Which term describes a valve that opens or closes in more than 3 seconds?

• A. Ramp breakover angle
• B. Pumper
• C. Slow operating valve
• D. Pressure relief device

Answer: (C)

Valves are classified by how quickly they move from closed to open. If a valve takes more than a short moment—specifically more than about three seconds—to fully open or close, it’s described as a slow operating valve. This slower action helps manage pressure changes and flow, reducing water hammer and giving operators smoother control in emergency pumping or hydraulic systems.

Other terms describe different things: ramp breakover angle relates to geometry that prevents binding, not timing; a pumper refers to a fire pump or the operator, not the valve’s speed; and a pressure relief device is about venting excess pressure, not how fast a valve operates.