MIL-DTL-23953D(SH)
4.4.17 Water-slug test. The vent-check valve shall be subjected to tests that simulate the condition that can
exist aboard ship when the header upstream of the vent-check valve is flooded with water at the time the emergency
blow system is actuated. The system for this test shall comprise a 4,500 psig air reservoir of not less than 25-ft³
capacity, a 2-inch quick-opening full-ported ball valve close-coupled to the reservoir, 8 feet of straight 2-inch pipe, a
2- by 1½-inch reducer, 12 feet of straight 1½-inch pipe, and the vent-check valve. The 20 feet of piping separating
the ball valve from the vent-check valve shall be laid out and sloped in such a manner that it can be completely
flooded, without any entrapped air, prior to each water-slug cycle. Isolatable vents shall be incorporated, as
necessary, to assure the elimination of all entrapped air. The vent-check valve shall be subjected to 40 water-slug
shots. Each shot shall consist of an initial reservoir pressure of not less than 4,500 psig, opening the ball valve in
20 milliseconds or less, and leaving the ball valve open at least 2 seconds. The system upstream of the vent-check
valve shall be completely flooded and purged of any entrapped air prior to each shot. At the completion of the
40 shots, the vent-check valve shall be removed and tested as specified in 4.4.7 through 4.4.10 and examined as
specified in 4.4.3. There shall be no damage or degradation to performance.
4.4.18 Underwater explosion shock test. The vent-check valve shall be subjected to and successfully pass the
underwater explosion shock test outlined herein. Extension of test qualification criteria for underwater explosion
shock testing is equivalent to that established in MIL-S-901 for mechanical shock test extensions. The vent-check
valve shall be structurally supported in a manner representing the most vulnerable shipboard installation. Shipboard
inlet and outlet piping runs shall be simulated in the test installation. The test shall consist of two shots of
125 pounds of HBX-1, with the vent-check valve on a horizontal radius from the centerline of the test vehicle and
the charge of an extension of that radius at a standoff of 15 feet from the valve outlet port for the first shot and
13.5 feet for the second shot. This test shall be conducted at a Government facility designated by NAVSEA. After
each shot, the vent-check valve shall be visually inspected, without dismantling, for leakage or distortion of the
pressure-containing envelope, cycled twice to demonstrate operability, and then tested to submergence pressure at
the outlet. Threaded parts shall be checked for tightness and retightened, if necessary. The amount of retightening
required, and the calculated loosening thus indicated, shall be noted. Following the second shot, the vent-check
valve shall be inspected and tested as specified for the first shot. It shall then be moved and tested as specified in
4.4.7 through 4.4.10 and examined as specified in 4.4.3. There shall be no damage or degradation to performance.
4.4.19 High-impact shock test. The valve shall be subjected to and meet the high-impact mechanical shock
tests for Grade A, Class 1 of MIL-S-901. At the completion of this test, the valve shall be tested in accordance with
4.4.20 Vibration test. The valve shall be vibration tested in accordance with Class 1 of MIL-STD-167-1.
Following completion of vibration testing, the valve shall be tested as specified in 4.4.10.
4.4.21 Burst test. Water shall be applied at 13,500 psig to the pressure containing envelope for not less than
5 minutes. Failure of the valve to safely contain pressure and remain structurally intact shall be cause for rejection.
4.4.22 Spring compression examination. The main poppet spring shall be visually inspected following
completion of operational tests to verify that no compressional reduction of spring length has occurred.
4.4.23 Material examination. Raw material used to manufacture components designated as "Level I" on
803-8436621 shall be tested in accordance with 0948-LP-045-7010 to verify that actual chemical and mechanical
properties of the material comply with the applicable material specification listed on 803-8436621.
5. PACKAGING
5.1 Packaging. For acquisition purposes, the packaging requirements shall be as specified in the contract or
order (6.2). When packaging of materiel is to be performed by DoD or in-house contractor personnel, these
personnel need to contact the responsible packaging activity to ascertain packaging requirements. Packaging
requirements are maintained by the Inventory Control Point s packaging activities within the Military Service or
Defense Agency, or within the military service s system commands. Packaging data retrieval is available from the
managing Military Department s or Defense Agency s automated packaging files, CD-ROM products, or by
contacting the responsible packaging activity.
6. NOTES
(This section contains information of a general or explanatory nature that may be helpful, but is not mandatory.)
6.1 Intended use. The vent-check valves specified herein are intended for installation in submarine main ballast
tank (MBT) high-pressure air blow lines.
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