Which description best characterizes a gate valve?

• A. Gate valve, a valve with a solid plate that is vertically actuated, used as an isolation valve and typically fully open or fully closed
• B. Globe valve
• C. Diaphragm valve
• D. Butterfly valve

Answer: (A)

Gate valves are designed for full isolation, not throttling. The defining feature is a solid plate, or gate, that moves up and down (vertically actuated) to block or allow flow. This setup gives a tight seal when closed and a straight, unobstructed path when open, so they are typically operated fully open or fully closed. That makes the description—solid plate moved vertically for isolation and fully open or closed—the best match. The other valve types work differently: globe valves regulate flow with a moving disk in a globe-shaped body, diaphragm valves seal with a flexible diaphragm, and butterfly valves use a rotating disk to modulate flow.