Repair; Single-Chamber Guns; Disassembly - Nordson A7A Product Manual

6. Repair

Single-Chamber Guns

1998 Nordson Corporation
All rights reserved
WARNING: Allow only qualified personnel to perform the follo-
wing tasks. Observe and follow the safety instructions in this
document and all other related documentation.
The following paragraphs provide procedures to repair single-chamber
guns.

Disassembly

NOTE: See Figures 6 or 7
1. If possible, flush the gun with clean solvent before you remove it from
the system.
WARNING: System or material pressurized. Relieve pressure.
Failure to observe this warning may result in serious injury or
death.
2. Relieve both fluid and air pressure to the gun.
3. If the position of the gun in relation to the material being coated is
critical, remove the two fillister head screws (11) to remove the gun
from the mounting block. Otherwise, remove the gun from its system
by loosening the square head screw (13) from the mounting
block (12).
4. Remove the screws (1), lock washers (2), and air cylinder(3) from the
gun body (15).
5. Remove the air cylinder gasket (4) from the gun body.
6. Use the Nordson wrenches provided with the gun to remove the
packing cartridge lock nut (6).
7. Use the Nordson wrenches to remove the seal nut (7).
8. Remove the screws (20) that attach the seat (18) to the gun body.
9. Remove the seat and O-ring (19) from the gun body.
10. Remove the packing cartridge (16) with the ball tip or needle tip (18)
attached by pushing at the air cylinder end.
11. Check the ball or needle tip for wear or scoring. If worn, replace
the tip.
12. Check and replace the packing cartridge and O-ring (17),
if necessary.
107 966E
Issued 1/98
A7A Airless Spray Gun
as applicable.
21
Manual 4-6