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CAT Pumps 781 Service Manual

CAT Pumps 781 Service Manual

8 & 28pfr plunger pump

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8 & 28PFR PLUNGER PUMP SERVICE MANUAL
8 FRAME BLOCK-STYLE MANIFOLD:
28 FRAME BLOCK-STYLE MANIFOLD:
Optimum performance of the pump is dependent upon the entire liquid system and will be obtained only
with the proper selection, installation of plumbing, and operation of the pump and accessories.
SPECIFICATIONS: Maximum specifications refer to individual attributes. It is not
implied that all maximums can be performed simultaneously. If more than one
maximum is considered, check with your CAT PUMPS supplier to confirm the proper
performance and pump selection. Refer to individual pump Data Sheet for complete
specifications, parts list and exploded view.
LUBRICATION: Fill crankcase with special CAT PUMP oil per pump specifications
[8PFR - 25 oz., 28PFR - 84 oz.]. DO NOT RUN PUMP WITHOUT OIL IN
CRANKCASE. Change initial fill after 50 hours running period. Thereafter, change oil
every 3 months or 500 hour intervals.
PUMP ROTATION: Pump was designed for forward rotation to allow optimum lubri-
cation of the crosshead area. Reverse rotation is acceptable if the crankcase oil
level is increased slightly above center dot to assure adequate lubrication.
PULLEY SELECTION: Select size of motor pulley required to deliver the desired flow
from Horsepower Requirement and Pulley Selection Chart (refer to Tech Bulletin
003 or individual Data Sheet).
DRIVE SELECTION: The motor or engine driving the pump must be of adequate
horsepower to maintain full RPM when the pump is under load. Select the electric
motor from the Horsepower Requirement Chart according to required pump
discharge flow, maximum pressure at the pump and drive losses of approximately
3-5%. Consult the manufacturer of gas or diesel engine for selection of the proper
engine size.
MOUNTING: Mount the pump on a rigid, horizontal surface in a manner to permit
drainage of crankcase oil. An uneven mounting surface will cause extensive dam-
age to the pump base. To minimize piping stress, use appropriate flexible hose to
inlet and discharge ports. Use the correct belt; make sure pulleys are aligned.
Excessive belt tension may be harmful to the bearings. Hand rotate pump before
starting to be certain shaft and bearings are free moving.
LOCATION: If the pump is used in extremely dirty or humid conditions, it is recom-
mended pump be enclosed. Do not store or operate in excessively high temperature
areas or enclosed without proper ventilation.
INLET CONDITIONS: Refer to complete Inlet Condition Check-List in this manual
before starting system. DO NOT STARVE THE PUMP OR RUN DRY.Temperatures
above 130°F are permissible. Add 1/2 PSI inlet pressure per each degree F over
130°F. Elastomer or RPM changes may be required. See Tech Bulletin 002 or call
CAT PUMPS for recommendations.
C.A.T.: Installation of a C.A.T. (Captive Acceleration Tube) is recommended in ap-
plications with stressful inlet conditions such as high temperatures, booster pump
feed, long inlet lines or quick closing valves.
DISCHARGE PLUMBING: OPEN ALL VALVES BEFORE STARTING SYSTEM to
avoid deadhead overpressure condition and severe damage to the pump or system.
Install a Pulsation Dampening device on the discharge head or in the discharge line
as close to the head as possible. Be certain the pulsation dampener (Prrrrr-o-lator) is
properly precharged for the system pressure (refer to individual Data Sheet).
All systems require both a primary pressure regulating device (i.e., regulator, unloader) and a secondary pressure safety relief device (i.e., pop-off valve, safety valve).
Failure to install such relief devices could result in personal injury or damage to the pump or to system components. CAT PUMPS does not assume any liability or responsibility
for the operation of a customer's high pressure system.
World Headquarters
CAT PUMPS
1681 - 94th Lane N.E. Minneapolis, MN 55449 - 4324
Phone (763) 780-5440 — FAX (763) 780-2958
e-mail: techsupport@catpumps.com
www.catpumps.com
International Inquiries
FAX (763) 785-4329
e-mail: intlsales@catpumps.com
®
INSTALLATION AND START-UP INFORMATION
®
The Pumps with Nine Lives
781, 781K
2831, 2831K
A reliable Pressure Gauge should be installed near the discharge outlet of the high
pressure manifold. This is extremely important for adjusting pressure regulating
devices and also for proper sizing of the nozzle or restricting orifice. The pump is
rated for a maximum pressure; this is the pressure that is read at the
discharge manifold of the pump, NOT AT THE GUN OR NOZZLE.
Use PTFE thread tape or pipe thread sealant (sparingly) to connect accessories or
plumbing. Exercise caution not to wrap tape beyond the last thread to avoid tape
from becoming lodged in the pump or accessories. This condition will cause a mal-
function of the pump or system.
PRESSURE REGULATION: All systems require both a primary pressure regulating
device (i.e., regulator, unloader) and a secondary pressure safety relief device (i.e.,
pop-off valve, safety valve). The primary pressure device must be installed on the
discharge side of the pump. The function of the primary pressure regulating device
is to protect the pump from over pressurization, which can be caused by a plugged
or closed off discharge line. Over pressurization can severely damage the pump,
other system components and can cause bodily harm. The secondary safety relief
device must be installed in-line between the primary device and the pump or on
the opposite side of the manifold head.This will ensure pressure relief of the sys-
tem if the primary regulating device fails. Failure to install such a safely device will
void the warranty on the pump.
If a large portion of the pumped liquid is by-passed (not used) when the high pressure
system is running, this by-pass liquid should be routed to an adequately sized, baffled
supply tank or to drain. If routed to the pump inlet, the by-pass liquid can quickly
develop excessive heat and result in damage to the pump. A temperature
control device to shut the system down within the pump limits or multiple THERMO
VALVES must be installed in the by-pass line to protect the pump.
NOZZLES: A worn nozzle will result in loss of pressure. Do not adjust pressure
regulating device to compensate. Replace nozzle and reset regulating device to
system pressure.
PUMPED LIQUIDS: Some liquids may require a flush between operations or
before storing. For pumping liquids other than water, contact your CAT PUMPS
supplier.
SPECIAL "K" MODELS: Standard pumps have internal weep holes between the
V-Packings and Lo-Pressure Seals allowing the pumped liquid to cool the back side
of the packings. The "K" models do not have the internal weep holes and do not
connect to the inlet side. They have special ports on both sides of the inlet manifold
that can be fitted to an external flushing system to provide cooling and flushing.
STORING: For extended storing or between use in cold climates, drain all pumped
liquids from pump and flush with antifreeze solution to prevent freezing and
damage to the pump. DO NOT RUN PUMP WITH FROZEN LIQUID (refer to Tech
Bulletin 083).
WARNING
CAT PUMPS (U.K.) LTD.
1 Fleet Business Park, Sandy Lane, Church Crookham
FLEET, Hampshire, GU52 8BF, England
Phone Fleet 44 1252-622031 — Fax 44 1252-626655
e-mail: sales@catpumps.co.uk
N.V. CAT PUMPS INTERNATIONAL S. A.
Heiveldekens 6A, B-2550 Kontich, Belgium
Phone 32- 3- 450.71.50 — Fax 32-3- 450.71.51
e-mail: cpi@catpumps.be www.catpumps.be
CAT PUMPS DEUTSCHLAND GmbH
Buchwiese 2, D-65510 Idstein, Germany
Phone 49 6126-9303 0 — Fax 49 6126-9303 33
e-mail: catpumps@t-online.de www.catpumps.de
PN 31997 Rev D 3833

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Summary of Contents for CAT Pumps 781

  • Page 1 All systems require both a primary pressure regulating device (i.e., regulator, unloader) and a secondary pressure safety relief device (i.e., pop-off valve, safety valve). Failure to install such relief devices could result in personal injury or damage to the pump or to system components. CAT PUMPS does not assume any liability or responsibility for the operation of a customer’s high pressure system.
  • Page 2 (HSH) from the VBM. score o-ring sealing area. 3. On the model 781, insert two M8 x 114 metric threaded bolts 6. To separate Valve Assemblies, insert screwdriver into into the upper left and lower right intermediate holes on the Spring Retainer and press the backside of Valve until Seat VBM face.
  • Page 3 Lo-Pressure Seal and Adapter Plunger arrangement Reassembly 9. On the model 781, place Seat with O-Rings and Back-up- Rings on work surface with dish side up. Then place the NOTE: For certain applications apply liquid gasket to the Valve onto the Seat with dish side down/Spring tab up. On O-Ring crevices and seal surfaces.
  • Page 4: Torque Sequence

    6. Invert IMDM and place on flat work surface with crankcase side up. Models 2831 and 2831K 7. On the model 781, use reverse pliers to remove three Inlet Adapter Assemblies by grasping the Inlet Adapter. 1. Examine Lo-Pressure Seals for wear to the internal ridges, outer surfaces or for broken springs and replace as needed.
  • Page 5 Retainer Studs. Thread on Plunger Retainer and torque per chart. 10. On the model 781, install Seal Retainers with drain slots facing the crankcase with openings to the top and bottom. On the model 2831 the drain openings must face the manifold.
  • Page 6: Preventative Maintenance Check-List

    Higher temperature liquids tend to vaporize and require positive heads and C. A.T. to assure adequate inlet supply. * If other than CAT PUMPS special multi-viscosity ISO68 oil is used, When using an inlet supply reservoir, size it to provide adequate liquid to accom- change cycle should be every 300 hours.
  • Page 7 Handy Formulas to Help You HOSE FRICTION LOSS PRESSURE DROP IN PSI PER 100 FT OF HOSE WITH TYPICAL WATER FLOW RATES Q. How can I find the RPM needed to get specific GPM Water* Hose Inside Diameters, Inches Flow (Gallons Per Minute) I want? 5/16 1"...
  • Page 8: Diagnosis And Maintenance

    CAT PUMPS are very easy pumps to service and require far less frequent service than most pumps. Typically, only common tools are required, making in-field service convenient, however, there are a few custom tools, special to certain models, that do simplify the process. This service manual is designed to assist you with the disassembly and reassembly of your pump.

This manual is also suitable for:

2831k2831781k