Why ARV is used in a multi-stage centrifugal pump and why they are used as boiler feedwater pump mostly?

An ARV (automatic recirculation valve) is a valve that can perform a wide range of functions. The basic aim of such a product is to make sure you face no issue with the pre-determined minimum flow through your multistage centrifugal pump. Considering the tendency of the centrifugal pumps to suffer from issues such as cavitation and overheating, this is an important factor for sure. If they run dry, they may suffer permanent damages. 

The design of the valves

The best companies manufacture different kinds of these ARVs. They also have customized designs that companies use for special processes.

They can also use these customized ARVs in operating environments that are rather severe. They are rather helpful in operating a multistage pump.

The operating principle of these valves

The companies that make the ARVs install them in the discharge line of the pump. They do so in the same position as the main check valves they are replacing with the ARVs. Whenever the pump builds a sufficient amount of flow to move the internal valve disc, these ARVs open too. In these cases, the pumps move the discs in open positions on the main lines. In such cases, the valves have a decreased flow.

This causes the spring-loaded discs in the multistage centrifugal pumps to return to their seats. This closes the process outlet. The pump also uncovers a bypass outlet in this same timeframe. This allows the minimum amount of liquid to flow back towards itself.

The features of these valves

These valves come with a modular design. They also have automatic bypass operation facilities and non-return function. They also have pressure modulation capabilities in bypass. The bores of these valves can clean themselves. With these valves, you can get a customized pressure control – if you want you can get it in a linear form too.

One valve that can play many roles

There are some excellent reasons why these ARVs are so integral to the proper functioning of a multistage centrifugal pump. One of them is the fact that it can play a wide range of roles. They have all the hardware that you need in a traditional bypass system present in a single housing. It has several important parts such as the check valve, the bypass valve, and the pressure let-down unit. All these play important roles in these contexts.

The checking valve runs vertically from the inlet of the multistage pump to the outlet that is there above it. This saves the pump from issues such as reverse flow. The bypass valve functions by sensing the main flow. It then automatically controls the medium flow to the bypass line. This makes sure that you need not use any electrical power, instrument air support, and control wiring. The companies that make these ARVs design the pressure let-down unit well. Therefore, it can handle the amount of pressure that needs to drop to the pump inlet from the processing system.

This is how an ARV performs so many roles at the same time.