hydraulic ball valve

Hydraulic Ball valves are quarter-turn, straight through flow valves that have a round closure element with matching rounded seats that permit uniform sealing stress.  Hydraulic pressure reducing valve are used in situations where tight shut-off is required.  The type of seat can vary with the valve pressure rating and materials of construction.  Some valve seats are composed of single molded forms, while other seats with higher-pressure ratings often incorporate a trunnion design where each face of the ball is separately sealed.  They are wide duty valves, able to transfer gases, liquids and liquids with suspended solids (slurries). Hydraulic rebuild valves are designed to provide protection from over-pressure in steam, gas, air and liquid lines. Relief valves and back pressure regulators are the same device, only differing in application. The pressure relief valve "lets off steam" when safe pressures are exceeded, then closes again when pressure drops to a preset level. A back pressure regulator maintains upstream pressure at the desired setting by opening to allow excess upstream pressure to flow downstream. Pneumatic valves adjust valve position by converting air pressure into linear or rotary motion. Linear motion devices open and close gate, globe, diaphragm, pinch and angle-style valves with a sliding stem that controls the position of the closure element. Rotary motion devices and the pneumatic valve control move ball, plug and butterfly valves a quarter-turn (90°) or more from open to close.  There are several actuation methods for pneumatic valves. Pneumatic valve control is essential as it helps the device to get in the best performance.