Hitachi 308640 User Manual

INSTRUCTIONS-PARTS LIST

308640

This manual contains important
warnings and information.
READ AND KEEP FOR REFERENCE.

INSTRUCTIONS

First choice when

quality counts.

t

HIGH PRESSURE AIR-ASSISTED

Model AA Plust Spray Gun

4000 psi (28 MPa, 280 bar) Maximum Working Fluid Pressure
100 psi (0.7 MPa, 7 bar) Maximum Working Air Pressure

Part No. 238402, Series A

Spray Gun with standard spray tip, tip guard, air cap,
and 1/4–18 npsm (R1/4–19) air line fitting.

Part No. 238851, Series B

Spray Gun with AA Reverse-A-Cleanr (RAC) assem­bly and 1/4–18 npsm (R1/4–19) air line fitting.

Part No. 238852, Series A

Spray Gun with standard spray tip, tip guard, air cap,
and quick-disconnect air line fitting.

Rev. J

Supersedes G

includes Rev. H

Part No. 238883, Series A

Hi-Flow Spray Gun with Hi-Flow fluid needle and
diffuser-seat, and standard spray tip, tip guard, air cap,
and 1/4–18 npsm (R1/4–19) air line fitting.

Part No. 239001, Series B

Hi-Flow Spray Gun with Hi-Flow fluid needle and
diffuser-seat, AA Reverse-A-Clean (RAC) assembly,
and 1/4–18 npsm (R1/4–19) air line fitting.

Part No. 241070, Series A

HVLP Spray Gun with standard spray tip, HVLP air
cap, and 1/4–18 npsm (R1/4–19) air line fitting.

U.S. Patent Nos. 3,843,052; 4,386,739; 5,285,965
United Kingdom Patent No. 2 1 11 406 B
Patented 1984 Canada
Brevete 1984
French Patent No. 82–21202
Patents Pending
Foreign Patents Pending

05985

Part No. 238402 Spray Gun shown

GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440–1441

ECOPYRIGHT 1996, GRACO INC.

Graco Inc. is registered to I.S. EN ISO 9001

Table of Contents

Warnings 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Installation 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operation 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General Troubleshooting 14. . . . . . . . . . . . . . . . . . . . . . .

Spray Pattern Troubleshooting 15. . . . . . . . . . . . . . . . . .

Service 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Parts 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

W ARNING

INJECTION HAZARD

Spray from the gun, hose leaks, or ruptured components can inject fluid into your body and cause an
extremely serious injury, including the need for amputation. Splashing fluid in the eyes or on the skin
can also cause a serious injury.

 Fluid injected into the skin might look like just a cut, but it is a serious injury. Get immediate medi-

cal attention.

 Do not point the spray gun at anyone or at any part of the body.
 Do not put hand or fingers over the spray tip.
 Do not stop or deflect fluid leaks with your hand, body, glove, or rag.

Spray Tip Selection Chart 22. . . . . . . . . . . . . . . . . . . . . .

Air Caps 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dimensions 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Technical Data 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Accessories 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Warranty 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Graco Phone Number 28. . . . . . . . . . . . . . . . . . . . . . . . . .

 Do not “blow back” fluid; this is not an air spray gun.
 Always have the tip guard on the spray gun when spraying.
 Check the gun diffuser operation weekly.
 Be sure the gun trigger safety operates before spraying.
 Lock the gun trigger safety when you stop spraying.
 Follow the Pressure Relief Procedure on page 7 whenever you: are instructed to relieve pres-

sure; stop spraying; clean, check, or service the equipment; or install or clean the spray tip.

 Tighten all the fluid connections before operating the equipment.
 Check the hoses, tubes, and couplings daily. Replace worn, damaged, or loose parts immediately.

Permanently coupled hoses cannot be repaired; replace the entire hose.

TOXIC FLUID HAZARD

Hazardous fluids or toxic fumes can cause serious injury or death if splashed in the eyes or on the
skin, swallowed, or inhaled.

 Know the specific hazards of the fluid you are using. Read the fluid manufacturer’s warnings.
 Store hazardous fluid in an approved container. Dispose of hazardous fluid according to all local,

state and national guidelines.

 Wear the appropriate protective clothing, gloves, eyewear and respirator.

RECOIL HAZARD

Due to the very high pressure fluid emitted, a strong recoil action will occur when you trigger this gun.
If you are unprepared, your hand could be forced back toward your body or you could lose your bal­ance and fall, resulting in serious injury.

2 308640

WARNING

EQUIPMENT MISUSE HAZARD

INSTRUCTIONS

Equipment misuse can cause the equipment to rupture, malfunction, or start unexpectedly and result
in serious injury.

 This equipment is for professional use only.
 Read all instruction manuals, tags, and labels before operating the equipment.
 Use the equipment only for its intended purpose. If you are uncertain about usage, call your Graco

distributor.

 Do not alter or modify this equipment. Use only genuine Graco parts and accessories.
 Check the equipment daily. Repair or replace worn or damaged parts immediately.
 Do not exceed the maximum working pressure of the lowest rated system component. This equip-

ment has a 4000 psi (28 MPa, 280 bar) maximum working pressure at 100 psi (0.7 MPa, 7 bar)
maximum incoming air pressure.

 Route the hoses away from the traffic areas, sharp edges, moving parts, and hot surfaces. Do not

expose Graco hoses to temperatures above 180F (82C) or below –40F (–40C).

 Do not use the hoses to pull the equipment.
 Use only Graco approved hoses. Do not remove hose spring guards, which help protect the hose

from rupture caused by kinks or bends near the couplings.

 Use fluids or solvents that are compatible with the equipment wetted parts. See the Technical

Data section of all the equipment manuals. Read the fluid and solvent manufacturer’s warnings.

 Wear hearing protection when operating this equipment.
 Comply with all applicable local, state and national fire, electrical and other safety regulations.

FIRE AND EXPLOSION HAZARD

Improper grounding, poor air ventilation, open flames, or sparks can cause a hazardous condition and
result in fire or explosion and serious injury.

 Ground the equipment and the object being sprayed. See Ground the System on page 6.
 Provide fresh air ventilation to avoid the buildup of flammable fumes from solvent or the fluid being

sprayed.

 Extinguish all the open flames or pilot lights in the spray area.
 Electrically disconnect all the equipment in the spray area.
 Keep the spray area free of debris, including solvent, rags, and gasoline.
 Do not turn on or off any light switch in the spray area while operating or if fumes are present.
 Do not smoke in the spray area.
 Do not operate a gasoline engine in the spray area.
 If there is any static sparking while using the equipment, stop spraying immediately. Identify and

correct the problem.

308640 3

Installation

C

L

A

KEY

A Air Line Filter
B Air Line Lubricator
C* Bleed-type Air Shutoff Valve
D Pump Air Regulator
E* Fluid Drain Valve
F Fluid Shutoff Valve
G Fluid Filter

Fig. 1

D

CB

H* Grounded Fluid Hose
J Pump
K Air Line
L Air Pressure Regulator
M Pump Fluid Inlet
N In-line Fluid Filter
P Pattern Adjustment V alve Knob
Q* Fluid Pressure Regulator

J

P

X

V

T

Q

K

S

W

N

05986

M

F

R

H

G
E

E

R Pressure Gauge
S T rigger Safety
T Pump Runaway Valve
V* Pump Ground Wire
W Gun Fluid Connector
X Air Shutof f Valve

*Equipment required for safe operation of the

system. Must be purchased separately.

Typical Installation

The typical installation shown in Fig. 1 is only a guide
for selecting and installing air-assisted spray systems.
It is not an actual system design. Contact your Graco
distributor for assistance in designing a system to meet
your needs.

4 308640

Ventilate the Spray Booth

WARNING

TOXIC FLUID HAZARD

To prevent hazardous concentrations of
toxic and/or flammable vapors, spray
only in a properly ventilated spray booth.

Never operate the spray gun unless ventilation
fans are operating.

Check and follow all of the National, State and
Local codes regarding air exhaust velocity require­ments.

Installation

Connect the Air Line

1. Install an air line filter (A) to ensure a clean, dry air
supply to the gun. Dirt and moisture in the line can
ruin the appearance of your finished piece. See
Fig. 1.

2. Install an air pressure regulator (L) on the gun air
supply line to control the air pressure to the gun.

3. Install an air pressure regulator (D) on the pump
air supply line to control air pressure to the pump.

4. Install a bleed-type air shutoff valve (C) on the
main air line and on the pump air line, downstream
of the pump air regulator, to shut off air to the
pump. Install an additional bleed-type valve on
each pump air supply line to relieve air trapped
between this valve and the pump after the air
regulator is shut off.

WARNING

The bleed-type air shutoff valve is required in your
system to relieve air trapped between this valve
and the pump after the air regulator is closed.
Trapped air can cause the pump to cycle unexpect­edly, which could result in serious injury.

NOTE:



Part No. 238402, 238851, 238883, 239001, and
241070 Guns:

(R1/4–19) compound male thread that is compat­ible with NPSM and BSP female swivel connectors.



Part No. 238852 Gun:

1/4–18 npsm quick-disconnect fitting.

The gun air inlet has a 1/4–18 npsm

The gun air inlet has a

Connect the Fluid Line

WARNING

INJECTION HAZARD

To reduce the risk of property damage or
serious injury, including fluid injection,
which could be caused by component
rupture or unrelieved fluid pressure,

 A fluid drain valve(s) (E) is required in your

system to assist in relieving fluid pressure in the
displacement pump, hose and gun; triggering
the gun to relieve pressure may not be suffi­cient.

 A fluid pressure regulator (Q) must be installed

in the system if the pump’s maximum working
pressure exceeds the gun’s maximum fluid
working pressure of 4000 psi (28 MPa, 280
bar).

1. Install a fluid filter (G) and drain valve(s) (E) close
to the pump’s fluid outlet. The drain valve assists
in relieving fluid pressure in the displacement
pump, hose, and gun. See Fig. 1.

2. Install a fluid pressure regulator (Q) to control fluid
pressure to the gun.

NOTE: Some applications require fine-tuned control of
fluid pressure. You can control fluid pressure more
accurately with a fluid pressure regulator than by
regulating the air pressure to the pump.

3. Install a fluid shutoff valve (F) to shut off the fluid
supply to the gun.

5. Install an air shutoff valve (X) on each gun air
supply line, downstream of the gun air regulator, to
shut off air to the gun(s).

6. Connect the air hose (K) from the air supply to the
gun air inlet.

4. Install an in-line fluid filter (N) on the gun fluid
fitting (W) to avoid clogging the spray tip with
particles from the fluid.

5. Connect the grounded fluid hose (H) to the gun
fluid fitting (W) or optional in-line filter (N).

308640 5

Installation

Ground the System

WARNING

FIRE AND EXPLOSION HAZARD

Improper grounding could cause static
sparking, which could cause a fire or
explosion. To reduce the risk of property
damage or serious injury, follow the
grounding instructions below.

The following grounding instructions are minimum
requirements for a system. Your system may include
other equipment or objects which must be grounded.
Check your local electrical code for detailed grounding
instructions for your area and type of equipment. Your
system must be connected to a true earth ground.

1. Pump: Ground the pump by connecting a ground
wire and clamp between the fluid supply and a true
earth ground as instructed in your separate pump
instruction manual.

2. Air compressors and hydraulic power sup-

plies: Ground them according to the manufacturer

recommendations.

3. Air, fluid, and hydraulic hoses connected to

the pump: Use only electrically conductive hoses

with a maximum of 500 feet (150 m) combined
hose length to ensure grounding continuity. Check
the electrical resistance of your air and fluid hoses
at least once a week. If the resistance exceeds the
recommended limits, replace the hose immediate­ly.

4. Spray gun: Ground the gun by connecting it to a
properly grounded fluid hose and pump.

5. Fluid supply container: Ground it according to
local code.

6. Object being sprayed: Ground it according to
local code.

7. All solvent pails used when flushing: Ground
them according to local code. Use only metal pails,
which are conductive. Do not place the pail on a
non-conductive surface, such as paper or card­board, which interrupts the grounding continuity.

8. To maintain grounding continuity when flush-

ing or relieving pressure: Always hold a metal

part of the gun firmly to the side of a grounded
metal pail, then trigger the gun.

6 308640

Operation

Safety

WARNING

INJECTION HAZARD

Remember, this is not an air spray gun.
For your safety be sure to read and
follow the Warnings on pages 2 and 3

and throughout the text of this instruction manual.
Keep the wallet sized warning card 179960, pro-

vided with the gun, with the operator of this equip­ment at all times. The card contains important
treatment information should an injection injury
occur. Additional cards are available at no charge
from Graco.

Pressure Relief Procedure

WARNING

INJECTION HAZARD

The system pressure must be manually
relieved to prevent the system from

starting or spraying accidentally. Fluid
under high pressure can be injected through the
skin and cause serious injury. To reduce the risk of
an injury from injection, splashing fluid, or moving
parts, follow the Pressure Relief Procedure
whenever you:

 are instructed to relieve the pressure,
 stop spraying,
 check or service any of the system equipment,
 or install or clean the spray tip.

5. Hold a metal part of the gun firmly to the side of a
grounded metal waste container and trigger the
gun to relieve the fluid pressure.

6. Lock the gun trigger safety again.

7. Open the pump drain valve (required in the sys­tem) to help relieve fluid pressure in the displace­ment pump. In addition, open the drain valve
connected to the fluid pressure gauge (in a system
with fluid regulation) to help relieve fluid pressure
in the hose and gun. Triggering the gun to relieve
pressure may not be sufficient. Have a container
ready to catch the drainage.

8. Leave the drain valve(s) open until you are ready
to spray again.

9. If you suspect that the spray tip or hose is com­pletely clogged or that pressure has not been fully
relieved after following the steps above
slowly loosen the hose end coupling and relieve
pressure gradually, then loosen the coupling
completely. Now clear the tip or hose obstruction.

Trigger Safety

Locked or in

ON SAFE

Position

, v

ery

1. Lock the spray gun trigger safety to avoid acciden­tally triggering the gun. See Fig. 2.

2. Shut off the power to the pump.

3. Close the bleed-type master air valve (required in
the system).

4. Unlock the gun trigger safety.

Fig. 2

Trigger Safety Unlocked

or in

OFF SAFE

Position

308640 7

05987

Operation

How the Air-Assisted Spray Gun Operates

The air-assisted spray gun combines airless and air
spraying concepts. The spray tip shapes the fluid into
a fan pattern, as does a conventional airless spray tip.
Air from the air cap further atomizes the fluid and
completes the atomization of the paint tails into the
pattern to produce a more uniform pattern. The width
of the pattern can be slightly adjusted by the pattern
adjustment valve.

Note that the air-assisted spray gun differs from an air
spray gun in that increasing the pattern air reduces the
pattern width. To increase the pattern width, less
pattern air or a larger size tip must be used.

The spray gun has a built-in lead and lag operation.
When triggered, the gun begins emitting air before the
fluid is discharged. When the trigger is released, the
fluid stops before the air flow stops. This helps assure
the spray is atomized and prevents fluid buildup on the
air cap.

Install a Spray Tip

WARNING

INJECTION HAZARD

To reduce the risk of a fluid injection
injury, follow the Pressure Relief Proce-
dure on page 7 before removing or

installing a spray tip.

Install a spray tip in the gun. The air cap and spray tip
position determines the direction of the spray pattern.

Rotate the air cap (the spray tip rotates with it) as
needed for the desired spray pattern direction. See
Fig. 3.

NOTE: If the gun has the AA RAC assembly, hand­tighten the air cap retaining ring, while holding the
orange tip guard in the desired direction. If the retain­ing ring is over-tightened, the spray tip will be difficult
to rotate.

Vertical Spray Pattern Horizontal Spray Pattern

Select a Spray Tip and Air Cap

The fluid output and pattern width depend on the size
of the spray tip, the fluid viscosity, and the fluid pres­sure. Use the Spray Tip Selection Chart, on page 22,
as a guide for selecting an appropriate spray tip for
your application.

Fig. 3

05991

8 308640

Operation

A

Adjust the Spray Pattern

WARNING

RECOIL HAZARD

Due to the very high pressure fluid
emitted, a strong recoil action will occur

when you trigger this gun. If you are
unprepared, your hand could be forced back
toward your body or you could lose your balance
and fall, resulting in serious injury.

WARNING

INJECTION HAZARD

To reduce the risk of component rupture

and serious injury, including injection, do

not exceed the gun’s maximum fluid
working pressure of 4000 psi (28 MPa, 280 bar) or
the maximum working pressure of the lowest rated
component in the system.

5. Set the atomizing air pressure at about 10 psi (0.7
bar, 70 kPa). Check the spray pattern, then adjust
the air pressure until the tails are completely
atomized and pulled into the spray pattern. See
Fig. 5. Do not exceed 100 psi (0.7 MPa, 7 bar) air
pressure to the gun.

For a narrower pattern,

valve knob clockwise. If the pattern is still not
narrow enough, increase the air pressure to the
gun slightly or use a different size tip.

NOTE: Pattern adjustment is not available with
guns with the AA RAC assembly as the air separa­tor, part no. 178414, must be removed when the
RAC assembly is installed.

turn the pattern adjustment

Pattern
Adjustment
Knob

1. Set the fluid pressure with the fluid regulator. Do
not turn on the air supply yet.

2. Trigger the gun to check the atomization; do not be
concerned about the pattern shape yet.

3. Increase the fluid pressure just to the point where
a further increase in fluid pressure does not signifi­cantly improve fluid atomization.

4. Close the pattern adjustment valve by turning the
knob (see Fig. 4) counterclockwise all the way.
This sets the gun for its widest pattern.

Fig. 4

No Air T oo Little Air Right Amount

of Air

Fig. 5

0789

0792

308640 9