MIL-DTL-87255A(USAF)
4.3.2
Sampling.
4.3.2.1
Inspection lot.
4.3.2.1.1 Valve.
An inspection lot size shall be expressed in units of valves, manufactured essentially under the
same conditions and from the same materials and components. The sample unit shall be one
valve.
4.3.2.2 Sampling for tests and inspections of valves.
The sample size, acceptance criteria, tests, and inspections required for the valves shall be as
specified in table II.
4.4
Test conditions
4.4.1 Environmental conditions.
Unless otherwise specified, all tests shall be conducted at local ambient temperature and
barometric pressure. Test instruments shall be calibrated or adjusted according to their required
usage in conducting individual tests. The temperature and barometric pressure shall be
recorded at the time of inspection. This information shall be available for computation of test
data, where required, to normal temperature and pressure (NTP) conditions. NTP conditions
shall be 29.92 inches of mercury and 70 °F.
4.4.2 Acceleration force.
When conducting the tests specified herein, the acceleration force (see 6.4.1) shall be applied
to the valve in the direction specified on figures 1, 2, or 3. Weights or any other means may be
used to simulate the acceleration force provided the weight of the sensing mass of the valve
shall be controlled, and verified by 100 percent inspection. In this case the total G force shall be
1 Gz plus the amount simulated by the test weights. The acquisition activity reserves the option
to verify the performance of the valve on a centrifuge as specified in 4.5.12.
4.4.3 Test medium.
Unless otherwise specified, the test medium used in testing the valves shall be air or nitrogen.
The moisture content of the air shall not exceed 0.02 milligram per liter. The nitrogen shall
conform to type I, grade B, class 1, of A-A-59503. When nitrogen is used as a test medium,
appropriate density corrections shall be made in determining that the test requirements are met.
4.4.4
Test equipment
4.4.4.1 Tank.
When specified, a rigid tank having a volume of 10 ±0.05 liters shall be used. The tank shall be
connected to the outlet port of the valve as specified in 4.4.4.2 and shall provide a connection
for the measurement of pressure in the tank. Unless otherwise specified, the sensing line port
(if applicable) shall be capped for all tests.
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