Which of the following statements about a gate valve is false?

A gate valve is primarily designed to be either fully open or fully closed, making it an ideal choice for isolation purposes, where a complete stop of flow is required. The mechanism of a gate valve involves a wedge-shaped gate that moves perpendicularly to the flow direction, allowing for a very minimal pressure drop when fully open.

When it comes to throttling, which refers to controlling the flow rate of fluid through partial opening, a gate valve is not suitable. This is due to the design that causes turbulence and potential damaging vibrations when left partially open. Gate valves do not provide the fine control that other valve types, such as globe valves, can provide when used for throttling applications. Thus, saying that a gate valve is used for throttling is inaccurate, making that statement false.

The other options make accurate claims about gate valves: they indeed can fully shut off flow and are commonly utilized for isolation. Their typical linear motion refers to the direct up-and-down movement of the gate, solidifying that they function effectively in their intended applications.