Zuercher Technik AG

Reducing Regulator Function

Spring-loaded pressure reducing regulators are “relative pressure regulators”, designed to keep the process pressure at a constant level. The nominal pressure is set by means of the setscrew, located at the spring housing. When at rest, the regulator remains in an open position. When the pressure rises, pressure is released through the open valve seat to the process side of the valve and through the internal feedback bore underneath the diaphragm. This will continue, until the diaphragm force exceeds the spring force, while the process pressure rises. The diaphragm is lifted and the vale seat closes. In the event that the process pressure drops below the preadjusted nominal pressure, the spring force presses the diaphragm downwards, so that the valve seat opens and admits gas until pressure equalization is reached again.

Relief Valve Function

Spring-loaded relief valves are “relative pressure regulators”, designed to keep the process pressure at a constant level. The nominal pressure is set by means of the setscrew, located at the spring housing. When at rest, the regulator remains in a closed position. When the process pressure increases, pressure is released through the internal feedback bore underneath the diaphragm. If the diaphragm force exceeds the spring force the valve seat opens and the over pressure is discharged to the vent side. If the process pressure drops, the diaphragm force is lower compared to the spring force and the valve seat closes. The pressure in the vent line can be atmospheric or vacuum. With vacuum in the vent line the flow capacity of the regulator is increased.