PM-HF

The PROTEGO® Type PM-HF pilot-controlled diaphragm valve is a highly developed valve for pressure and vacuum relief. Primarily used as a device for outbreathing in tanks, vessels, and process engineering equipment it also offers reliable protection from vacuum and overpressure. It prevents intake of air and unacceptable product vapor loss up to and until the set-to-operate pressure is reached. The valve can be used as an inbreathing device as well. In such an application, the main valve is directly controlled when exposed to a vacuum, i.e. it functions as a weight-loaded diaphragm valve.

As the working pressure rises, the closing force acting on the main valve increases, i.e. the valve's tight-sealing is enhanced until the set-to-operate pressure is reached, thus preventing leakage. Once the valve has commenced to lift it opens fully within a 10% pressure rise or the opening pressure difference and the nominal volumetric fl ow is discharged through a fully open valve. If and when this level is exceeded the pressure increase will follow the performance curve (Δp/V.curve). From set pressure to full capacity (fully open valve) the pressure increase is 100% in case of vacuum venting/inbreathing function.