Which multi-turn valve is used for full open or no flow applications ONLY?

• A. Globe valve
• B. Diaphragm valve
• C. Gate valve
• D. Pinch valve

Answer: (C)

Gate valves are built for on/off service. Their multi-turn screw mechanism moves a straight-moving gate that either blocks the flow or clears it completely. When fully open, the path through the valve is unobstructed, causing minimal pressure loss; when closed, the gate seals firmly against seats to stop flow. This makes them ideal for full open or no flow applications, rather than for precise flow regulation. Globe valves, by contrast, are designed to throttle and regulate flow, which introduces more resistance and makes them less suitable for simple on/off service. Pinch and diaphragm valves have specialty uses (pinch for squeezing a sleeve to stop flow, often with slurries, and diaphragm for sanitary or chemical services) and are not the standard for routine isolation. So the valve best suited for full open or no flow only is the gate valve.