Graco GX-8 Quick start guide

Operation, Parts, Service, Repair
GX-8P Spray Gun
For use with non-flammable polyurethane foams, two-component coating systems
(polyureas), and some two-component epoxy systems. For professional use only.
Not for use in explosive atmospheres.
3500 psi (24 MPa, 240 bar) Maximum Working Pressure
125 psi (90 KPa, 9 bar) Maximum Air Working Pressure
Important Safety Instructions
Read all warnings and instructions
in this manual. Save these instructions.
GX-8 Model 297898
GX-8P Auto Model 297860
311338N
EN

Models
2311338N
Contents
Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Important Two-Component Material Information . 5
Isocyanate Conditions . . . . . . . . . . . . . . . . . . . . . 5
For all applications except spray foam . . . . . . . . 6
Material Self-ignition . . . . . . . . . . . . . . . . . . . . . . 6
Keep Components A and B Separate . . . . . . . . . 6
Moisture Sensitivity of Isocyanates . . . . . . . . . . . 6
Foam Resins with 245 fa Blowing Agents . . . . . . 7
Changing Materials . . . . . . . . . . . . . . . . . . . . . . . 7
Overall View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Centerline Components . . . . . . . . . . . . . . . . . . . 8
Mixing Module . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Operation Basics . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Safety Position . . . . . . . . . . . . . . . . . . . . . . . . . 10
Air Hose Connection . . . . . . . . . . . . . . . . . . . . . 10
Coupling Block . . . . . . . . . . . . . . . . . . . . . . . . . 11
Air Inlet Configuration . . . . . . . . . . . . . . . . . . . . 12
Mixing Module and PCD Installation . . . . . . . . . 13
Valving Rod Adjustment . . . . . . . . . . . . . . . . . . 14
Initial Set Up . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Daily Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Daily Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . 16
Pressure Relief Procedure . . . . . . . . . . . . . . . . . . 17
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Gun Service Kits . . . . . . . . . . . . . . . . . . . . . . . . 18
Clean Spray Gun Procedure . . . . . . . . . . . . . . . 19
Flush Gun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Service Screen Screw . . . . . . . . . . . . . . . . . . . . 20
Remove Check Valve . . . . . . . . . . . . . . . . . . . . 20
Remove Centerline Components . . . . . . . . . . . 21
Install Centerline Components . . . . . . . . . . . . . 21
Replace End Cap and Air Piston Assembly . . . 22
Replace Trigger Valve O-Rings . . . . . . . . . . . . . 24
Clean Mixing Module . . . . . . . . . . . . . . . . . . . . . 25
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
GX-8 Gun Final Assembly (297898) . . . . . . . . . 27
GX-8 Handle Assembly (297702) . . . . . . . . . . . 29
GX-8P Spray Gun Final Assembly (297860) . . . 31
GX-8P Auto Cylinder Assembly (297861) . . . . . 33
Auto GX-8P Optional Parts . . . . . . . . . . . . . . . . 35
Coupling Block Assembly (295383) . . . . . . . . . . 36
Coupling Block (297902) . . . . . . . . . . . . . . . . . . 37
Coupling Block Assembly (24N996) . . . . . . . . . 38
Set-up Chart for GX-8P Modules . . . . . . . . . . . . . 39
GX-8P Model Specifications . . . . . . . . . . . . . . . 39
Tool Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Graco Standard Warranty . . . . . . . . . . . . . . . . . . . 42
Graco Information . . . . . . . . . . . . . . . . . . . . . . . . . 42
Models

Part No. Description
Includes:
Mix Module Tip Manifold Starter
Kit
Flushing
Kit
297898 Gun, GX-8
295338 (013) 297192 (201)
Not Included
297860 Gun, GX-8, Auto
24P633 Gun, GX-8, with manifold 24N996 297911 296980

Warnings
311338N 3
Warnings
The following warnings are for the setup, use, grounding, maintenance, and repair of this equipment. The exclama-
tion point symbol alerts you to a general warning and the hazard symbols refer to procedure-specific risks. When
these symbols appear in the body of this manual, refer back to these Warnings. Product-specific hazard symbols and
warnings not covered in this section may appear throughout the body of this manual where applicable.
WARNING
PERSONAL PROTECTIVE EQUIPMENT
Always wear appropriate personal protective equipment and cover all skin when spraying, servicing
equipment, or when in the work area. Protective equipment helps prevent serious injury, including
long-term exposure; inhalation of toxic fumes, mists or vapors; allergic reaction; burns; eye injury and
hearing loss. This protective equipment includes but is not limited to:
• A properly fitting respirator, which may include a supplied-air respirator, chemically impermeable
gloves, protective clothing and foot coverings as recommended by the fluid manufacturer and local
regulatory authority.
• Protective eyewear and hearing protection.
TOXIC FLUID OR FUMES HAZARD
Toxic fluids or fumes can cause serious injury or death if splashed in the eyes or on skin, inhaled or
swallowed.
• Read Safety Data Sheet (SDS) for handling instructions and to know the specific hazards of the
fluids you are using, including the effects of long-term exposure.
• When spraying, servicing equipment, or when in the work area, always keep work area well
ventilated and always wear appropriate personal protective equipment. See Personal Protective
Equipment warnings in this manual.
• Store hazardous fluid in approved containers, and dispose of it according to applicable guidelines.
SKIN INJECTION HAZARD
High-pressure fluid from gun, hose leaks, or ruptured components will pierce skin. This may look like just
a cut, but it is a serious injury that can result in amputation. Get immediate
surgical treatment.
• Do not point gun at anyone or at any part of the body.
• Do not put your hand over the spray tip.
• Do not stop or deflect leaks with your hand, body, glove, or rag.
• Engage trigger lock when not spraying.
•Follow Pressure Relief Procedure in this manual, when you stop spraying and before cleaning,
checking, or servicing equipment.
PRESSURIZED EQUIPMENT HAZARD
Fluid from the gun/dispense valve, leaks, or ruptured components can splash in the eyes or on skin and
cause serious injury.
• Follow Pressure Relief Procedure in this manual, when you stop spraying and before cleaning,
checking, or servicing equipment.
• Tighten all fluid connections before operating the equipment.
• Check hoses, tubes, and couplings daily. Replace worn or damaged parts immediately.

Warnings
4311338N
FIRE AND EXPLOSION HAZARD
Flammable fumes, such as solvent and paint fumes, in work area can ignite or explode. To help prevent
fire and explosion:
• Use equipment only in well ventilated area.
• Eliminate all ignition sources; such as pilot lights, cigarettes, portable electric lamps, and plastic drop
cloths (potential static arc).
• Keep work area free of debris, including solvent, rags and gasoline.
• Do not plug or unplug power cords, or turn power or light switches on or off when flammable fumes
are present.
• Ground all equipment in the work area. See Grounding instructions.
• Use only grounded hoses.
• Hold gun firmly to side of grounded pail when triggering into pail.
• If there is static sparking or you feel a shock, stop operation immediately. Do not use equipment
until you identify and correct the problem.
• Keep a working fire extinguisher in the work area.
EQUIPMENT MISUSE HAZARD
Misuse can cause death or serious injury.
• Do not operate the unit when fatigued or under the influence of drugs or alcohol.
• Do not exceed the maximum working pressure or temperature rating of the lowest rated system
component. See Technical Data in all equipment manuals.
• Use fluids and solvents that are compatible with equipment wetted parts. See Technical Data in all
equipment manuals. Read fluid and solvent manufacturer’s warnings. For complete information
about your material, request MSDS forms from distributor or retailer.
• Check equipment daily. Repair or replace worn or damaged parts immediately with genuine
Graco/Gusmer replacement parts only.
• Do not alter or modify equipment.
• Use equipment only for its intended purpose. Call your Graco/Gusmer distributor for information.
• Route hoses and cables away from traffic areas, sharp edges, moving parts, and hot surfaces.
• Do not kink or over bend hoses or use hoses to pull equipment.
• Keep children and animals away from work area.
• Comply with all applicable safety regulations.
PRESSURIZED ALUMINUM PARTS HAZARD
Do not use 1,1,1-trichloroethane, methylene chloride, other halogenated hydrocarbon solvents or fluids
containing such solvents in pressurized aluminum equipment. Such use can cause serious chemical
reaction and equipment rupture, and result in death, serious injury, and property damage.
WARNING

Important Two-Component Material Information
311338N 5
Important Two-Component Material Information
Isocyanate Conditions
Spraying or dispensing fluids that contain isocyanates creates potentially harmful mists, vapors, and atomized
particulates.
• Read and understand the fluid manufacturer’s warnings and Safety Data Sheet (SDS) to know specific haz-
ards and precautions related to isocyanates.
• Use of isocyanates involves potentially hazardous procedures. Do not spray with this equipment unless you
are trained, qualified, and have read and understood the information in this manual and in the fluid manu-
facturer’s application instructions and SDS.
• Use of incorrectly maintained or mis-adjusted equipment may result in improperly cured material.which
could cause off gassing and offensive odors. Equipment must be carefully maintained and adjusted accord-
ing to instructions in the manual.
• To prevent inhalation of isocyanate mists, vapors and atomized particulates, everyone in the work area
must wear appropriate respiratory protection. Always wear a properly fitting respirator, which may include
a supplied-air respirator. Ventilate the work area according to instructions in the fluid manufacturer’s SDS.
• Avoid all skin contact with isocyanates. Everyone in the work area must wear chemically impermeable
gloves, protective clothing and foot coverings as recommended by the fluid manufacturer and local regu-
latory authority. Follow all fluid manufacturer recommendations, including those regarding handling of con-
taminated clothing. After spraying, wash hands and face before eating or drinking.
• Hazard from exposure to isocyanates continues after spraying. Anyone without appropriate personal pro-
tective equipment must stay out of the work area during application and after application for the time period
specified by the fluid manufacturer. Generally this time period is at least 24 hours.
• Warn others who may enter work area of hazard from exposure to isocyanates. Follow the recommenda-
tions of the fluid manufacturer and local regulatory authority. Posting a placard such as the following outside
the work area is recommended:
TOXIC FUMES
HAZARD
DO NOT ENTER DURING
SPRAY FOAM APPLICATION
OR FOR ___ HOURS AFTER
APPLICATION IS COMPLETE
DO NOT ENTER UNTIL:
DATE:
TIME:
____________
____________

Important Two-Component Material Information
6311338N
For all applications except spray
foam
Material Self-ignition
Keep Components A and B
Separate
Moisture Sensitivity of
Isocyanates
Exposure to moisture (such as humidity) will cause ISO
to partially cure, forming small, hard, abrasive crystal
that become suspended in the fluid. Eventually a film will
form on the surface and the ISO will begin to gel,
increasing in viscosity.
NOTE: The amount of film formation and rate of crystal-
lization varies depending on the blend of ISO, the
humidity, and the temperature.
Spraying or dispensing fluids that contain isocya-
nates creates potentially harmful mists, vapors, and
atomized particulates.
• Read and understand the fluid manufacturer’s
warnings and Safety Data Sheet (SDS) to know
specific hazards and precautions related to iso-
cyanates.
• Use of isocyanates involves potentially hazard-
ous procedures. Do not spray with this equip-
ment unless you are trained, qualified, and have
read and understood the information in this man-
ual and in the fluid manufacturer’s application
instructions and SDS.
• Use of incorrectly maintained or mis-adjusted
equipment may result in improperly cured mate-
rial. Equipment must be carefully maintained and
adjusted according to instructions in the manual.
• To prevent inhalation of isocyanate mists,
vapors, and atomized particulates, everyone in
the work area must wear appropriate respiratory
protection. Always wear a properly fitting respira-
tor, which may include a supplied-air respirator.
Ventilate the work area according to instructions
in the fluid manufacturer’s SDS.
• Avoid all skin contact with isocyanates. Everyone
in the work area must wear chemically imperme-
able gloves, protective clothing and foot cover-
ings as recommended by the fluid manufacturer
and local regulatory authority. Follow all fluid
manufacturer recommendations, including those
regarding handling of contaminated clothing.
After spraying, wash hands and face before eat-
ing or drinking.
Some materials may become self-igniting if applied
too thick. Read material manufacturer’s warnings and
Safety Data Sheet (SDS).
Cross-contamination can result in cured material in
fluid lines which could cause serious injury or dam-
age equipment. To prevent cross-contamination:
•Never interchange component A and component
B wetted parts.
• Never use solvent on one side if it has been con-
taminated from the other side.
NOTICE
Partially cured ISO will reduce performance and the
life of all wetted parts.
• Always use a sealed container with a desiccant
dryer in the vent, or a nitrogen atmosphere. Never
store ISO in an open container.
• Keep the ISO pump wet cup or reservoir (if
installed) filled with appropriate lubricant. The
lubricant creates a barrier between the ISO and
the atmosphere.
• Use only moisture-proof hoses compatible with
ISO.
• Never use reclaimed solvents, which may contain
moisture. Always keep solvent containers closed
when not in use.
• Always lubricate threaded parts with an appropri-
ate lubricant when reassembling.

Important Two-Component Material Information
311338N 7
Foam Resins with 245 fa
Blowing Agents
Some foam blowing agents will froth at temperatures
above 90°F (33°C) when not under pressure, especially
if agitated. To reduce frothing, minimize preheating in a
circulation system.
Changing Materials
NOTICE
Changing the material types used in your equipment
requires special attention to avoid equipment damage
and downtime.
• When changing materials, flush the equipment
multiple times to ensure it is thoroughly clean.
• Always clean the fluid inlet strainers after flushing.
• Check with your material manufacturer for chemi-
cal compatibility.
• When changing between epoxies and urethanes
or polyureas, disassemble and clean all fluid com-
ponents and change hoses. Epoxies often have
amines on the B (hardener) side. Polyureas often
have amines on the B (resin) side.

Overall View
8311338N
Overall View
Centerline Components
125 PSI MAX
Trigger
Air Cap Air
Adjustment
Valve
Safety Stop
Gun Block
Air Cap
Gun Block
Manual
Coupling
Mounting Screw
Valves
Block
FIG. 1: GX-8P Overall View
B-Screen Screw
Screen
Gun Block
Screen
Mixing
Pattern Control
PCD
Air Cap
B-Check
Coupling Coupling Block
A-Check
Screen
A-Screen
Screen
Rear Seal
Packing Nut
Valving Rod
Jam Nut
O-Ring
Module
Disc (PCD)
Retainer
Valve
Block Gasket Mounting Screw
Valve
Retainer
Retainer
Screw
Assembly
FIG. 2: GX-8P Centerline Components

Overall View
311338N 9
Mixing Module
Graco offers a variety of spray tip configurations to meet
most applications that spray fast-reaction chemical sys-
tems at low outputs. GX-8P spray tip components con-
sist of a Pattern Control Disc (PCD) and a Mixing
Module (Figure 3). Tip components are available in a
range of sizes in both round and fan spray patterns.
Please contact your authorized Graco distributor to help
you determine the best configurations for your specific
application.
Valving Rod
Mixing
Pattern
Fan Spray
Assembly
Pattern
Round
Spray Pattern
Module
Control
Disc (PCD)
FIG. 3: Mixing Module & PCD

Operation Basics
10 311338N
Operation Basics
Grounding
Check your local electrical code and proportioner man-
ual for detailed grounding instructions.
Ground spray gun through connection to
Graco-approved grounded fluid supply hose.
Safety Position
GX-8P guns have a two-position safety stop. When
engaged, it prevents accidental triggering of gun during
servicing or down time. When disengaged, it allows gun
to dispense.
Engage Safety Stop
To engage safety stop, push in and turn safety stop
clockwise to place gun in CLOSED safety position.
FIG. 4: Safety Stop - Engaged
Disengage Safety Stop
To disengage safety stop, push in and turn safety stop
counterclockwise to place gun in OPEN position.
FIG. 5: Safety Stop - Disengaged
Air Hose Connection
Connect Air Hoses
Pull back sleeve of female fitting, insert male fitting and
slide sleeve forward to secure connection.
Disconnect Air Hoses
Pull back sleeve of female fitting and pull out male fit-
ting.
FIG. 6: Disconnect Air Hose
To prevent accidental gun operation, always discon-
nect air supply before servicing gun or anytime gun is
not in use.
Engage the
Safety Stop
125 PSI MAX
125 PSI MAX
Disengage the
Safety Stop
Pull Sleeve

Operation Basics
311338N 11
Coupling Block
Chemical hoses are joined to gun block by a coupling
block to ease installation and removal of gun.
Manual Valves
Two manual valves located on coupling block control
flow of each chemical component to gun.
NOTE: Triggering gun with manual valves closed may
cause crossover if any residual chemical remains in gun
ports.
Open Manual Valves
Use 5/16 in. nut driver to turn manual valve counter-
clockwise approximately three full turns.
FIG. 7: Open Manual Valves
Close Manual Valves
Use 5/16 in. nut driver to turn manual valve fully clock-
wise.
Installation and Removal
Install Coupling Block
1. Replace nicked, damaged, or worn coupling block
gaskets.
2. Ensure A-(isocyanate) and B-(resin) check valves
are inserted into their proper recesses in gun block.
Isocyanate valve is notched for easy identification.
Never open manual valve unless coupling block is
secured to gun or unless you point gun into waste con-
tainer.
Coupling
Block
Manual
Valves
To prevent accidental gun operation, always set
safety stop to CLOSED, close both manual valves,
and disconnect air supply.
To prevent release of pressurized chemicals, close
both manual valves before coupling block is removed.

Operation Basics
12 311338N
3. Fit coupling block into gun block and insert coupling
block mounting screw. Use 5/16 in. nut driver to
tighten to gun block.
FIG. 8: Install Coupling Block
Remove Coupling Block
1. CLOSE safety stop.
2. Disconnect air hose.
3. Close both manual valves.
4. Remove coupling block mounting screw.
5. Separate coupling block from gun.
6. Wipe mating surfaces of gun block and coupling
block to remove residual chemicals.
7. Cover exposed openings with grease.
NOTE: To avoid accidental gun operation, ensure cou-
pling block manual valves are closed before attempting
to service gun, or any time gun is not in use.
Air Inlet Configuration
There are two configurations for the air inlet. In the stan-
dard configuration, the air inlet is at base of handle. In
the alternate configuration, the air inlet is at rear of gun.
FIG. 9: Air Inlet Configuration
To change to alternate configuration:
1. Use 6 in. adjustable wrench to remove 4 in. pipe
nipple from base of gun.
2. Use 3/16 in. hex key to remove 1/8 in. pipe plug
from rear of gun.
3. Use 3/16 in. hex key to install 1/8 in. pipe plug in
location previously occupied by 4 in. pipe nipple.
4. Use 6 in. adjustable wrench to install pipe nipple in
location previously occupied by 1/8 in. pipe plug.
125 PSI MAX
B-Check
Valve
A-Check
Valve
Coupling Block
Gaskets
Coupling Screw
Mounting Screw
125 PSI MAX
Pipe Plug
Optional
Pipe Plug
Pipe
Nipple

Operation Basics
311338N 13
Mixing Module and PCD
Installation
1. Loosen air cap by hand and remove.
2. Install mixing module:
a. Disconnect gun from coupling block.
b. Connect air supply to gun.
c. Set safety stop to OPEN.
d. Hold down trigger and place module over tip of
valving rod.
e. Align keying pin with slot in gun block and keep
gun trigger held down.
3. Install PCD:
a. Hold down gun trigger and thread PCD retainer
in place by hand.
b. Use 10 in. adjustable wrench to carefully tighten
PCD retainer until snug enough to ensure no
leak will occur.
c. Release gun trigger.
4. Install air cap and tighten by hand.
5. Adjust valving rod (see Valving Rod Adjustment,
page 14).

Operation Basics
14 311338N
Valving Rod Adjustment
Valving rod should not require adjustment if it was
shipped from factory with mixing module and PCD in-
stalled. Valving rod should only require adjustment
when:
• Piston/rod assembly/ring is changed
• Valving rod is changed
• PCD is installed or changed
• Mixing module is installed or changed
To adjust valving rod:
1. Perform Clean Spray Gun Procedure,(see page
19.
2. Connect air supply to gun.
3. Use 5/16 in. open-end wrench to loosen packing nut
3 or 4 turns. This relieves pressure between seals
and makes adjustment easier.
FIG. 10: Valving Rod Adjustments
4. Use 3/8 in. wrench on hex-shaped valving rod
shank and 1/2 in. wrench on jam nut to loosen and
back it away from valving rod by 3 or 4 full turns.
Then move valving rod toward gun cylinder. Turn
valving rod shank 2 or 3 full turns clockwise.
5. Slowly turn valving rod counterclockwise to move it
toward PCD until resistance is felt. Valving rod tip
should touch inside spherical surface of PCD.
6. Carefully maintain 3/8 in. wrench in position and
tighten jam nut up against valving rod shank to lock
adjustment into place.
7. Re-tighten packing nut.
8. Check rear safety stop by attempting to disengage
it. If knob will not turn, valving rod is adjusted too far
forward. Repeat steps 3 - 7. Make sure not to adjust
valving rod past the point resistance is felt. If safety
stop disengages, proceed to step 9.
9. Trigger gun with safety stop disengaged to confirm
rear seal adjustment. Make sure rod moves freely. If
not, loosen packing nut slightly until it does. Start to
spray and check for chemical seepage from packing
nut and re-tighten if necessary.
NOTE: If valving rod required adjustment as part of ini-
tial mixing module and PCD installation on a new spray
gun, proceed to Initial Set Up, page 15.
Valving Rod
Assembly
Jam Nut
Packing
Nut

Operation Basics
311338N 15
Initial Set Up
1. Remove coupling block from gun.
2. Use two 6 in. adjustable wrenches to install female
quick disconnect fitting onto air supply hose bundled
with chemical supply hoses.
3. Use two 6 in. adjustable wrenches to connect A-iso-
cyanate hose (red-taped) to notched fitting on cou-
pling block. Connect B-resin hose (blue-taped) to
fitting without notches on coupling block.
4. Close both manual valves.
5. Pressurize A and B chemical hoses and check for
leaks (see Proportioner manual as needed).
6. Bleed air from chemical hoses:
a. Hold coupling block with exit ports pointed into
waste container.
b. Use 5/16 in. nut driver to open each manual
valve; this allows any trapped air to escape.
Bleed each side for a short time until chemicals
leaving hoses are free of air.
c. Close both manual valves.
7. Use cloth soaked in gun cleaner to clean coupling
block and mating surfaces.
8. CLOSE safety stop.
9. Install coupling block to gun.
10. Proceed with daily start-up and shutdown proce-
dures as required.
NOTICE
Do not apply grease to mating surfaces of coupling
block to avoid accumulation of dirt and other contami-
nants.

Operation Basics
16 311338N
Daily Start-up
1. Connect air supply to gun.
2. Adjust air cap adjustment valve. Turn knob counter-
clockwise to open valve and clockwise to close
valve.
3. Open both manual valves.
4. OPEN safety stop.
5. Test spray on a disposable surface and evaluate.
Daily Shutdown
NOTE: Follow daily shutdown procedure when gun is
out of service for any length of time, or for mid- or
end-of-day service. See Clean Spray Gun Procedure,
page 19.
1. CLOSE safety stop.
2. Close both manual valves.
3. Disconnect air supply from gun.
4. Shut down proportioning unit as required.
5. Clean as required (see Clean Spray Gun Proce-
dure, page 19).
NOTE: Disassembling gun for daily cleaning is not rec-
ommended if gun has been operating properly. How-
ever, if gun is removed from coupling block, it must be
flushed and cleaned thoroughly.
Ensure gun is attached to coupling block and air hose.
Ensure proportioning unit is at desired temperature
and pressure. Properly ground equipment to avoid
static sparking that may result in fire or explosion.

Pressure Relief Procedure
311338N 17
Pressure Relief
Procedure
1. Close both manual valves.
FIG. 11: Close Manual Valves
2. OPEN safety stop.
3. Trigger gun onto cardboard or into waste container
to relieve pressure.
FIG. 12: Trigger Gun
4. Release gun trigger, CLOSE safety stop, and close
manual valves.
FIG. 13: Open Manual Valves
Relieve pressure before cleaning or repairing gun.
Manual Valves
!
2
If fluid in hose and proportioner is still under pressure,
follow Pressure Relief Procedure in proportioner man-
ual
To relieve pressure in hose after gun is removed, place
fluid manifold over containers, facing away from you.
Very carefully open fluid valves (FIG. 13). Under high
pressure, fluid will spray sideways from fluid ports.

Maintenance
18 311338N
Maintenance
Gun Service Kits
Use either 1-Quart Gun Service Kit (296980) or 3-Gallon
Gun Service Kit (296981) to perform daily flushing of
spray gun without disassembly.
FIG. 14: 1-Quart Gun Service Kit
For more information about 1-Quart Gun Service Kit,
see Manual 311340.
FIG. 15: 3-Gallon Gun Service Kit
For more information about 3-Gallon Gun Service Kit,
see Manual 311341.

Maintenance
311338N 19
Clean Spray Gun Procedure
Thoroughly flush gun block with gun cleaner before
removing valving rod or mixing components from gun
block. Also allow chemicals in spray gun to cool before
cleaning.
This procedure makes use of the 1-Quart or 3-Gallon
Gun Service Kit.
1. CLOSE safety stop.
2. Close both manual valves.
3. Remove gun from coupling block.
4. Attach service block of gun service kit to spray gun,
and then tighten using 5/16 in. nut driver.
5. Pressurize service kit container up to 100 psi. DO
NOT EXCEED 100 psi (0.7 MPa, 7 bar).
6. Clean gun:
a. Set safety stop to OPEN.
b. Open either manual valve on service block.
c. Trigger gun and gun service kit simultaneously
with gun aimed into waste container.
d. Release both triggers and close manual valves
on service block.
e. Repeat procedure for other side of gun.
f. After initial cleaning, remove air cap, PCD
retainer, and PCD. Flush a second time to
ensure thorough cleaning.
7. CLOSE safety stop.
8. Disconnect air supply from gun.
9. Remove service block of gun service kit from gun.
10. Clean screens, check valves and screen screw (see
Service Screen Screw, page 20.
NOTE: Inspect air cap, PCD, mixing module, and gun
block for build up of material and clean as required.
Do not use metal cleaning devices to clean plastic com-
ponents.
Flush Gun
1. CLOSE safety stop.
2. Close both manual valves.
3. Loosen B-Screen screw and then remove by hand.
4. Use flush can to thoroughly flush screen screw and
screen screw cavity.
5. Loosen A-Screen screw and then remove by hand.
6. Use flush can to thoroughly flush screen screw and
screen screw cavity.
7. Service gun, see Maintenance procedures, page
18.
To avoid static sparking that may result in fire or explo-
sion, ensure all equipment in cleaning procedure is
grounded. Do not clean on or near foamed or coated
surfaces or any other flammable surfaces or objects.
To avoid static sparking that may result in fire or explo-
sion, ensure all equipment in flushing procedure is
grounded. Do not flush on or near foamed or coated
surfaces.

Repair
20 311338N
Repair
Service Screen Screw
1. Flush gun see Clean Spray Gun Procedure, page
19.
2. Unthread screen screw from gun block.
3. Remove screen screw retainer before removing
screen.
4. Remove screen from screen screw. Soak in gun
cleaner or replace if clogged or dirty.
5. Clean screen screw cavity. If any particles are visi-
ble, clean with clean out drills and flush with gun
cleaner.
NOTE: Any material left in cavity on downstream side of
screen will clog mixing module.
6. Inspect screen screw seal for damage. Replace if
necessary.
7. Reinstall screen screw in gun block. Ensure it is
tight.
8. Flush gun with mixing module removed.
Remove Check Valve
Check valves are located in cavities of gun block under
each coupling block gasket. Check valves are triangular
pieces with a spring inserted in one end. The isocyanate
valve is notched for easy identification.
To remove check valve:
1. Clean gun (see Clean Spray Gun Procedure, page
19).
2. Use check valve seal removal/cleaning tool to
remove gaskets from recesses in coupling block.
Inspect gaskets for damage and replace if neces-
sary.
3. Remove check valves. If valve does not come out
easily, insert machined end of removal/cleaning tool
over valve and rotate it while extracting valve.
4. Clean valves and springs with gun cleaner. Inspect
for damage and replace if necessary.
5. Inspect each check valve cavity. Use cleaning tool
to remove any visible particles. Use gun cleaner to
flush thoroughly.
6. Insert each check valve into its cavity spring end
first. Ensure check valve is oriented correctly. Isocy-
anate valve is notched for easy identification.
7. Install coupling block gaskets.
Shutdown proportioner and allow chemicals to cool
before servicing gun.
To avoid static sparking that may result in fire or explo-
sion, ensure all equipment in flushing procedure is
grounded. Do not flush on or near foamed or coated
surfaces.
To avoid static sparking that may result in fire or explo-
sion, ensure all equipment in flushing procedure is
grounded. Do not flush on or near foamed or coated
surfaces.