TM-9-6920-430-14

COOLANT RECHARGING UNIT, TRAINING GUIDED MISSILE SYSTEM M80 AND CHARGER, BATTERY PP-7309/T

TECHNICAL MANUAL; OPERATOR’S AND ORGANIZATIONAL DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL

AUGUST 1980

TM-9-6920-430-14 - Page 145 of 180

TM 9-6920-430-14

3-23. RUPTURE DISC REPLACEMENT (Figure 3-9).

a.

Disconnect the power cable from the AC source.

b.

Close the argon gas supply valve fully clockwise.

c.

Remove housing enclosure by removing 18 retaining screws from the lower edge of enclosure

and 14 screws from the front panel assembly. Remove 4 mounting screws holding interlock safety

switch to rear of enclosure. Retain securing hardware for reinstallation. Disconnect inlet and outlet

flexible hoses from the GPU. Replace the protective plugs on the ends of the hoses, finger tight. Lift

enclosure upward to remove. Tape interlock safety switch in closed position.

d.

Remove rupture disc with 1/4-inch hex wrench and replace with a new disc. Apply sealant

tape, MIL-T-27730, to threads of rupture disc. Tape should not be applied to first two threads that

engage.

e.

Reconnect flexible hose from gas bottle to GPU inlet port.

f.

Close INLET SHUTOFF, lNLET BLEED, OUTLET SHUTOFF, OUTLET BLEED valves

fully clockwise. Open PROOF TEST SHUTOFF valve fully counterclockwise.

g.

Slowly open the argon gas supply valve two complete turns counterclockwise. Squirt leak

detecting fluid around the inlet hose fitting at the GPU. Check for gas bubbles indicating leakage. If

leaks are detected, close argon gas supply valve fully clockwise. Open INLET BLEED valve to

relieve gas then, close INLET BLEED valve fully clockwise. Tighten leaking fitting and repeat this

step.

h.

Purge the system in accordance with paragraph 3-18h, steps (3) through (10) (page 3-76).

i.

Disconnect inlet flexible hose and replace protective plug finger tight. Replace housing.

Figure 3-9. Rupture Disc Replacement

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