Wilo American-Marsh Pumps SXT-3"X3" User manual

490 Series SXT 3”x3”
Self-Priming Pumps
Installation and Operating Manual
*077-0238-000*

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IOM 490 SXT 3”X3”_1222
TABLE OF CONTENTS
INTRODUCTION .............................................................................................................................. 3
SAFETY SECTION A ......................................................................................................................... 5
INSTALLATION SECTION B .............................................................................................................. 6
Pump Dimensions ............................................................................................................... 6
PREINSTALLATION INSPECTION ............................................................................................... 7
POSITIONING PUMP .................................................................................................................. 7
Lifting ................................................................................................................................. 7
Mounting ............................................................................................................................ 7
Clearance ........................................................................................................................... 7
SUCTION AND DISCHARGE PIPING ........................................................................................... 8
Materials ............................................................................................................................. 8
Line Configuration ............................................................................................................. 8
Connections to Pump ......................................................................................................... 8
Gauges ................................................................................................................................ 8
SUCTION LINES ......................................................................................................................... 8
Fittings ............................................................................................................................... 8
Strainers ............................................................................................................................. 8
Sealing ................................................................................................................................ 9
Suction Lines In Sumps ...................................................................................................... 9
Suction Line Positioning .................................................................................................... 9
DISCHARGE LINES ................................................................................................................... 10
Siphoning ......................................................................................................................... 10
Valves ............................................................................................................................... 10
Bypass Lines ..................................................................................................................... 11
AUTOMATIC AIR RELEASE VALVE .......................................................................................... 11
Theory of Operation ......................................................................................................... 11
ALIGNMENT ............................................................................................................................ 13
Coupled Drives ................................................................................................................. 13
Drive Belts ........................................................................................................................ 14
OPERATION SECTION C ................................................................................................................ 15
PRIMING .................................................................................................................................. 15
STARTING ............................................................................................................................... 15
Rotation ........................................................................................................................... 15
OPERATION ............................................................................................................................ 16
Lines With a Bypass .......................................................................................................... 16
Lines Without a Bypass .................................................................................................... 16
Leakage ............................................................................................................................ 16
Liquid Temperature And Overheating ............................................................................. 16
Strainer Check .................................................................................................................. 17
Pump Vacuum Check ....................................................................................................... 17

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IOM 490 SXT 3”X3”_1222
STOPPING ............................................................................................................................... 17
Cold Weather Preservation .............................................................................................. 17
BEARING TEMPERATURE CHECK ............................................................................................ 18
TROUBLESHOOTING SECTION D ................................................................................................... 18
PREVENTIVE MAINTENANCE .................................................................................................. 20
PERFORMANCE CURVE ........................................................................................................... 22
ILLUSTRATION ........................................................................................................................ 23
PARTS LIST ............................................................................................................................. 24
PUMP AND SEAL DISASSEMBLY AND REASSEMBLY ............................................................... 25
Back Cover and Wear Plate Removal ............................................................................... 25
Suction Check Valve Removal ......................................................................................... 26
Rotating Assembly Removal ............................................................................................ 26
Impeller Removal ............................................................................................................. 27
Seal Removal .................................................................................................................... 28
Shaft and Bearing Removal and Disassembly .................................................................. 28
Shaft and Bearing Reassembly and Installation ............................................................... 29
Seal Installation ................................................................................................................ 30
Impeller Installation and Adjustment .............................................................................. 33
Rotating Assembly Installation ........................................................................................ 33
Suction Check Valve Installation ..................................................................................... 34
Back Cover and Wear Plate Installation and Adjustment ................................................ 34
PRESSURE RELIEF VALVE MAINTENANCE .............................................................................. 36
Final Pump Assembly ....................................................................................................... 36
LUBRICATION ......................................................................................................................... 36
Seal Assembly .................................................................................................................. 36
Power Source ................................................................................................................... 37
WARRANTY ................................................................................................................................... 38

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IOM 490 SXT 3”X3”_1222
INTRODUCTION
Thank You
for purchasing an American-Marsh 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.
Because pump installations are seldom identical, this manual cannot possibly provide detailed
instructions and precautions for every aspect of each specific application. Therefore, it is the
responsibility 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
compromised by the installation. Pumps and related equipment must be installed and operated
according to all national, local and industry standards.
If there are any questions regarding the pump or its application which are not covered in this manual
or in other literature accompanying this unit, please contact your AMP distributor:
American-Marsh Pumps
550 E. South St.
Collierville, TN 38017
Phone: [phone]
For information or technical assistance on the power source, contact the power source
manufacturer's local dealer or representative.
RECORD YOUR PUMP MODEL AND SERIAL NUMBER
Please record your pump model and serial number in the spaces provided below.
Your American-Marsh Pumps (AMP) distributor needs this information when you require parts or service.
Pump Model:
Serial Number:

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IOM 490 SXT 3”X3”_1222
HAZARD AND INSTRUCTION DEFINITIONS
The following are used to alert maintenance personnel to procedures which require special attention,
to those which could damage equipment, and to those which could be dangerous to personnel:
DANGER: Immediate hazards which WILL result in severe personal injury or death. These
instructions describe the procedure required and the injury which will result from failure to
follow the procedure.
WARNING: 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
CAUTION: Hazards or unsafe practices which COULD result in minor personal injury or
product or property damage. These instructions describe 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.

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IOM 490 SXT 3”X3”_1222
SAFETY SECTION A
This information applies to the 490 Series SXT 3”x3” pumps. AMP has no control over or particular
knowledge of the power source which will be used. Refer to the manual accompanying the power
source before attempting to begin operation.
This manual will alert personnel to known procedures 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 instructions and precautions 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 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.
This pump is designed to handle most non ‐ volatile, non ‐ flammable liquids containing
specified entrained solids. DO NOT attempt to pump volatile, corrosive, or flammable
materials which may damage the pump or endanger personnel as a result of pump
failure.
After the pump has been positioned, make certain that the pump and all piping
connections are tight, properly supported, and secure
before operation.
DO NOT operate the pump without the guards in place over the rotating parts. Exposed
rotating parts can catch clothing, fingers, or tools, causing severe injury to personnel.
DO NOT remove plates, covers, gauges, pipe plugs, or fittings from an overheated
pump. Vapor pressure within the pump can cause parts being disengaged to be ejected with great
force. Allow the pump to cool before servicing.
DO NOT operate the pump against a closed discharge valve for long periods of time. If
operated against a closed discharge valve, pump components will deteriorate, and the
liquid could come to a boil, build pressure, and cause the pump casing to rupture or
explode.
Death or serious personal injury and damage to the pump or components can occur if proper
lifting procedures are not observed. Make certain that hoists, chains, slings, or cables are in good
working condition and of sufficient capacity and that they are positioned so that loads will be
balanced, and the pump or components will not be damaged when lifting. Suction and discharge
hoses and piping must be removed from the pump before lifting. Lift the pump or component
only as high as necessary and keep personnel away from suspended objects
.

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IOM 490 SXT 3”X3”_1222
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 arrange 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
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 AMP distributor.
Pump Dimensions
See Figures 1 for the approximate physical dimensions of the pump.
OUTLINE DRAWING
Figure 1. Pump Model SXT-3”X3”

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IOM 490 SXT 3”X3”_1222
PREINSTALLATION INSPECTION
The pump assembly was inspected and tested before shipment from the factory. Before installation,
inspect the pump for damage which may have occurred 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 hardware. Since gaskets tend to shrink after drying, check
for loose hardware at mating surfaces.
c.
Carefully read all warnings and cautions contained in this manual or affixed to the pump, and
perform all duties indicated. Note the direction of rotation indicated on the pump. Check that
the pump shaft rotates counterclockwise when facing the impeller.
Only operate this pump in the direction indicated by the arrow on the pump body and on
the accompanying decal. Refer to ROTATION in OPERATION, Section C.
d. Check levels and lubricate as necessary. Refer to LUBRICATION in the MAINTENANCE AND
REPAIR section of this manual and perform duties as instructed.
e.
If the pump and power source have been stored for more than 12 months, some of the
components or lubricants may have exceeded their maximum shelf life. These must be inspected
or replaced to ensure maximum pump service.
If the maximum shelf life has been exceeded, or if anything appears to be abnormal, contact your
AMP distributor to determine the repair or updating policy. DO NOT put the pump into service until
appropriate action has been taken.
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.
Death or serious personal injury and damage to the pump or components can occur if
proper lifting procedures are not observed. Make certain that hoists, chains, slings or
cables are in good working condition and of sufficient capacity and that they are
positioned so that loads will be balanced, and the pump or components will not be
damaged when lifting. Suction and discharge hoses and piping must be removed from the pump
before lifting. Lift the pump or component only as high as necessary and keep personnel.
Mounting
Locate the pump in an accessible place as close as practical to the liquid being pumped. Level
mounting is essential for proper operation.
The pump may have to be supported or shimmed to provide for level operation or to eliminate
vibration
Clearance
It is recommended that
18 inches (457 mm) of clearance be provided in front of the back cover to

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IOM 490 SXT 3”X3”_1222
permit removal of the cover and easy access to the pump interior. A minimum clearance of 9 inches
(229 mm)
must be maintained to permit removal of the cover.
SUCTION AND DISCHARGE PIPING
Pump performance is adversely affected by increased suction lift, discharge elevation, and friction
losses. See the performance curve and operating range shown in
SECTION E to be sure your overall
application allows 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,
reinforced type to prevent collapse under suction. Using piping couplings in suction lines is not
recommended.
Line Configuration
Keep suction and discharge lines as straight as possible to minimize friction losses. Make minimum
use of elbows and fittings, which substantially 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 exactly with the pump port. Never pull a pipeline into
place by tightening the flange bolts and/or couplings.
Lines near the pump must be independently supported 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
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 priming, 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 installed with the flat part of the reducers uppermost to
avoid creating air pockets. Valves are not normally used in suction lines, but if a valve is used, install
it with the stem horizontal to avoid air pockets.
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.

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IOM 490 SXT 3”X3”_1222
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 2-1/2-inch (63,5 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 recommendations when selecting and applying the pipe
dope. The pipe dope should be compatible with the liquid being pumped.
Suction Lines In Sumps
If a single suction line is installed in a sump, it should be positioned away from the wall of the sump
at a distance equal to 1 1/2 times the diameter 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
suction inlet because the inflow will carry air down into the sump, and air entering the suction line
will reduce pump efficiency.
If it is necessary to position inflow close to the suction 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
distance equal to at least 3 times the diameter of the suction pipe.
Suction Line Positioning
The depth of submergence of the suction line is critical to efficient pump operation. Figure 2 shows
recommended minimum submergence vs. velocity.
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).

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IOM 490 SXT 3”X3”_1222
Figure 2. Recommended Minimum Suction Line Submergence vs. Velocity
DISCHARGE LINES
Siphoning
DO NOT terminate the discharge line at a level lower than that of the liquid being pumped unless a
siphon breaker is used in the line. Otherwise, a siphoning 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
installed in the discharge line to protect the pump from excessive shock pressure and reverse
rotation when it is stopped.
If the application involves a high discharge head, gradually close the discharge throttling
valve before stopping the pump.

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IOM 490 SXT 3”X3”_1222
Bypass Lines
Self ‐ priming pumps are not air compressors. During 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
discharge side of the pump must be opened to atmospheric pressure through a bypass line installed
between 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 discharge check valve closed.
NOTE
The bypass line should be sized so that it does not affect pump discharge capacity; however, the
bypass line should be at least 1 inch in diameter to minimize the chance of plugging.
In low discharge head applications (less than 30 feet or 9 meters), 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 line may be terminated with a six
‐ to ‐ eight-foot
length of 1 1/4-inch 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 installed at each
90°elbow in a bypass line to ease disassembly and maintenance.
In high discharge head applications (more than 30 feet), 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
reduce overall pumping efficiency.
Therefore, it is recommended that Automatic Air Release Valve
(ARV) be installed in the bypass line
.
Automatic Air Release Valves (ARV’s) are reliable and require minimum maintenance. See
AUTOMATIC AIR RELEASE VALVE in this section for installation and theory of operation of the
Automatic Air Release Valve.
If the installation involves a flooded suction such as a below
‐ ground lift station. A pipe union and
manual shut
‐ off valve may be installed in the bleed line to allow service of the valve without shutting
down the station, and to eliminate the possibility of flooding. 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.
If a manual shut ‐ off valve is installed in a bypass line, it must not be left closed during
operation. 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 severely injured.
Allow an over ‐ heated pump to cool before servicing. DO NOT remove plates, covers, gauges, or
fittings from an over
‐ heated pump. Liquid within the pump can reach boiling temperatures, and
vapor 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 removing the casing drain plug. Use
caution when removing the plug to prevent injury to personnel from hot liquid.
AUTOMATIC AIR RELEASE VALVE
Theory of Operation
When properly installed, an Automatic Air Release Valve (ARV) will permit air to escape through the
bypass line and then close automatically when the pump is fully primed and pumping at full capacity.

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IOM 490 SXT 3”X3”_1222
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.
Air Release Valve Installation
The Automatic Air Release Valve must be independently mounted in a horizontal position between
the pump discharge port and the inlet side of the discharge check valve (see
Figure 3 ).
Figure 3. Typical Automatic Air Release Valve Installation
Connect the valve outlet to a bleed line which slopes back to the wet well or sump. The bleed line
must be the same size as the outlet opening or larger, depending on which Air Release Valve is being
used. If piping is used for the bleed line, avoid the use of elbows whenever possible.
NOTE
For multiple pump installations, 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,
DO NOT direct bleeder lines to a common manifold pipe.

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IOM 490 SXT 3”X3”_1222
ALIGNMENT
The alignment of the pump and its power source is critical for trouble ‐ free mechanical operation. In
either a flexible coupling or V
‐ belt driven system, the driver and pump must be mounted so that their
shafts are aligned with and parallel to each other. It is imperative that alignment be checked after
the pump and piping are installed, and before operation.
NOTE
Check
Rotation , Section C , before final alignment of the pump.
When mounted at the AMP factory, driver and pump are aligned before shipment. Misalignment will
occur in transit and handling. Pumps must be checked and realigned before operation. Before
checking alignment, tighten the foundation bolts. The pump casing feet and/or pedestal feet, and
the driver mounting bolts should also be tightly secured.
When checking alignment, disconnect the power source to ensure that the pump will
remain inoperative.
Adjusting the alignment in one direction may alter the alignment in another direction.
check each procedure after altering alignment
.
Coupled Drives
When using couplings, the axis of the power source must be aligned to the axis of the pump shaft in
both the horizontal and vertical planes. Most couplings require a specific gap or clearance between
the driving and the driven shafts. Refer to the coupling manufacturer's service literature.
Figure 4. Aligning Spider Type Couplings
Figure 5. Aligning Non-Spider Type Couplings
Align spider insert type couplings by using calipers to measure the dimensions on the circumference
of the outer ends of the coupling hub every 90°. The coupling is in alignment when the hub ends are
the same distance apart at all points (see
Figure 4 ).
Align non
‐ spider type couplings by using a feeler gauge or taper gauge between the coupling halves

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IOM 490 SXT 3”X3”_1222
every 90°. The coupling is in alignment when the hubs are the same distance apart at all points (see
Figure 5 ).
Check parallel adjustment by laying a straightedge across both coupling rims at the top, bottom, and
side. When the straightedge rests evenly on both halves of the coupling, the coupling is in horizontal
parallel alignment. If the coupling is misaligned, use a feeler gauge between the coupling and the
straightedge to measure the amount of misalignment.
Drive Belts
When using drive belts, the power source and the pump must be parallel. Use a straightedge along
the sides of the pulleys to ensure that the pulleys are properly aligned (see
Figure 6 ). In drive systems
using two or more belts, make certain that the belts are a matched set; unmatched sets will cause
accelerated belt wear.
MISALIGNED:
SHAFTS NOT PARALLEL
MISALIGNED:
SHAFTS NOT IN LINE
ALIGNED:
SHAFTS PARALLEL AND
SHEAVES IN LINE
Figure 6. Alignment of V ‐ Belt Driven Pumps
Tighten the belts in accordance with the belt manufacturer's instructions. If the belts are too loose,
they will slip; if the belts are too tight, there will be excessive power loss and possible bearing failure.
Select pulleys that will match the proper speed ratio; over speeding the pump may damage both
pump and power source.
DO NOT operate the pump without the guard in place over the rotating parts. Exposed
rotating parts can catch clothing, fingers, or tools, causing severe injury to personnel.
DRIVE BELT TENSIONING
General Rules of Tensioning
For new drive belts, check the tension after 5, 20 and 50 hours of operation and re ‐ tension as
required (see the following procedure for measuring belt tension). Thereafter, check and re
‐ tension
if required monthly or at 500-hour intervals, whichever comes first.
Ideal drive belt tension is the lowest tension at which the belt will not slip under peak load conditions.
DO NOT over
‐ tension drive belts. Over ‐ tensioning will shorten both drive belt and bearing life.
Under
‐ tensioning will cause belt slippage. Always keep belts free from dirt, grease, oil and other

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IOM 490 SXT 3”X3”_1222
foreign material which may cause slippage.
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 liquids containing large, entrained solids and slurries.
DO NOT attempt to pump volatile, corrosive, or flammable liquids which may damage
the pump or endanger personnel as a result of pump failure.
Pump speed and operating conditions must be within performance range shown in
SECTION E.
PRIMING
Install the pump and piping as described in the INSTALLATION section. Make sure that the piping
connections are tight, and that the pump is securely mounted. Check that the pump is properly
lubricated (see
LUBRICATION in MAINTENANCE AND REPAIR ).
This pump is self
‐ priming, but the pump should never be operated unless there is liquid in the pump
casing.
Never operate this pump unless there is liquid in the pump casing. The pump will not
prime when dry. Extended operation of a dry pump will destroy the seal assembly.
Add liquid to the pump casing when:
1.
The pump is being put into service for the first time.
2.
The pump has not been used for a considerable length of time.
3.
The liquid in the pump casing has evaporated.
Once the pump casing has been filled, the pump will prime and reprime as necessary.
After filling the pump casing, reinstall and tighten the fill plug. DO NOT attempt to
operate the pump unless all connecting piping is securely installed. Otherwise, liquid in
the pump forced out under pressure could cause injury to personnel.
To fill the pump, remove the pump casing fill cover or fill plug in the top of the casing, and add clean
liquid until the casing is filled. Replace the fill cover or fill plug before operating the pump.
STARTING
Consult the operations manual furnished with the power source.
Rotation
The correct direction of pump rotation is counterclockwise when facing the impeller. The pump
could be damaged, and performance adversely affected by incorrect rotation. If pump performance
is not within the specified limits (see the curve on page
SECTION E ), check the direction of power
source rotation before further troubleshooting.
If an electric motor is used to drive the pump, remove V
‐ belts, couplings, or otherwise disconnect

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IOM 490 SXT 3”X3”_1222
the pump from the motor before checking motor rotation. Operate the motor independently while
observing the direction of the motor shaft, or cooling 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 literature supplied with the motor for specific instructions.
OPERATION
Lines With a Bypass
If an Automatic Air Release Valve has been installed, the valve will automatically open to allow the
pump to prime, and automatically close after priming is complete (see
INSTALLATION for Air
Release Valve operation).
If the bypass line is open, air from the suction line will be discharged through the bypass line back
to the wet well during the priming cycle. Liquid will then continue to circulate through the bypass
line while the pump is in operation.
Lines Without a Bypass
Open all valves in the discharge line and start the power source. Priming is indicated by a positive
reading on the discharge pressure gauge or by a quieter operation. The pump may not prime
immediately because the suction line must first fill with liquid. If the pump fails to prime within five
minutes, stop it and check the suction line for leaks.
After the pump has been primed, partially close the discharge line throttling valve in order to fill the
line slowly and guard against excessive shock pressure which could damage pipe ends, gaskets,
sprinkler heads, and any other fixtures connected to the line. When the discharge line is completely
filled, adjust the throttling valve to the required flow rate.
DO NOT operate the pump against a closed discharge throttling valve for long periods
of time. If operated against a closed discharge throttling valve, pump components will
deteriorate, and the liquid could come to a boil, build pressure, and cause the pump
casing to rupture or explode.
Leakage
No leakage should be visible at pump mating surfaces, or at pump connections or fittings. Keep all
line connections and fittings tight to maintain maximum pump efficiency.
Liquid Temperature And Overheating
The
maximum liquid temperature for this pump is 160°F (71°C). DO NOT apply it at a higher
operating temperature.
Overheating can occur if operated with the valves in the suction or discharge lines closed. Operating
against closed valves could bring the liquid to a boil, build pressure, and cause the pump to rupture
or explode. If overheating occurs, stop the pump and allow it to cool before servicing it. Refill the
pump casing with cool liquid.
Allow an over ‐ heated pump to completely cool before servicing. DO NOT remove
plates, covers, gauges, or fittings from an over
‐ heated pump. Liquid within the pump
can reach boiling temperatures, and vapor pressure within the pump can cause parts
being disengaged to be ejected with great force. After the pump completely cools, drain the
liquid from the pump by removing the casing drain plug. Use caution when removing the plug to

17
IOM 490 SXT 3”X3”_1222
prevent injury to personnel from hot liquid.
As a safeguard against rupture or explosion due to heat, this pump is equipped with a pressure relief
valve which will open if vapor pressure within the pump casing reaches a critical point. If overheating
does occur, stop the pump immediately and allow it to cool before servicing it. Approach any
overheated pump cautiously. It is recommended that the pressure relief valve assembly be replaced
at each overhaul, or any time the pump casing overheats and activates the valve. Never replace this
valve with a substitute which has not been specified or provided by AMP.
Strainer Check
If a suction strainer has been shipped with the pump or installed by the user, check the strainer
regularly, and clean it as necessary. The strainer should also be checked if pump flow rate begins to
drop. If a vacuum suction gauge has been installed, monitor, and record the readings regularly to
detect strainer blockage.
Never introduce air or steam pressure into the pump casing or piping to remove a blockage. This
could result in personal injury or damage to the equipment. If backflushing is absolutely necessary,
liquid pressure must be limited to 50% of the maximum permissible operating pressure shown on
the pump performance curve.
Pump Vacuum Check
With the pump inoperative, install a vacuum gauge in the system, using pipe dope on the threads.
Block the suction line and start the pump. At operating speed, the pump should pull a vacuum of 20
inches (508,0 mm) or more of mercury. If it does not, check for air leaks in the seal, gasket, or
discharge valve.
Open the suction line and read the vacuum gauge with the pump primed and at operation speed.
Shut off the pump. The vacuum gauge reading will immediately drop proportionate to static suction
lift and should then stabilize. If the vacuum reading falls off rapidly after stabilization, an air leak
exists. Before checking for the source of the leak, check the point of installation of the vacuum
gauge.
STOPPING
Never halt the flow of liquid suddenly. If the liquid being pumped is stopped abruptly, damaging
shock waves can be transmitted to the pump and piping system. Close all connecting valves slowly.
On engine driven pumps, reduce the throttle speed slowly and allow the engine to idle briefly before
stopping.
If the application involves a high discharge head, gradually close the discharge throttling
valve before stopping the pump.
After stopping the pump, lock out or disconnect the power source to ensure that the
pump will remain inoperative
.
DO NOT operate the pump against a closed discharge throttling valve for long periods
of time. If operated against a closed discharge throttling valve, pump components will
deteriorate, and the liquid could come to a boil, build pressure, and cause the pump
casing to rupture or explode.
Cold Weather Preservation
In below freezing conditions, drain the pump to prevent damage from freezing. Also, clean out any
solids by flushing with a hose. Operate the pump for approximately one minute; this will remove any

18
IOM 490 SXT 3”X3”_1222
remaining liquid that could freeze the pump rotating parts. 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, drain the pump, and
flush it thoroughly with clean water. To prevent large solids from clogging the drain port and
preventing the pump from completely draining, insert a rod or stiff wire in the drain port, and agitate
the liquid during the draining process. Clean out any remaining solids by flushing with a hose.
BEARING TEMPERATURE CHECK
Bearings normally run at higher than ambient temperatures because of heat generated by friction.
Temperatures up to 160°F (71°C) are considered normal for bearings, and they can operate safely to
at least 180°F (82°C).
Checking bearing temperatures by hand is inaccurate. Bearing temperatures can be measured
accurately by placing a contact
‐ type thermometer against the housing. Record this temperature for
future reference.
A sudden increase in bearing temperature is a warning that the bearings are at the point of failing to
operate properly. Make certain that the bearing lubricant is of the proper viscosity and at the correct
level (see
LUBRICATION in MAINTENANCE AND REPAIR ). 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.
Continued operation should bring the temperatures down to normal levels.
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. Follow approved local Lock-Out/Tag-Out procedures 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 cautiously.
7. Drain the pump.

19
IOM 490 SXT 3”X3”_1222
TROUBLE
POSSIBLE CAUSE
PROBABLE REMEDY
PUMP FAILS TO
PRIME
Not enough liquid in casing.
Add liquid to casing. See PRIMING.
Suction check valve contaminated or
damaged.
Clean or replace check valve.
Air leak in suction line.
Correct leak.
Lining of suction hose collapsed.
Replace suction hose.
Leaking or worn seal or pump gasket.
Check pump vacuum. Replace leaking or
worn seal or gasket.
Suction lift or discharge head too high.
Check piping installation and install bypass
line if needed. See INSTALLATION.
Strainer clogged.
Check strainer and clean if necessary.
PUMP STOPS OR
FAILS TO DELIVER
RATED FLOW OR
PRESSURE
Air leak in suction line.
Correct leak.
Lining of suction hose collapsed.
Replace suction hose.
Leaking or worn seal or pump gasket.
Check pump vacuum. Replace leaking or
worn seal or gasket.
Strainer clogged.
Check strainer and clean if necessary.
Suction intake not submerged at proper level
or sump too small.
Check installation and correct submergence
as needed.
Impeller or other wearing parts worn or
damaged.
Replace worn or damaged parts. Check that
impeller is properly centered and rotates
freely.
Impeller clogged.
Free impeller of debris.
Pump speed too slow.
Check driver output; check belts or couplings
for slippage.
Discharge head too high.
Install bypass line.
Suction lift too high.
Measure lift w/vacuum gauge. Reduce lift
and/or friction losses in suction line.
PUMP REQUIRES
TOO MUCH POWER
Pump speed too high.
Check driver output; check that sheaves or
couplings are correctly sized.
Discharge head too low.
Adjust discharge valve.
Liquid solution too thick.
Dilute if possible.
Bearing(s) frozen.
Disassemble pump and check bearing(s).
PUMP CLOGS
FREQUENTLY
Liquid solution too thick.
Dilute if possible.
Discharge flow too slow.
Open discharge valve fully to increase flow
rate and run power source at maximum
governed speed.
Suction check valve or foot valve clogged or
binding.
Clean valve.