Vatac Cast Floating ball design supports the ball with two PTFE seats, one on the upstream and the other on the downstream side of the ball. The upstream pressure pushes the ball which compresses the downstream side seat to completely shut off fluid control. All Casted Floating Ball Valves manufactured by Vatac are with reliable high quality castings and fire safe design certified according to BS 6755, API607 & API 6FA. Meet all applicable ASME standards. http://www.vatacvalve.net/