TM 55-1520-240-23-6
7-258
TEST PRESSURE REDUCING VALVE (AVIM)
(Continued)
7-258
INSTABILITY TEST
32.
Connect tube (16) of test setup No. 3 to INLET
port (1) of valve (2).
33.
Connect tube (17) to OUTLET port (3).
34.
Connect tube (18) to RETURN port (4).
35.
Open shutoff valve (19). Close switch (20) to
open solenoid shutoff valve (21).
36.
Apply pressure to INLET port (1) of valve (2).
Bleed valve until valve is air free.
37.
Close shutoff valve (19). Open switch (20) to
close solenoid shutoff valve (21).
38.
Raise pressure to solenoid shutoff valve (21) to
3,000 psi.
39.
Close and open switch (20) to actuate solenoid
shutoff valve (21).
40.
Check valve (2) for squeals, chattering or other
signs of instability. There shall be no squeals
or chattering.
41.
Repeat steps 39 and 40 10 times.
42.
Reduce pressure to solenoid shutoff valve (21)
to 0 psi.
43.
Disconnect tubes (16, 17, and 18) from ports
(1, 3, and 4).
44.
Torque locknut (22) to 200 inch-pounds.
45.
Lockwire locknut (22) to valve (2). Use lockwire
(E231).
FOLLOW-ON MAINTENANCE:
None
END OF TASK
7-949
