This is a 3D model of a Automatic Recirculation Valve.
3D Model Annotations
Recirculation valves are provided on the suction side of centrifugal pumps to deliver a minimum flow amount to the pump even if the system pressure should be low. Recirculation valves are designed to prevent centrifugal pumps being thermally or mechanically damaged due to low flow.
The body forms the main pressure boundary of all valves and must be constructed from suitable materials to withstand the service pressure to which it will be subjected. It is often cast as a single piece, although it is possible to construct the body from several pieces.
A spring-loaded check valve (non-return valve) forms the valve’s main disc; the spring is located within the disc. This type of valve is a proportional response device. As the system pressure increases, the valve opens and allows more flow. As the system pressure decreases, flow through the valve decreases. Flow from the reverse direction closes the valve.
The valve disc presses against the valve seat. It is imperative that the disc and seat surfaces remain clean. If the seat or disc surfaces are damaged, or not clean, it will not be possible to obtain a seal between the seat and disc; this will lead to the valve passing (leaking) when in the closed position.
Many valves require a bonnet. A valve bonnet allows personnel to access a valve’s internals (known as ‘valve trim’) without needing to dismount the valve. The bonnet is attached to the valve body using nuts and bolts (or studs). Gaskets are used to seal the space between the bonnet and body.
Flanges are attached to the valve body; they allow for associated piping to be attached.
Provides backpressure for better flow control.
Provides a minimum amount of flow to the centrifugal pump if the main line pressure is low.
The lever throttles (regulates flow) the bypass valve depending upon the position of the check valve.