There are different specifications for valves depending on the application for which they are used. The API-Q1 is a specification for quality programs used by the American Petroleum Institute. The ASME/ANSI- B16.10 is a face-to-face and end-to-end dimensions valve specification used by the American Society of Mechanical Engineers.
The Manufacturers Standardization Society of the Valves and Fittings Industry uses the MSS SP-25 standard for fittings, valves, unions and flanges. The MSS SP-70 is the organization's specification for threaded ends and cast iron gate valves, whereas the MSS SP-80 is for globes, gate valves, angle and check valves.
The National Association of Corrosion Engineers uses the NACE-MR0175 specification for crack resistant metallic materials for equipment used in the oilfields.
Valve manufacturers design valves according to numerous criteria. The pipe size, the flow rate, the corrosiveness of the media being handled, ambient and internal temperature and weight are all factors that determine the valve specifications, according to Valve Manufacturers Association of America. Additionally, before valves get to the market, manufacturers ensure that engineering services are available to install them and replacement parts are on hand. They also provide testing guidelines, maintenance instructions and design diagrams to ensure that the valves perform optimally over time.