Figure 4-2. Set-up for Testing High Pressure Regulator
e. Adjust handle pf high pressure regulator to
reduce outlet pressure to 2500 psig. Outlet pressure
f. Brush a soap-water solution over entire surface
shall stabilize at this set point. Repeat procedure for
of low pressure regulator except vent hole. External air
outlet pressures of 2000, 1500, 1000 and 500 psig.
leakage, as indicated by air bubbles, shall not exceed
three cubic centimeters per hour.
f. Close shut-off valve. Adjust inlet pressure to
NOTE
3000 psig. Adjust outlet pressure to 3000 psig.
Air leakage from the vent hole can
g. Brush a soap-water solution over entire surface
be checked by immersing the end
of high pressure regulator except vent hole. External air
of the regulator in a container of
leakage, as indicated by air bubbles, shall not exceed
water.
three cubic centimeters per hour.
g. Wipe all traces of soap-water solution from low
h. Wipe all traces of soap-water solution from high
pressure regulator, relieve air pressure in test setup, and
pressure regulator, relieve air pressure in test set-up,
disconnect test equipment.
and disconnect test equipment.
4.5.6 HIGH PRESSURE REGULATOR TESTS. Test
the high pressure regulator in accordance with the
4.5.7 REASSEMBLY. Reassembly of the instrument
following procedure once every six months or whenever
panel assembly is obvious from the exploded view,
its operation is questionable.
Figure 5-2. Make certain all items are securely mounted
a. Connect pressure regulator to test set-up as
and all pneumatic and electrical connections are made
shown schematically in Figure 4-2.
in accordance with the original equipment configuration.
When installing bulkhead type fittings (i. e., elbows,
b. Close shut-off valve. Adjust inlet pressure
tees, etc. requiring fitting nuts) proceed as follows: a.
regulator to obtain an inlet pressure of 3000 psig. Adjust
Lubricate male threads, gasket back-up ring and tube
handle of high pressure regulator to obtain an outlet
fitting gasket with aircraft instrument lubricating oil
pressure of 200 psig.
(Specification MIL-L-6085A).
c. Open shut-off valve to pressurize air bottle.
b. Screw fitting nut well up on second set of
Regulated outlet pressure shall return to, and stabilize
threads on fitting.
Place gasket back-up ring in
at, initial set pressure within 50 psi. Leakage from vent
counterbore of nut. Place tube fitting gasket in groove
port shall not exceed one cubic centimeter (10 air
between two sets of threads.
bubbles) per minute.
NOTE
d. Repeat tests of steps b and c, preceding, at set
Cover threads of fitting with thin
pressures of 500, 1000, 1500, 2000, 2500 and 3000
shim stock or bullet-nose fixture
psig.
to avoid damaging gasket and
back-up ring during installation.
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