Pressure Relief Valves

The Pressure relief valve comprise a combination of an overflow unit of either type LV (control air available) or alternatively of type LNV (control air not available), as well as a pneumatic pinch valve from the VF or VMC series.

When in use, pre-load pressure (differential pressure) is applied to the valves body; this means that they are always closed when in the normal position. The pre-load pressure (differential pressure) is between 2 - 2.5 bar above the maximal feed or medium pressure depending on the nominal diameter and type of elastomer. Depending on the nominal diameter involved the Pressure relief valves range of applied pressure is between 0 - 6 bar. The maximum operating temperature is 60° C.

The pressure relief units are available in the following versions:

• With compressed air, incl. a digital pressure switch
• With compressed air, without a digital pressure switch
• Without compressed air, with a digital pressure switch
• Without compressed air, without a digital pressure switch

The Pressure relief valves main area of application is to be found in the bypasses of pumps for conveying waste water, sludge and other suspensions. However, they are also frequently used as regulating or relief valves in diverse installations, tanks or silos. 

Function of Pressure Relief Valve

As soon as the maximal feed or medium pressure is exceeded because of restrictions in the pipeline or other blockages, the Pressure relief valve starts opening steadily and the excess pressure is able to circulate through the pump's bypass or the installation's pipeline. It is therefore able to protect diverse pumps and tanks from excess pressures and the overload of engines and materials arising as a result. Changes in control pressures can be monitored via integrated pressure switches.