Can butterfly valves be used for throttling?

Industrial valves can be classified according to their function. There are valves stop or start the flow of media; there are those that control where the fluid flows. There are others that can vary the amount of media flowing.

If you need to adjust the flow of media anywhere in your piping system, you need a throttle valve. In addition to stopping and starting the flow of liquid or gaseous media, throttle valves allow the system operator to reduce the volume and pressure of the media flowing through the system.

Can butterfly valves be used for throttling?

Butterfly valves are another common type. They have a disc that pivots at right angles to the flow path and seals against seats in the valve body when fully opened. Butterfly valves have excellent throttling characteristics. They can respond to both pressures and flow so that the flow response is linear. Butterfly valves are also compact and easy to use and have high rangeability. In addition to throttling, they have good rangeability.

Among the most common valves, the butterfly valve is the most suitable for throttling. A full quarter turn can open or close the valve. For throttling to happen, it only needs to open a bit for the media to pass.

Unlike gate valves, butterfly valves can be used for throttling or regulating flow as well as in the full open and fully closed position. The pressure loss through a butterfly valve is small in comparison with the gate valve. They are generally used for handling large flows of gases or liquids, including slurries, but should not be used for throttling for extended periods of time.

Limitations

One of the limitations of the butterfly valves is that the disc is always in the path of the media flow. The entire disc is more susceptible to erosion. Also, because of this design, cleaning the internal parts is difficult.

What is the flow characteristic of a butterfly valve?

Linear – Liner flow characteristic means the flow-rate is directly proportional to the amount of disk travel. For example, at 50% open, the flow-rate is 50% of maximum flow.

For the butterfly valve to be effective, proper calculations must identify the maximum flow and pressure requirements.

For more information about butterfly valves and our complete selection of butterfly valves at VALTECCN butterfly valve supplies, contact us today on email [email protected].