Gormann-Rupp Pumps GRP33-07 Application guide

GL‐00073‐03
July 15, 1986
Rev. T 06-30-20
GORMAN‐RUPP PUMPS
www.grpumps.com
e1986 Gorman‐Rupp Pumps Printed in U.S.A.
INSTALLATION, OPERATION,
AND MAINTENANCE MANUAL
WITH PARTS LIST
AUTOMATIC AIR RELEASE VALVES
MODELS
GRP33-07 GRP33-07A GRP33-07B GRP33-07C
GRP33-07D GRP33-07E GRP33-07F GRP33-07G
GRP33-07H GRP33-07J GRP33-07K GRP33-07L
GRP33-07M GRP33-07N GRP33-07P GRP33-07R
GRP33-07S GRP33-07T

Register your new
Gorman‐Rupp pump online at
www.grpumps.com/register.
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....................................
PREINSTALLATION INSPECTION PAGE B - 1............................................
AIR RELEASE VALVE INSTALLATION PAGE B - 1........................................
OPERATION - SECTION C PAGE C - 1......................................
THEORY OF OPERATION PAGE C - 1...................................................
ADJUSTMENT PAGE C - 2............................................................
LEAKAGE PAGE C - 2................................................................
TROUBLESHOOTING - SECTION D PAGE D - 1..............................
MAINTENANCE AND REPAIR - SECTION E PAGE E - 1.......................
AIR RELEASE VALVE CONSTRUCTION AND APPLICATION CHART PAGE E - 1.............
PARTS LISTS:
GRP33-07, 07A, 07B, 07J, 07K, 07M And 07P Air Release Valves PAGE E - 3...........
GRP33-07C, 07D, 07E And 07F Air Release Valves PAGE E - 5........................
GRP33-07G, 07H, 07L, 07N, 07R And 07T Air Release Valves PAGE E - 7...............
AIR RELEASE VALVE DISASSEMBLY AND REASSEMBLY PAGE E - 8......................
Air Release Valve Disassembly PAGE E - 9...........................................
Air Release Valve Reassembly PAGE E - 9...........................................
Lubrication PAGE E - 11............................................................

G‐R OM-00073
PAGE I - 1INTRODUCTION
INTRODUCTION
Thank You for purchasing a Gorman‐Rupp Auto
matic Air Release Valve. Read this manual careful
ly to learn how to safely install and operate your
pump. Failure to do so could result in personal inju
ry or damage to the pump.
Because pump installations are seldom identical,
this manual cannot possibly provide detailed in
structions and precautions for every aspect of
each specific application. Therefore, it is the re
sponsibility of the owner/installer of the pump to
ensure that applications not addressed in this
manual are performed only after establishing that
neither operator safety nor pump integrity are com
promised by the installation. Pumps and related
equipment must be installed and operated ac
cording to all national, local and industry stan
dards.
If there are any questions regarding the pump or
its application which are not covered in this man
ual or in other literature accompanying this unit,
please contact your Gorman‐Rupp distributor, or
The Gorman‐Rupp Company:
The Gorman‐Rupp Company
P.O. Box 1217
Mansfield, Ohio 44901-1217
Phone: [phone]
or:
Gorman‐Rupp of Canada Limited
70 Burwell Road
St. Thomas, Ontario N5P 3R7
Phone: [phone]
HAZARD AND INSTRUCTION
DEFINITIONS
The following are used to alert maintenance per
sonnel to procedures which require special atten
tion, to those which could damage equipment, and
to those which could be dangerous to personnel:
Immediate hazards which WILL result in
severe personal injury or death. These
instructions describe the procedure re
quired and the injury which will result
from failure to follow the procedure.
Hazards or unsafe practices which
COULD result in severe personal injury
or death. These instructions describe
the procedure required and the injury
which could result from failure to follow
the procedure.
Hazards or unsafe practices which COULD
result in minor personal injury or product
or property damage. These instructions
describe the requirements and the possi
ble damage which could result from failure
to follow the procedure.
NOTE
Instructions to aid in installation, operation, and
maintenance or which clarify a procedure.

G‐R GL-00073
PAGE A - 1SAFETY
SAFETY - SECTION A
This information applies to Gorman‐
Rupp Automatic Air Release Valves. Re
fer to the manual accompanying the
pump and power source before at
tempting 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 installing the Automatic Air Re
lease Valve, check the chemical com
patibility of the valve components with
the liquid being pumped. For applica
tions involving volatile, flammable or
corrosive liquids, use a stainless steel
valve fitted with an optional fluorocar
bon (DuPont Vitonror equivalent) dia
phragm (see the Parts Lists in Section
E). Misapplication of materials could re
sult in damage to the valve and/or dan
ger to personnel as a result of valve fail
ure.
Before attempting to service the Air Re
lease Valve:
1. Familiarize yourself with this man
ual.
2. Disconnect or lock out the power
source to ensure that the pump will
remain inoperative.
3. Allow the pump and liquid to com
pletely 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.
If the application involves volatile, cor
rosive or hazardous liquids, wear pro
tective safety equipment, such as
goggles, rubber gloves and apron when
servicing the pump or Automatic Air Re
lease Valve.
If the application involves petroleum
products such as fuel oil or gasoline,
provide adequate ventilation, prohibit
smoking, and wear static‐resistant
clothing and shoes before servicing the
Automatic Air Release Valve. Clean up
all fuel spills immediately after occur
ence.
Some leakage (1 to 5 gallons[3,8 to 19 li
ters] per minute) will occur when the
valve is fully closed. Be sure the bleeder
line is directed back to the wet well or
tank to prevent hazardous spills.
Do not use fingers to move the plunger
rod or to check spring compression
while the pump is operating. Sudden re
lease of spring tension could pinch fin
gers or seriously injure personnel.

GL-00073G‐R
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 and install the Auto
matic Air Release Valve. Refer to the literature ac
companying the pump or contact the factory for
specific pump installation instructions. Refer to
MAINTENANCE AND REPAIR, Section E in this
manual for disassembly and reassembly of the Au
tomatic Air Release Valve.
PREINSTALLATION INSPECTION
The Automatic Air Release Valve was fully as
sembled and inspected before shipment from the
factory. Before installation, inspect the valve for
damage which may have occurred during ship
ment. Check as follows:
a. Inspect the valve for cracks, dents, damaged
threads, and other obvious damage.
b. Check for and tighten loose attaching hard
ware at mating surfaces.
c. Check the plunger rod for free movement by
compressing the spring with an appropriate
tool. Note the color code on the spring for fu
ture reference.
d. If the valve has been in stock for over 1 year,
re‐lubricate the shaft as indicated in LU
BRICATION, Section E.
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 B-1).
NOTE
If the Air Release Valve is to be installed on a staged
pump application, contact the factory for specific
installation instructions.
DISCHARGE PIPE
DISCHARGE
CHECK VALVE
PUMP DISCHARGE
SELF‐PRIMING
CENTRIFUGAL
PUMP
SUCTION
LINE
SUPPORT
BRACKET
CLEAN‐OUT
COVER
INSTALL AIR RELEASE VALVE
IN HORIZONTAL POSITION
90_LONG
RADIUS
ELBOW
WET WELL
OR SUMP
BLEED LINE 1”
(25,4 MM) DIA. MIN.
(CUSTOMER FUR
NISHED) DO NOT EX
TEND BELOW PUMP
OFF LIQUID LEVEL
Figure B-1. Typical Automatic Air Release Valve Installation

GL-00073 G‐R
PAGE B - 2 INSTALLATION
The valve inlet line must be installed between the
pump discharge port and the non‐pressurized side
of the discharge check valve. The valve inlet is at
the large end of the valve body, and is provided
with standard 1‐inch NPT pipe threads.
The valve outlet is located at the opposite end of
the valve, and is also equipped with standard
1‐inch NPT pipe threads. The outlet should be con
nected to a bleed line which slopes back to the wet
well or sump. The bleed line must be the same size
as the inlet piping, or larger. If piping is used for the
bleed line, avoid the use of elbows whenever pos
sible.
NOTE
It is recommended that each Air Release Valve be
fitted with an independent bleeder line directed
back to the wet well. If multiple Air Release Valves
are installed in a system, they must be fitted with in
dependent bleeder lines; never use a common
manifold pipe. Contact your Gorman‐Rupp dis
tributor or the Gorman‐Rupp Company for informa
tion about installation of an Automatic Air Release
Valve for your specific application.
If the liquid to be pumped contains large entrained
solids, grease or other substances likely to cause
clogging, use smooth‐bore hose at least one size
larger than the outlet. Air and liquid vented during
the priming process will agitate the hose, loosen
ing any build‐up, greatly reducing the chance of
clogging.
A bypass line returned to a wet well could
be drawn into the pump suction inlet,
which could result in damage to the sys
tem. Secure the bypass line to prevent this
from occurring.
It is recommended that pipe unions be installed at
the valve inlet, and at each 90_elbow to ease dis
assembly and maintenance. A shut‐off valve may
be installed before the valve inlet to allow the Air
Release Valve to be removed for service while the
pump remains in operation.
If the Air Release Valve is installed on a
pump with a flooded suction (such as a
below ground lift station), a pipe union and
shut‐off valve must be installed in the
bleed line to eliminate the possibility of
flooding the station while servicing the Air
Release Valve.
If a manual shut‐off valve is installed anywhere in
the air release piping, it must be a full‐opening,
ball‐type valve to prevent plugging by solids.
Any shut‐off valve installed in a bypass
line must not be left closed during oper
ation. A closed manual shut‐off valve
may cause a pump which has lost prime
to continue to operate without reaching
prime, causing dangerous overheating
and possible explosive rupture of the
pump casing. Personnel could be se
verely injured.
Allow an over‐heated pump to com
pletely cool before servicing. Do not re
move plates, covers, gauges, or fittings
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 with great force. Af
ter the pump cools, drain the liquid from
the pump by removing the casing drain
plug. Use caution when removing the
plug to prevent injury to personnel from
hot liquid.

G‐R GL-00073
OPERATION PAGE C - 1
OPERATION - SECTION C
THEORY OF OPERATION
Review all SAFETY information in Section A.
A self‐priming centrifugal pump will not prime if
there is sufficient static liquid head to hold the dis
charge check valve closed. Self‐priming pumps
are not air compressors. During the priming cycle,
air from the suction line must be vented to atmos
phere on the discharge side. It is therefore neces
sary to open the discharge side of the pump to at
mospheric pressure and allow the air to bleed off
during ther priming cycle. If the bleed line is not
closed after the pump is primed, liquid would be
forced back to the wet well under the full working
pressure of the pump. This wasteful recirculation of
liquid is controlled by the Automatic Air Release
Valve.
When properly installed and correctly adjusted to
the specific hydraulic operating conditions, the Au
tomatic Air Release Valve will permit air to escape,
and will close automatically when the pump is fully
primed and pumping at full capacity.
Figures C-1 and C-2 show a cross‐sectional view
of the valve, and a corresponding description of
operation.
Air from the pump casing passes through the valve
to the wet well during the priming cycle (Figure
C-1).
É
É
É
Figure C-1. Valve in Open Position
When the pump is fully primed, pressure resulting
from flow against the valve diaphragm com
presses the spring and closes the valve (Figure
C-2). The valve will remain closed, reducing the
bypass of liquid to 1 to 5 gallons (3,8 to 19 liters) per
minute, until the pump loses its prime or stops.
Some leakage (1 to 5 gallons [3,8 to 19
liters] per minute) will occur when the
valve is fully closed. Be sure the bypass
line is directed back to the wet well or
tank to prevent hazardous spills.
É
É
É
É
Figure C-2. Valve in Closed Position
When the pump shuts down, the spring returns the
diaphragm to its original position. Any solids that
may have accumulated in the diaphragm chamber
settle to the bottom and are flushed out during the
next priming cycle.
NOTE
The valve will remain open until the total dynamic
discharge head exceeds the static discharge head.
The range of the valve closing pressure is estab
lished by the tension rate of the spring as ordered
from the factory. Valve closing pressure can be fur
ther adjusted to satisfy system requirements by
moving the spring retaining pin up or down the
plunger rod to increase or decrease tension on the
spring. Contact your Gorman‐Rupp distributor or
the Gorman‐Rupp Company for additional informa
tion.

G‐RGL-00073
OPERATIONPAGE C - 2
AIR RELEASE VALVE CONSTRUCTION
AND APPLICATION DATA
Refer to the table on page E-1 for Air Release
Valve Construction and Application Data
ADJUSTMENT
The valve closing pressure within the ranges indi
cated in Table E-1 can be adjusted by increasing
or decreasing the spring tension on the plunger
shaft while the Air Release Valve is in the Open
position. This can be accomplished by moving the
pin in the spring centering washer either up or
down the plunger rod. Five holes are provided for
adjusting the spring tension. An optional spring
compression tool, G‐R part number 48781-003,
will ease spring adjustment.
Do not use fingers to move the plunger
rod or to check spring compression
while the pump is operating. Sudden re
lease of spring tension could pinch fin
gers or seriously injure personnel.
With the pin located in the hole nearest the dia
phragm, the valve will close at the minimum dis
charge head (pressure) for that particular spring.
With the pin located in the hole farthest from the di
aphragm, the valve will close at the maximum dis
charge head (pressure) for that spring. Adjust
ment is correct when the valve closes as the dis
charge check valve opens during pumping. The
valve will stay closed during the pumping cycle un
less the pump loses its prime.
Depending on the frequency of operation and the
initial spring tension, the valve plunger may even
tually stick or operate erratically. If this occurs, re
move the inspection plate on the valve cover and
check for debris that may be clogging the dia
phragm. Refer to Lubrication in MAINTENCNCE
AND REPAIR.
LEAKAGE
All Automatic Air Release Valves have a slight index
channel machined into the end of the plunger rod.
This index acts as a pressure relief to prevent the
valve from becoming hydraulically locked when
the pump is shut down. This happens most often in
a closed system where the Air Release Valve is iso
lated in the piping system by suction and dis
charge flap valves.
The pressure relief index releases the plunger rod
by allowing liquid to drain out of the valve and back
to the wet well during shutdown. As a result, some
leakage (1 to 5 gallons [3,8 to 19 liters] per minute)
will occur during both priming and pump opera
tion. If greater leakage occurs, the valve may not
be completely closing (see ADJUSTMENT in this
section).

G‐R GL-00073
TROUBLESHOOTING PAGE D - 1
TROUBLESHOOTING - SECTION D
Review all SAFETY information in Section A.
Before attempting to service the Air Re
lease Valve:
1. Familiarize yourself with this manual.
2. Lock out or disconnect the power
source to ensure that the pump will
remain inoperative.
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 pump slowly and cautiously.
7. Drain the pump.
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
VALVE FAILS
TO CLOSE
Inlet line to valve clogged. Clean inlet line.
Spring tension incorrect. Select spring and/or adjust tension
based on discharge head condi
tions (see Table E-1).
Pump not producing designed flow ca
pacity or discharge head.
Operate pump at designed
speed. Refer to literature accom
panying pump.
Plunger rod movement restricted by
debris.
Disassemble and clean valve.
Plunger rod needs lubrication. Lubricate rod as indicated in
LUBRICATION, Section E.
VALVE BODY
LEAKS
Rubber diaphragm loose or damaged. Tighten hardware at body flange or
replace diaphragm.
Worn lip seal or leaking O‐ring. Replace worn parts.

GL-00073 G‐R
TROUBLESHOOTINGPAGE D - 2
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
Valve hydraulically locked. Introduce air behind suction check
valve. Clean index channel at end
of plunger rod.
Spring tension incorrect. Select spring and adjust tension
based on discharge head condi
tions (See Table E-1).
Plunger rod movement restricted by
debris.
Disassemble and clean valve.
VALVE FAILS TO
OPEN Plunger rod needs lubrication. Lubricate rod as indicated in
LUBRICATION, Section E.
Bleed line or diaphragm cavity
clogged.
Clean bleed line (particularly at 90_
elbows). Remove inspection cover
and clean diaphragm cavity.

G‐R GL-00073
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 provide general recommendations and
practices for preventive maintenance. Regardless
of the application however, following a routine pre
ventive maintenance schedule will help assure
trouble‐free performance and long life from your
Gorman‐Rupp pump. For specific questions con
cerning your application, contact your Gorman‐
Rupp distributor or the Gorman‐Rupp Company.
Record keeping is an essential component of a
good preventive maintenance program. Changes
in suction and discharge gauge readings (if so
equipped) between regularly scheduled inspec
tions can indicate problems that can be corrected
before system damage or catastrophic failure oc
curs. The appearance of wearing parts should also
be documented at each inspection for comparison
as well. Also, if records indicate that a certain part
(such as the seal) fails at approximately the same
duty cycle, the part can be checked 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 inspec
tions 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*

GL-00073
G‐R
MAINTENANCE & REPAIR PAGE E - 1
MAINTENANCE AND REPAIR - SECTION E
MAINTENANCE AND REPAIR OF THE AUTOMATIC AIR RELEASE VALVE WILL MAINTAIN PEAK
OPERATING PERFORMANCE.
VALVE
PART
NUMBER
C. I. CONSTRUCTION SST CONSTRUCTION
RED SPRING
10# COMP
4‐17 FT.
DISCH. HEAD
GRP33-07
GRP33-07A
GRP33-07B
GRP33-07C
GRP33-07D
GRP33-07E
GRP33-07G
GRP33-07H
GRP33-07J
X
X
X
X
X
X
X
X
X
GRP33-07K X
GRP33-07L X
GRP33-07M X
NO PAINT
25# COMP
18‐49 FT.
DISCH. HEAD
BLACK SPRING
80# COMP
50 FT. +
DISCH. HEAD
RED SPRING
10# COMP
4‐17 FT.
DISCH. HEAD
NO PAINT
25# COMP
18‐49 FT.
DISCH. HEAD
BLACK SPRING
80# COMP
50 FT. +
DISCH. HEAD
GRP33-07N
GRP33-07P
X
X
GRP33-07F X
GRP33-07R X
GRP33-07S X
GRP33-07T X
Table E-1. Air Release Valve Construction and Application Data
Before installing the Automatic Air Re
lease Valve, check the chemical com
patibility of the valve components with
the liquid being pumped. For applica
tions involving volatile, flammable or
corrosive liquids, use a stainless steel
valve fitted with an optional fluorocar
bon (DuPont Vitonror equivalent) dia
phragm (see the Parts Lists in Section
E). Misapplication of materials could re
sult in damage to the valve and/or dan
ger to personnel as a result of valve fail
ure.

GL-00073 G‐R
MAINTENANCE & REPAIRPAGE E - 2
ILLUSTRATION
PARTS PAGE
Figure 1. GRP33-07, GRP33-07A, GRP33-07B GRP33-07J, GRP33-07K,
GRP33-07M And GRP33-07P Air Release Valves

GL-00073
G‐R
MAINTENANCE & REPAIR PAGE E - 3
PARTS LIST
GRP33-07, GRP33-07A And GRP33-07B Air Release Valves
This Parts List Represents Bill of Material Issue 3 For These Valves
GRP33-07J, GRP33-07K, GRP33-07M And GRP33-07P Air Release Valves
This Parts List Represents Bill of Material Issue 1 For These Valves
ITEM
NO. PART NAME PART NUMBER QTY
1 INSPECTION COVER 38346-610 10010 1
2 OUTER DIAPHRAGM WASHER 31711-029 17270 1
3NYLON LOCK NUT BC08 17000 1
4GRP33-07, 07A, 07B, 07J, 07M, 07P 25152-152 1
INSPECTION COVER O‐RING
GRP33-07K INSPECTION COVER O‐RING 25150-412 1
5 VALVE COVER 38346-609 10010 1
6 HEX HD CAPSCREW B0605 15991 6
7 HEX NUT DO6 15991 8
8 HEX HD CAPSCREW B0604 15991 6
9 LOCKWASHER J06 15991 6
10 HEX HD CAPSCREW B0611 15991 2
11 GREASE FITTING S186 1
12 PIPE PLUG P02 15079 1
13 INNER DIAPHRAGM WASHER 31711-030 15180 1
14 OIL SEAL 25225-025 1
15 SPRING ADJUSTING PIN 21154-709 1
16 VALVE BODY 38344-004 10010 1
17 GRP33‐07, GRP33‐07A, GRP33‐07B O‐RING S816 1
GRP33‐07J, GRP33‐07M, GRP33‐07P O‐RING 25154-214 1
GRP33-07K O‐RING 25150-413 1
18 PLUNGER ROD 31612-001 17038 1
19 GRP33-07A, 07M SPRING (10# COMPRESS) 38571-715 17110 1
GRP33-07, 07K, 07P SPRING (25# COMP) 38571-610 17110 1
GRP33-07B, 07J SPRING (80# COMPRES) 38571-717 17110 1
20 SPRING RETAINING WASHER 31514-007 17030 1
21 GRP33-07, 07A, 07B DIAPHRAGM 38676-404 19260 1
GRP33-07J, 07M, 07P DIAPHRAGM 38676-404 19510 1
GRP33-07K DIAPHRAGM 38676-404 19570 1
OPTIONAL:
SPRING COMPRESSION TOOL 48781-003 1
INDICATES PARTS RECOMMENDED FOR STOCK

GL-00073 G‐R
MAINTENANCE & REPAIRPAGE E - 4
ILLUSTRATION
Figure 2. GRP33-07C, GRP33-07D, GRP33-07E And GRP33-07F Air Release Valves

GL-00073
G‐R
MAINTENANCE & REPAIR PAGE E - 5
PARTS LIST
GRP33-07C, GRP33-07D, GRP33-07E And GRP33-07F Air Release Valves
This Parts List Represents Bill of Material Issue 2 For These Valves
ITEM
NO. PART NAME PART NUMBER QTY
1 INSPECTION COVER 38346-610 17070 1
2 OUTER DIAPHRAGM WASHER 31711-029 1
3NYLON LOCK NUT BC08 17040 1
4INSPECTION COVER O‐RING 25152-152 1
5 VALVE COVER 38346-609 17070 1
6 HEX HD CAPSCREW B0605 17090 6
7 HEX NUT D06 17090 8
8 HEX HD CAPSCREW B0604 17090 6
9 LOCKWASHER J06 17090 6
10 HEX HD CAPSCREW B0611 17090 2
11 GREASE FITTING 26711-003 1
12 PIPE PLUG P02 17090 1
13 INNER DIAPHRAGM WASHER 31711-030 1
14 OIL SEAL 25225-025 1
15 SPRING ADJUSTING PIN 21154-709 1
16 VALVE BODY 38344-004 17070 1
17 O‐RING S816 1
18 PLUNGER ROD 31612-001 17048 1
19 GRP33-07D SPRING (10# COMPRESSION) 38571-715 17110 1
GRP33-07C SPRING (25# COMPRESSION) 38571-610 17110 1
GRP33-07E, 07F SPRING (80# COMPRES) 38571-717 17110 1
20 SPRING RETAINING WASHER 31514-007 17030 1
21 GRP33-07C, 07D, 07E, 07F DIAPHRAGM 38676-404 19260 1
OPTIONAL:
SPRING COMPRESSION TOOL 48781-003 1
INDICATES PARTS RECOMMENDED FOR STOCK

GL-00073 G‐R
MAINTENANCE & REPAIRPAGE E - 6
ILLUSTRATION
Figure 3. GRP33-07G, GRP33-07H, GRP33-07L, GRP33-07N, GRP33-07R,
GRP33-07S AND GRP33-07T Air Release Valves

GL-00073
G‐R
MAINTENANCE & REPAIR PAGE E - 7
PARTS LIST
GRP33-07G, GRP33-07H, GRP33-07L, GRP33-07N, GRP33-07R,
GRP33-07S And GRP33-07T
Air Release Valves
This Parts List Represents Bill of Material Issue 1 For These Valves
ITEM
NO. PART NAME PART NUMBER QTY
1 INSPECTION COVER 38346-610 17070 1
2 OUTER DIAPHRAGM WASHER 31711-029 1
3NYLON LOCK NUT BC08 17040 1
4GRP33-07G, 07H, 07R INSPECT CVR O‐RING 25158-658 1
GRP33-07L, 07N, 07T INSPECT CVR O‐RING 25154-152 1
GRP33-07S INSPECTION COVER O‐RING 25150-412 1
5 VALVE COVER 38346-609 17070 1
6 HEX HD CAPSCREW B0605 17090 6
7 HEX NUT D06 17090 8
8 HEX HD CAPSCREW B0604 17090 6
9 LOCKWASHER J06 17090 6
10 HEX HD CAPSCREW B0611 17090 2
11 GREASE FITTING 26711-003 1
12 PIPE PLUG P02 17090 1
13 INNER DIAPHRAGM WASHER 31711-030 1
14 OIL SEAL 25225-025 1
15 SPRING ADJUSTING PIN 21154-709 1
16 VALVE BODY 38344-004 17070 1
17 GRP33-07G, 07H O‐RING 25150-918 1
GRP33-07L, 07N, 07T O‐RING 25154-214 1
GRP33-07S O‐RING 25150-413 1
18 PLUNGER ROD 31612-001 17048 1
19 GRP33-07H, 07N, 07S SPRING (25# COMP) 38571-610 17110 1
GRP33-07G, 07L SPRING (80# COMP) 38571-717 17110 1
GRP33-07R, 07T SPRING (10# COMP) 38571-715 17110 1
20 SPRING RETAINING WASHER 31514-007 17030 1
21 GRP33-07G, 07H, 07R DIAPHRAGM 38676-404 19400 1
GRP33-07L, 07N, 07T DIAPHRAGM 38676-404 19510 1
GRP33-07S DIAPHRAGM 38676-404 19570 1
NOT SHOWN:
CAP PLUG 25141-151 1
OPTIONAL:
SPRING COMPRESSION TOOL 48781-003 1
INDICATES PARTS RECOMMENDED FOR STOCK

GL-00073 G‐R
MAINTENANCE & REPAIRPAGE E - 8
AIR RELEASE VALVE DISASSEMBLY
AND REASSEMBLY
Review all SAFETY information in Section A.
Gorman‐Rupp Automatic Air Release Valves re
quire little service due to their rugged, minimum‐
maintenance design. However, if it becomes nec
essary to replace parts, follow these instructions
which are keyed to the sectional views (Figures 1, 2
or 3) and the accompanying parts lists.
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 the integrity of the Air Release Valve are com
promised by such practices.
Before attempting to service the Air Release Valve,
disconnect or lock out the power supply to the
pump and take precautions to ensure that it will re
main inoperative. Close all valves in the suction
and discharge lines.
Before attempting to service the Air Re
lease Valve:
1. Familiarize yourself with this man
ual.
2. Disconnect or lock out the power
source 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.
If a manual shut‐off valve is installed in
the bypass line to facilitate service of
the Air Release Valve, be sure to open
the shut‐off valve after servicing the Air
Release Valve. A closed manual shut‐
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 com
pletely cool before servicing. Do not re
move plates, covers, gauges, or fittings
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 with great force. Af
ter the pump cools, drain the liquid from
the pump by removing the casing drain
plug. Use caution when removing the
plug to prevent injury to personnel from
hot liquid.
If the application involves volatile, cor
rosive or hazardous liquids, wear pro
tective safety equipment, such as
goggles, rubber gloves and apron when