High Differential Pressure, Low Torque Precision Temperature Control Valve

摘要

A high differential pressure, low torque precision temperature control valve is disclosed herein. This valve is trunnionated with stem components that are separable from the plug for ease of maintenance and manufacturability and thus reducing the need to remove the entire plug and sealing assemblies in the field. Field repair of stem sealing devices can be accomplished inline. The stem design can be smaller in diameter with smaller bearing surfaces than would be anticipated creating a lower requirement of torque to rotationally transposition the plug within the fluid chamber while under high pressure. This valve's lower trunnionated stem is stationery reducing the problems associated with o-ring failure and leakage problems with objects that rotate. Due to the design of the orifices in the plug, this valve is capable of repeatability at lower opening ranges than prior art valves and reduces jetting, caviation and erosion often associated with lower opening ranges. Sealing devices are tensioned onto the plug through the use of non-metallic o-rings reducing wear and friction issues thereby further reducing the torque requirement to adjust the valve. This valve is created in a bypass configuration, and as such, the plug orifices have been modified to efficiently reduce pump loads in the full bypass condition. The throughports of the plug in this valve are designed such as to create an equal percentage characteristic that does not exceed prescribed linear flow characteristics and provides a relatively constant total combined C_v over the travel range of the plug. It is preferable that this valve is made from cast iron components, but other materials who have similar stabilities over the pressure ranges and fluid characteristics introduced are acceptable.