Graco 238338 Operation manual

308612
Rev. D
INSTRUCTIONS-PARTS LIST
INSTRUCTIONS
This manual contains important
warnings and information.
READ AND KEEP FOR REFERENCE.
Stainless Steel, Air-Operated
Bead Spray Gun
200 psi (13.8 bar) Maximum Working Pressure
Model 238338, Series A
GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440–1441
ECOPYRIGHT 1996, GRACO INC.
Graco Inc. is registered to I.S. EN ISO 9001
05949

2 308612
Table of Contents
Warnings 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operation 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Data 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Graco Phone Number 12. . . . . . . . . . . . . . . . . . . . . . . . . .
Warranty 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Symbols
Warning Symbol
WARNING
This symbol alerts you to the possibility of serious
injury or death if you do not follow the instructions.
Caution Symbol
CAUTION
This symbol alerts you to the possibility of damage to
or destruction of equipment if you do not follow the
instructions.
WARNING
PRESSURIZED EQUIPMENT HAZARD
Beads sprayed from the gun, leaks or ruptured components can splash in the eyes and cause serious
injury.
DDo not point the gun at anyone or at any part of the body.
DDo not put your hand or fingers over the spray tip.
DDo not stop or deflect leaks with your hand, body, glove or rag.
DFollow the Pressure Relief Procedure on page 5 if the spray tip clogs and before cleaning,
checking or servicing the equipment.
DTighten all fluid connections before operating the equipment.
DCheck the hoses, tubes, and couplings daily. Replace worn or damaged parts immediately.

3
308612
WARNING
INSTRUCTIONS
EQUIPMENT MISUSE HAZARD
Equipment misuse can cause the equipment to rupture or malfunction and result in serious injury.
DThis equipment is for professional use only.
DRead all instruction manuals, tags, and labels before operating the equipment.
DUse the equipment only for its intended purpose. If you are not sure, call your distributor.
DDo not alter or modify this equipment.
DCheck equipment daily. Repair or replace worn or damaged parts immediately.
DDo not exceed the maximum working pressure of the lowest rated system component. Refer to the
Technical Data on page 12 for the maximum working pressure of this equipment.
DDo not use hoses to pull equipment.
DRoute hoses away from traffic areas, sharp edges, moving parts, and hot surfaces. Do not expose
Graco hoses to temperatures above 82_C (180_F) or below –40_C (–40_F).
DDo not lift pressurized equipment.
DComply with all applicable local, state, and national fire, electrical, and safety regulations.

4 308612
Installation
NOTE: Reference numbers in parentheses in the text
refer to the numbers in the Parts.
Accessories are available from Graco. Be sure all
accessories are properly sized to withstand the pres-
sures in the system.
Mount Valve
Mount the valve on a 0.50 in. (12.7 mm) diameter rod
on a mounting fixture or a dispensing machine. The
bead gun has a clamping set screw (6) for mounting.
Connect the Air Lines
Clean all lines and connections of dirt, burrs, etc. and
blow them out with clean air before connecting them to
the system. Install an air filter in the air supply line to
remove harmful dirt and moisture from the compressed
air.
Grounding
Proper grounding is essential to maintaining a safe
system.
To reduce the risk of static sparking, ground the pump,
bead spray gun, paint spray gun and all other system
equipment.
1. Pump: use a ground wire and clamp.
2. Air compressors and hydraulic power supplies:
follow manufacturer’s recommendations.
3. Air and fluid hoses connected to the pump: use
only grounded hoses with a maximum of 500 feet
(150 m) combined hose length to ensure ground-
ing continuity.
4. Dispensing valve: obtain grounding through con-
nection to a properly grounded fluid hose, frame
and pump.
5. Fluid supply container: according to local code.
6. All solvent pails used when flushing: ground ac-
cording 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.

5
308612
Operation
Pressure Relief Procedure
FLUID INJECTION HAZARD
To reduce the risk of serious bodily inju-
ry, including fluid injection,splashing in
the eyes or on the skin, or injury from
moving parts, always follow this procedure when-
ever you shut off the pump, when checking or serv-
icing any part of the dispensing system, when
installing, cleaning, or changing part of the valve,
and whenever you stop dispensing.
WARNING
1. Shut off the air supply to the bead tank. Bleed the
bead tank.
2. Close the bleed-type master air valve (required
with air-powered pumps).
3. Actuate the dispensing valve to relieve pressure.
4. Leave the drain valve(s) open until you are ready
to dispense again.
If you suspect that the dispensing valve or hose is
completely clogged, or that pressure has not been fully
relieved after following the steps above, very slowly
loosen the hose end coupling and relieve pressure
gradually, then loosen completely. Now clear the valve
or hose.
Adjustments
Set the actuating air to at least 50 psi (3.5 bar) and
start the pump. Set the glass bead supply tank pres-
sure between 30 psi and 75 psi for desired flow rate.
Note: Bead delivery will vary with each application.
Always test the system for actual delivery and adjust
air pressure or nozzle size as needed.
Application Data
See Road Lazer System Manual 308611.
Nozzle Size Selection
Use the Nozzle Size Selection and Bead Delivery
Tables to select the size of nozzle for the travel speed
and bead coverage to be used. These tables are
based on a 15 mil paint application.
1. Go to Bead Delivery (Lb/Min) Table and select:
a. Speed in MPH or KPH row.
b. Bead coverage in Pounds Per Gallon
column.
c. Value at intersection of MPH row and Pounds
Per column is bead delivery in lb/min.
2. Go to Nozzle Size Selection Table and select:
a. Bead Delivery (lb/min) column determined by
Bead delivery (lb/min) value.
b. Psi value Glass Bead Tank psi row.
c. Curve (1, 2, 3 or 4) at intersection of Glass
Bead Tank psi row and Bead Delivery (lb/min)
column is nozzle size value.
d. Select nozzle size that allows range of adjust-
ment for more or less flow.

6 308612
Operation
Bead Delivery Lb/Min (kg/Min)
Speed Bead Coverage in Pounds Per Gallon (kg/L)
MPH KPH 4 (.48) 5 (.60) 6 (.72) 7 (.84) 8 (.96) 9 (1.08)
2 3.2 2.4 (1.09) 3.0 (1.36) 3.6 (1.63) 4.1 (1.86) 4.7 (2.13) 5.3 (2.40)
3 4.8 3.6 (1.63) 4.4 (2.0) 5.3 (2.40) 6.2 (2.81) 7.1 (3.22) 8.0 (3.62)
4 6.4 4.7 (2.13) 5.9 (2.68) 7.1 (3.22) 8.3 (3.76) 9.5 (4.31) 10.7 (4.85)
5 8 5.9 (2.68) 7.4 (3.36) 8.9 (4.04) 10.4 (4.72) 11.9 (5.40) 13.3 (6.03)
6 9.6 7.1 (3.22) 8.9 (4.04) 10.7 (4.85) 12.4 (5.62) 14.2 (6.44) 16.0 (7.26)
7 11.2 8.3 (3.76) 10.4 (4.72) 12.4 (5.62) 14.5 (6.58) 16.6 (7.53) 18.7 (8.48)
8 12.8 9.5 (4.31) 11.9 (5.40) 14.2 (6.44) 16.6 (7.53) 19.0 (8.62) 21.3 (9.66)
9 14.4 10.7 (4.85) 13.3 (6.03) 16.0 (7.26) 18.7 (8.48) 21.3 (9.66) 24.0 (10.9)
10 16 11.9 (5.40) 14.8 (6.71) 17.8 (8.07) 20.7 (9.39) 23.7 (10.8) 26.7 (12.1)
11 17.6 13.0 (5.90) 16.3 (7.39) 19.6 (8.89) 22.8 (10.3) 26.1 (11.8) 29.3 (13.3)
12 19.2 14.2 (6.44) 17.8 (8.07) 21.3 (9.66) 24.9 (11.3) 28.4 (12.9) 32.0 (14.5)
Nozzle Size Selection
0
10
20
30
40
50
60
70
0 5 10 15 20 25 30 35 40 45
1 2 3
1
2
3
4
ORIFICE DIAMETER
0.203
0.234
0.280
0.344
Glass Bead Tank psi
(bar)
Bead Delivery lb/min (kg/min)
(2.27) (4.54) (6.80) (9.07) (11.3) (13.6) (15.9)
(0.68)
(1.36)
(2.04)
(2.72)
(3.40)
(4.08)
(4.76)
45
5 0.420
(20.4)(18.2)

7
308612
Maintenance
Clean Dispensing Valve and System Daily
CAUTION
Be sure that the solvent you use is compatible with
the fluid being dispensed, to avoid clogging the
valve’s fluid passages.
An important part of the care and maintenance of your
automatic dispensing valve is proper flushing. Flush
the valve daily with a compatible solvent until all traces
of fluid are removed from the valve passages. Follow
the Pressure Relief Procedure on page 5 before
flushing.
Clean the outside surfaces of the valve by wiping with
a soft cloth dampened with a compatible solvent.
CAUTION
Never immerse the entire dispensing valve in
solvent. Immersing in solvent removes lubricants
and tends to damage packings.
To remove a hardened particle from the orifice, blow
air through the orifice from the front.
Service
Needle, Seat and Packings
To clean or replace the needle (18), its seat (17) or
packings (19 or 15), proceed as follows:
1. Follow Pressure Relief Procedure on page 5
2. Remove retaining nut (3).
3. Remove valve housing (4).
4. Remove valve seat (2) and o-ring (19) from valve
housing (4). Remove o-ring.
5. Remove gun needle (18).
6. Remove seal nut (21).
7. Remove o-ring (15).
8. Clean all parts.
9. Lubricate o-ring (15) with one drop of oil. Install
o-ring.
10. Install seal nut (21).
11. Install gun needle (18).
12. Install o-ring (19) on valve seat (2) and insert into
valve housing (4).
13. Install retaining nut (3).
Air Piston, Spring and Seals
Follow the Pressure Relief Procedure on page 5,
then remove the valve as explained, preceding. Re-
move the air cylinder cap (7), take out the spring (8)
and pull the piston (10) out. Clean and inspect all
parts. Check the piston o-rings (11, 12) carefully.
Lubricate all parts with a light waterproof grease and
reassemble the valve using new parts as necessary.
Repair Kit
Repair Kit 238340 includes the parts listed with an * in
Parts on page 11.

8 308612
Troubleshooting
NOTE: Check all possible solutions before disassembling the pump.
Problem Cause Solution
Uneven spray pattern Bead pressure too low Increase pressure to bead tank, or
adjust bead pressure regulator
Spray gun will not stop spraying Gun needle binding Clean, repair
Obstructed or worn needle seat Clean or replace
Spray gun will not spray Bead line clogged Clear
Bead valve closed Open
Clogged orifice or needle seat Clean
No trigger or actuator air pressure Check, clean air lines
Wet beads Drain beads from tank and replace
with dry beads.

9
308612
Notes

10 308612
Parts
7
8
9
11*
10
12*
5
6
4
16
18*
2**
3
13*
14
20
1
19**
15*
17
Model 238338
21*
05950A