Which valve type is typically used for throttle and isolation applications in boiler systems?

In boiler systems, the gate valve is typically chosen for throttle and isolation applications due to its design and functionality. Gate valves are constructed to provide a straight-line flow of fluid with minimal resistance and are primarily used in fully open or fully closed positions. This makes them ideal for isolation purposes, where a full shut-off is required, as they do not constrict flow when fully open.

While gate valves are excellent for isolation, they are not designed for precise throttling; however, in many boiler systems, their robust nature and capability to handle high pressures and temperatures also make them suitable when throttling is occasionally needed. In situations where precise flow control is essential, other valve types, like globe valves, are often more appropriate. Nonetheless, for broader usage in boilers, particularly for complete isolation, the gate valve is the go-to choice.

The other valve types serve different primary functions, such as butterfly valves, which are often used for throttling, or ball valves, which provide good on/off control but are not typically used for throttle applications due to their design, and check valves, which prevent backflow but are not intended for isolation in the way that gate valves are.