Officially founded in 1924, the Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry is a non-profit technical association organized for development and improvement of industry, national and international codes and standards for: Valves, Valve Actuators, Valve Modification, Pipe Fittings, Pipe Hangers, Pipe Supports, Flanges, and Associated Seals.

The primary function of MSS is to provide its members the means to develop engineering standard practices for the use and benefit of the industry and users of its products. The Society, the only organization dedicated solely to the technical needs of the industry, is currently comprised of 24 technical committees to write, revise and reaffirm industry standards.