DeVilbiss AGF-508 Operation Manual

© ITW LTD 1994

SB-E-2-782-B

Operation Manual:

AGF-508 Automatic Gun

Important:

Read and follow all instructions and SAFETY PRECAUTIONS

before using this equipment

A lightweight automatic spray gun for small work suitable for use with most solvent based coating materials. The design
features, a single air supply to operate the single acting cylinder and provide the atomising air. A remotely positioned two-way
control valve (supplied by user) triggers the gun. Coating material supply is by a pressure feed system.

IMPORTANT: These guns are not designed for use with highly corrosive or highly abrasive coating material and if used with
such materials it must be expected that the need for thorough cleaning and/or the necessity for replacement parts will be
increased. If there is any doubt regarding the suitability of a specific material, advise what material is to be used and/or submit
a sample for test.

AGF-508EL-92 Spray gun fitted with 1.8 mm nozzle and No. 92 air cap.
AGF-508FL-90 Spray gun fitted with 1.0 mm nozzle and No. 90 air cap.

When ordering add the hose connecting thread required.

HOSE CONNECTION: THREAD CODE

‘B’ ‘N’

Air supply:

1

/4" BSP

1

/4" NPS

Coating material supply:

1

/4" BSP

1

/4" NPS

MAXIMUM RECOMMENDED WORKING PRESSURES:

Air supply : P1= 7 bar (100 lbf/in2).
Coating material supply : P2= 7 bar (100 lbf/in2).

MINIMUM CYLINDER AIR PRESSURE:

: 4 bar (60 lbf/in2).

WEIGHT:

Gun less mounting stud : 375g.
Mounting stud : 110g.

SPECIFICATIONS

MODELS

DESCRIPTION

2

Figure 1

Ref. Order No. Description Qty.

1 TGA-31 Air cap retaining nut 1
2 CV-39-90 Air cap 1
3 CV-439-92 Air cap / retaining ring 1

*4 Chart 1 Nozzle 1

5 AGF-5 Baffle 1
6 AGF-403 Valve assembly 2
7 AGF-7 Valve 2
8 AGF-8 Body 2
9 AGF-9 Seal 2

10 AGF-10 Washer 2

11 KN-40-K5 Spring 2
12 21172-007-K10 Washer 2
13 25746-007-K5 Circlip 2

*14 AG-12-K5 Needle Packing 1
*15 23162-024-K10 ‘0’ ring 1

16 AGF-6 Seal retainer 1

Ref. Order No. Description Qty.

*17 Chart 1 Needle 1
*18 MBC-1164-K5 ‘0’ ring 1
*19 SST-8402 Circlip 1

20 AGF-19 Spacer 1

*21 VA-246 Piston seal 1

22 AGF-36 Piston 1
23 21175-093 Washer 1

24 AGF-15 Nut 1
*25 AGF-33 Spring 1
*26 AGF-32 Spring 1

27 AGF-31 End cap 1

28 AGF-35 Locknut 1

29 AGF-34 Screw 1

30 H-1766 Connector 1/4" NPS

PA-H-1766 Connector 1/4" BSP
31 SS-555 Screw 1
32 AGF-20 Mounting stud 1

Parts List

2 SB-E-2-782 – © ITW LTD 1994

1. Mix, prepare and filter the coating material to be sprayed to the manufacturer’s instructions.

2. Adjust the spray gun controls and pressures before turning on the air and coating material supplies.

2.1 Fan pattern valve (6) marked ‘FAN’ on the gun body. Turn adjusting screw to fully open position, by turning
counter-clockwise.

2.2 Atomising control valve (6) marked ‘ATOM’ on the gun body. Turn adjusting screw to fully open position, by
turning counter-clockwise.

2.1 Needle adjustment. Fully close needle adjusting screw (29), release locknut (28), turn clockwise until resistance is
felt, then turn to the fully open position by turning counter-clockwise ten turns and secure with locknut (28).

3. Regulate the air supply pressure to 4 bar (60 lbf/in2) and coating material pressure to 1 bar (15 lbf/in2)

4. Turn on air and coating material supplies and test spray by operating control valve. The recommended spray distance is 150
mm (6"). If the finish is too wet, reduce the coating material supply pressure, or turn the needle adjusting screw (29) fully
clockwise then gradually open until the desired pattern is achieved. If the atomisation is too coarse increase the air
pressure. The spray width can be reduced from fan to round by turning fan adjusting valve (6) marked ‘FAN’ clockwise.

Note. If both ‘FAN’ and ‘ATOM’ valves (6) are closed the air supply operates the cylinder only and will allow coating material to

be jetted from the nozzle.

5. To prevent accidental discharge of coating material, always turn off and release pressure when the gun is not in use.

Flushing the system:

1. Turn off coating material supply and relieve pressure.

2. Close both air valves (6) marked ‘FAN’ and ‘ATOM’.

3. Replace coating material with a suitable solvent, reduce pressure and turn on supply.

4. Remove air cap, trigger the gun by operating the control valve. Flush system until clean.

Clean air cap by immersing in solvent, brush or wipe clean. If any holes in the air cap are blocked use a toothpick or broom
straw to remove the obstruction. Never use a steel wire or hard implement which will damage the air cap and result in a
distorted pattern.

Lubrication: Daily lubricate with light mineral oil the valve stems (7) and needle seal (14) through holes in seal retainer (16).
Occasionally coat the gun body cylinder section and springs (25 & 26) with mineral based grease.

Note: Order numbers shown in parts list for figure 1 with suffix ‘-K5’, etc. at the end of the order No. indicates a kit of parts.
Example AG-12-K5 is a kit of five seals.

Nozzle (4) or Baffle (5)

Remove parts (1, 2, 3, 27, 28, 29, 25 and 26) unscrew nozzle (4) and pull baffle (5) out from body.
Caution: Do not twist baffle (5) when removing from the gun body as this will bend the locating pin in the gun body.
Replace any worn or damaged parts. Reassembly, position baffle (5), ensure gun body locating pin is engaged in the narrow
slot in the baffle. Replace nozzle (4) and tighten. Recommended torque 13-14 Nm (115-125 lbf in). Fit parts (25, 26,27, 28, 29,
1, 2 or 3).

Seal (9)
Caution: Always turn valve (7) fully counter-clockwise before fitting or removing valve assembly (6) from gun body.

Remove valve assembly (6) from gun body. Remove parts (13, 12, 11, 10 and 9). Lubricate seal (9) with mineral oil and
replace parts (9, 10, 11, 12 and 13). Refit valve assembly (6) to gun.

Seal (14), (SEE SAFETY WARNINGS UNDER MISUSE), and ‘0’ ring (15)

Remove parts (29, 28, 27, 26 and 25). Withdraw needle and piston assembly, insert a wide blade screwdriver into the slot and
unscrew seal retainer (16) and remove seal (14). Lubricate new seal (14) with mineral oil, replace ‘0’ ring (15), place seal (14)
into retainer (16) and screw into gun body. Tighten retainer (16) sufficiently to seal but not to impede free needle (17)
movement. Lightly coat seal (21) and ‘0’ ring (18) with mineral based grease. Fit needle and piston assembly into gun body.
Reassemble parts (29, 28, 27, 26 and 25).

Needle (17)

Remove parts (29, 28, 27, 26 and 25) and withdraw needle and piston assembly. Unscrew nut (24), remove needle (17) and
washer (23). Replace needle (17), position washer (23) and tighten nut (24). Adjust needle seal (14) with retainer (16)
sufficiently to seal but not to impede free needle (17) movement. Lightly coat seal (21) and ‘0’ ring (18) with mineral based
grease. Fit needle and piston assembly into gun body. Reassemble parts (29, 28, 27, 26 and 25).

Piston seal (21) and ‘0’ ring (18)

Remove parts (29, 28, 27, 26 and 25) and withdraw needle and piston assembly. Remove parts (18, 19, 20, 21). Replace seal
(21) and ‘0’ ring (18). Reassemble parts (18, 19, 20, 21) see figure 3 for the direction of circlip bow. Lightly coat seal (21) and ‘
0’ ring (18) with mineral based grease. Fit needle and piston assembly into gun body. Reassemble parts (25, 26, 27, 28 and

29). Adjust screw (29) and secure with locknut (28).

Connectors (30)

Remove connector (30) and clean threads in gun body. Apply a medium strength thread locking/sealing compound to the
external threads of the new connector. Screw into gun body and tighten. Recommended torque: 14 Nm (125 lbf in).

REPLACEMENT OF PARTS (see figures 1 and 3)

PREVENTIVE MAINTENANCE

OPERATION

3 SB-E-2-782 – © ITW LTD 1994