Relief and back pressure valves control primary pressure (p1, ahead the valve) and can be used for gas and liquids applications. The pressure relief valves are ideal regulator for primary pressure control (back pressure control) and can be used wherever pressure has to be kept constant or limited.
High-pressure back pressure regulators are dome or spring loaded pressure relief valves. Under non operating conditions, the adjustable range spring or the dome pressure act on top of diaphragm and closes the valve via a stem. Under operating conditions, gas enters from primary (p1) to the valve seat and reaches counter side of diaphragm. So, primary pressure is exactly in balance with the force of adjustable range spring or with dome pressure. The valve will be opened as soon as primary (p1) raises set point of adjustable range screw. Valves will be closed with primary (p1) below set point for constant back pressure service. Valve seat tightness is at least in accordance with VDI/VDE 2174. Optional D-connection is available for pilot line connection in case of dome loaded service. High-pressure back pressure regulators are vacuum-proof, manufactured in decreasing design and uses no external energy.