http://www.hpvalve.net - Ball Valve involve the result of Innovative engineering. It embodies all the quality, Performance, value and safety features required for critical applications. The ball rotates without moving on the horizontal axis, where as seats are floating and free to move on the same axis. As the pressure increases the force on the seat ring by the pressure pushes towards the ball giving 'BIDIRECTIONAL' sealing. Thrust due to Fluid Pressure and spring on the upstream and downstream, pushes seat ring towards the ball for positive sealing under all conditions. When the valve is in closed position, the fluid trapped in the body cavity is subjected to thermal expansion and the valve cavity pressure increases. The excessive pressure buildup within the valve cavity is relieved automatically when the pressure inside exceed the spring load on the seat.