Cast Steel and Trunnion Ball Valve

Forged Steel Trunnion Mounted Ball Valves are used mainly in Oil, Gas Transmission and Distribution Pipeline, Petroleum, Chemistry, Chemical Fiber, Metallurgy, Paper Pulp etc. The forging material can ensure sufficient rigidity and strength under maximum rated operation pressure without inherent flaw of cast. The Forged Steel Body assures uniform fine grain structure and toughness free from inevitable casting defects such as porosity, abscess, crackle, gas hole. Enough wall thickness of separate Body and Adapters and high strength tie bolts are convenient for valve manufacturer and sufficient to bear the stress of pipe. The internal parts of valve are carefully designed and selected to ensure reliability under all kinds of work condition. 1. Upstream Sealing Bi-Directional Forged Steel Trunnion Mounted Ball Valves are equipped with two self energized seats. The upstream sealing of the valve is fulfilled by the advanced spring pre-tighting seat package which has a feature of self-tightness. The Bi-Directional valve has two seats that can be sealed on two directions, so there's no limitation of flow direction during installation. (PIC. 1) 2. Trunnion-Mounted Ball The ball is fized and the seat rings are floating, it is free to move along the valve axis. Side load generated by the pressure acting on the ball is absorbed by bearings. At low pressure, the seat sealing action is achieved by the thrust of the spring action on the seat rings. As the pressure increases, the fluid pressure pushes the seat rings against the ball. http://forums.pelicanparts.com/members/6239.html