MIL-DTL-46725D(AT)
4.3.3 Material, design and construction. Use one or more of the methods outlined in
4.3 or 4.3.1 to verify that the valve is built in accordance with Drawings 9093264, 9098279, and
9094352. Conformance shall be determined by inspection of the contractor records providing
proof or certification that design, construction, processing, and materials conform to
requirements. Applicable records shall include drawings, specifications, design data, receiving
inspection records, processing and quality control standards, vendor catalogs and certifications,
industry standards, test reports, and rating data.
4.3.4 Operating requirements verification.
4.3.4.1 Flow rate and pressure drop test. Verify that the flow rate of the valve shall be
accurately maintained at 7.6 L/min (2 gal/min) with no more than 1034 kPa (150 psi) pressure
drop across the valve for type I, 7.6 L/min (2 gal/min) with less than 689 kPa (100 psi) for class A
type II, and 22.7 L/min (6 gal/min) with less than 1724 kPa (250 psi) for class B type II, using a
manometer to measure pressure drop from one port to another. Failure to maintain the specified
flow rate shall constitute failure of the test.
4.3.4.2 Operating torque test. With a hydraulic pressure of 20 684 kPa (3000 psi) at the
pressure port, the torque required to operate the valves shall be 5.6 N-m (50 lb-in.) for type I,
2.8 N-m (25 lb-in.) for class A type II, and 5.9 N-m (52 lb-in.) for class B type II. Measurement
outside the specified range shall constitute failure of the test.
4.3.4.3 Operating pressure test. Pressure shall be applied to each port, except the return
port, and varied throughout a range of 0 psi to 20 684 kPa (3000 psi). Operation shall be
observed. Failure of the valve to operate satisfactorily throughout the specified range shall
constitute failure of the test.
4.3.4.4 Proof pressure. Proof pressure of 31 026 kPa (4500 psi) shall be applied at the
pressure and return ports for a period of 2 minutes. The valve shall be manually actuated after
application of pressures. There shall be no evidence of external leakage, permanent deformation
or failure.
4.3.4.5 Burst pressure. This test shall be performed after completion of all other tests.
The valve shall be subjected to a hydraulic pressure of 51 711 kPa (7500 psi) for the pressure
ports for a period of 3 minutes. The valve shall be subjected to 5723 kPa (830 psi) for type I
valves and 17 237 (2500 psi) for type II valves for the return port, for a period of 3 minutes at
each application without bursting. This test shall be performed for all three positions. When
testing pressure ports, the return port shall be open. The rate of application of pressure shall not
exceed 179 267 kPa (26 000 psi) per minute. The valve need not be operable after these tests.
9
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business