What type of valve is designed to be operated either fully open or fully closed?

A gate valve is specifically designed to be operated either in a fully open or fully closed position. This characteristic allows for minimal resistance to flow when the valve is open, making it suitable for applications where a straight-line flow of fluid is required. Typically, gate valves are used in systems where the flow needs to be shut off completely and do not have the capability to throttle or control flow rates effectively. By lifting the gate completely out of the flow path, they provide a full bore opening, ensuring that fluid can pass through with little to no obstruction, which is essential in many industrial applications.

The other types of valves mentioned have different operational characteristics. For instance, ball valves and butterfly valves can also be used to perform similar functions but are often designed to allow for throttling capabilities. A check valve, on the other hand, automatically prevents backflow and does not have a fully open or closed position manual control as its primary function is to allow flow in one direction only.