Graco GX-7A Quick start guide

Operation, Parts, Service, Repair
GX-7A
™
, GX-7
®
DI, and GX-7 400
Spray Guns
For use with non-flammable polyurethane foams, two-component coating systems
(polyureas), and some two-component epoxy systems. For professional use only.
See page 2 for model information.
3500 psi (24 MPa, 240 bar) Maximum Working Pressure
Important Safety Instructions
Read all warnings and instructions
in this manual. Save these instructions.
GX-7A
GX-7 DI
2!
GX-7 400
311321N
EN

Models
2311321N
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 . . . . . . . . . . . . . . . . . . . . . . . 10
Mixing Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Operation Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Isocyanate Hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Keep A and B Components Separate . . . . . . . . . . . . . 13
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Safety Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Air Hose Connection . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Coupling Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Air Inlet Configuration . . . . . . . . . . . . . . . . . . . . . . . . . 16
Mixing Module and PCD Installation . . . . . . . . . . . . . . 17
Valving Rod Adjustment . . . . . . . . . . . . . . . . . . . . . . . 18
Valving Rod Adjustment . . . . . . . . . . . . . . . . . . . . . . . 18
Initial Set Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Daily Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Daily Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Pressure Relief Procedure . . . . . . . . . . . . . . . . . . . . . . . 21
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Gun Service Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Clean Spray Gun Procedure . . . . . . . . . . . . . . . . . . . . 22
Flush Gun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Service Screen Screw . . . . . . . . . . . . . . . . . . . . . . . . 24
Remove Centerline Components . . . . . . . . . . . . . . . . 24
Install Centerline Components . . . . . . . . . . . . . . . . . . 26
Replace End Cap and Air Piston Assembly . . . . . . . . 27
Replace Trigger Valve O-Rings . . . . . . . . . . . . . . . . . 28
Clean Mixing Module . . . . . . . . . . . . . . . . . . . . . . . . . 29
Install Mixing Module . . . . . . . . . . . . . . . . . . . . . . . . . 30
Clean Pattern Control Disc . . . . . . . . . . . . . . . . . . . . . 31
Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
GX-7A Model Final Assembly . . . . . . . . . . . . . . . . . . . 32
GX-7 DI Model Final Assembly (295541) . . . . . . . . . . 34
GX-7 400 Model Final Assembly (295540) . . . . . . . . . 36
GX-7A Model Handle Assembly (24K734) . . . . . . . . . 38
GX-7 DI Model Handle Assembly (295809) . . . . . . . . 40
GX-7 400 Model Handle Assembly (24K733) . . . . . . . 42
Coupling Block Assembly (295383) . . . . . . . . . . . . . . 44
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
GX-7A Mix Module Kit . . . . . . . . . . . . . . . . . . . . . . . . 45
Set-Up Chart for GX-7A Model . . . . . . . . . . . . . . . . . . 46
GX-7 400 Mix Module Kit . . . . . . . . . . . . . . . . . . . . . . 47
Set-up Chart for GX-7 400 Model . . . . . . . . . . . . . . . 48
GX-7 DI Model Specifications . . . . . . . . . . . . . . . . . . . 49
Tip Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Tool Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Graco Standard Warranty . . . . . . . . . . . . . . . . . . . . . . . . 52
Graco Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Models
Part No. Description
Includes:
Mix Module Tip
295540 GX-7 400 296859 (451) 296853 (212)
295541 GX-7 DI - 4/213 296901 (4) 296706 (213)
295542 GX-7A - 1/90 296909 (1) 296712 (90)
295543 GX-7A - 10/210 296906 (10) 296704 (210)
295544 GX-7A - 3/70 296226 (3) 296710 (70)
295545 GX-7A - 5/70 296923 (5) 296710 (70)

Warnings
311321N 3
Warnings
The following general warnings are for the setup, use, grounding, maintenance, and repair of this
equipment. Additional, more specific warnings may be found throughout the body of this manual
where applicable. Symbols appearing in the body of the manual refer to these general warnings.
When these symbols appear throughout the manual, refer back to these pages for a description
of the specific hazard.
WARNING
PERSONAL PROTECTIVE EQUIPMENT
Always wear appropriate personal protective equipment and cover all skin when spraying, ser-
vicing 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.
• Do not spray without tip guard and trigger guard installed.
• Engage trigger lock when not spraying.
•FollowPressure Relief Procedure in this manual, when you stop spraying and before
cleaning, checking, or servicing equipment.

Warnings
4311321N
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 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 com-
plete 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 infor-
mation.
• Route hoses and cables away from traffic areas, sharp edges, moving parts, and hot sur-
faces.
• 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 EQUIPMENT HAZARD
Fluid from the gun/dispense valve, leaks, or ruptured components can splash in the eyes or on
skin and cause serious injury.
•FollowPressure 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.
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 prop-
erty damage.
WARNING

Important Two-Component Material Information
311321N 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
6311321N
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 par-
tially cure, forming small, hard, abrasive crystal that become
suspended in the fluid. Eventually a film will form on the sur-
face and the ISO will begin to gel, increasing in viscosity.
NOTE: The amount of film formation and rate of crystallization
varies depending on the blend of ISO, the humidity, and the
temperature.
Spraying or dispensing fluids that contain isocyanates cre-
ates potentially harmful mists, vapors, and atomized partic-
ulates.
• Read and understand the fluid manufacturer’s warn-
ings and Safety Data Sheet (SDS) to know specific
hazards and precautions related to isocyanates.
• Use of isocyanates involves potentially hazardous pro-
cedures. 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 manufac-
turer’s application instructions and SDS.
• Use of incorrectly maintained or mis-adjusted equip-
ment may result in improperly cured material. Equip-
ment 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 respirator, which may include a sup-
plied-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 rec-
ommended by the fluid manufacturer and local regula-
tory authority. Follow all fluid manufacturer
recommendations, including those regarding handling
of contaminated clothing. After spraying, wash hands
and face before eating 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 damage equip-
ment. To prevent cross-contamination:
•Never interchange component A and component B
wetted parts.
• Never use solvent on one side if it has been contami-
nated 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 mois-
ture. Always keep solvent containers closed when not in
use.
• Always lubricate threaded parts with an appropriate
lubricant when reassembling.

Important Two-Component Material Information
311321N 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 sys-
tem.
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
8311321N
Overall View
FIG. 1: GX-7A Overall View
FIG. 2: GX-7 DI Overall View
2 !
Model GX-7A
Valving Rod Rear Stop
Air Cap Adjustment Valve
Valving Rod Forward Stop
Rear Packing Nut
Trigger
Manual Valves
Gun Block
Forward Stop
Locknut
Model GX-7 DI

Overall View
311321N 9
FIG. 3: GX-7 400 Overall View
!
2
Model GX-7 400
Valving Rod
Rear Stop
Valving Rod
Forward Stop
Air Cap Valve
Rear Packing Nut
Forward Stop
Locknut
Gun Block
Trigger

Overall View
10 311321N
Centerline Components
FIG. 4: GX-7A Centerline Components
FIG. 5: GX-7 DI Centerline Components
Model GX-7A
Valving Rod
Packing
Nut
Rear Packing
Gun Block
Rear Packing
Retainer
A-Screen Screw
Screen
Screw
Seal
Screen
Check Valve
Mixing
Module PCD Body
Front Packing
PCD Retainer
Air Cap
O-ring
Pattern Control
Disc (PCD)
Coupling Block
Gasket
R-Screen Screw
Check Valve
Assembly
Screen
Screen
Screw Seal
Model GX-7 DI
Rear Seal Retainer
Assembly
Rear Packing
Gun Block
Rear Seal Gland
Screen
R-Screen Screw
Check Valve
Mixing Module
Mixing Module
Retainer
Pattern Control
Disc (PCD)
Air Cap
PCD
Retainer
Check Valve
Screen
A-Screen
Screw
Coupling Block
Coupling Block
Mounting Screw
Gasket

Overall View
311321N 11
FIG. 6: GX-7 400 Centerline Components
Valving Rod
Rear Seal Retainer
Rear Packing
Retainer
Rear Packing
A-Screen Screw
Screen Screw Seal
Screen
Check Valve
Coupling Block
Mounting Screw
Coupling Block
Gasket
Gun Block
PCD Retainer
Air Cap
Pattern Control
Disc (PCD)
Mixing Module
Check Valve
Spring
Screen
Screw Seal
R-Screen Screw
Model GX-7 400

Overall View
12 311321N
Mixing Module
All gun models employ the concept of impinge-
ment mixing through the use of a single-part
MIXING MODULE. This system is cleaned by
a mechanical self-cleaning process, eliminat-
ing the need for solvent or air purging between
dispenses.
The gun can be assembled with two styles of
mixing components; their selection is depen-
dent upon the type of system sprayed. The
Set-Up Charts on pages 46 and 48 show sev-
eral of the more common sets of these config-
urations.
The Mixing Module, in combination with a Pat-
tern Control Disc (PCD), produce a thoroughly
mixed chemical and reliable spray patterns.
The module can be set up to spray at its maxi-
mum rated output. Additionally, by changing to
a smaller PCD the module can spray at the low
outputs and pressures that are required for
detail work.
FIG. 7: GX-7A Mixing Module
FIG. 8: GX-7 400 Mixing Module
FIG. 9: GX-7 DI Mixing Module
Valving
Rod
Mixing Module
(round or flat)
PCD (round or flat)
Valving Rod
Mixing Module (round or flat)
PCD (round or flat)
Valving Rod
Mixing Module (round or flat)
PCD (round or flat)

Operation Basics
311321N 13
Operation Basics
Isocyanate Hazard
Keep A and B Components
Separate
Grounding
Check your local electrical code and propor-
tioner manual for detailed grounding instruc-
tions.
Ground the spray gun through connection to a
Graco-approved grounded fluid supply hose.
Safety Position
The guns have a two-position valving rod rear
stop. The SERVICE position allows for minimal
rearward travel of valving rod but will not allow
chemical to discharge. The OPEN position
allows full rearward travel of valving rod and
permits gun to dispense. Whenever gun is not
spraying, set to SERVICE position.
Engage Safety Stop
To engage safety stop, push in and turn safety
stop clockwise to place gun in CLOSED (SER-
VICE) position.
FIG. 10: Safety Stop - Closed
To prevent accidental gun operation, always
disconnect air supply before servicing gun or
anytime gun is not in use.
Spraying materials containing isocyanates
creates potentially harmful mists, vapors,
and atomized particulates.
Read material manufacturer’s warnings and
material MSDS to know specific hazards and
precautions related to isocyanates.
Prevent inhalation of isocyanate mists,
vapors, and atomized particulates by provid-
ing sufficient ventilation in the work area. If
sufficient ventilation is not available, a sup-
plied-air respirator is required for everyone in
the work area.
To prevent contact with isocyanates, appro-
priate personal protective equipment, includ-
ing chemically impermeable gloves, boots,
aprons, and goggles, is also required for
everyone in the work area.
CAUTION
To prevent cross-contamination of the gun’s
wetted parts, do not interchange A compo-
nent (isocyanate) and B component (resin)
parts. The gun is shipped with the A side on
the left.
CLOSED (SERVICE)
When not spraying in
safety position.

Operation Basics
14 311321N
Disengage Safety Stop
To disengage safety stop, push in and turn
safety stop counterclockwise to place gun in
OPEN position (red band is exposed).
FIG. 11: Safety Stop - Open
Close Manual Valves
Closing manual valves prevents chemicals in
heated hoses from entering gun. For your own
safety, close manuals valves before servicing
gun.
FIG. 12: Close Manual Valves
Air Hose Connection
Connect Air Hoses
Pull back sleeve of female fitting, insert male
fitting and slide sleeve forward to secure con-
nection.
Disconnect Air Hoses
Pull back sleeve of female fitting and pull out
male fitting.
FIG. 13: Disconnect Air Hose
OPEN
Red band exposed
when spraying.
Red Band
Manual Valves -
rotate clockwise to
close.
Pull Sleeve

Operation Basics
311321N 15
Coupling Block
Chemical hoses are joined to gun block by
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.
Open Manual Valves
Use 5/16 in. nut driver to turn manual valve
counterclockwise three full turns.
FIG. 14: Open Manual Valves
Close Manual Valves
Use 5/16 in. nut driver to turn manual valve
fully clockwise.
Installation and Removal
Install Coupling Block
1. Replace nicked, damaged, or worn cou-
pling block gaskets.
2. With gaskets in place, fit coupling block to
gun block.
Triggering gun with manual valves closed
may cause crossover if any residual chem-
ical remains in gun ports.
Never open manual valve unless coupling
block is secured to gun or unless you point
gun into waste container.
Coupling
Block
Manual Valves
CAUTION
To prevent accidental gun operation, always
set safety stop to CLOSED (SERVICE),
close both manual valves, and disconnect air
supply.
To prevent release of pressurized chemicals,
close both manual valves before removing
coupling block.

Operation Basics
16 311321N
3. Insert coupling block mounting screw and
use 5/16 in. nut driver to tighten to gun
block.
FIG. 15: Install Coupling Block
Remove Coupling Block
1. Set safety stop to CLOSED (SERVICE).
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 chemi-
cal.
7. Cover exposed openings with grease.
Optional Configuration
Refer to page 44. If bottom-mount hose con-
nection is desired, alternate swivel fitting (2
and 3) with pipe plugs (1). Use pipe thread
sealant. Do not cross-over which side each fit-
ting is on.
Air Inlet Configuration
There are two configurations for the air inlet. In
the standard configuration the air inlet is at the
base of the handle, and in the alternate config-
uration the air inlet is at the rear of the gun.
FIG. 16: Air Inlet Configuration
To change to alternate configuration,
1. Remove pipe nipple.
2. Remove pipe plug from rear of gun.
3. Install pipe plug in location previously occu-
pied by pipe nipple.
4. Install pipe nipple in location previously
occupied by pipe plug.
Coupling Block
Gaskets
Coupling Block
Mounting Screw
Pipe
Plug
Optional Pipe
Nipple
Pipe Nipple

Operation Basics
311321N 17
Mixing Module and PCD
Installation
1. 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 hole in gun block
and push in firmly (GX-7 DI model only).
f. Install front packing into module retainer
(GX-7 model only).
g. Install module retainer, hand tight.
Release trigger.
h. Use wrench to strongly tighten module
retainer (250 in.-lbs.).
GX-7 DI model only: use wrench to
tighten module retainer (150 in.-lbs.).
DO NOT OVERTIGHTEN.
2. Install PCD:
a. Disconnect air supply from gun.
b. Loosen forward stop screw (GX-7
model only).
c. Turn forward stop nut clockwise (as
viewed from front of gun) 1-2 turns
(GX-7 model only).
d. Slightly loosen rear seal retainer
assembly.
e. Remove safety stop.
f. Use wrench to loosen piston locknut.
Turn valving rod rearward as far as it
will turn.
g. Place and orient PCD over mixing mod-
ule retainer.
h. Install PCD retainer and hand tighten
(GX-7 DI model only).
i. Install PCD retainer and wrench tighten
(GX-7 model only).
3. Adjust valving rod. See procedure for
appropriate gun model.
4. Set safety stop to OPEN position.
5. Check adjustment of valving rod:
a. With air supply connected, hold down
gun trigger and loosen PCD retainer.
Release trigger.
b. Hand tighten PCD retainer.
c. While maintaining tightening torque,
trigger gun. Retainer should rotate
approximately 1/10 of turn.
d. Release trigger.

Operation Basics
18 311321N
Valving Rod Adjustment
GX-7A and GX-7 400 Models Only
1. Push in rear stop to SERVICE position.
2. If attached, turn both manual valves fully
clockwise to close (see Manual Valves,
page 15).
3. Connect air line from gun to air source to
pressurize air cylinder forward to CLOSED
position.
4. Loosen forward stop locknut.
FIG. 17: Forward Stop
5. Completely loosen (full CCW) forward
stop. Then slowly tighten (CW) forward
stop until a snug resistance is felt. From
this point, reverse and loosen approxi-
mately 1/16 of a turn.
6. Tighten forward stop locknut. Do not over-
tighten. If locknut bottoms out before resis-
tance is felt, replace friction plug.
FIG. 18: One Wrench Flat
Valving Rod Adjustment
GX-7 DI Model Only
Valving rod requires adjustment in only the fol-
lowing instances:
• disassembly and service of air cylinder
• changing valving rod
• changing mixing module
1. Clean gun according to Clean Spray Gun
Procedure, page 22.
2. Connect air supply to gun.
3. Loosen rear seal retainer assembly one or
two turns.
4. Loosen locknut from valving rod three or
four turns.
5. Set safety stop to OPEN.
6. Use 5/16 in. nut driver through rear of gun
to thread valving rod forward to engage
PCD. When valving rod contacts PCD
tighten another 1/10 turn.
7. Carefully maintain position of valving rod
and tighten locknut against piston rod.
8. Retighten rear seal retainer assembly.
As a reference point, movement of one
wrench flat corresponds to 1/6 turn.
Forward
Stop
Forward Stop
Locknut

Operation Basics
311321N 19
Initial Set Up
1. Install female quick disconnect fitting to air
supply hose bundled with chemical supply
hoses.
2. Connect coupling block to hose bundle.
Connect A-Isocyanate hose (red-tape) to
notched fitting on coupling block. Connect
R-Resin hose (blue-tape) to fitting without
notches on coupling block.
3. Close both manual valves.
4. Pressurize A and R chemical hoses. Check
for leaks. See Proportioner manual.
5. Bleed air from chemical hoses.
a. Use separate waste containers for
A-ISO and R-Resin.
b. Hold coupling block with exit ports
pointed into waste container.
c. Open one manual valve at a time to dis-
pense into waste container.
d. Bleed each side until chemical leaving
hoses is free of air.
e. Close both manual valves.
6. Use cloth soaked in gun cleaner to clean
coupling block and mating surfaces.
7. Set safety stop to CLOSED (SERVICE).
8. Install coupling block to gun.
9. Proceed with daily start-up and shutdown
procedures.

Operation Basics
20 311321N
Daily Start-up
1. Connect air supply to gun.
2. Adjust air cap adjustment valve. Turn knob
counterclockwise to open valve and clock-
wise to close valve
3. Adjust rear seal retainer.
4. Open both manual valves. See Coupling
Block section, page 15.
5. Set safety stop to OPEN.
6. Test spray on disposable surface.
Daily Shutdown
1. Set safety stop to OPEN.
2. Close both manual valves.
3. Disconnect air supply from gun.
4. Shutdown proportioning unit as required.
See Proportioner manual.
5. Clean as required. See Clean Spray Gun
Procedure, page 22.
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.
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 22.
Do not disassemble gun daily for cleaning
if it is operating properly. However, if gun is
removed from coupling block, it must be
flushed and cleaned thoroughly.