MSS SP-121 - 1997 Qualification Testing Methods for Stem Packing for Rising Stem Steel Valves

Manufacturers Standardization Society (MSS). 1997. 20 p. This Standard Practice provides procedures and guidelines for testing and evaluation of valve stem packing materials and material combinations. This testing provides qualification by verifying the adequacy of specific packing material combinations for service within defined limits of size, pressure, temperature, and cyclic duty. Such specific combinations generally represent products of individual manufacturers, although generic qualification of raw materials may be demonstrable in certain cases.