API spec 6D Ball Valves Trunnion supported ball, forged steel, 3 pieces split body side entry, metal to metal or soft seated sealing design self relieving spring loaded seats or double piston effect sealing system, anti-static device, anti-blow-out proof stem double block and bleed or block and bleed, venting and drain fittings, self lubricating stem and trunnion bearings to assure low operating torque throughout entire valve life, fire safe design to BS 6755 parts 2.