Solenoid Valves

Pressure Relief Valve.

A pressure relief valve is a safety pressure release valves that is designed to protect process systems from over pressure damage. The valve will stay closed during normal working or operating conditions and will quickly open when the upstream pressure (inlet pressure) reaches or gets close to the maximum pressure safety setting. At which point the excess pressure will quickly vent through the relief valve downstream.

When the system pressure drops back within the safe pre-set pressure the safety relief valve will slowly close preventing back pressure shock waves and thus maintain safe system pressures.

Pressure relief valves typically have a manual adjustment range so that the release pressure can be adjusted within the maximum and minimum valve pressure range to suit each application, with the back pressure or system pressure displayed by an external pressure gauge. Read more about pressure relief valves here...

Pressure Ranges.

Pressure relief valves are available across a wide range of pressure settings such as 0.2 to 1.5 bar, 0.2 to 10 bar, and 1 to 25 bar, and all can be manually adjusted within these pressure ranges, with custom pressure ranges typically available upon request.

Connection Sizes.

Pressure relief valves are available with either threaded or flanged connections ranging from 1/2, 3/4, 1, 11/2 and 2" BSP or NPT thread or DN15, DN20, DN25, DN40, DN50, DN80, DN100, DN125, DN150, DN200, DN250, DN300, DN350, DN400, DN450, DN500 up to DN1000 PN16 or ANSI150Lb flange.

Body Materials.

Pressure relief valves are available in 316 stainless steel, bronze, cast or ductile iron with epoxy coatings. Most pressure relief valves are designed for water process systems, with valve bodies chosen according to application parameters. Most food industry and chemical industry applications will require stainless steel pressure relief valves, however typical water industry applications will use a more cost effective brass or ductile iron safety pressure release valve.

Variants

Like most valve products the pressure relief valve has evolved to meet the specific needs of the many industrial applications and processes that employ them. Three of the most popular variants are:

The Direct Acting Pressure Relief Valve

Direct acting safety pressure relief valves have the advantage of offering an adjustable, stable and accurate safety pressure release system, without the need for guaranteed pressure differentials. These pressure release valves stay closed until required, and will display the system pressure visually by means of a glycerine filled pressure gauge. Typically a very robust design and typically offering a fully adjustable pressure release range from between 1 bar and about 25 bar.

The Pressure Relief Valve for Low Pressure

Direct acting low pressure pressure relief valves are designed specifically for low pressure applications, with a larger pressure balanced diaphragm for more accurate pressure relief settings. These low pressure release valves stay closed until required, and will display the system pressure visually by means of a pressure gauge. Typically a quite robust design and typically offering a fully adjustable pressure release range between 0.2 bar through to about 1.5 bar.

The Pilot Operated Pressure Relief Valve

The pressure assisted or pilot operated safety pressure release valve is designed for larger pipeline systems with higher flow characteristics. This system offers a reduced cost safety release system that utilises the pressure difference between the inlet pressure and open to atmosphere outlet, and therefore can open quickly to release excess pressure down stream to protect upstream equipment from over pressure damage. Typically a quite robust design, dependant on body size and material of construction offering a fully adjustable pressure release range from about 0.2 bar through to 13 bar.

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