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|  MIL-V-24694(SH)
TABLE II.
Vibratory displacement, single amplitude.
1/ For Government-conducted tests, the maximum amplitude will not exceed the
minimum required amplitude by more than 20 percent.
4.7.6 Shock. The valve shall be subjected to high-impact mechanical shock
tests in accordance with the requirements for grade A, class I, lightweight,
type B, fixture 4A of MIL-S-901. A valve shall be considered to have failed
the shock test if it does not meet the leakage test of 4.7.3.3, or shows any
signs of external or internal damage when examined in accordance with 4.7.1.
The valve shall be pressurized to a setting not less than 75 percent of its
maximum set pressure during shock testing.
4.7.7 Endurance. The valve shall be subjected to 100,000 cycles while set
at the highest pressure setting for the class or group of classes. Each cycle _
shall consist of imposing rated flow through the valve and then reducing the pres-
sure to zero. Cycling shall be accomplished at a rate not to exceed 60 cycles
per minute. Fluid temperature shall be maintained at not less than 40C. Leakage
at the reseat pressure determined in 4.7.3.2 shall be not greater than two times
the allowable reseat leakage identified in the applicable specification sheet.
Operating temperature.
4.7.8
4.7.8.1 Low temperature. Unless otherwise specified (see 3.1), the fluid
for this test shall be in accordance with MIL-H-83282. The test setup shall
include a handpump or power driven pump that shall provide a flow of not less
than 1 liter per minute to the relief valve. The test shall be conducted on two
valves, one adjusted to the lowest setting of the lowest pressure range tested
and one adjusted to the highest setting of the highest pressure range tested.
Operate the pump at room temperature at not less than the minimum flow rate and
note the highest pressure developed at the relief valve inlet. Unless otherwise
specified (see 3.1), the test setup shall then be maintained at a temperature
not warmer than minus 40C for 2 hours with the valve unpressurized. The valve
shall then be pressurized to 75 percent of the set pressure and the low tempera-
ture maintained for 2 additional hours. The pump shall then be operated at the
same rate as at room temperature and the highest pressure noted. The pressure
value obtained at minus 40C shall not vary more than plus or minus 10 percent
from those obtained during the room temperature test.
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