MSS - Manufacturers Standardization Society of the Valve and Fittings Industry.
Scope
This Standard Practice covers requirements for material@ design@ dimensions@ fabrication@ non-destructive examination and pressure testing of stainless steel and other alloy cryogenic service valves with body/bonnet extensions. Requirements for check valves for cryogenic service@ which may not require body/bonnet extensions@ are also covered. This Standard Practice applies to cryogenic gate@ globe@ butterfly@ ball and check valves and may be used in conjunction with other valve-specific standards including the following identified in this Standard Practice as a parent standard: ASME B16.34@ Valves-Flanged@ Threaded@ and Welded End. API 600@ Steel Gate Valves-Flanged and Buttwelding Ends@ Bolted Bonnets. API 602@ Steel Gate@ Globe@ and Check Valves for Sizes NPS 4 (DN 100) and Smaller for the Petroleum and Natural Gas Industries. API 603@ Corrosion-resistant@ Bolted Bonnet Gate Valves-Flanged and Butt-Welding Ends. API 608@ Metal Ball Valves-Flanged@ Threaded and Welding End. API 609@ Butterfly Valves: Double Flanged@ Lug- and Wafer-type. API 6D/ISO 14313@ Specification for Pipeline Valves. The requirements in this Standard Practice are not intended to supersede or replace requirements of a parent valve standard. This Standard Practice includes additional construction detail requirements specifically related to valves@ including body/bonnet extensions essential for cryogenic applications.