Butterfly valves are primarily used for which purpose?

Butterfly valves are primarily used for isolation purposes in piping systems. They are designed to provide a tight seal when closed, allowing for the complete shutdown of flow through the pipeline. The construction of a butterfly valve, which features a rotating disc, makes it particularly effective for controlling flow.

While butterfly valves can indeed be used for throttling, their efficiency in this regard is often limited compared to other types of valves, such as globe valves, which are better suited for precise flow control. Throttling involves adjusting the flow rate through the valve, and while butterfly valves can do this to some extent, they are not primarily designed for that purpose. Therefore, their main function is to isolate sections of a system, allowing for maintenance or control of the flow without significant loss of pressure.