The Automatic Recirculation Valve (ARV) protects centrifugal pumps against overheating and cavitation problems by automatically maintaining a minimum flow when the system flow is in low load condition. The application itself is usually a closed loop application and consists of a suction and recirculation line from and to the tank. Typically the ARV is directly mounted on the pump discharge flange. SCHROEDAHL is the world market leader in this sector and invented the automatic recirculation valve. Moreover, the business is one of the first companies to receive ISO 19443 certification for the nuclear energy sector.

Every Schroedahl valve is bespoke manufactured to follow the customers pump curve. The valve system comprises a high quality check valve in the main line and a special control device for the minimum flow recirculation (the bypass control system). The general valve functioning is related to the process flow quantity – all SCHROEDAHL ARVs are flow sensitive.

Simplifed function explanation: an increasing process flow will automatically reduce the bypass flow. At a certain level of process flow (the valve switch point), the recirculating bypass is closed.

The Automatic Recirculation Valve, manufactured by SCHROEDAHL combines the 4 functions:

1. Flow sensing and modulating function
2. Check valve
3. Automatic bypass end connection
4. Pressure reduction of the bypass flow without cavitation

The entire production and manufacturing is in a line with national and international regulations and engineering standards (DIN, UVV, Vd TUV, AD-data sheets, TRD, ASME, ANSI such as DIN ISO 9001 / EN 29001). In addition valves can be manufactured according to NORSOK and NACE standards.

The below download gives a concise explanation on the functionality of SCHROEDAHL’s range of ARV’s and their benefits compared to conventional bypass systems.