TM 5-4310-335-14
WARNING
Exercise extreme care when working with high pressure air to prevent injury to personnel or
damage to equipment. Do not attempt to tighten any fitting or perform any work on
equipment when the system is under pressure. Do not tamper with any pressure relief
valves.
(a) Cap the free tube end with a pipe cap and attach inlet to air supply.
(b) Increase air pressure slowly. Valve shall have opened and be passing 5 scfm free air at 425 psi
(29.8755 kgs per sq cm) maximum.
(c) Reduce air pressure 50 psi (3.5150 kgs per sq cm) and then increase pressure. Valve shall reseat at
300 (21.0900 kgs per sq cm) psi minimum.
NOTE
A leakage flow of 15 cc per minute or less shall be considered as resealed.
(d) Lockwire the valve and secure with seal (1).
1. Install preformed packing (6) into groove of seat (7) and lubricate with oil, MIL-L6085A.
2. Lubricate bore and threads of body (8).
3. Place seat (7) with packing (6) on retainer (5) and insert into body (8) holding body in an upside down position.
Turn retainer clockwise with thumb until screw threads engage. Maintaining inverted position, screw in retainer with a flat
1/2 inch wide screwdriver until retainer bottoms. Back off a fraction of a turn.
4. Cap the free tube fitting end of the valve body and connect the inlet end to the air line of a suitable test stand.
Torque the seat retainer (5) to 10 inch-pounds (.1259 kg-m).
5. Installed cleaned check (4), spring (3) and plug (2) into valve body (8). Screw in plug until top of plug is
approximately 1/16 inch above the valve body.
6. Test the valve as follows:
(a) With the pipe thread capped and with check (4) retained, proof pressure test the valve for 1/2 minute
using 2000 psi (140.6000 kgs per sq cm) minimum pressure clean air or nitrogen. No audible leakage or evidence of
permanent distortion is permissible.
(b) Apply regulated air pressure of 1300 psi (91.3900 kgs per sq cm) and loosen or tighten plug (2) until
valve pops This is a preliminary setting and is not critical.
(c) Relieve pressure and remove valve, from the stand. Remove cap from tube end and put valve on tray
for oven treatment.
(d) Preheat oven to 200 (93 ). Place tray with valves into oven for 2-3 hours
F
C
at 200 . (930C).
F
(e) Allow the valves to cool off at room temperature for at least 2 hours. Cooling overnight is
recommended.
(f) Cap the free tube end and attach the inlet to the air line on a suitable test stand.
(g) Adjust the regulator for 1350 psi (94.90 kgs per sq cm) and screw plug (2, fig. 7-5) in or out until valve
just starts popping. If none of the slots in the plug meets a hole in the valve body, turn the plug either way to meet the next
wire hole.
(h) Recheck this final setting by dropping the regulator pressure 50 psi (3.5150 kgs per sq cm) and raising
again The valve should pop at 1300 psi (91.3900 kgs per sq cm)1400 psi (98.4200 kgs per sq cm), preferably on the high
side. If the valve does not pop, readjust the plug to the next wire hole, as cycling the valve often shifts the plug.
(i) Drop the regulator pressure and raise again to 1150 psi (80.8450 kgs per sq cm). Check the valve for
leakage for approximately 30 seconds until all trapped air has escaped. Leakage shall not exceed 60 cc per hour.
(j) Relieve pressure and remove valve from stand. Lockwire the valve and install seal (1). Cap tube ends if
valve is to be stored.
1. Assemble the valve in the reverse order of disassembly, observing the following precautions.
2. Lubricate the preformed packings (8 and 11), threads of fitting (10), and ID and threads of body (14) with grease
MIL-G-4343B.
3. Do not lockwire or seal the valve until testing has been completed.
4. Test the reassembled valve as follows:
WARNING
Exercise extreme care when working with high pressure air to prevent injury to personnel or
damage to equipment. Do not attempt to tighten any fitting or perform any work on
equipment when the system is under pressure. Do not tamper with any pressure relief
valves.
7-8
