CAT Pumps 7670 User manual

FEATURES
●Provides system pressure setting and protection
for single gun (non-weep) and pump installation.
●Compact size with optional ports for easy
installation.
●New ergonomic handle permits easy adjustments
of pressure.
●Pressure sensitive feature permits wide range
of flows and immediate pressure when gun
opens.
●Color coded spring for easy identification and
simple change from one model to another.
●Also functions as a secondary Relief Valve
without the check valve.
●Model 7691 has a quick start valve to relieve
pump discharge line pressure at start up.
SPECIFICATIONS
U.S. Measure Metric Measure
MODEL 7670
Flow Range ................................2.5-8.0 GPM (9.5-30 L/M)
Pressure Range........................150-1750 PSI (10-120 BAR)
Weight...............................................1.66 lbs. (0.75 kg)
Dimensions ...........................7.0 x 3.12 x 2.0" (178 x 79 x 51 mm)
MODEL 7672
Flow Range ................................2.5-8.0 GPM (9.5-30 L/M)
Pressure Range........................850-3200 PSI (60-220 BAR)
Weight...............................................1.72 lbs. (0.78 kg)
Dimensions ...........................7.0 x 3.12 x 2.0" (178 x 79 x 51 mm)
MODEL 7690
Flow Range ................................2.5-8.0 GPM (9.5-30 L/M)
Pressure Range......................1000-4050 PSI (70-280 BAR)
Weight...............................................1.75 lbs. (0.79 kg)
Dimensions ...........................7.0 x 3.12 x 2.0" (178 x 79 x 51 mm)
MODEL 7691WITH QUICK START
Flow Range ................................2.5-8.0 GPM (9.5-30 L/M)
Pressure Range......................1000-4050 PSI (70-280 BAR)
Weight...............................................1.75 lbs. (0.79 kg)
Dimensions ...........................7.0 x 3.12 x 2.0" (178 x 79 x 51 mm)
COMMON SPECIFICATIONS
Maximum Temperature.........................195°F (90°C)
Inlet Ports (2)..................................3/8" NPTF (3/8" NPTF)
Discharge Port (1)..........................3/8" NPTF (3/8" NPTF)
By-Pass Port (1).............................3/8" NPTF (3/8" NPTF)
Unloader is stamped with a European safety pressure. Use only at above
specifications to assure proper unloader life and performance.
For Relief Valve version add .100 to unloader model number.
For FPM o-ring version add .0110 to unloader model number.
Pressure Sensitive
Regulating Unloader
Models
7670,7672
7690,7691
®
“Customer confidence is our greatest asset”
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.

TYPICAL UNLOADER INSTALLATION
1 Pressure Gauge
2 By-Pass Hose
3 Thermal Valve
4 Pop-off Valve
(secondary safety relief valve)
5 Triplex Plunger Pump
6 Pressure Sensitive Regulating Unloader
SELECTION
This is a pressure sensitive regulating unloader designed for
systems with single or multiple pumps, solenoid (gate) valves,
nozzles, standard or “weep” guns.
This pressure sensitive regulating unloader should meet both the
desired system flow (combined nozzle flow rate requirement) and
system pressure.
Note: Operation below the minimum flow of the unloader causes
the unloader to cycle. Operation above the maximum flows of the
unloader causes premature unloader wear, cycling and prevents
attaining desired system pressure.
INSTALLATION
This unloader operates properly when mounted in any direction,
however, it is preferred to keep the plumbing to a minimum and
the adjusting handle easily accessible. The best mounting
location is directly on the pump discharge manifold head.
The inlet connections on this unloader are 3/8" NPTF ports and
are located on the left side and bottom. Arrows and the word “IN”
are cast into the body indicating the direction of flow. A new
unloader will have a plug in the bottom port, but this plug can be
switched to the left side port if needed. Liquid form the discharge
of the manifold goes through these connections.
The discharge connection on this unloader is a 3/8" NPTF port
and is located on the front side (hex end). An arrow and the word
“OUT” is cast into the body indicating the direction of flow.
Plumbing to the spray guns, solenoid (gate) valves or nozzles are
connected here.
The by-pass connections on this unloader are 3/8" NPTF ports and
are located on the back side and front face. The word “BY PASS” is
cast into the body indicating the direction of flow. By-pass liquid
is directed out of this port and can be routed to a reservoir
(preferred method), or to a drain or to the pump inlet.
OPERATION
This pressure sensitive regulating unloader holds established
system pressure in the discharge line when the trigger gun is
closed or solenoid (gate) valve is closed or the nozzle is clogged,
thus by-passing all unrequired flow. Squeezing the trigger gun or
opening the solenoid (gate) valve will close off the by-pass and
return to established system pressure without delay.
PRESSURE ADJUSTMENT
1. Setting and adjusting the unloader pressure must be done
with the system “on”.
2. Start the system with unloader backed off to the lowest
pressure setting (counterclockwise direction).
3. Squeeze the trigger and read the pressure on the gauge at
the pump.
Note: Do not read the pressure at the gun or nozzle.
4. If more pressure is desired, release the trigger, turn adjusting
handle one quarter turn in clockwise direction.
5. Squeeze the trigger and read the pressure.
6. Repeat this process until desired system pressure is attained.
7. Once the desired system pressure is reached, stop turning
the adjusting handle.
Note: Pressure is not set at the factory.
CAUTION: A minimum by-pass flow of 5% of the unloader rated
flow capacity is required for proper unloader performance. If the
entire output is directed through the unloader (zero by-pass) the
“cushioning” feature of the by-pass liquid is eliminated and the
unloader can malfunction or wear prematurely.
8. If desired system pressure cannot be reached, review
TROUBLESHOOTING chart.
9. When servicing existing systems, follow adjustment
procedures as stated above for new unloaders.
Note: Do not adjust unloader pressure setting to compensate for
a worn nozzle. Check the nozzle as part of the regular
maintenance and replace if worn.
Note: A secondary pressure safety relief device (i.e. pop-off
valve, safety valve) should be used along with this pressure
sensitive regulating unloader. Final adjustment for the relief valve
should relieve at 200 psi above the system operating pressure.
1
2
3INLET
BY-PASS
DISCHARGE
6
5
4

TROUBLESHOOTING
Unloader cycles ●Worn O-ring or check valve
●Fitting leaking downstream
●O-ring in gun worn
Liquid leaking ●O-ring for seat or inlet fitting cut or worn
from bottom
Liquid leaking ●O-ring for piston worn or cut
from middle
Unloader will not ●Not properly sized for system pressure
come up to pressure ●Foreign material in unloader
●Piston o-rings worn
●Nozzle worn
●Jam nuts not properly set
Extreme pressure ●Adjusting handle turned completely into
spikes unloader
●Restricted by-pass or no by-pass
●System flow exceeds unloader rating
Approximate Gauge Gauge
Pressure Reading Between Between
at Gauge Pump/Unloader Unloader/Gun-Nozzle-Valve
System in operation system pressure system pressure
(gun open)
System in by-pass low pressure system pressure
(gun closed) 0-150 PSI +200 PSI
SERVICING
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.
Disassembly:
1. Disconnect by-pass, discharge and inlet plumbing from
unloader.
2. Remove unloader from pump.
3. Secure body of unloader in a vise with adjusting handle facing
up.
4. Remove discharge fitting and o-ring, spring, check valve and
o-ring.
5. Inspect check valve and discharge fitting for wear, spring for
wear or fatigue and o-rings for cuts or wear and replace as
needed with check valve kit.
Note: While the discharge fitting is removed, inspect sealing area
where the check valve makes contact within the internal body of
the unloader for grooves, pitting and wear. If damage is found,
stop the repair and replace with complete new unloader. If not,
proceed with disassembly.
6. Remove black nylon cap on top of adjusting handle.
7. Unscrew and remove hex nylock nut.
8. Unscrew and remove adjusting handle, flat washer and
spring.
9. Inspect all parts for scale build up or wear and replace as
needed. Examine spring for fatigue or wear and replace as
needed.
10.Remove piston lock pin.
11.Unscrew piston retainer from body of unloader.
12.Grasp threaded end of piston stem and pull from body of
unloader. Piston retainer and all associated o-rings should
come out upon removal.
13.Unscrew and remove two jam nuts from piston stem.
14.Remove piston retainer, o-rings and back-up-ring. Examine
piston retainer for wear. Examine o-rings and back-up-ring for
cuts or wear and replace as needed.
15.Examine piston stem for wear. Examine o-ring and back-up-
rings for cuts or wear and replace as needed.
16.Remove bottom inlet fitting and o-ring, spring, ball and seat
w/o-ring from bottom inlet connection. Examine seat for
grooves and o-ring for cuts or wear and replace as needed.
Reassembly:
1. At bottom inlet port, lubricate and install o-ring on outside
diameter of seat and press seat squarely into position in the
body.
2. Install ball and then spring, thread in inlet fitting with o-ring.
3. Lubricate and install back-up-ring and then o-ring into inside
diameter of piston retainer. Lubricate and install larger o-ring
over threads of piston retainer body. Slide piston retainer with
threads facing downwards over piston stem.
4. Apply Loctite®242®to the last few threads of the piston stem.
Hand thread two jam nuts to bottom threads of piston stem.
5. Lubricate and install in this order: back-up-ring, o-ring and
then back-up-ring onto opposite end of piston stem.
6. Pull piston retainer by hand towards piston stem tip and align
slot in piston retainer with hole in piston stem. Install piston
lock pin.
7. Grasp threaded end of piston stem and thread in by hand into
unloader body, tighten with wrench.
8. Slide spring over piston stem. Install flat washer on top of
spring.
9. Thread adjusting handle onto piston stem.
10.Install hex nylock nut onto piston stem.
11.At discharge side of unloader, lubricate and install o-ring onto
check valve. Place spring inside check valve. Insert check
valve with o-ring and spring into discharge port of unloader
body.
12.Lubricate and install o-ring onto threaded end of discharge
fitting. Thread in discharge fitting to discharge port of unloader
body and tighten with wrench.
13.Remove unloader from vise.
14.Re-install unloader onto pump.
15.Reconnect by-pass, discharge and inlet plumbing to unloader.
16.Proceed to PRESSURE ADJUSTMENT.
Loctite®and 242®are registered trademarks of the Henkel Corporation.
90 DAY WARRANTY
Refer to complete CAT PUMPS Warranty for further information.

CUTAWAYEXPLODED VIEW
PARTS LIST
ITEM DESCRIPTION MODEL NUMBER QTY
7670 MATL 7672 MATL 7690 MATL 7691 MATL
397 Washer, Flat — STL — STL — STL — STL 1
398 Nut, Jam (M8x1.25) 32116 BB 32116 BB 32116 BB 32116 BB 3
399 Handle, Adjusting, Assembly (Inclds: 397,398,401,402,403,404) 31395 NY 31395 NY 31395 NY 31395 NY 1
401 Handle, Adjusting 31284 NY 31284 NY 31395 NY 31395 NY 1
402 Cap, Handle 31286 NY 31286 NY 31286 NY 31286 NY 1
403 Nut, Hex, NyLock (M8) 32811 STZP 32811 STZP 32811 STZP 32811 STZP 1
404 Nut, Adjust (M8) — BB — BB — BB — BB 1
408 Spring, White (1750 PSI) 32090 STL —— —— —— 1
Spring, Blue (3450 PSI) — — 32092 STL 32092 STL 32092 STL 1
412 Stem, Piston 33219 S 33219 S 33219 S 33219 S 1
413 Pin, Piston, Lock 32818 S 32818 S 32818 S 32818 S 1
414 Back-up-Ring, Piston Stem 32873 PTFE 32873 PTFE 32873 PTFE 32873 PTFE 1
415 O-Ring, Piston Stem — NBR/FPM — NBR/FPM — NBR/FPM — NBR/FPM 1
416 O-Ring, Retainer — NBR/FPM — NBR/FPM — NBR/FPM — NBR/FPM 1
425 Retainer, Piston 33318 BB 33318 BB 33318 BB 33318 BB 1
429 O-Ring, Piston — NBR/FPM — NBR/FPM — NBR/FPM — NBR/FPM 1
430 Back-up-Ring, Piston 33303 PTFE 33303 PTFE 33303 PTFE 33303 PTFE 2
432 Ball 32289 SSSS 32289 SSSS 31075 SSSS 31075 SSSS 1
434 Spring — STZP — STZP — STZP — — 1
436 Seat, w/O-Ring — NBR —NBR 33806 NBR 33806 NBR 1
437 O-Ring, Seat - 85D — NBR/FPM — NBR/FPM — NBR/FPM — NBR/FPM 1
440 Body — FBB — FBB — FBB — FBB 1
441 O-Ring, Check Valve — NBR/FPM — NBR/FPM — NBR/FPM — NBR/FPM 1
442 O-Ring, Inlet Fitting — NBR/FPM — NBR/FPM — NBR/FPM — NBR/FPM 1
443 Valve, Check 33852 BB 33852 BB 33852 BB 33852 BB 1
444 Spring, Check Valve 33843 S 33843 S 33843 S 33843 S 1
446 O-Ring, Discharge Fitting — NBR/FPM — NBR/FPM — NBR/FPM — NBR/FPM 1
448 Kit, Check Valve (Inclds: 441,443,444,446) 31370 NBR 31370 NBR 31371 BB 31371 BB 1
450 Plug, Inlet (3/8" NPTM) 46690 BB 46690 BB 46690 BB 46690 BB 1
455 Fitting, Inlet (3/8" NPTF) 32111 BB 32111 BB 31211 BB —— 1
457 Plug, Quick Start — — — — — — — BB 1
458 Kit, Valve (Inclds: 432,434,436,442) 33147 NBR 33147 NBR 31147 NBR —— 1
460 Fitting, Discharge (3/8" NPTF) 33855 BB 33855 BB 33855 BB 33855 BB 1
468 Kit, O-Ring (Inclds: 414,415,416,429,430,437,441,442,446) 31365 NBR 31365 NBR 31366 NBR 31366 NBR 1
Kit, O-Ring (Inclds: 414,415,416,429,430,437,441,442,446) 31375 FPM 31375 FPM 31375 FPM 31375 FPM 1
Bold print part numbers are unique to a particular model. Italics are optional items.
MATERIAL CODES (Not Part of Part Number): BB=Brass FPM=Fluorocarbon NBR=Medium Nitrile (Buna-N)
NY=Nylon PTFE=Pure Polytetrafluoroethylene S=304SS SSSS=440SS STL=Steel STZP=Steel/Zinc Plated
High tensile
strength Forged
Brass Body.
Convenient locking
nut under cap to
secure desired
system pressure.
Standard Buna-N
or optional FPM
o-rings for liquid
compatibility.
Color coded
springs for easy
identification of
model.
Stainless Steel
piston stem, ball
and seat for
durability over
thousands of
cycles.
Optional inlet
ports for
flexibility in
mounting.
PN 993194 Rev D 9816
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] www.catpumps.co.uk
N.V. CAT PUMPS INTERNATIONAL S.A.
Heiveldekens 6A, B-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