More about Relief Valves

Click here to find Relief Valves Manufacturers | Discuss Relief Valves & Other Topics

Found in many pressurized systems, a relief valve is a device used to help regulate and alleviate pressure by providing an alternate passage for the media to travel. In most systems, this valve is engineered to be active when the contents of the system reach a certain pressure, then to re-close after the system returns to normal operating conditions. When the pressure exceeds the level specified, the valve piston is forced from its seat to relieve the excess pressure. After the pressurized media is released through the relief valve, it can be returned to the system by a variety of methods (pumps, etc.).

Relief valves are often incorporated into system design, and are considered a standard component in many devices. However, numerous systems that require or benefit from relief valves do not include them into their design. Relief valves must be installed in these systems in order to prevent problems and enhance performance. Numerous manufacturers produce a wide range of custom and standard valves for such purposes.

Relief valves are manufactured in a variety of materials, from brass to polysulfone. Different media and pressure ratings call for different materials; a steam release pressure valve, for example, might be made out of cast aluminum with a polyester diaphragm, while a bronze valve is excellent choice for low-temperature applications. Many relief valves utilize components fabricated from a different material than the body. Fluoro-silicone, neoprene, propylene and ethylene all find use in relief valve seals and similar components. The combination of various materials yields a sturdy, durable body that takes full advantage of the sealing and elastic properties of synthetic polymers and plastics. All-plastic valves, while not suited to all applications, are not susceptible corrosion failure.

Relief valves can be designed to withstand extreme internal pressures and to operate in air, steam or liquid environments. Some valves can be set to react to different pressure levels by a simple turn of a hand-wheel or dial. Others may be custom designed to react to a specific pressure rating.