MIL-DTL-46725D(AT)
4.3.4.6 Leakage. The valve shall be tested for leakage by applying a hydraulic pressure
of 20 684 kPa (3000 psi) to each sealing member of individual fluid chambers, in succession for a
2 minute period each. The pressure shall then be lowered to 34 to 69 kPa (5 to 10 psig) and held
for 2 minutes. There shall be no external leakage.
4.3.4.7 Life test. The valve shall be subjected to a hydraulic pressure of 20 684 kPa
(3000 psi) with a flow rate of 7.6L/min (2 gal/min) for both type I and type II (class A), and
22.7 L/min (6 gal/min) for type II (class B), for 20 000 cycles. Each cycle shall consist of
operating the valve from one extreme position to the other extreme position and return to the
starting position. The valve shall be observed for evidence of external leakage during cycling.
After cycling, internal leakage shall not exceed 10 cm3/min. The valve shall evidence no excessive
wear or breakdown.
4.3.5 Interface requirements verification. Use one or more of the methods outlined in
4.3 or 4.3.1 to verify the interchangeability of like parts.
4.3.5.1 Weight inspection. Weigh the valve to be less than 0.9 kg (2 lb) for type I and
1.1 kg (2.5 lb) for type II
4.3.6 Support and ownership requirements verification.
4.3.6.1 Finish. Flush valve with rust inhibiting fluid. Verify that all parts are covered.
4.3.6.2 Identification marking. Verify the presence of the required marking. After all
environmental testing, re-inspect marking for legibility.
4.3.6.3 Safety. Visually inspect valve for burrs, chips, sharp edges, or other imperfections
that pose physical danger to an installer/operator.
4.3.7 Environmental requirements verification.
4.3.7.1 High temperature. The valve shall be placed within a test chamber and exposed to
a temperature of 71°C (160°F) for 24 hours duration. After 24 hours of exposure, the valve shall
be charged to 20 684 kPa (3000 psi) hydraulic pressure and flow rate (see 3.3.1) which shall be
maintained for a period of 4 hours. At the conclusion of the exposure period, the valve shall be
tested as specified in 4.3.4.7 for 50 cycles. After testing, cool the valve to room temperature and
verify that it passes the tests of 4.3.4.1, 4.3.4.6, and 4.3.4.7 for 50 cycles.
4.3.7.2 Low temperature . The valve shall be placed within a test chamber and exposed
to a temperature of -54°C (-65°F) for 24 hours duration. After 24 hours of low temperature
exposure, the valve shall be charged to a hydraulic pressure of 20 684 kPa (3000 psi), and a flow
10
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business