The control orifice in the spool is factory set to the flow specification. High pressure HPLC pumps and similar applications commonly use small inlet and outlet ball check valves with balls of (artificial) ruby and seats made of sapphire or both ball and seat of ruby, for both hardness and chemical resistance. As trusted pressure control valve manufacturer we supply into the major industrial markets all over the world. The VREL provides 56 turns from full y open to full y closed, giving it much more surface area to reduce the pressure and greater ability to adjust than a needle valve. The valves are used in several applications: car wash systems, stationary high pressure cleaning, mobile cleaning vehicles and dust bindings systems, fire fighting water mist systems etc. Subjects that are addressed include: Nelprof ® 6 sizing software Step-by-Step Guide Control valve sizing Control valve noise Cavitation in control valves Liquid vapor pressure Gas compressibility factor Pressure maintaining valves. https://automationforum.co/pressure-reducing-valves-applications The control valve manipulates a flowing fluid, such as gas, steam, water, or chemical compounds to compensate for the load disturbance and keep the regulated process variable as close as possible to the desired set point. Some applications require that upstream pressure is sensed and controlled and this type of valve is often referred to as a âPressure Maintaining Valveâ or âPMVâ. The set pressure is adjusted by pretensioning this spring with the adjusting screw. Pressure maintaining valves are also known as surplussing valves or spill valves in certain applications. R estrictive-type pressure compensated flow control valves are two-ported valves that maintain a constant flow rate from 1 to 2 regardless of load pressure changes in the circuit downstream of 2. Most needle valves have a 10-1 or 20-1 turndown range, which provides less than optimum pressure and flow control in high-pressure applications. ... Peter Jessee, P.E., is a process control application engineer for Valin Corporation, a technical solutions provider for the technology, energy, life sciences, natural resources and transportation industries. Discover how control valves are used to maintain operating conditions such as flow, pressure, temperature, and liquid level. Determining the control valve pressure drop. The VDHT valve series are designed for several applications in neutral media compatible with the sealing and O-ring materials used. Valve service environments and operating conditions are often extreme with high temperatures (greater than 1,500°F) and high pressure (greater than 25,000 psig) or cryogenic and very low pressure applications. Pressure relief valves and their operation There are two types of pressure relief valves: spring-loaded pressure relief valves and pilot operated pressure relief valves. The valve begins to respond to load changes when flow through the valve creates a pressure differential across the control ⦠Another feature important to valves used in the oil and gas industry is the capacity for remote control. In a spring-loaded pressure relief valve, the closing force is generated by a helical spring. Links to articles I have written on the subject of control valve application Books I have written or recommend.