Which type of valve is generally not recommended for throttling service?

A gate valve is generally not recommended for throttling service because its primary design is intended for fully open or fully closed positions. This type of valve has a wedge-shaped disk that moves up and down to either allow or block flow, making it poorly suited for applications where flow control is needed. When operated in a partially open position, a gate valve can cause turbulence and excessive wear, which may result in seat damage and leakage over time.

In contrast, other valve types like globe valves and butterfly valves are constructed to provide better control over flow rates, making them more suitable for throttling applications. Check valves, on the other hand, are designed to prevent backflow and do not have a throttling capability at all. Thus, the gate valve's design and intended use make it the least appropriate for situations requiring precise control over flow.