Function

The discharge pressure acts upon the piston. The power resulting from this pressure compresses the spring as soon as it exceeds the spring resistance, thus closing the valve. This position persists as long as no medium is taken off the discharge pipe. Thus, the discharge pressure is kept at the value required by the setting.

When media are taken off the discharge pipe the discharge pressure is reduced. The spring presses the diaphragm and causes opening of the valve. If the medium flows for a longer time, a self-adjustment of the valve opening will ensue instead of an abrupt succession of opening and closing movements. Pressure reducing valves for gaseous media have a damping device against pressure impacts.

Settings

Setting of the pressure reducing valve always takes place without flow, the manometer showing static pressure.

Rising discharge pressure:
Turn the set screw clockwise.

Reducing discharge pressure:
Turn set screw counter-clockwise. Take off some medium, thus reducing the pressure. Then tighten the screw until required pressure is attained.

Decreasing pressure during media take-off is normal, it is caused by loss of pressure.