1 February 2014 SUPERSEDING MIL-V-23953C(SH) 11 May 1990 DETAIL SPECIFICATION VALVES, COMBINED VENT-CHECK, FOR SUBMARINE MBT BLOW LINES (SIZES 2.00 AND 2.50 INCHES) This specification is approved for use by the Naval Sea Systems Command, Department of the Navy, and is available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers the construction, testing, and operation of combined vent-check valves with a nominal pres