The Manufactures Standardization Society (MSS) of the valve and fittings industry is a non-profit technical association. Their goal is to develop and improve industrial, national and international codes and standards for valves, valve actuators, pipe fittings, and valve modifications. MSS standards are used around the world and in many industries. Examples of their standards are below.
- MSS SP-25 - Standard marking system for valves, fittings, flanges and unions
- MSS SP-67 - Butterfly valves
- MSS SP-82 - Valves pressure testing methods