Gorman-Rupp Pumps T8A60S-4045H User Manual
ACDEU
OM-06522-01
January 26, 2012
INSTALLATION, OPERATION,
AND MAINTENANCE MANUAL
WITH PARTS LIST
SUPER T SERIES PUMP
MODEL
T8A60S-4045H
THE GORMAN‐RUPP COMPANY D MANSFIELD, OHIO
GORMAN‐RUPP OF CANADA LIMITED D ST. THOMAS, ONTARIO, CANADA Printed in U.S.A.
www.grpumps.com
E2012 The Gorman‐Rupp Company
Register your new
Gorman‐Rupp pump online at
www.grpumps.com
Valid serial number and e‐mail address required.
The engine exhaust from this
product contains chemicals
known to the State of California to
cause cancer, birth defects or
other reproductive harm.
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
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 - 2............................................
Battery Specifications And Installation PAGE B - 2....................................
POSITIONING PUMP PAGE B - 2.......................................................
Lifting PAGE B - 2.................................................................
Mounting PAGE B - 3.............................................................
Clearance PAGE B - 3.............................................................
SUCTION AND DISCHARGE PIPING PAGE B - 3.........................................
Materials PAGE B - 3..............................................................
Line Configuration PAGE B - 3......................................................
Connections to Pump PAGE B - 3..................................................
Gauges PAGE B - 3...............................................................
SUCTION LINES PAGE B - 3...........................................................
Fittings PAGE B - 3...............................................................
Strainers PAGE B - 4..............................................................
Sealing PAGE B - 4...............................................................
Suction Lines In Sumps PAGE B - 4.................................................
Suction Line Positioning PAGE B - 4................................................
FLOAT SWITCHES PAGE B - 5.........................................................
Installation PAGE B - 5............................................................
OPTIONAL SUBMERSIBLE TRANSDUCER PAGE B - 6...................................
DISCHARGE LINES PAGE B - 7........................................................
Siphoning PAGE B - 7.............................................................
Valves PAGE B - 7................................................................
Bypass Lines PAGE B - 7..........................................................
AUTOMATIC AIR RELEASE VALVE PAGE B - 8...........................................
Theory of Operation PAGE B - 8....................................................
Air Release Valve Installation PAGE B - 9............................................
ALIGNMENT PAGE B - 10..............................................................
OPERATION - SECTION C PAGE C - 1......................................
PRIMING PAGE C - 1.................................................................
STARTING PAGE C - 2................................................................
Manual Starting PAGE C - 2........................................................
Automatic Starting PAGE C - 2.....................................................
OPTIONAL EPS CONTROL PAGE C - 2.................................................
Features PAGE C - 2..............................................................
Functional Description PAGE C - 2..................................................
EPS Functions PAGE C - 3.........................................................
EPS Calibration PAGE C - 4........................................................
Zero Adjustment PAGE C - 4.......................................................
Span Adjustment PAGE C - 4......................................................
Level Adjustment PAGE C - 4......................................................
i
TABLE OF CONTENTS
(continued)
Horn Delay PAGE C - 5............................................................
OPERATION PAGE C - 5..............................................................
Lines With a Bypass PAGE C - 5....................................................
Lines Without a Bypass PAGE C - 5.................................................
Leakage PAGE C - 5..............................................................
Liquid Temperature And Overheating PAGE C - 5.....................................
Strainer Check PAGE C - 6.........................................................
Pump Vacuum Check PAGE C - 6..................................................
STOPPING PAGE C - 6................................................................
Manual Stopping PAGE C - 6.......................................................
Automatic Stopping PAGE C - 6....................................................
Safety Shutdown System PAGE C - 6...............................................
OPERATION IN EXTREME HEAT PAGE C - 7............................................
Cold Weather Preservation PAGE C - 7..............................................
BEARING TEMPERATURE CHECK PAGE C - 7..........................................
TROUBLESHOOTING - SECTION D PAGE D - 1..............................
PREVENTIVE MAINTENANCE PAGE D - 4...............................................
PUMP MAINTENANCE AND REPAIR ‐ SECTION E PAGE E - 1.................
STANDARD PERFORMANCE CURVE PAGE E - 1........................................
PARTS LISTS:
Pump Model PAGE E - 3..........................................................
Power Unit Kit PAGE E - 5.........................................................
Pump End Assembly PAGE E - 7...................................................
Repair Rotating Assembly PAGE E - 9...............................................
Drive Assembly PAGE E - 10........................................................
PUMP AND SEAL DISASSEMBLY AND REASSEMBLY PAGE E - 11.........................
Back Cover And Wear Plate Removal PAGE E - 11.....................................
Suction Check Valve Removal PAGE E - 12...........................................
Separating Intermediate And Drive Assembly From Engine PAGE E - 12..................
Loosening Impeller PAGE E - 12.....................................................
Rotating Assembly Removal PAGE E - 13.............................................
Impeller Removal PAGE E - 13......................................................
Seal Removal PAGE E - 13..........................................................
Shaft and Bearing Removal and Disassembly PAGE E - 14.............................
Shaft and Bearing Reassembly and Installation PAGE E - 15............................
Seal Installation PAGE E - 16........................................................
Impeller Installation PAGE E - 19.....................................................
Rotating Assembly Installation PAGE E - 19...........................................
Suction Check Valve Installation PAGE E - 19.........................................
Back Cover Installation And Adjustment PAGE E - 19..................................
Securing Pump End To Engine PAGE E - 20..........................................
PRESSURE RELIEF VALVE MAINTENANCE PAGE E - 21..................................
Final Pump Assembly PAGE E - 21..................................................
LUBRICATION PAGE E - 22.............................................................
Seal Assembly PAGE E - 22.........................................................
Bearings PAGE E - 22..............................................................
Engine PAGE E - 22................................................................
ii
SUPER T SERIES
OM-06522
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 pump is a Super T Series, semi‐open impeller,
self‐priming centrifugal model with a suction check
valve. The pump also is designed with external
shimless adjusters for setting the wear plate to im
peller clearance. The pump is close coupled to a
John Deere 4045H diesel engine, and is designed
for handling dirty water containing specified en
trained solids and slurries. The basic material of
construction is gray iron, with ductile iron impeller
and steel wearing parts.
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.
For information or technical assistance on the en
gine, contact the engine manufacturer's local
dealer or representative.
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.
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: (419) 755-1011
or:
Gorman‐Rupp of Canada Limited
70 Burwell Road
St. Thomas, Ontario N5P 3R7
Phone: (519) 631-2870
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.
PAGE I - 1INTRODUCTION
SUPER T SERIES
OM-06522
SAFETY ‐ SECTION A
This information applies to Super T Se
ries engine driven pumps. Refer to the
manual accompanying the engine be
fore 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. Switch off the engine ignition, re
move the key, and disconnect the
positive battery cable to ensure
that the pump will remain inopera
tive.
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.
ing away from the unit to prevent injury
during automatic operation. Disconnect
the positive battery cable before per
forming any maintenance. Failure to do
so may result in serious personal injury.
This pump is designed to handle dirty
water containing specified entrained
solids. Do not attempt to pump volatile,
corrosive, or flammable liquids which
may damage the pump or endanger per
sonnel 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. The bail is intended
for use in lifting the pump assembly
only. Suction and discharge hoses and
piping must be removed from the pump
before lifting.
After the unit has been installed, make
certain that the pump and all piping or
hose connections are tight, properly
supported and secure before operation.
This pump is equipped with an automat
ic starting system, and is subject to au
tomatic restart. Keep hands and cloth
Do not operate the pump against a
closed discharge valve for long periods
of time. If operated against a closed dis
charge valve, pump components will
deteriorate, and the liquid could come
PAGE A - 1SAFETY
SUPER T SERIESOM-06522
to a boil, build pressure, and cause the
pump casing to rupture or explode.
Do not remove plates, covers, gauges,
pipe plugs, or fittings from an over
heated pump. Vapor pressure within the
pump can cause parts being disen
gaged to be ejected with great 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. Always use the correct type of fuel.
Never tamper with the governor to gain
more power. The governor establishes
safe operating limits that should not be
exceeded. Refer to the performance
curve, page E-1, for the maximum op
erating speed for this pump.
PAGE A - 2 SAFETY
SUPER T SERIES OM-06522
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
static lift application where the pump is positioned
above the free level of liquid to be pumped.
If installed in a flooded suction application where
the liquid is supplied to the pump under pressure,
some of the information such as mounting, line
configuration, and priming must be tailored to the
OUTLINE DRAWING
specific application. Since the pressure supplied
to the pump is critical to performance and safety,
be sure to limit the incoming pressure to 50% of the
maximum permissible operating pressure as
shown on the pump performance curve.
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.
Figure 1. Pump Model T8A60S-4045H
PAGE B - 1INSTALLATION
OM-06522 SUPER T SERIES
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 assembly for cracks, dents,
damaged threads, and other obvious dam
age.
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.
Table 1. Battery Specifications
Reserve
Capacity
@ 80
_ F
(Minutes)
120
Amp/
Hr.
Rating
75
Approx.
Overall
Dims.
(Inches)
10.25L
x
6.75W
x
8.88H
Voltage
12 Volts
Cold
Crank
Amps
@ 0_ F
850
Refer to the information accompanying the battery
and/or electrolyte solution for activation and charg
ing instructions.
Before installing the battery, clean the positive and
negative cable connectors, and the battery termi
nals. Secure the battery by tightening the
holddown brackets. The terminals and clamps
may be coated with petroleum jelly to retard corro
sion. Connect and tighten the positive cable first,
then the negative cable.
POSITIONING PUMP
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
maximum shelf life. These must be inspected
or replaced to ensure maximum pump serv
ice.
If the maximum shelf life has been exceeded, or if
anything appears to be abnormal, contact your
Gorman‐Rupp distributor or the factory to deter
mine the repair or updating policy. Do not put the
pump into service until appropriate action has
been taken.
Battery Specifications And Installation
Unless otherwise specified on the pump order, the
engine battery was not included with the unit. Re
fer to the following specifications when selecting a
battery.
Use lifting and moving equipment in
good repair and with adequate capacity
to prevent injuries to personnel or dam
age to equipment. The bail is intended
for use in lifting the pump assembly
only. Suction and discharge hoses and
piping must be removed from the pump
before lifting.
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
PAGE B - 2 INSTALLATION
SUPER T SERIES OM-06522
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.
If the pump has been mounted on a moveable
base, make certain the base is stationary by setting
the brake and blocking the wheels before attempt
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, the engine manufacturer should be
consulted for continuous operation at angles
greater than 15_.
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.
Connections to Pump
Before tightening a connecting flange, align it ex
actly with the pump port. Never pull a 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
lines are used, they should have adequate support
to secure them when filled with liquid and under
pressure.
Gauges
Clearance
When positioning the pump, allow a minimum
clearance of 18 inches (457,2 mm) in front of the
back cover to permit removal of the cover and easy
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
on Page E‐1 to be sure your overall application al
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
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
Most pumps are drilled and tapped for installing
discharge pressure and vacuum suction gauges.
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 pump may result in erratic
readings.
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.
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
PAGE B - 3INSTALLATION
OM-06522 SUPER T SERIES
stalled with the flat part of the 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
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 3‐inch (76,2
mm) diameter spherical solids.
sump at a distance equal to 1 1/2 times the diame
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 carry air 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
tion inlet, install a baffle between the inflow and the
suction inlet at a distance 1‐1/2 times the diameter
of the suction pipe. The baffle will allow entrained
air to escape from the liquid before it is drawn into
the suction inlet.
If two suction lines are installed in a single sump,
the flow paths may interact, reducing the efficiency
of one or both pumps. To avoid this, position the
suction inlets so that they are separated by a dis
tance equal to at least 3 times the diameter of the
suction pipe.
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
Suction Line Positioning
The depth of submergence of the suction line is
critical to efficient pump operation.
recommended minimum submergence vs. veloc
ity.
Figure 2 shows
NOTE
The pipe submergence required may be reduced
by installing a standard pipe increaser fitting at the
end of the suction 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).
PAGE B - 4 INSTALLATION
SUPER T SERIES OM-06522
Figure 2. Recommended Minimum Suction Line Submergence vs. Velocity
FLOAT SWITCHES
Installation
The standard pump is equipped with an auto‐start
control system, and can be conformed to start and
stop as the liquid level in the wet well or sump rises
and falls. The autostart unit employs either a single
or double float switch system, where a bulb raises
or lowers (floats) with the liquid level, thus activat
ing an enclosed miniature switch. The floats are
equipped with a socket type connector that plugs
into a matching receptacle on the auto‐start control
box.
Standard floats are equipped with 50 feet (15,2 m)
of cable.
When installing the floats, note the following:
a. Be sure to provide sufficient room in the wet
well or sump so that floats do not get ob
structed or drawn into the suction line. If a flex
ible suction hose is used, it may be extended
to lay along the bottom of the wet well or sump
and the float can be attached to the hose
above the point where it bends along the bot
tom. Direct the suction line toward the flow,
and the float(s) away from the flow. If a stand
pipe is available, attach the float switch cable
to the standpipe in the sump at the approxi
mate desired liquid level.
b. In a single float system, the cable can be teth
ered to the suction line or standpipe approxi
mately 6 inches (152 mm) above the float.
This setting allows approximately 9 inches
(229 mm) of liquid rise between pump start/
stop. The start/stop interval may be increased
by extending the float end of the cable. The
liquid level in the sump will increase approxi
mately 8 inches (203 mm) between start/stop
intervals for every 6 inches (152 mm) of cable
increase.
c. If a double float switch system is used, posi
tion the “Start” float at the desired high water
level in the sump, and the “Stop” float at the
desired low water level in the pump.
d. Refer to Figure 3 for additional float switch
data.
PAGE B - 5INSTALLATION
OM-06522 SUPER T SERIES
ENGINE
CONTROL
BOX
ON
(Emptying)
OFF
(Filling)
OPERATING
CABLE
TETHER
RANGE
(See Table Below)
POINT
OFF
(Emptying)
1.25” Pipe
(Not Furnished)
ON
(Filling)
Figure 3. Float Switch Data
OPTIONAL SUBMERSIBLE
TRANSDUCER
This unit may be equipped with an optional Elec
tronic Pressure Switch (EPS) that works in con
junction with a submersible transducer. The sub
mersible transducer converts pressure to an elec
trical signal proportional to liquid level. This electri
cal signal is distributed to the digital display on the
EPS through a scaling circuit which converts the
electrical signal to “feet of water”.
3.0
(0.9)
2.5
(.76)
2.0
(0.6)
1.5
(.46)
1.0
(0.3)
0.5
(.15)
1.0
(0.3)
APPROXIMATE FREE CORD LENGTH IN FT. (M)
2.0
(0.6)
3.0
(0.9)
above the point where it bends along the bot
tom. See Figure B-4 for a typical installation.
c. The wet well or sump must be vented to atmo
sphere.
d. The EPS is scaled in feet of water column. If
the measured medium is other than 1.0 spe
cific gravity, the reading on the EPS should be
divided by the specific gravity of the mea
sured medium to obtain the actual level.
4.0
(1.2)
When installing the submersible transducer, note
the following:
a. Handle the signal cable and transducer with
care during installation. Carefully lower the
transducer into the wet well or sump; do not
drop it to the bottom. To avoid clogging, sus
pend the transducer off the bottom.
b. Be sure to provide sufficient room in the wet
well or sump so that the transducer does not
get drawn into the suction line. To prevent this,
a flexible suction hose may be extended to lay
along the bottom of the wet well or sump. The
transducer can then be attached to the hose
e. Thoroughly clean the transducer after each
use to prevent clogging.
Do not disassemble the transducer or
loosen the compression nut at the signal
cable entry. This will void warranty. There
are no user‐serviceable parts inside. Do
not nick or cut the jacket of the signal
cable; this will cause leakage and void
warranty.
PAGE B - 6 INSTALLATION
SUPER T SERIES OM-06522
SUCTION
DISCHARGE
LINE
LINE
SIGNAL CABLE
(ATTACH TO
SUCTION LINE)
SUBMERSIBLE
TRANSDUCER
(DOWNSTREAM
FROM SUCTION)
SUCTION
STRAINER
Figure 4. Typical Submersible Transducer Installation
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,
use a valve as large as the largest pipe to minimize
friction losses. Never install a throttling valve in a
suction line.
With high discharge heads, it is recommended that
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.
FLOW
If the application involves a high discharge
head, gradually close the discharge
throttling valve before stopping the pump.
Bypass Lines
Self‐priming pumps are not air compressors. Dur
ing the priming cycle, air from the suction line must
be vented to atmosphere on the discharge side. If
the discharge line is open, this air will be vented
through the discharge. However, if a check valve
has been installed in the discharge line, the dis
charge side of the pump must be opened to atmos
pheric pressure through a bypass line installed be
tween the pump discharge and the check valve. A
self‐priming centrifugal pump will not prime if
there is sufficient static liquid head to hold the dis
charge check valve closed.
NOTE
The bypass line should be sized so that it does not
PAGE B - 7INSTALLATION
OM-06522 SUPER T SERIES
affect pump discharge capacity; however, the by
pass line should be at least 1 inch (25,4 mm) in di
ameter to minimize the chance of plugging.
In low discharge head applications (less than 30
feet (9,1 m)), it is recommended that the bypass
line be run back to the wet well, and located 6
inches below the water level or cut‐off point of the
low level pump. In some installations, this bypass
outline may be terminated with a six‐to‐eight foot
(1,8 to 2,4 m) length of 1‐1/4 inch (31,8 mm) I.D.
smooth‐bore hose; air and liquid vented during
the priming process will then agitate the hose and
break up any solids, grease, or other substances
likely to cause clogging.
A bypass line that is returned to a wet well
must be secured against being drawn into
the pump suction inlet.
It is also recommended that pipe unions be in
stalled at each 90_ elbow in a bypass line to ease
disassembly and maintenance.
In high discharge head applications (more than
30 feet (9,1 m), an excessive amount of liquid may
be bypassed and forced back to the wet well under
the full working pressure of the pump; this will re
duce overall pumping efficiency. Therefore, it is
recommended that a Gorman‐Rupp Automatic
Air Release Valve be installed in the bypass line.
Gorman‐Rupp Automatic Air Release Valves are
reliable, and require minimum maintenance. See
Automatic Air Release Valves in this section for
installation and theory of operation of the Auto
matic Air Release Valve. Consult your Gorman‐
Rupp distributor, or contact the Gorman‐Rupp
Company for selection of an Automatic Air Release
Valve to fit your application.
Except in certain specific applications (to
prevent flooding during service of an auto
matic air release valve in a below‐ground
lift station), if a manual shut‐off valve is in
stalled anywhere in a bypass line, it must
be a full‐opening, ball‐type valve to pre
vent plugging by solids.
A manual shut‐off valve should not be
installed in any bypass line. A manual
shut‐off valve may inadvertently be left
closed during operation. A pump which
has lost prime may continue to operate
without reaching prime, causing dan
gerous overheating and possible explo
sive rupture of the pump casing. Per
sonnel could be severely injured.
Allow an over‐heated pump to cool be
fore servicing. Do not remove plates,
covers, gauges, or fittings from an over‐
heated pump. Liquid within the pump
can reach boiling temperatures, and va
por pressure within the pump can cause
parts being disengaged to be ejected
with great force. After the pump cools,
drain the liquid from the pump by re
moving the casing drain plug. Use cau
tion when removing the plug to prevent
injury to personnel from hot liquid.
AUTOMATIC AIR RELEASE VALVE
When properly installed, a Gorman‐Rupp Auto
matic Air Release Valve will permit air to escape
through the bypass line and then close automati
cally when the pump is fully primed and pumping
at full capacity.
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.
Consult the manual accompanying the Air Release
Valve for additional information on valve installation
and performance.
PAGE B - 8 INSTALLATION
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