The Manufacturers Standardization Society (MSS), a non profit technical association organized for development and improvement of industry, national and international codes and standards for valves, valve actuators, valve modifications, pipe fittings, flanges, pipe hangers and supports, and associated seals, has recently announced the new standard, MSS SP-151-2016, Pressure Testing of Knife Gate Valves. This Standard Practice establishes requirements and acceptance criteria for shell and seat closure pressure testing of resilient, non-metallic (e.g. ceramic), and metal-to-metal seated knife gate valves of all types.
The new SP-151 was developed for the purpose of providing a uniform means of testing knife gate valves commonly used in the “full open” and “full closed” type of service for isolation. This Standard Practice is not intended for use with control valves.