CAT Pumps 66DX Series User manual

PN 30004 Rev E 5510
WARNING
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.
Products described hereon are covered by one or more of the following U.S. patents 3558244, 3652188, 3809508, 3920356, 3930756 and 5035580
CAT PUMPS (U.K.) LTD.
1 Fleet Business Park, Sandy Lane, Church Crookham, Fleet
Hampshire GU52 8BF, England
Phone Fleet 44 1252-622031 — Fax [phone]
e-mail: [email protected]
N.V. CAT PUMPS INTERNATIONAL S.A.
Heiveldekens 6A, 2550 Kontich, Belgium
Phone [phone] — Fax [phone]
e-mail: [email protected] www.catpumps.be
CAT PUMPS DEUTSCHLAND GmbH
Buchwiese 2, D-65510 Idstein, Germany
Phone [phone] — Fax [phone]
e-mail: [email protected] www.catpumps.de
World Headquarters
CAT PUMPS
1681-94th Lane N.E. Minneapolis, MN 55449-4324
Phone [phone] — FAX [phone]
e-mail:[email protected]
www.catpumps.com
International Inquiries
FAX [phone]
e-mail:[email protected]
®
The Pumps with Nine Lives
5DX, 6DX, 66DX PLUNGER PUMP SERVICE MANUAL
®
5DX MODELS: 5DX30G1, 5DX35G1, 5DX40G1, 5DX50G1
6DX MODELS: 6DX35G1I, 6DX40G1I
66DX MODELS: 66DX30G1I, 66DX35G1I, 66DX40G1I
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 Data Sheets for complete specifications, parts list and
exploded view.
LUBRICATION: Fill crankcase with special CAT PUMP Hydraulic oil per
pump specifications [5DX-22.65 oz., 6DX-18.6 oz., 66DX-18.0 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.
DRIVE SELECTION: The pump shaft size is a 1" gas shaft. The engine
driving the pump must be of adequate horsepower to maintain full
RPM when the pump is under load. Select the horsepower requirement
according to required pump discharge flow and maximum pressure at the
pump! Consult the manufacturer of gas or diesel engine for selection of
the proper engine.
MOUNTING: All DX models are direct-drive and come with a flange adapter
that mounts to a gas engine. Before mounting pump to gas engine, apply
PN 6106 antiseize lubricant to pump shaft. Refer to Technical Bulletin 055
for instructions on removing pump from gas engine. To minimize piping
stress, use appropriate flexible hose to inlet and discharge ports.
LOCATION: If the pump is used in extremely dirty or humid conditions, it is
recommended pump be enclosed. Do not store or operate in excessively
high temperature areas or without proper ventilation. Liquid 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.
INLET CONDITIONS: Refer to complete Inlet Condition Check-List in this
manual before starting system. DO NOT STARVE THE PUMP OR RUN DRY.
DISCHARGE CONDITIONS: OPEN ALL VALVES BEFORE STARTING
SYSTEM to avoid deadhead overpressure condition and severe damage
to the pump or system.
Areliable 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 which would be 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 acces-
sories 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 malfunction 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 pump or
on the opposite side of the manifold head. This will ensure pressure
relief of the system if the primary regulating device fails. Failure to install
such a safely device will void the warranty on 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 opera-
tions or before storing. For pumping liquids other than water, contact
your CAT PUMPS supplier.
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).
INSTALLATION AND START-UP INFORMATION
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.

SERVICING THE VALVES
Disassembly
1. Using an M24 hex tool, remove the top discharge and
bottom inlet Valve Plugs.
2. Using a pliers, grasp the Spring Retainer by the tab at
the top and remove from the valve chamber.
3. If the Valve assembly separates during removal, remove
the Spring and Valve with a needle nose pliers. Then
with a reverse pliers, remove the Valve Seat from the
valve chamber.
4. To separate the Valve assembly, insert a screwdriver into
the side of the Retainer and press on the back side of
the Valve until Seat separates from the Spring Retainer.
5. Remove O-Ring from each Seat and Valve Plug.
Reassembly
1. Examine Spring Retainers for internal wear or breaks in
the structure and replace as needed.
2. Examine Springs for fatigue or breaks and replace as
needed.
3. Examine Valves and Seats for grooves, pitting or wear
and replace as needed.
4. Examine Seat and Valve Plug O-Rings for cuts or wear
and replace as needed.
NOTE: Inlet and Discharge Valve Assemblies are
interchangeable. Two Valve Kits are needed for a
complete valve change.
5. Lubricate and install new O-Ring onto outside diameter
of Seat.
6. Place Seat on work surface with small diameter side
up.
7. Place Valve onto Seat with concave side down.
8. Place Spring on Valve.
9. Install Spring Retainer with deep stepped end over
Spring and snap onto Seat.
10. Press complete Valve assembly into each valve cham-
ber until completely seated.
11. Lubricate and install new O-Ring onto each Valve Plug.
12. Apply Loctite®242®to threads of each Valve Plug and
thread in hand tight. Torque to specifications per chart.
CAUTION: Before commencing with service, shut off drive (electric motor, gas or diesel engine) and
turn off water supply to pump. Relieve all discharge line pressure by triggering gun or opening valve in
discharge line. Inspect and service all system accessories on the same schedule as your pump.
After servicing is completed, turn on water supply to pump, start drive, reset pressure regulating device and
secondary valve, read system pressure on the gauge at the pump head. Check for any leaks, vibration or
pressure fluctuations and resume operation
Removal of Valve Assemblies Valve Assembly Components Separation of Manifold Head from Crankcase

SERVICING THE SEALS
Disassembly
1. Using an M6 allen wrench, remove the eight Hex
Socket Head (HSH) screws from the face of the
Manifold Head.
2. Insert flat head screwdrivers on each side between the
Crankcase and Manifold Head. Gently apply pressure to
the head to begin separation.
3. Support the Manifold Head from the underside and pull
the Manifold Head away from the crankcase.
CAUTION: Keep the Manifold Head properly
aligned with the Ceramic Plungers when removing
to avoid damage to the plungers.
NOTE: The Seal Case may stay in the manifold or
on the plungers.
4. Place Manifold Head on work surface with crankcase
side up.
5. Remove Seal Retainer from each Plunger Rod.
6. Use a screwdriver to pry out the Lo-Pressure Seal from
each Seal Case.
CAUTION: Screwdriver will damage seal during
removal.
7. Use reverse pliers to remove Seal Case from each seal
chamber.
NOTE: Insert the reverse pliers into the second lip
to avoid damage to the Seal Case.
8. Carefully insert a small screwdriver under the O-Ring
and roll the O-Ring off each Seal Case.
CAUTION: Exercise caution as the screwdriver may
score O-Ring sealing surface.
9. Remove V-Packing and Male Adapter from each seal
chamber by hand or with a reverse pliers.
Reassembly
1. Examine the manifold chamber walls for scale buildup
or damage.
2. Examine V-Packings for frayed edges or uneven wear
and replace as needed.
3. Examine Seal Case O-Rings for cuts or deterioration
and replace as needed.
4. Examine Lo-Pressure Seals for wear to the internal
ridges and outer surfaces or for broken springs and
replace as needed.
NOTE: Seals and O-Rings are available in Seal Kits.
5. Examine Seal Retainers for deformation and replace as
needed.
6. Lubricate and install Male Adapter with notch side
down. Lubricate and install new V-Packing by hand
into seal chamber with grooved side down.
7. Lubricate and install O-Ring on each Seal Case. Press
small end of Seal Case into each seal chamber.
8. Lubricate and press new Lo-Pressure Seal into each
Seal Case with the garter spring down.
9. Examine Ceramic Plungers for scoring, scale buildup,
chips or cracks and replace as needed.
10. Slide Seal Retainer over each Ceramic Plunger with
the openings to the top and bottom. Press into the
Crankcase.
11. Rotate crankshaft by hand so the two outside plungers
are extended equally.
12. Lightly lubricate Ceramic Plungers, then carefully slide
the Manifold Head over the Ceramic Plungers, sup-
porting it from the underside to avoid damage to the
plungers or seals. Press the Manifold Head flush with
the Crankcase.
13. Thread HSH screws in hand tight. Torque in sequence
to specifications in torque chart.
Removal of Seal Case and Lo-Pressure Seal V-Packing and Lo-Pressure Seal Components Reassembly of V-Packings

SERVICING THE PLUNGERS
Disassembly
NOTE: Refer to Tech Bulletin 071 (old 4HP Plunger
Rod Change) for additional information on Ceramic
Plungers.
1. Disconnect all plumbing from the manifold head.
2. Remove unloader by using a M22 wrench to remove
the top unloader Flow-Thru screw and a M27 wrench to
remove the bottom unloader Flow-Thru screw.
3. Using an M6 Allen Tool remove the eight HSH screws
from the face of the Manifold head.
4. Insert flat head screwdrivers on each side between the
Crankcase and Manifold Head and gently apply pres-
sure to the head to begin separation.
5. Support the Manifold Head from the underside and pull
the Manifold Head away from the crankcase.
CAUTION: Keep the Manifold Head properly
aligned with the Ceramic Plungers when removing
to avoid damage to the plungers or seals.
6. Remove Seal Retainer from each Plunger Rod.
7. Using a M10 hex tool, loosen the Plunger Retainer on
each Plunger Rod approximately three to four turns.
8. Push the Ceramic Plunger back towards the Crankcase
to separate from the Plunger Retainer and proceed with
unthreading the Plunger Retainer by hand.
9. Remove the Barrier Slinger, Ceramic Plunger and Seal
Washer from each Plunger Retainer.
Reassembly
1. Visually inspect the Crankcase Oil Seals for deteriora-
tion or leaks. Contact CAT PUMPS for assistance with
replacement. See SERVICING THE CRANKCASE
SECTION.
2. Examine Seal Washers and Barrier Slingers for cuts for
wear and replace as needed.
3. Examine Plunger Retainers for damaged threads and
replace as needed.
4. Examine the Ceramic Plungers for scoring, scale
buildup, chips or cracks and replace as needed. The
Ceramic Plungers typically do not need to be replaced
with every seal servicing.
5. Install new Seal Washer onto each Plunger Retainer.
6. Slide Plunger Retainer with Seal Washer into flat end of
Ceramic Plunger. Install Barrier Slinger on Plunger
Retainer.
NOTE: Ceramic Plungers can only be installed in
one direction. Slotted end of Ceramic Plunger
should face toward crankcase.
7. Apply Loctite®242®to exposed threaded end of Plunger
Retainer.
8. Install Ceramic Plunger with Plunger Retainer, Seal
Washer and Barrier Slinger over each Plunger Rod
shoulder and thread hand tight. Torque to specifications
per chart.
9. Slide Seal Retainer over each Ceramic Plunger with the
openings to the top and bottom. Press into Crankcase.
10. Rotate crankshaft by hand so the two outside plungers
are extended equally.
11. Lightly lubricate Ceramic Plungers, then carefully slide
the Manifold Head over the Ceramic Plungers, sup-
porting it from the underside to avoid damage to the
plungers or seals. Press the Manifold Head flush with
the Crankcase.
12. Thread HSH screws in hand tight. Torque in sequence
to specifications in torque chart.
Removal of Plunger Retainer Ceramic Plunger and Retainer Components

TORQUE SEQUENCE
SERVICING THE CRANKCASE SECTION
1. While Manifold, Plungers and Seal Retainers are
removed, examine Crankcase Oil Seals for leaking and
wear.
2. Check for any signs of leaking at Bearing Covers, Rear
Cover, Drain Plug or Bubble Gauge.
3. Check oil level and for evidence of water in oil. Change
crankcase oil on a regular schedule. See Preventative
Maintenance Check-List.
4. Rotate Crankshaft by hand to feel for smooth bearing
movement.
5. Examine Crankshaft Oil Seals externally for drying,
cracking or leaking.
6. Contact CAT PUMPS or your local distributor if
crankcase service is evidenced.
SERVICING THE UNLOADER/CHEMICAL INJECTOR
Disassembly
1. Remove black Adjusting Handle.
2. Remove brass Adjusting Cap by turning in a counter-
clockwise direction.
3. Remove exposed Coil Spring and flat Spring Retainer.
4. Using a wrench, remove Piston Retainer by turning in a
counterclockwise direction.
NOTE: The Piston Stem and Valve Assembly
may fall out when the piston retainer is removed. If
so, proceed to step 7., If not, continue with step 5.
5. Use a needle nose pliers to remove Piston Stem and
Valve Assembly.
6. Separate Piston Stem from Valve/Ball Assembly by
securing the Valve/Ball Assembly near the Spacer.
Insert a screwdriver into slotted head of Piston Stem
and unthread from Valve/Ball Assembly.
CAUTION: Exercise extreme caution to avoid contact
and damage to the tapered surface of Valve/Ball
Assembly.
7. Examine Seat at the bottom of the unloader chamber
for grooves, pitting or wear, replace only as needed.
CAUTION: Seat will be damaged when removed.
8. On the 5DX model, remove Discharge Fitting with
O-Ring. On the 6DX and 66DX models remove
Chemical Injector with O-Ring.
9. Remove Spring and Check Valve with O-Ring.
Reassembly
NOTE: All O-Rings are available in an O-Ring Kit.
Other components sold separately.
1. If seat is worn or damaged, press new seat into
unloader chamber until squarely seated.
2. Examine Piston Stem, Washer, Spacer and Valve/Ball
Assembly for grooves, pitting or wear and replace as
needed. Examine O-Rings and Back-up Ring for cuts
or wear and replace as needed.
3. Lubricate and install O-Ring over slotted head of Piston
Stem, then position Back-up Ring on top of O-Ring.
4. Lubricate and install O-Rings on Spacer.
5. Install Washer and then Spacer with O-Rings onto
Piston Stem. Apply Loctite®242®to threads of Piston
Stem and screw Valve/BallAssembly onto Piston Stem.
6. Lower complete Piston Stem and Valve Assembly into
unloader chamber with Valve/Ball Assembly facing
downward.
7. Examine Piston Retainer for damaged threads or wear
and replace as needed. Examine O-Ring for cuts or
wear and replace as needed.
8. Apply Loctite®242®to Piston Retainer threads and then
hand thread Piston Retainer into unloader by turning in
a clockwise direction, and then tighten with wrench.
9. Examine Spring Retainer and Coil Spring for fatigue or
breaks and replace as needed.
10. Place Spring Retainer into Piston Retainer, followed by
Coil Spring.
11. Thread brass Adjusting Cap onto Piston Retainer by
turning in a clockwise direction.
12. On the 66DX models, slide blackAdjusting Handle over
brass Adjusting Cap.
13. On the 6DX and 66DX models, examine Chemical
Injector Check Valve and Spring for fatigue or wear and
replace as needed. Examine O-Ring for cuts or wear
and replace as needed.
14. Install Spring into inlet port of Chemical Injector.
15. Lubricate and install Check Valve with O-Ring into inlet
port of Chemical Injector with O-Ring facing out.
16. Apply Loctite®242®to threads of Chemical Injector and
hand thread into unloader by turning in a clockwise
direction and then tighten with wrench.
71 35
64 28
Loctite and 242 are registered trademarks of the Henkel Corporation

INLET CONDITION CHECK-LIST
Review Before Start-Up
Inadequate inlet conditions can cause serious malfunctions in the best
designed pump. Surprisingly, the simplest of things can cause the most
severe problems or go unnoticed to the unfamiliar or untrained eye.
REVIEW THIS CHECK-LISTBEFORE OPERATION OFANYSYSTEM.
Remember, no two systems are alike, so there can be no ONE best
way to set-up a system. All factors must be carefully considered.
INLET SUPPLY should exceed the maximum flow being delivered by the
pump to assure proper performance.
❏Open inlet shut-off valve and turn on water supply to avoid starving the
pump. DO NOT RUN PUMP 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.
❏Avoid closed loop systems especially with high temperature, ultra-high
pressure or large volumes. Conditions vary with regulating/unloader
valve.
❏Higher temperature liquids tend to vaporize and require positive heads.
❏When using an inlet supply reservoir, size it to provide adequate
liquid to accommodate the maximum output of the pump, generally a
minimum of 6-10 times the GPM (however, a combination of system fac-
tors can change this requirement); provide adequate baffling in the tank
to eliminate air bubbles and turbulence; install diffusers on all return
lines to the tank.
INLET LINE SIZE should be adequate to avoid starving the pump.
❏Line size must be a minimum of one size larger than the pump inlet
fitting. Avoid tees, 90 degree elbows or valves in the inlet line of the
pump to reduce the risk of flow restriction and cavitation.
❏The line MUST be a FLEXIBLE hose, NOT a rigid pipe, and reinforced
on SUCTION systems to avoid collapsing.
❏The simpler the inlet plumbing the less the potential for problems. Keep
the length to a minimum, the number of elbows and joints to a minimum
(ideally no elbows) and the inlet accessories to a minimum.
❏Use pipe sealant to assure air-tight, positive sealing pipe joints.
INLET PRESSURE should fall within the specifications of the pump.
❏Acceleration loss of liquids may be increased by high RPM, high
temperatures, low vapor pressures or high viscosity and may require a
pressurized inlet to maintain adequate inlet supply.
❏Optimum pump performance is obtained with +20 PSI (1.4 BAR) inlet
pressure. With adequate inlet plumbing, most pumps will perform with
flooded suction. Maximum inlet pressure is 75 PSI (5.25 BAR).
❏After prolonged storage, pump should be rotated by hand and purged
of air to facilitate priming. Disconnect the discharge port and allow liquid
to pass through pump and measure flow.
INLET ACCESSORIES are designed to protect against over pressuriza-
tion, control inlet flow, contamination or temperature and provide ease of
servicing.
❏A shut-off valve is recommended to facilitate maintenance.
❏A stand pipe can be used in some applications to help maintain a
positive head at the pump inlet line.
❏Inspect and clean inlet filters on a regular schedule to avoid flow restriction.
❏A pressure transducer is necessary to accurately read inlet pressure.
Short term, intermittent cavitation will not register on a standard
gauge.
❏All accessories should be sized to avoid restricting the inlet flow.
❏All accessories should be compatible with the solution being pumped to
prevent premature failure or malfunction.
BY-PASS TO INLET
❏The standard 5DX, 6DX and 66DX pump comes with a Regulating
Unloader. This Regulating Unloader has a built-in by-pass channel
which routes liquid back to the inlet during the by-pass mode. No addi-
tional plumbing is required.
❏It is critical that a Thermo Valve be installed to protect the pump during
prolonged by-pass. The Thermo Valve may be installed on the
opposite side of the Manifold Head or by replacing the Flow-Thru Screw
with the Flow-Thru Direct Mount Thermo Valve (PN 33920).
TORQUE CHART
Torque
Pump Model Thread Tool Size [P/N] in.lbs. ft.lbs. Nm
Plunger Retainer M6 M10 Hex [25082] 55 4.6 6.2
Flow-Thru Screws
Inlet 1/2" NPT M27 Hex 360 30 40
Discharge 3/8" NPT M22 Hex 384 32 44
Manifold Head Screws M8 M6 Allen [30941] 132 11.0 15
Valve Plugs M22 M24 Hex [44046] 870 72.5 98
Rear Cover Screws M6 M10 Hex [25082] 50 4.0 5.4
Bearing Cover Screws
5DX, 6DX M8 M13 Hex [25324] 115 9.58 13
66DX M6 M10 Hex [25082] 50 4.0 5.4
Bubble Oil Gauge M28 Oil Gauge Tool [44050] 45 3.6 5
TECHNICAL BULLETIN REFERENCE CHART
No. Subject Models
002 Inlet Pressure VS Liquid Temperature All Models
024 Lubrication of Lo-Pressure Seals All Models
036 Cylinder and Plunger Reference Chart All Models
043 Plunger Pump LPS and HPS Servicing All Plunger Models
055 Removing Pumps from Gas or Electric Motor 2SF, 2SFX, 2X, 2DX, 3DX, 3SP,
4SF, 4HP, 5DX, 6DX, 66DX
060 Baffle Assembly 34170
071 Plunger Rod Change - HP Pumps 4HP, 5DX
074 Torque Chart All Models
083 Winterizing a Pump All Models
PREVENTATIVE MAINTENANCE CHECK-LIST
Check Daily Weekly 50 hrs. 500 hrs.* 1500 hrs.** 3000 hrs.**
Clean Filters x
Oil Level/Quality x
Oil Leaks x
Water Leaks x
Belts, Pulley x
Plumbing x
Initial Oil Change x
Oil Change x
Seal Change x
Valve Change x
Accessories x
* If other than CAT PUMPS special multi-viscosity ISO68 oil is used,
change cycle should be every 300 hours.
** Each system’s maintenance cycle will be exclusive. If system perfor-
mance decreases, check immediately. If no wear at 1500 hours, check
again at 2000 hours and each 500 hours until wear is observed.
Valves typically require changing every other seal change.
Duty cycle, temperature, quality of pumped liquid and inlet feed
conditions all effect the life of pump wear parts and service cycle.
** Remember to service the regulator/unloader at each seal servicing
and check all system accessories and connections before resuming
operation.

Q. How can I find the RPM needed to get specific GPM
(Gallons Per Minute) I want? Rated RPM
A. Desired RPM = Desired GPM x Rated GPM
Q. I have to run my pump at a certain RPM. How do I figure
the GPM I’ll get? Rated GPM
A. Desired GPM = Desired RPM x Rated RPM
Q. Is there a simple way to find the approximate horsepower
I’ll need to run the pump?
A. Electric Brake GPM x PSI (Standard 85%
Horsepower Required =1460 Mech. Efficiency)
Q. What size motor pulley should I use?
Pump RPM
A. Pump Pulley (Outer Diameter) x Motor/Engine RPM
Q. How do I calculate the torque for my hydraulic drive
system? GPM x PSI
A. Torque (ft. lbs.) = 3.6 RPM
( )
One or several of the conditions shown in the chart below may
contribute to cavitation in a system resulting in premature wear,
system downtime and unnecessary operating costs.
CONDITION SOLUTION
Inadequate inlet ●Increase line size to the inlet port or one size
line size larger
Water hammering ●Install C.A.T. Tube
liquid acceleration/ ●Move pump closer to liquid supply
deacceleration
Rigid Inlet Plumbing ●Use flexible wire reinforced hose to absorb
pulsation and pressure spikes
Excessive Elbows in ●Keep elbows to a minimum and less than 90°
Inlet Plumbing
Excessive liquid ●Use Thermo Valve in bypass line
Temperature ●Do not exceed pump temperature specifications
●Substitute closed loop with baffled holding tank
●Adequately size tank for frequent or high
volume bypass
●Pressure feed high temperature liquids
●Properly ventilate cabinets and rooms
Air Leaks in Plumbing ●Check all connections
●Use PTFE thread tape or pipe thread sealant
Agitation in Supply ●Size tank according to pump output —
Tank Minimum 6-10 times system GPM
●Baffle tank to purge air from liquid and
separate inlet from discharge
High Viscosity Liquids ●Verify viscosity against pump specifications
before operation
●Elevate liquid temperature enough to reduce
viscosity
●Lower RPM of pump
●Pressure feed pump
●Increase inlet line size
Clogged Filters ●Perform regular maintenance or use clean
filters to monitor build up
●Use adequate mesh size for liquid and pump
specifications
Handy Formulas to Help You
(Consult
Engine Mfr.)
TYPICAL RESERVOIR TANK
RECOMMENDED 6 TO 10 TIMES SYSTEM CAPACITY
Avoid Cavitation Damage
1/4 5/16 3/8 1/2 5/8 3/4 1"
0.5 16 5 2
154 20 7 2
2180 60 25 6 2
3380 120 50 13 4 2
4220 90 24 7 3
5320 130 34 10 4
6220 52 16 7 1
8300 80 25 10 2
10 450 120 38 14 3
15 900 250 80 30 7
20 1600 400 121 50 12
25 650 200 76 19
30 250 96 24
40 410 162 42
50 600 235 62
60 370 93
*At a fixed flow rate with a given size hose, the pressure drop across a given hose length
will be directly proportional. A 50 ft. hose will exhibit one-half the pressure drop of a 100 ft.
hose. Above values shown are valid at all pressure levels.
PRESSURE DROP IN PSI PER 100 FT OF HOSE
WITH TYPICAL WATER FLOW RATES
Hose Inside Diameters, Inches
Water*
Flow
Gal/Min
HOSE FRICTION LOSS
Water
GPM
1
2
3
5
8
10
15
25
40
60
80
100
Steel Pipe—Nominal Dia.
1/4 3/8 1/2 3/4 1 11/411/2
8.5 1.9
30 7.0 2.1
60 14 4.5 1.1
150 36 12 2.8
330 86 28 6.7 1.9
520 130 43 10 3.0
270 90 21 6.2 1.6
670 240 56 16 4.2 2.0
66 17 8.0
37 17
52 29
210 107 48
Brass Pipe—Nominal Dia.
1/4 3/8 1/2 3/4 1 11/411/2
6.0 1.6
20 5.6 1.8
40 11 3.6
100 28 9.0 2.2
220 62 21 5.2 1.6
320 90 30 7.8 2.4
190 62 16 5.0 1.5
470 150 40 12 3.8 1.7
39 11 5.0
23 11
40 19
61 28
Copper Tubing O.D. Type L
1/4 3/8 1/2 5/8 3/4 7/8
120 13 2.9 1.0
400 45 10 3.4 1.3
94 20 6.7 2.6
230 50 17 6.1 3.0
500 120 40 15 6.5
180 56 22 10
120 44 20
330 110 50
550 200 88
WATER LINE PRESSURE LOSS
PRESSURE DROP IN PSI PER 100 FEET
1/2 0.622 0.41 18.5 9.3 0.78 1.67 3.71 0.93 3.33
3/4 0.824 0.54 24.5 12.3 1.03 2.21 4.90 1.23 4.41
1 1.049 0.69 31.2 15.6 1.31 2.81 6.25 1.56 5.62
11/41.380 0.90 41.0 20.5 1.73 3.70 8.22 2.06 7.40
11/21.610 1.05 48.0 24.0 2.15 4.31 9.59 2.40 8.63
2 2.067 1.35 61.5 30.8 2.59 5.55 12.30 3.08 11.60
21/22.469 1.62 73.5 36.8 3.09 6.61 14.70 3.68 13.20
3 3.068 2.01 91.5 45.8 3.84 8.23 18.20 4.57 16.40
4 4.026 2.64 120.0 60.0 5.03 10.80 23.90 6.00 21.60
Nominal
Pipe
Size
Inches
Inside
Diameter
Inches
RESISTANCE OF VALVES AND FITTINGS
Gate
Valve Globe Valve Angle Valve 45˚ Elbow 90˚ Elbow
180˚
Close
Ret
Tee
Thru
Run
Arriving at a total line pressure loss, consideration should then be given to
pressure loss created by valves, fittings and elevation of lines.
If a sufficient number of valves and fittings are incorporated in the system to
materially affect the total line loss, add to the total line length, the equivalent
length of line of each valve or fitting.
Tee
Thru
Branch
Equivalent Length of Standard Pipe in Feet
Bypass Line
(from regulator or unloader)
Level Sensing
Device
Bypass Line
(from regulator or
unloader)
MIN. 4"
1.5 x D (Min.)
Minimum Two Baffles
Sealed at Bottom
Minimum
Liquid
Level
FILTER
MIN. 4"
Flexible Hose
to Pump
Supply Line
(Dia of pipe)
T
XD
→
→
→
→
→
→
→
→
→

DIAGNOSIS AND MAINTENANCE
One of the most important steps in a high pressure system is to establish a regular maintenance program. This will vary slightly with each
system and is determined by various elements such as the duty cycle, the liquid being pumped, the actual specifications vs rated specifications
of the pump, the ambient conditions, the inlet conditions and the accessories in the system. A careful review of the necessary inlet conditions
and protection devices required before the system is installed will eliminate many potential problems.
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. The following guide will assist in determining the cause
and remedy to various operating conditions. You can also review our FAQ or SERVICE sections on our WEB SITE for more facts or contact CAT
PUMPS directly.
PROBLEM PROBABLE CAUSE SOLUTION
Low pressure •Worn nozzle. •Replace with properly sized nozzle.
•Air leak in inlet plumbing. •Tighten fittings and hoses. Use PTFE liquid or tape.
•Pressure gauge inoperative or not registering accurately. •Check with new gauge. Replace worn or damaged gauge.
•Relief valve stuck, partially plugged or improperly adjusted. •Clean/adjust relief valve. Replace worn seats/valves and o-rings.
•Inlet suction strainer (filter) clogged or improperly sized. •Clean filter. Use adequate size filter. Check more frequently.
•Abrasives in pumped liquid. •Install proper filter.
•Leaky discharge hose. •Replace discharge hose with proper rating for system.
•Inadequate liquid supply. •Pressurize inlet and install C.A.T.
•Severe cavitation. •Check inlet conditions.
•Worn seals. •Install new seal kit. Increase frequency of service.
•Worn or dirty inlet/discharge valves. •Clean inlet/discharge valves or install new valve kit.
Pulsation •Faulty Pulsation Dampener. •Check precharge. If low, recharge, or install a new dampener.
•Foreign material trapped in inlet/discharge valves. •Clean inlet/discharge valves or install new valve kit.
Water leak
•Under the manifold •Worn V-Packings or Lo-Pressure Seals. •Install new seal kit. Increase frequency of service.
•Worn adapter o-rings. •Install new o-rings.
•Into the crankcase •Humid air condensing into water inside the crankcase. •Install oil cap protector. Change oil every 3 months or 500 hours.
•Excessive wear to seals and V-Packings. •Install new seal kit. Increase frequency of service.
Knocking noise
•Inlet supply •Inadequate inlet liquid supply. •Check liquid supply. Increase line size, pressurize or install C.A.T.
•Bearing •Broken or worn bearing. •Replace bearing.
Oil leak
•Crankcase oil seals. •Worn crankcase oil seals. •Replace crankcase oil seals.
•Crankshaft oil seals and o-rings. •Worn crankshaft oil seals or o-rings on bearing cover. •Remove bearing cover and replace o-rings and/or oil seals.
•Drain plug •Loose drain plug or worn drain plug o-ring. •Tighten drain plug or replace o-ring.
•Bubble gauge •Loose bubble gauge or worn bubble gauge gasket. •Tighten bubble gauge or replace gasket.
•Rear cover •Loose rear cover or worn rear cover o-ring. •Tighten rear cover or replace o-ring.
•Filler cap •Loose filler cap or excessive oil in crankcase. •Tighten filler cap. Fill crankcase to specified capacity.
Pump runs extremely rough
•Inlet conditions •Restricted inlet or air entering the inlet plumbing •Correct inlet size plumbing. Check for air tight seal.
•Pump valves •Stuck inlet/discharge valves. •Clean out foreign material or install new valve kit.
•Pump seals •Leaking V-Packings or Lo-Pressure seals. •Install new seal kit. Increase frequency of service.
Premature seal failure •Scored plungers. •Replace plungers.
•Over pressure to inlet manifold. •Reduce inlet pressure per specifications.
•Abrasive material in the liquid being pumped. •Install proper filtration at pump inlet and clean regularly.
•Excessive pressure and/or temperature of pumped liquid. •Check pressure and inlet liquid temperature.
•Running pump dry. •DO NOT RUN PUMP WITHOUT LIQUID.
•Starving pump of adequate liquid. •Increase hose one size larger than inlet port size. Pressurize and
install C.A.T.
•Eroded manifold. •Replace manifold. Check liquid compatibility.