Automatic Recirculation Valve

• It is called Automatic Recirculation Valve (ARC valve or ARV), or minimum flow valve.
•  It is considered as the best industrial practice to protect centrifugal pump from cavitation, overheating, high load on thrust bearing, high vibration, high noise, shaft wear and deflection and other serious problems as, when using this valve, minimum stable flow is always assured.

• It’s is installed on the discharge of centrifugal pump, so when high flow is assured the spring loaded disc is opened to main discharge port, and if decreased flow, spring loaded ring returned to its seat closing main process outlet and open bypass outlet.

• No need to electrical power, control wiring, nor instrument air supply as it is AUTOMATICALLY controlled.
• It is used in a variety of application (cooling water supply pumps, boiler feed water pumps, crude oil pumps, process liquid pump, fire fighting pumps), and so many other applications. 

• Using ARC valve, centrifugal pump will always operate on its pump curve, as flow never declined to zero flow.    

ARC valve operation conditions

1.Main flow only – bypass closed. (Figure-1)

2.Combined flow.                       (Figure-2)

3.No main flow – Bypass only    (figure-3)

Installation

• Usually, vertically installation, but it may be installed horizontally.

Maintenance

• This video shows maintenance for arc valve from Schroedahl

• Centrifugal Pump Protection Scenarios

See also

• https://tinyurl.com/y4mqz9uc
• https://tinyurl.com/yx96t3jn