Safety Head Assembly

TM 3-1040-220-34&P

(s) Using a wrench, tighten flare nut of metal

from the compressed gas cylinders (8 and 9) to the dial

tube assembly (31) at adapter (32).

indicating pressure gage (29) and the pressure regulator

(t) Screw flare nut on pipe tee (33) until

(23). Turning the valve handle clockwise closes the

fingertight.

valve, and turning the handle counterclockwise opens

(u) Tighten flare nut with wrench.

the valve.

(v) Screw flare nut of metal tube assembly (1) on

Maintenance.

Direct support

maintenance

pipe tee (33) until fingertight.

personnel are authorized to replace the pipe to pipe

(w) Tighten connection with wrench.

extension fitting and the dial indicating pressure valve.

(x) Connect nonmetallic hose assembly (17, fig.

(1) Removal.

2-3) to quick-disconnect coupling half (16).

(a) Follow steps (a) through (o) of removal

(y) Reconnect nonmetallic hose assembly (34)

procedure for the pressure regulator in paragraph 2-

swivel connector to elbow (35) and tighten with wrench.

3b(l).

(z) Reconnect nonmetallic hose assembly (27,

(b) Using a wrench, remove nipples (14 and 17,

fig. 2-1) at swivel connector and tighten with wrench.

fig. 2-1), connector block (16), elbow (13) pipe tee (33),

and pipe fitting seal (30) from the globe valve (18) as a

unit.

2-4. Safety Head Assembly

Description and Function.

The safety head

from plumbing at pipe to pipe extension fitting (19).

assembly (6, fig. 2-3) is a pressure relieving safety

(d) Reinstall the valve handle on the globe valve

device used to prevent a possible pressure explosion of

and secure it in place with screw, using a screwdriver.

the disperser. It is mounted in a cross (31) and

(2) Installation.

protrudes through the control panel. In the event of a

(a) Coat threads of nipple (20) with sealing

malfunction of the pressure regulator (23, fig. 2-1) and

compound (Table 1-1) and screw into pipe extension

failure of the safety relief valve (40, fig. 2-3), excessive

fitting (19).

pressure could build up in the plumbing components.

(b) Screw globe valve (18, fig. 2-1) on nipple

Should this happen, rupture disk (5) located in the safety

(20) and tighten with wrench. Position valve properly for

head assembly (6) will rupture and permits the air to

later installation in support assembly.

escape to the. atmosphere.

b. Maintenance. Direct support maintenance

compound (Table 1-1) and screw it into plumbing.

personnel are authorized to replace the safety head

(d) Screw nipple (17) into the globe valve (18) as

assembly (6).

a unit and tighten with a wrench. Make certain to

(1) Removal

properly position plumbing for later installation in the

(a) Close all valve.

support assembly.

(b) Relieve pressure by manually operating the

(e) Reinstall assembled plumbing in support

lever of the safety relief valve (40).

assembly by following steps (i) through (z) for pressure

regulator in paragraph 2-3b(2).

panel using an open end wrench.

(d) Place an open end wrench on safety head

assembly (6), and loosen and remove safety head and

2-6. Lever Plug Valve

pipe fitting (7).

a. Description and Function. The lever plug

(e) Remove pipe fitting seal (7) from safety head

valve (25, fig. 2-3) is a two-way plug type valve mounted

assembly (6) with fingers.

on the control panel. The lever plug valve controls the

(2) Installation.

flow of regulated air pressure from the pressure

(a) Coat threads of safety head assembly (6)

regulator. Turning the valve handle clockwise opens the

with sealing compound (Table 1-1).

lever plug valve, and turning the handle counterclockwise

(b) Screw pipe fitting seal (7) onto safety head

closes the lever plug valve.

assembly (6) loosely.

b. Maintenance. Direct support maintenance

personnel are authorized to replace the lever plug valve.

(31) until fingertight.

(1) Removal.

(d) Tighten pipe fitting seal (7) with open end

(a) Follow steps (a) through (o) of removal

wrench.

procedure for the pressure regulator in paragraph 2-3

(1).

(b) Using a wrench, loosen pipe fitting seal

2-5. Globe Valve

a. Description and Function. The globe valve (18, fig.

2-1) is a needle type valve. This globe valve is used to

control the flow of pressurized air

2-8