Nordson A7A User manual

Instruction Sheet
E1999 Nordson Corporation
All rights reserved 331 279A
Issued 6/99 Manual 4-45
P/N 331 279A
A7A Stainless Steel Valve
WARNING: Allow only qualified personnel to perform the
following tasks. Follow the safety instructions in this document
and all other related documentation.
WARNING: System or material pressurized. Relieve pressure.
Failure to observe may result in serious burns.
See Figure 1. The valve is a compact stainless steel airless spray valve.
It may be used in a wide variety of applications, most specifically as a
component of the CanWorks manifold assembly.
0445001A
Fig. 1 A7A Stainless Steel Valve
1. Description

2
A7A Stainless Steel Valve
E1999 Nordson Corporation
All rights reserved
331 279A
Issued 6/99
Manual 4-45
See Figure 2. When the valve is actuated, air enters at the air input (1).
This air lifts the piston/locknut assembly (2), and allows the packing
cartridge (3) and the ball tip (4) to rise. The coating material passes
through the opening in the seat (5), and exits the port (6). When the air
pressure is removed, the ball tip (4) returns to the seat (5) and stops the
flow of coating material.
0445002A
0.406 mm–0.584 mm
(0.016 in.–0.023 in.)
1
2
3
4
5
6
Fig. 2 Valve Operation
1. Air input
2. Piston/locknut assembly 3. Packing cartridge 4. Ball tip 5. Seat 6. Port
Theory of Operation

3
A7A Stainless Steel Valve
E1999 Nordson Corporation
All rights reserved 331 279A
Issued 6/99 Manual 4-45
See Figure 3. To install the valve, perform the following steps:
1.Apply lubricant to the O-ring (20).
2.Insert the valve into the manifold assembly.
3.Tighten the socket screws (19).
4.Install pneumatic line to air inlet (12).
5.Connect fluid tubing to fluid inlet (11) or insert the pipe plug (14).
NOTE: If possible, flush the valve with clean solvent before removing the
valve from the system.
1.Remove both the fluid and air pressure to the valve.
2.Remove the A7A valve from the manifold assembly.
3.See Figure 3. Remove the screws (1), lockwashers (2), and
cylinder(3) from the gun body (13).
4.Remove the gasket (4) from the gun body (13).
5.Remove the locknut (5).
6.Remove the seal nut (8).
7.Remove the screws (19) attaching the valve adapter (18) to the gun
body (13).
8.Pull the valve adapter (18) and O-ring (11) from the gun body (13).
9.Remove the packing cartridge (15) with the ball tip (16) by pushing at
the air cylinder end.
10.Check the ball tip (16) for wear or scoring, and replace the ball tip if
necessary.
11.Check the packing cartridge (15) and O-ring (11). Replace the
packing cartridge or O-ring if necessary.
2. Installation
3. Repair
Disassembly

4
A7A Stainless Steel Valve
E1999 Nordson Corporation
All rights reserved
331 279A
Issued 6/99
Manual 4-45
1.See Figure 3. After coating the packing cartridge (15) with a small
amount of non-detergent grease, install the packing cartridge.
2.Install the valve adapter (18). Tighten the screws (19) evenly to
compress the packing cartridge spring.
3.Insert the seal nut (8) and O-ring (9) into the piston disc (10).
4.Screw the piston/locknut assembly (7) into the packing cartridge (15)
clockwise until it rests against the gun body (13).
5.Screw the piston/locknut assembly (7) counterclockwise 3/4until a
0.41 to 0.58-mm (0.016 to 0.023-in.) gap exists between the piston
and the gun body (13).
6.Hold the piston/locknut assembly (7), and lock it into place with the
locknut (5) and thread locking compound.
See Figure 3. If you need assistance when ordering parts, contact your
Nordson Corporation representative.
Item Part Description Quantity Note
—334 867 Valve assembly, A7A, stainless steel 1
—- - - - - SValve assembly, A7A, stainless steel 1
1981 140 SSScrew, fillister-head, #10-32 x 1.00, slotted, zinc 4
2983 120 SSLockwasher, external, split, #10, steel, nickel 4
3153 028 SSCylinder 1
4153 031 SSGasket, gun, H20 1 A
5984 539 SSLocknut, #10-32, upper 1 A
6900 424 SSCompound, thread lock, VC-3 AR
7- - - - - SSPiston, locknut, assembly 1 A
8240 274 SS S Nut, seal, lock 1 A
9940 090 SS S O-ring, Viton, 0.208 ID x 0.070 in. wide, brown 1 A
10 - - - - - SS S Disc, piston 2
NOTEA:This part is also available in the A7A Piston with seals repair kit, part 106 230.
AR: As Required
Continued on next page
Assembly
4. Parts

5
A7A Stainless Steel Valve
E1999 Nordson Corporation
All rights reserved 331 279A
Issued 6/99 Manual 4-45
Item Part Description Quantity Note
NS - - - - - SSSRetainer, piston 1
NS - - - - - SSSSeal, piston 1
11 940 159 SS O-ring, EPR, 0.563 x 0.688 x 0.063 in. 2B, C
12 972 119 SS Elbow, male, 1/4tube x 1/8NPT 1
13 - - - - - SS Body, gun 1
14 900 784 SS Cap/plug, tapered, 0.485 OD 1
15 170 497 SS Cartridge, packing, stainless steel, EPR 1
NS 330 438 SS Plate, adapter, valve 1 B
16 - - - - - SSSTip, ball 1 B
NS - - - - - SSSSeat, cartridge 1 B
17 940 176 SSSO-ring, EPR, 0.688 x 0.813 x 0.063 in. 1A, B, C
18 - - - - - SS Adapter, valve 1
19 981 893 SS Screw, socket head, #10-32 x 0.500, zinc 4
20 940 159 SS O-ring, EPR, 0.563 x 0.688 x 0.063 in. 2B, C
NS 900 755 SS Cap/plug, tapered, 0.788 OD 1
NS 900 481 SS Adhesive, pipe/thread/hydraulic sealant AR
NS 703 191 SS Plug, pipe, socket, flush, stainless steel, 1/4in. 1 D
NS 981 800 SS Screw, drive, round, 0 x 0.125 in., zinc 2
NS 900 223 SS Lubricant, O-ring, Parker, 4 oz AR
NS 152 999 SWrench 1
NOTE A: This part is also available in the A7A Piston with seals repair kit, part 106 230.
B: This part is also available in the seat assembly service kit, part 330 242.
C: This part is also available in the A7A valve EPR soft goods service kit, part 334 877.
D: This is a special-order part. Contact your Nordson Corporation representative for more information.
AR: As Required
NS: Not Shown

6
A7A Stainless Steel Valve
E1999 Nordson Corporation
All rights reserved
331 279A
Issued 6/99
Manual 4-45
0445003A
1
2
3
4
8
9
10
15
11
13
18
12
19
16
17
14
5
6
7
20
Fig. 3 Exploded View of the A7A Stainless Steel Valve
Parts (contd.)

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A7A Stainless Steel Valve
E1999 Nordson Corporation
All rights reserved 331 279A
Issued 6/99 Manual 4-45
See Figure 3.
Seat Assembly
Item Part Description Quantity Note
—330 242 Service kit, seat assembly 1
11 940 159 SO-ring, EPR, 0.563 x 0.688 x 0.063 in. 2
NS - - - - - SSeat, valve 1
16 - - - - - SSTip, ball 1
NS - - - - - SSSeat, cartridge 1
18 - - - - - SSAdapter, valve 1
17 940 176 SO-ring, EPR, 0.688 x 0.813 x 0.063 in. 1
NS: Not Shown
A7A Piston with Seals
Item Part Description Quantity Note
—106 230 Service kit, piston with seals, A7A 1
4153 031 SGasket, gun, H20 1
NS 153 022 SPiston, assembly, H20 1
7- - - - - - SSPiston, locknut, assembly 1
8240 274 SS S Nut, seal, lock 1
9940 090 SSO-ring, Viton, 0.208 ID x 0.070 in. wide, brown 1
5984 539 SSLocknut, #10-32, upper 1
11 940 159 SO-ring, EPR, 0.563 x 0.688 x 0.063 in. 2
18 940 176 SO-ring, EPR, 0.688 x 0.813 x 0.063 in. 1
NS: Not Shown
Service Kits

8
A7A Stainless Steel Valve
E1999 Nordson Corporation
All rights reserved
331 279A
Issued 6/99
Manual 4-45
A7A Valve EPR Soft Goods
Item Part Description Quantity Note
NS 334 877 Kit, soft goods, A7A valve, EPR 1
11 940 159 SO-ring, EPR, 0.563 x 0.688 x 0.063 in. 2
NS 940 136 SO-ring, EPR, 0.438 x 0.563 x 0.063 in. 1
17 940 176 SO-ring, EPR, 0.688 x 0.813 x 0.063 in. 1
NS: Not Shown
Original copyright date 1999. CanWorks, Nordson, and the Nordson logo are registered trademarks of Nordson Corporation.
Parker Lubricant is a registered trademark of Parker Seal.
Viton is a registered trademark of E.I. DuPont de Nemours & Co.