What is the relation of relief valve size to standard pipe size?

Relief valves are critical components in hydronic and process systems, designed to prevent overpressure conditions. The sizing of relief valves is dictated by the flow capacity required to safely relieve pressure without causing system failure. Typically, the sizes of relief valves are standardized for compatibility with various piping systems, which allows for effective integration into existing setups.

The correct answer indicates that relief valve sizes typically fall between 3/4 inch and 4-1/2 inches. This range is significant because it accommodates a variety of applications, providing flexibility to meet different pressure and flow rate requirements. The existence of such a standard sizing range ensures that the valves can handle the necessary capacity while being compatible with different duct sizes used in hydronic and process piping.

Having standard sizes helps in selecting and installing relief valves efficiently, ensuring that they can interface properly with the corresponding piping systems, enhancing overall safety and performance.