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TM 07661B-14/1
APPENDIX A
A 3-18. DRY CHEMICAL PRESSURE REGULATOR.
a.
Removal.
(1)
Completely depressurize dry chemical system, paragraph 3-12.
(2)
Remove dry chemical nitrogen cylinder. Refer to paragraph 3-10c.
(3)
Disconnect hose (3, figure 3-9) from swivel adapter (9) at outlet of pressure regulator.
(4)
Remove bolt (5) and lock washer (6) which fastens regulator tee to hose reel mounting bracket on skid
frame. Remove the regulator with the regulator tee.
(5)
Remove hose (1), elbow (2) and short. nipple (7) from regulator inlet. Remove tee (4) and short nipple
(10) from regulator outlet.
b.
Installation.
(1)
Before assembling or installing pipe fittings, seal threads using instructions in NOTE, paragraph 3-14c.
Assemble short nipples (7 and 10, figure 3-9) into inlet and outlet ports of pressure regulator. Install elbow (2), with
attached hose (1), on nipple in regulator inlet port. Install tee (4) on nipple in outlet port.
(2)
Fasten regulator assembly to frame as shown, figure 3-9, using 1/2-inch x 3/4-inch stainless steel bolt and
lock washer installed into threads of merchant plug (8) in regulator tee.
(3)
Connect hose (3) to swivel adapter (9) on outlet.
(4)
Reinstall dry chemical nitrogen cylinder. Refer to paragraph 3-10c.
(5)
Pressurize system and check for leaks, paragraph 3-14.
(6)
Return system to standby status, paragraph 2-12a.
A 3-19. AFFF SHUTOFF VALVE.
a.
Removal.
(1)
Depressurize AFFF system and drain AFFF tank below level of discharge port. Draining can be
accomplished without removing the fusible drain plug by disconnecting discharge hose (1, figure 3-10) from tee (2), then
opening shut-off valve (3) and allowing AFFF solution to drain into suitable container. Leave hose disconnected.
Remove protective covering, insulation and heat tape from outlet tube and shutoff valve.
(2)
Disconnect valve rod (4) from AFFF shutoff valve by removing nut (5).
(3)
Uncouple piping at union (6). Using a pipe wrench, rotate elbow (7) and attached piping slightly outward
away from tank. Remove purge valve (8) along with attached piping as an assembly from short pipe (9).
(4)
Remove pipe (10) and tee (2) from shutoff valve. Then remove shutoff valve (3) from pipe (11).
b.
Installation.
(1)
Before assembling or installing pipe fittings, seal threads using instructions in NOTE, paragraph 3-14c.
Assemble shut-off valve (3) to short pipe (11). Assemble pipe (10) and tee (2) to shut-off valve. Assemble purge valve
(8) and attached piping to tee (2) as shown, figure 3-10.
A 3-26
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