Which type of valve is best suited for isolating a liquid?

The gate valve is specifically designed to be used for isolation purposes, particularly when it comes to liquid services. Its fundamental design allows for minimal resistance to fluid flow when fully opened, which means it acts like a straight line in the pipework, thereby causing very little pressure drop. This makes it ideal for scenarios where the fluid must move freely without obstruction.

Gate valves operate by raising or lowering a gate within the valve body that completely opens or closes the flow of liquid. When fully opened, there is a clear path for the fluid, and when closed, the tight seal prevents any liquid from passing through, effectively isolating a section of the piping system.

In situations where isolation is needed without any restriction in flow, gate valves are preferred. They are not designed for throttling or regulating flow, which is where other types of valves like globe valves might be used, but for the specific need to isolate a liquid, the gate valve provides the best performance and reliability.