LEAKAGE TEST

TO 33D2-10-10-41

TM 55-6695-217-13

WARNING

c. Accomplish a leakage test of the assembled test

equipment. The leakage rate of the test equipment

Zinc Chromate primer is toxic to skin,

must be subtracted from the leakage rate experienced

eyes and respiratory tract. Us In a well

after the tester is included in the test setup.

ventilated area.

Avoid prolonged

d. Include tester In test setup by attaching the

breathing of vapors. Avoid eye and

supply connection line to one inlet of the tester tee inlet

repeated skin contact. Keep away

fitting. Make sure the other inlet Is securely capped.

from sparks and flames.

e. Open line shut-off valve and then the oxygen

supply shut-off valve.

Paints,

primers,

lacquers

and

varnishes must be handled carefully

f. Adjust the oxygen supply pressure regulator

and used only in a well ventilated

until line pressure gauge indicates 450 psi.

approved area.

Avoid prolonged

g. Close line shut-off valve and note the time. At

breathing of vapors. Avoid eye and

the end of 7 minutes the line pressure gauge shall

repeated skin contact. Keep away

indicate 400 psi minimum. If the reading is less than

from spark and flames.

400 psi, leakage within the oxygen system of the tester

is indicated. Use Leak Tec, manufactured by American

c. Repair of Finish. Touch up finish as required

Gas & Chemical Co., (MIL-L-25567), NSN 6850-00-621-

with zinc chromate primer, MIL-P-6889, and black semi-

1850, or soap and water solution around each

gloss enamel, MIL-E-7729.

connection to determine the location of leak.

d. Assembly.

Assemble tester in reverse of

disassembly order as determined by inspection of

5-6. CALIBRATION. The tester does not require

Illustrated Parts Breakdown illustration and parts list.

calibration; however, some components of the tester

may require calibration. The oxygen cylinder pressure

gauge and oxygen regulator may be calibrated as

5-5. LEAKAGE TEST. Leakage test shall be made at

follows:

atmospheric pressure of 28 to 32 inches of mercury at

a. Oxygen Cylinder Pressure Gauge. Compare

temperature of 77 degrees F, plus or minus 18 degrees

pressure reading of suspect gauge with those of a

F, and at a relative humidity of 80 percent or less. Tests

known accurate gauge, with both connected to same

performed with atmospheric pressure or temperature

oxygen supply. If the pointer of oxygen pressure gauge

substantially different from these values shall have the

under test is within 10 percent of full scale with pressure

proper allowance made for the change In instrument

applied, and the pressure gauge indicates zero pressure

readings. Oxygen used for test purposes should be

when the oxygen pressure is removed, the gauge may

commercial grade breathing oxygen or per Federal

be regarded as calibrated.

Specification BB-O-925, Type 1, Grade A. Perform

leakage test as follows:

b. Oxygen Regulator. Type A14 oxygen regulators

may be calibrated by those activities which possess the

a. Accomplish operational checkout for oxygen

required equipment to meet the limits specified in TO.

system to assure tester is functional.

15X6-3-2-23, paragraphs 3.8a, 3.8b (10,000 ft only), and

b. Assemble test setup consisting of an external

4.28b. If the oxygen regulator fails to meet these

oxygen supply, an oxygen shut-off valve, an oxygen

requirements, it should be replaced by qualified

supply pressure regulator set to deliver 450 psi, an

personnel. The leakage test outlined in paragraph 5-5

oxygen pressure regulator gauge, a line shut-off valve, a

shall be performed on the tester oxygen system after

line pressure gauge calibrated to read in 1 pound

any repair or replacement of parts within that system is

divisions and a suitable line to connect to the tester.

completed.

Change 4 5-2