Graco Inc 311321H User Manual
Operation, Parts, Service, Repair
GX-7A, GX-7 DI, and GX-7 400
311321H
Spray Guns
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.
See page 2 for model information.
ENG
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
2!
GX-7 400
GX-7 DI
Models
Contents
Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Overall View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Centerline Components . . . . . . . . . . . . . . . . . . . 8
Mixing Module . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Operation Basics . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Isocyanate Hazard . . . . . . . . . . . . . . . . . . . . . . 11
Keep A and B Components Separate . . . . . . . . 11
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Safety Position . . . . . . . . . . . . . . . . . . . . . . . . . 11
Air Hose Connection . . . . . . . . . . . . . . . . . . . . . 12
Coupling Block . . . . . . . . . . . . . . . . . . . . . . . . . 13
Air Inlet Configuration . . . . . . . . . . . . . . . . . . . . 14
Mixing Module and PCD Installation . . . . . . . . . 15
Valving Rod Adjustment . . . . . . . . . . . . . . . . . . 16
Valving Rod Adjustment . . . . . . . . . . . . . . . . . . 16
Initial Set Up . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Daily Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Daily Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . 18
Pressure Relief Procedure . . . . . . . . . . . . . . . . . . 19
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Gun Service Kits . . . . . . . . . . . . . . . . . . . . . . . . 20
Clean Spray Gun Procedure . . . . . . . . . . . . . . . 20
Flush Gun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Service Screen Screw . . . . . . . . . . . . . . . . . . . . 22
Remove Centerline Components . . . . . . . . . . . 22
Install Centerline Components . . . . . . . . . . . . . 24
Replace End Cap and Air Piston Assembly . . . 25
Replace Trigger Valve O-Rings . . . . . . . . . . . . . 26
Clean Mixing Module . . . . . . . . . . . . . . . . . . . . . 27
Install Mixing Module . . . . . . . . . . . . . . . . . . . . . 28
Clean Pattern Control Disc . . . . . . . . . . . . . . . . 29
Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
GX-7A Model Final Assembly . . . . . . . . . . . . . . 30
GX-7 DI Model Final Assembly (295541) . . . . . 32
GX-7 400 Model Final Assembly (295540) . . . . 34
GX-7A Model Handle Assembly (295810) . . . . . 36
GX-7 DI Model Handle Assembly (295809) . . . 38
GX-7 400 Model Handle Assembly (295799) . . 40
Coupling Block Assembly (295383) . . . . . . . . . . 42
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
GX-7A Mix Module Kit . . . . . . . . . . . . . . . . . . . . 43
Set-Up Chart for GX-7A Model . . . . . . . . . . . . . 44
GX-7 400 Mix Module Kit . . . . . . . . . . . . . . . . . . 45
Set-up Chart for GX-7 400 Model . . . . . . . . . . . 46
GX-7 DI Model Specifications . . . . . . . . . . . . . . 47
Tip Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Tool Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Graco Standard Warranty . . . . . . . . . . . . . . . . . . . 50
Graco Information . . . . . . . . . . . . . . . . . . . . . . . . . 50
Models
.
Includes:
Part No. Description
295540 GX-7 400 296859 (451)
295541 GX-7 DI - 4/213 296901 (4)
295542 GX-7A - 1/90 296909 (1)
295543 GX-7A - 10/210 296906 (10)
295544 GX-7A - 3/70 296226 (3)
295545 GX-7A - 5/70 296923 (5)
2 311321H
Mix Module Tip
296853 (212)
296706 (213)
296712 (90)
296704 (210)
296710 (70)
296710 (70)
Warnings
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
You must wear appropriate protective equipment when operating, servicing, or when in the
operating area of the equipment to help protect you from serious injury, including eye injury,
inhalation of toxic fumes, burns, and hearing loss. This equipment includes but is not limited to:
• Protective eyewear
• Clothing and respirator as recommended by the fluid and solvent manufacturer
•Gloves
• 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 MSDS’s to know the specific hazards of the fluids you are using.
• 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.
•Follow Pressure Relief Procedure in this manual, when you stop spraying and before
cleaning, checking, or servicing equipment.
311321H 3
Warnings
WARNING
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 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 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.
4 311321H
Warnings
WARNING
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.
311321H 5
Overall View
2 !
Overall View
Model GX-7A
Gun Block
Manual Valves
FIG. 1: GX-7A Overall View
Forward Stop
Locknut
Valving Rod Rear Stop
Air Cap Adjustment Valve
Valving Rod Forward Stop
Rear Packing Nut
Tr ig ge r
Model GX-7 DI
IG. 2: GX-7 DI Overall View
F
6 311321H
Overall View
Model GX-7 400
Gun Block
Trigger
FIG. 3: GX-7 400 Overall View
Forward Stop
Locknut
Valving Rod
Rear Stop
2
!
Air Cap Valve
Valving Rod
Forward Stop
Rear Packing Nut
311321H 7
Overall View
Centerline Components
Model GX-7A
Packing
Nut
Rear Packing
Retainer
Screen
Screen
Screw Seal
R-Screen Screw
Valving Rod
Rear Packing
Check Valve
Assembly
FIG. 4: GX-7A Centerline Components
Gun Block
Coupling Block
Gasket
A-Screen Screw
Check Valve
Front Packing
Pattern Control
Disc (PCD)
Mixing
Module
PCD Retainer
Screen
Screw
Seal
Screen
PCD Body
O-ring
Air Cap
Model GX-7 DI
Check Valve
Mixing Module
Mixing Module
Retainer
PCD
Retainer
Air Cap
IG. 5: GX-7 DI Centerline Components
F
R-Screen Screw
Pattern Control
Disc (PCD)
Screen
Gun Block
Rear Seal Gland
Rear Packing
Coupling Block
Gasket
Coupling Block
Mounting Screw
Rear Seal Retainer
Assembly
Check Valve
Screen
A-Screen
Screw
8 311321H
Model GX-7 400
Overall View
R-Screen Screw
Screen
Screw Seal
Check Valve
Mixing Module
Pattern Control
Disc (PCD)
Air Cap
Spring
PCD Retainer
Coupling Block
Gasket
Coupling Block
Mounting Screw
Rear Packing
Retainer
Gun Block
Rear Packing
Valving Rod
Rear Seal Retainer
Check Valve
Screen
Screen Screw Seal
A-Screen Screw
FIG. 6: GX-7 400 Centerline Components
311321H 9
Overall View
Mixing Module
All gun models employ the concept of impingement mixing through the use of a single-part
MIXING MODULE. This system is cleaned by
a mechanical self-cleaning process, eliminating the need for solvent or air purging between
dispenses.
The gun can be assembled with two styles of
mixing components; their selection is dependent upon the type of system sprayed. The
Set-Up Charts on pages 44 and 46 show several of the more common sets of these configurations.
The Mixing Module, in combination with a Pattern Control Disc (PCD), produce a thoroughly
mixed chemical and reliable spray patterns.
The module can be set up to spray at its maximum 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.
.
Valving Rod
Mixing Module (round or flat)
PCD (round or flat)
FIG. 8: GX-7 400 Mixing Module
.
Valving Rod
Mixing Module (round or flat)
Valving
Rod
Mixing Module
(round or flat)
FIG. 7: GX-7A Mixing Module
PCD (round or flat)
PCD (round or flat)
FIG. 9: GX-7 DI Mixing Module
10 311321H
Operation Basics
To prevent accidental gun operation, always
disconnect air supply before servicing gun or
anytime gun is not in use.
Isocyanate Hazard
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 providing sufficient ventilation in the work area. If
sufficient ventilation is not available, a supplied-air respirator is required for everyone in
the work area.
To prevent contact with isocyanates, appropriate personal protective equipment, including chemically impermeable gloves, boots,
aprons, and goggles, is also required for
everyone in the work area.
Operation Basics
Grounding
Check your local electrical code and proportioner manual for detailed grounding instructions.
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 (SERVICE) position.
Keep A and B Components Separate
CLOSED (SERVICE)
CAUTION
To prevent cross-contamination of the gun’s
wetted parts, do not interchange A component (isocyanate) and B component (resin)
parts. The gun is shipped with the A side on
the left.
311321H 11
FIG. 10: Safety Stop - Closed
When not spraying in
safety position.
Operation Basics
Disengage Safety Stop
To disengage safety stop, push in and turn
safety stop counterclockwise to place gun in
OPEN position (red band is exposed).
Red Band
OPEN
Red band exposed
when spraying.
FIG. 11: Safety Stop - Open
Close Manual Valves
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 fitting.
Pull Sleeve
Closing manual valves prevents chemicals in
heated hoses from entering gun. For your own
safety, close manuals valves before servicing
gun.
Manual Valves rotate clockwise to
close.
FIG. 12: Close Manual Valves
FIG. 13: Disconnect Air Hose
12 311321H
Operation Basics
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.
Triggering gun with manual valves closed
may cause crossover if any residual chemical remains in gun ports.
Never open manual valve unless coupling
block is secured to gun or unless you point
gun into waste container.
Close Manual Valves
Use 5/16 in. nut driver to turn manual valve
fully clockwise.
CAUTION
To prevent accidental gun operation, always
set safety stop to CLOSED (SERVICE),
close both manual valves, and disconnect air
supply.
Installation and Removal
To prevent release of pressurized chemicals,
close both manual valves before removing
coupling block.
Install Coupling Block
1. Replace nicked, damaged, or worn coupling block gaskets.
Open Manual Valves
Use 5/16 in. nut driver to turn manual valve
counterclockwise three full turns.
Coupling
Block
Manual Valves
FIG. 14: Open Manual Valves
2. With gaskets in place, fit coupling block to
gun block.
311321H 13
Operation Basics
3. Insert coupling block mounting screw and
use 5/16 in. nut driver to tighten to gun
block.
Coupling Block
Gaskets
Coupling Block
Mounting Screw
Optional Configuration
Refer to page 42. If bottom-mount hose connection is desired, alternate swivel fitting (2
and 3) with pipe plugs (1). Use pipe thread
sealant. Do not cross-over which side each fitting 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 configuration the air inlet is at the rear of the gun.
Pipe
Plug
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 chemical.
7. Cover exposed openings with grease.
Optional Pipe
Nipple
Pipe Nipple
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 occupied by pipe nipple.
4. Install pipe nipple in location previously
occupied by pipe plug.
14 311321H
Operation Basics
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).
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:
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).
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.
d. Slightly loosen rear seal retainer
assembly.
e. Remove safety stop.
311321H 15
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