CAT Pumps 7693 User manual

FEATURES
lProvides system pressure setting and protection for
single gun (non-weep) and pump installation.
lCompact size with optional ports for easy
installation.
lPressure sensitive feature permits wide range of
flows and immediate pressure when gun opens.
lColor coded spring for easy identification and
simple change from one model to another.
SPECIFICATIONS
U.S. Measure Metric Measure
MODEL 7693
Flow Range.............................................. 2.5-10.5 gpm (9.5-40 lpm)
Pressure Range........................................ 230-2300 psi (16-160 bar)
Weight..................................................................1.56 lbs. (0.71 kg)
Dimensions..................................... 7.51 x 3.25 x 1.97” (190.7 x 82.5 x 50.0 mm)
MODEL 7694
Flow Range.............................................. 2.5-10.5 gpm (9.5-40 lpm)
Pressure Range........................................ 400-4050 psi (28-280 bar)
Weight..................................................................1.63 lbs. (0.74 kg)
Dimensions..................................... 7.51 x 3.25 x 1.97” (190.7 x 82.5 x 50.0 mm)
COMMON SPECIFICATIONS
Maximum Operating Temperatures:
Standard Buna o-rings.........................................140°F (60°C)
Standard Buna o-rings (Intermittent) ............195°F (90°C)
Optional FPM o-rings...........................................240°F (116°C)
Inlet Ports (2)..................................................3/8” NPTF (3/8” NPTF)
Discharge Port (1).........................................3/8” NPTF (3/8” NPTF)
By-Pass Port (2)..............................................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
7693
7694
All High Pressure Systems require a primary pressure regulating device (i.e. regulator,
unloader) and a secondary pressure relief device (i.e. pop-off valve, relief valve). Failure
to install such relief devices could result in personal injury or damage to pump or
property. CAT PUMPS does not assume any liability or responsibility for the operation
of a customer’s high pressure system.
Read all CAUTIONS and WARNINGS before commencing service or operation of any
high pressure system. The CAUTIONS and WARNINGS are included in each service
manual and with each Accessory Data sheet. CAUTIONS and WARNINGS can also be
viewed online at www.catpumps.com/cautions-warnings or can be requested directly
from CAT PUMPS.
Model 7693 Shown

TYPICAL UNLOADER INSTALLATION
1 Pressure Gauge
2 Pop-off Valve
(secondary safety relief valve)
3 Pressure Sensitive Regulating Unloader
4 Triplex Plunger Pump
SELECTION
These pressure sensitive regulating unloaders are designed for systems
with single or multiple pumps, solenoid (gate) valves, nozzles, standard or
“weep” guns.
These pressure sensitive regulating unloaders should meet both the
desired system flow (combined nozzle flow rate requirement) and the
designed system pressure.
Notice: 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
These unloaders operate 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 from 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
These pressure sensitive regulating unloaders hold 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 the by-pass and return to established system
pressure.
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.
Notice: 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 nozzle (zero by-pass) the “cushioning” feature of
the by-pass liquid is eliminated and the unloader can wear or malfunction
prematurely.
8. If desired system pressure cannot be reached, review
TROUBLESHOOTING chart.
9. When servicing existing systems, follow adjustment procedures as
stated above.
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.
Note: By removing the check valve and spring, these unloaders can
function as a secondary relief valve.
3
4
Read all CAUTIONS and WARNINGS before commencing
service or operation of any high-pressure system
2
1

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. Examine 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. Examine all parts for scale build up or wear and replace as needed.
Examine spring for fatigue or wear and replace as needed.
10. Unscrew and remove two jam nuts from piston stem.
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. 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.
14. Examine piston stem for wear. Examine o-ring and back-up-rings for
cuts or wear and replace as needed.
15. 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.
Note: Polished chamfer towards the ball.
2. Install ball and then spring, thread in inlet fitting with o-ring.
3. Lubricate and install o-ring and then back-up-ring into groove near
piston stem tip end. Lubricate and install o-ring and then back-up
ring onto threaded end of piston stem.
4. Grasp threaded end of piston stem and press by hand into unloader
body.
5. Lubricate and install larger o-ring over threads of piston retainer
body. Slide piston retainer with threads facing downwards over
piston stem and thread into body.
6. Apply Loctite®242®to the last few threads of the piston stem. Hand
thread two jam nuts to bottom threads of piston stem.
7. Slide spring over piston stem. Install flat washer on top of spring.
8. Thread adjusting handle onto piston stem.
9. Install hex nylock nut onto piston stem.
10. 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.
11. 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.
12. Remove unloader from vise.
13. Re-install unloader onto pump.
14. Reconnect by-pass, discharge and inlet plumbing to unloader.
15. Proceed to PRESSURE ADJUSTMENT.
Loctite®and 242®are registered trademarks of the Henkel Corporation.
Read all CAUTIONS and WARNINGS before commencing
service or operation of any high-pressure system
TROUBLESHOOTING
Unloader cycles lWorn O-ring or check valve
lFitting leaking downstream
lO-ring in gun worn
Liquid leaking lO-ring for seat or inlet fitting cut or worn
from bottom
Liquid leaking lO-ring for piston worn or cut
from middle
Unloader will not lNot properly sized for system pressure
come up to pressure lForeign material in unloader
lPiston o-rings worn
lNozzle worn or too large.
lJam nuts not properly set
Extreme pressure lAdjusting handle turned completely into
spikes unloader
lRestricted by-pass or no by-pass
lSystem 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
(all guns,valves closed) 0-150 PSI +200 PSI
PRESSURE READING

EXPLODED VIEW
CAT PUMPS
1681  94TH LANE N.E. MINNEAPOLIS, MN 554494324
PHONE 763 7805440  FAX 763 7802958
e-mail: techsuppor[email protected]
www.catpumps.com
For International Inquiries go to www.catpumps.com and navigate to the “Contact Us” link. PN 993481 Rev A 2/13 13063
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 STL=Steel STZP=Steel/Zinc Plated
ITEM PN MATL DESCRIPTION QTY
397 33633 STZP Washer, Flat 1
398 32116 BB Nut, Jam (M8) 2
401 31766 NY Handle, Cap 1
403 — STZP Nut, Hex Lock 1
408 32090 STL Spring, Pressure (White) 7693 1
32092 STL Spring, Pressure (Blue) 7694 1
412 31537 S Stem, Piston 1
414 33586 PTFE Backup-Ring, Piston Stem 1
415 in kit NBR O-Ring, Piston Stem 1
in kit FPM O-Ring, Piston Stem 1
425 76747 S Retainer, Piston 1
428 in kit NBR O-Ring, Piston Retainer 1
in kit FPM O-Ring, Piston Retainer 1
429 in kit NBR O-Ring, Piston Stem 1
in kit FPM O-Ring, Piston Stem 1
430 30423 PTFE Ring Seal 1
434 32325 S Spring 1
436 76743 — Seat, Ball Assembly 1
440 — BB Housing 1
ITEM PN MATL DESCRIPTION QTY
441 in kit NBR O-Ring, Check Valve 1
in kit FPM O-Ring, Check Valve 1
442 in kit NBR O-Ring, By-Pass Fitting 1
in kit FPM O-Ring, By-Pass Fitting 1
443 76736 BB Valve, Check 1
444 33843 S Spring, Check Valve 1
446 in kit NBR O-Ring, Discharge Fitting 1
in kit FPM O-Ring, Discharge Fitting 1
455 76752 BB Fitting, By-Pass 3/8” NPTF 1
460 76753 BB Fitting, Discharge 3/8”NPTF 1
462 — BB Plug 1
468 76740 NBR Kit, O-Ring (Includes 414, 415, 428,
429, 430, 441, 442, 446)
1
76741 FPM Kit, O-Ring (Includes 414, 415, 428,
429, 430, 441, 442, 446)
1
469 76036 NBR Kit, Repair (Includes 414, 415, 428, 429,
430, 436, 441, 442, 446)
1
PARTS LIST
403
397
398
398
408
401
414
415
462
Discharge
By-Pass
Inlet
Inlet
441443
444 446 460
425
428
412
430
429
440
436
434
442
455
462
By-Pass