api 5000API Specification 6A covers wellhead and tree equipment as follows: API Specification 6A Wellhead Equipment Valves, Chokes, and Actuators Plugs, Connectors, and Gaskets OtherAPI 6A6B6BX FLANGE STANDARD, Class 2000PSI, 3000PSI, 5000PSI, 10000PSI, 20000PSI,data sheet including OD, ID, Thickness, Neck dimensions, bolt holes