate and repair your pump. Failure to do so could
result in personal injury or damage to the pump.
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 provide detailed in
structions and precautions for each specific ap
plication or for every situation that might occur dur
ing maintenance of the unit. Therefore, it is the re
sponsibility of the owner, installer and/or mainte
nance personnel to ensure that applications and/
or maintenance procedures not addressed in this
manual are performed only after establishing that
neither personal safety nor pump integrity are
compromised by such applications or procedures.
In addition to this manual, a separate Parts List is
shipped with the pump. Refer to the Parts List when
ordering parts. If your pump is furnished with a
drive unit, refer to the drive unit manufacturer's in
stallation and operation instructions in the litera
ture accompanying the pump.
These pumps can transfer a wide range of light,
medium, and heavy viscosity liquids, depending
on design and components. Some models are
not recommended for use with water; others
when fitted with specific options, may be used
with water; consult the factory.
If there are any questions regarding the pump or
drive unit which are not covered in this manual or
in other literature accompanying this unit, please
contact your Gorman‐Rupp distributor or the Gor
man‐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]
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 proce
dures which require special attention, to those
which could damage equipment, and to those
which could be dangerous to personnel:
Immediate hazards which will result in
severe personal injury or death. These
instructions describe the procedure re
quired and the injury which will result
from failure to follow the procedure.
Hazards or unsafe practices which
COULD result in severe personal injury
or death. These instructions describe
the procedure required and the injury
which could result from failure to follow
the procedure.
Hazards or unsafe practices which COULD
result in minor personal injury or product or
property damage. These instructions de
scribe the requirements and the possible
damage which could result from failure to
follow the procedure.
NOTE
Instructions to aid in installation, operation, and
maintenance or which clarify a procedure.

GMS SERIESOM-04386
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
distributor needs this information when you require
parts or service.
Pump Model:
Serial Number:

OM-07468-05GMS SERIES
SAFETY PAGE A-1
SAFETY - SECTION A
This information is specific to Gorman‐Rupp GMS
Series Rotary Gear Pumps. It applies throughout
this manual and any manual or literature ac
companying the pump.
In addition to this manual, see the separate litera
ture covering the drive unit used to operate this
pump.
Pumps and related equipment must be in
stalled and operated according to all na
tional, local and industry standards.
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 not addressed in this
manual are performed only after estab
lishing that neither personal safety nor
pump integrity are compromised by
such applications or procedures.
Before attempting to install, operate, or
service this pump, familiarize yourself
with this manual, and with all other liter
ature shipped with the pump. Unfamil
iarity with all aspects of pump operation
covered in this manual could lead to de
struction of equipment, injury, or death.
The standard version of this pump is de
signed to handle a wide range of light,
medium, and heavy viscosity liquid, de
pending on design and components,
and a range of temperatures when fitted
with different seals. Do not apply at
higher temperatures than the seal will
handle. Do not attempt to pump liquids
which may damage the pump or endan
ger personnel as a result of pump fail
ure; consult the factory for chemical
compatibility.
If the pump and motor are furnished
mounted on a base, make certain that all
lifting devices have adequate capacity.
If chains or cables are used in lifting,
make certain that they are positioned so
as not to damage components, and so
that the load will be balanced.
After the pump has been installed, make
certain that the pump and all piping or
hose connections are secure before op
eration. Loose connections can result in
damage to the equipment and serious
injury to personnel.
Never operate the pump without a pres
sure relief valve installed on the pump
or in the discharge piping. Make certain
that pump‐mounted pressure relief

GMS SERIESOM-07468-05
PAGE A-2 SAFETY
valves are installed with their adjusting
ends toward the suction port. If bi‐rota
tional operation is required, a pressure
relief device must be provided for both
directions of flow. Operation without a
pressure relief valve or with an improp
erly installed relief valve could cause
the pump to explode, resulting in seri
ous injury or death to personnel.
Before attempting to open or service the
pump:
1. Familiarize yourself with this man
ual.
2. Lock out incoming power to the
drive unit to ensure that the pump
will remain inoperative.
3. Allow the pump to completely cool
if overheated.
4. Close the discharge and suction
valve (if used).
An overheated pump can cause severe
burns and injury. If overheating occurs:
1. Stop the pump immediately.
2. Allow the pump to completely cool.
3. Refer to the instructions in this
manual before restarting the
pump.
Do not remove plates, covers, gauges,
pipe plugs or fittings from an over
heated pump. Vapor pressure within the
pump can cause parts being disen
gaged to be ejected with great force. Al
low the pump to completely cool before
servicing.
Do not operate this pump without
guards in place over the rotating parts.
Exposed rotating parts can catch cloth
ing, fingers or tools, causing severe in
jury to personnel.
This pump may be used to handle liq
uids which may cause serious illness or
injury through direct exposure or
emitted fumes. Wear protective cloth
ing, such as rubber gloves, face mask
and rubber apron, as necessary, before
disconnecting or servicing the pump or
piping.

GHC SERIES OM-07468-05
PAGE B-1INSTALLATION
INSTALLATION - SECTION B
Review all SAFETY information in Section A.
Pumps and related equipment must be in
stalled and operated according to all na
tional, local and industry standards.
Since pump installations are seldom identical, this
section is intended only to summarize general rec
ommendations and practices required to inspect,
position, and arrange the pump and piping. If there
are any questions concerning your specific instal
lation, contact your Gorman‐Rupp distributor or
the Gorman‐Rupp Company.
Most of the information applies to a flooded suction
installation where liquid is supplied under pres
sure.
If the pump is positioned above the liquid in a static
lift installation, information such as mounting, pip
ing configuration and priming must be tailored to
specific conditions.
These pumps are not recommended for
use with water. Some models, when fitted
with specific options, may be used with wa
ter; consult the factory.
PUMP MODEL DESIGNATION
Following is a description of the model numbering
system for Gorman‐Rupp rotary gear pumps.
Rotary gear pump model numbers include design
style, port size, hydraulic size and construction
code.
Typical Pump Model
GHS 1 1/2 GF 32
Design
Style
Port
Size
Hydraulic
Size
Construction
Code
Design Style: Gorman‐Rupp rotary gear pumps
are available in five basic designs:
GMC - Medium Duty - Compact
GMS - Medium Duty
GHC - Heavy Duty - Compact
GHS - Heavy Duty
GHA - Abrasive Duty
Port Size: Gorman‐Rupp rotary gear pumps are
available in port sizes from 1 to 6 inches, depend
ing on the design style. Consult your Gorman‐
Rupp distributor or the factory for additional sizes.
Hydraulic Size: The first letter in the hydraulic size
is a rotor diameter code. The second letter indi
cates tooth length.
Construction Code: Construction Codes for Gor
man‐Rupp rotary gear pumps are as follows:
Code Description
3 Iron w/Mechanical Seal(s)
4 Iron w/Packing or Lip Seal(s)
9 316 SST w/Mechanical Seal(s)
10 316 SST w/Packing or Lip Seal(s)
32 Steel w/Mechanical Seal(s)
38 Steel w/Packing or Lip Seal(s)
Theoretical Displacement: Table B‐1 indicates
theoretical displacement values for each hydraulic
size.
NOTE
Actual capacities and recommended shaft speeds
vary according to application. Consult your Gor
man‐Rupp distributor or the factory for addtional in
formation.

GMS SERIES
OM-07468-05
PAGE B-2 INSTALLATION
Table B‐1. Theoretical Displacement
Hydraulic
Size
Theoretical Displacement
Per Revolution
Gallons Centimeters3
DC 0.00568 21.486
DE 0.00704 26.646
GC 0.00967 36.619
GF 0.01405 53.186
GH 0.01915 72.479
GJ 0.02317 87.700
JG 0.03579 135.49
JJ 0.05159 195.28
JL 0.07078 267.94
JP 0.10078 381.48
NK 0.10665 403.71
NM 0.14173 536.51
NP 0.17681 669.31
RM 0.24030 909.65
RP 0.29979 1134.8
RR 0.35927 1360.0
RS 0.41876 1585.1
SR 0.65752 2489.0
SU 1.10240 4173.2
TU 1.91280 7240.7
PREINSTALLATION INSPECTION
The pump assembly was inspected and tested be
fore shipment from the factory. Before installation,
check for damage which may have occurred dur
ing shipment. Check as follows:
a. Inspect the pump assembly for cracks, dents,
damaged threads, and other obvious dam
age.
b. Check for loose attaching hardware. Since
gaskets tend to shrink after drying, check for
loose hardware at the mating surfaces.
c. Carefully read all tags, decals, and markings
on the pump assembly, and perform all duties
indicated.
STORAGE
Due to the extreme close machining toler
ances within rotary gear pumps, proper
storage before installation is essential to
prevent damage to the pump.
If the pump will not be immediately installed, follow
these procedures or damage to the pump will oc
cur.
a. Do not flush the pump. Ensure that the port
plugs shipped with the pump remain in place
until piping is installed to help prevent dust or
other foreign objects from entering the pump.
b. Pumps that will not be installed for an ex
tended period should be stored indoors if
possible. The factory‐installed port plugs will
not ensure protection from excessive humid
ity, splash water or rain. In very humid or wet
conditions, install air‐tight plugs in the ports
and fill the pump completely with a lubricating
preservative liquid that is compatible with the
liquid to be pumped.
c. Pumps stored outdoors must be fully pre
served as described above, completely cov
ered with plastic or other water‐tight material,
and the covering anchored to ensure that it
will not be blown off.
Flushing
Clean piping is essential because of close‐
tolerance moving parts in this pump. Flush
all dirt, grit, weld beads or scale from the
suction piping before installing the pump.
Damage to the pump because of debris in
the suction line is not covered by the pump
warranty.
The pump may have been tested using a petro
leum‐based preservative, or a preservative may
have been used for long‐term storage of the pump.
If flushing is required, do not do so until just before
installation; the test oil protects close‐tolerance
pump parts from corrosion.
Most cleaning solvents are toxic and
flammable. Use them only in a well ven
tilated area free from flame, sparks, and
excessive heat. Read and follow all pre
cautions printed on solvent containers.