Automatic Recirculation Valve Portfolio

AR Valve - Purpose & Function

Automatic recirculation valves, sometimes referred to as pump protection valves or minimum flow valves are installed on the outlet of a centrifugal pump discharge line. Their purpose is to prevent the pump from overheating by ensuring that there is a minimum flow through the pump at all times. They have replaced traditional multi valve pump protection solutions. The Fetterolf AR Valve unites three important functions of a pump protection system:

• a non return function in the main line, that prevents medium flowing backwards to the pump
• automatic bypass control, that ensures that a minimum flow is allowed to return to the pump in low demand periods
• pressure letdown functionality, that ensures that the recirculating medium is kept at the correct pressure and flashing and cavitation are avoided

The AR minimum flow valve opens as soon as the pump builds sufficient flow to move the internal valve disc in the main line into an open position. Decreasing flow causes the spring loaded disc to return to its seat, closing the process Outlet. At the same time the bypass outlet is uncovered allowing a minimum flow of liquid to be routed (or recirculated) back to the pump.See more details of operation in the SureFlo and HighFlo automatic recirculation valve section.