MSS - Manufacturers Standardization Society of the Valve and Fittings Industry.
Scope
This Standard Practice applies to small valves and manifold valves developed for and predominately used in instrument@ control@ and sampling piping systems. It covers steel and alloy valves of nominal pipe size (NPS) 1 and smaller@ and pressure ratings of 15@000 psi and lower at 100?? This Standard Practice applies to instrument valve designs including@ but not limited to@ needle valves@ packless valves@ ball valves@ plug valves@ check valves and manifold valves. Instrument valves are generally of proprietary design; this Standard Practice is not intended to define or limit designs@ construction@ performance@ envelope dimensions@ or valve types. The application of valve type@ size@ rating@ materials of construction@ and suitability for the service are the responsibility of the purchaser and are outside the scope of this Standard Practice.