Reflux blocking valves prevent reliably reverse flow (back flow) of gas and liquids in processes pipelines.
The reflux blocking valve PRR is a self actuating device to prevent reflux. It is typically installed in applications, where a reverse flow (reflux) needs to be prevented at all.
The device is especially designed for applications in reactors, centrifuges, storage tanks and vessels as used in chemical and pharmaceutical industries or any other application.
PRR is a spring loaded reflux blocking valve. Under non operating conditions, the blocking spring closes valve seat from bottom and acts via a stem on bottom side of diaphragm as well. Under operating conditions, gas enters from primary side (p1) to the valve seat and reaches upper side of diaphragm. The valve will be opened as soon as primary pressure (p1) raises set point of blocking spring. Valve will be closed with primary (p1) below set point of blocking spring or with rising secondary pressure (p2). So any reflux will be prevented reliably. Valve seat tightness is at least in accordance with VDI/VDE 2174.
Optional service-connections are also available. Via service connection, perfor-mance can be tested without dismantling device from process. PRR is vacuum-proof, manufactured in decreasing design and uses no external energy.