Section VI. TANK BLOCK ASSEMBLY (Fig. 4-3, 4-4, and 4-5)

TB 5-4220-200-12-1

(20) With the equipment assembled, connect the first stage regulator to a high pressure air supply. Turn

on the air supply to the first stage regulator and check for air leakage in the second stage regulator.

(21) Push in on the purge button (2) and release. If free flow or very little flow occurs, see troubleshooting

section for instructions.

(22) Test breath the second stage regulator. If free flow or hard breathing occurs, see troubleshooting sec-

tion for instructions.

(23) Turn off the air supply, press purge button (2) and disconnect the first stage regulator from the air

supply.

(24) Reconnect major components and conduct an operational check in accordance with steps 2 and 4 of

the Weekly Preventive Maintenance Checklist table 3-1.

Second Stage Regulator Adjustment.

Attempts to turn disc and retainer with a screwdriver applied to the slotted end will

cause damage.

(1)

Place the blade of a flat tip 5/32 inch offset (45" bend in shank) in the slot of the threaded end of the

disc retainer (15), fig. 2, using a 1/4 inch box wrench, adjust nut (20) until lever (18) is flush with the

box bottom (11) rim.

(2)

Connect the first stage regulator to a high pressure air supply. Turn on the air supply and check for

air leakage. If leakage occurs, turn off the air supply. Using the tools specified in Step (1). loosen nut

(20) until the air supply can be turned on without air leakage.

(3)

With the first stage regulator providing 130 ± 5 PSIG air supply to the second stage regulator, proper

adjustment of lever (18) is accomplished by adjusting nut (20) until a six inch metallic ruler will touch

both sides of the box bottom (11) and lever (18) at the same time. Press and release the lever and

recheck the lever setting, and readjust until no further adjustment is necessary. Disconnect the first

stage regulator from the air supply.

NOTE

Proceed with the reassembly instructions in b (14) above.

Section VI. TANK BLOCK ASSEMBLY (Fig. 4-3, 4-4, and 4-5)

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GENERAL.

This section contains the disassembly and reassembly of the tank block manifold assembly, and the twin tank har-

ness. It further provides instructions, paragraph 4-18, for completing the annual internal (visual) inspection of SCU-

BA tanks.

4-16

TANK BLOCK ASSEMBLY (P/N 0638).

Tank Block Manifold Disassembly.

NOTE

Insure the On-Off valve handle (18) is open and reserve lever (39), fig. 4-3, is in

the down position prior to disassembly.

(1)

Bleed off all air inside the tanks. Place the tank block on a flat surface so the repairman is facing the

manifold assembly and the center yoke O-Ring (9) is visible.

(2)

Pull the looped end of the pull rod (fig. 4-5) (18) upward until it is released from the lower stabilizer

band assembly clip (14). Push the middle of the push rod downward until the pull rod is released from

the top stabilizer band assembly clip (14).

(3)

Rotate the tanks so the repairman is facing the manifold assembly and the pull rod is hanging down.

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