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TM 07661B-14/1
APPENDIX A
(5)
Connect valve rod (6) to AFFF shutoff valve by installing nut (7) on ball valve (8).
(6)
Install AFFF nitrogen cylinder. Refer to paragraph 3-10c.
(7)
Pressurize system and check for leaks. Use a soap solution of dishwashing detergent and water, to detect
minor leakage.
NOTE
Slow bubble leakage only permitted through pipe joint compound in packings and gasketed
joints. No leakage permitted in taper threaded joints.
(8)
Return AFFF system to standby status, paragraph 2-12a.
A 3-14. DRY CHEMICAL TANK REPLACEMENT.
For ease of removal and installation, the dry chemical system piping should be removed with the tank. Before
disassembling or removing system piping, adhere to WARNING below.
WARNING
The nitrogen pressure used in fire extinguisher operation can be extremely dangerous to
personnel if proper precautions are not taken. Before attempting replacement of any part of a
system, close the nitrogen cylinder valve and vent all pressure in system by opening nozzle
on hose reel.
a.
Removal.
(1)
Depressurize system, paragraph 3-12.
(2)
Remove dry chemical nitrogen cylinder. Refer to paragraph 3-10c.
(3)
Disconnect hose (1, figure 3-7) from regulator tee assembly (20) in tank inlet piping.
NOTE
Be sure dry chemical shutoff valve is closed to prevent spillage during removal.
(4)
Disconnect hose reel inlet hose (3) from tank discharge plumbing at nipple (4).
(5)
Disconnect valve rod (5) from dry chemical shutoff valve by removing nut (6) from ball valve (7).
(6)
Remove four mounting bolts (8) with flat washers, lockwashers, and nuts. The mounting hardware is
stainless steel. Retain for reassembly.
(7)
Use suitable equipment to lift tank and piping from skid frame.
b.
Disassembly. Remove piping from dry chemical tank as follows:
(1)
Remove hose (21, figure 3-7) from swivel adapter (22).
(2)
Uncouple two unions (9) in tank inlet piping.
(3)
Disconnect hose (10) from swivel adapter (23) using a pipe wrench, unscrew short pipe (12) from tank
discharge port.
(4)
With a pipe wrench, unscrew short pipe (13) from vent port on top of tank.
A 3-21
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