BECAUSE OF POSSIBLE VACUUM
PUMP EXPLOSION, ONLY WATER-
PUMPED NITROGEN, TYPE 1, CLASS
1, GRADE B, (FED. SPEC BB-N-411)
WILL BE USED IN TESTING OXYGEN
REGULATORS. USE ONLY NITRO-
GEN FROM GRAY CYLINDERS
MARKED NITROGEN OIL FREE IN
WHITE LETTERS. TWO 3-INCH WIDE
BLACK BANDS MARK THE TOPS OF
THESE CYLINDERS. OXYGEN TEST
STANDS CONTAIN A MERCURY
MANOMETER. MERCURY IS A
TOPIC METAL. AVOID BREATH-
ING MERCURY VAPORS. AVOID
CONTACT WITH SKIN OR CLOTH-
OVERLOAD TEST. To perform the overload
test, proceed as follows:
1. Cap the regulator inlet and attach the
regulator outlet to the short hose attached to
piezometer (26) in the chamber. Ensure all test
stand valves are in the secured position, then open
the N2 supply cylinder valve.
NOTE: Ensure the regulator outlet and
piezometer (26) are one inch apart.
2. Using the hose supplied with the test stand,
connect LOW PRESS connection (19) to REF.
TAP connection (21) in the chamber.
3. Ensure the FLOW SELECTOR valve (M)
is in the REGULATOR position.
4. Adjust LOW PRESS. REGULATOR (N)
so that regulated LOW PRESS. gauge (11)
indicates 70 psig.
NOTE: When the in-system leakage
rotameters are used, an inlet pressure of
70 psig will normally be used, as this is the
pressure used to calibrate the rotameters.
5. Place PRESS. SELECTOR valve (D) in the
6. Slowly open LEAKAGE CONTROL valve
(E) until 1.85 inches in Hg is indicated on Hg
manometer (5). Maintain 1.85 inches of Hg for
2 minutes. If no leakage is indicated on HIGH
RANGE LEAKAGE rotameter (B), turn LEAK-
AGE SELECTOR valve (F) to the LOW RANGE
position and check for leakage on the LOW
RANGE LEAKAGE rotameter (7). The max-
imum allowable leakage will be no more than the
allowable leakage for each model shown on the
performance test sheet. If the leakage is excessive,
dispose of the regulator in accordance with your
NOTE: A body leakage testis done on the
model 900-002-025-05 regulator only.
Refer to the NAVAIR 13-1-6.4, DEMAND
VALVE LEAKAGE TEST.
NEVER BLOCK THE OUTLET OF THE
MINIATURE REGULATOR WHILE A
PRESSURE IS APPLIED TO THE
INLET. THIS WILL SERIOUSLY
DAMAGE THE REGULATOR.
NOTE: If a high reading is encountered
during this test, make sure the pressure
breathing aneroid is not screwed into the
regulator housing too far before disposing
of the regulator. Turn the pressure breath-
ing aneroid counterclockwise out of the
regulator housing and then recheck the
7. Disconnect the hose from LOW PRESS
connection (19) and REF TAP connection (21) in
the altitude chamber.
8. Uncap the regulator inlet and connect the
regulator inlet to N2 input connection (18) in the
9. Ensure PRESS SELECTOR valve (D) is
in the Hg position.
10. Turn on the vacuum pump.
11. Turn INLET PRESS on/off valve (L) to
12. Using LOW PRESS REGULATOR (N),
apply 110 psig to the regulator inlet. The pressure
will be indicated on N2 INPUT PRESS gauge (27).
13. Open OUTPUT valve (C) to draw a
flow through the regulator, then close valve
14. Place PRESS SELECTOR valve (D) in
H2O position. Observe the PRESS/SUCTION
manometer (4) for 5 minutes. The pressure must
not exceed 2.5 inches of H2O. After the 5 minute
period, read manometer (4) and enter the reading
on the performance test stand. If the leakage is
excessive, dispose of the regulator.
15. Leave the positions of all controls and
SAFETY PRESSURE TEST. To perform the
safety pressure test, proceed as follows:
1. Adjust LOW PRESSURE REGULATOR
(N) to 50 psig as indicated on N2 INPUT PRESS