api 5000API Specification 6A covers wellhead and tree equipment as follows: API Specification 6A Wellhead Equipment Valves, Chokes, and Actuators Plugs, Connectors, and Gaskets OtherPO BOX 639 • Bakersfield, CA 93302 855-535-1555 phone • sales@ API FLANGE BOLT & RING CHART API Pressure Rating Flange Size & Bore