Pressure Relief Valves

Safety relief valves are designed to be fast-acting components that protect systems with the potential for sudden pressure spikes. These valves may sit dormant for indeterminate amounts of time before needing to be used, so it’s crucial that they always work as intended. Our safety relief valves are available in low-leak and tight hysteresis configurations. To ensure reliable operation, we 100% test each component for crack, flow point and reseat pressure.

Our safety relief valves are available in 0.187, 0.250, 0.281 and 0.375 inch insert diameters and 0.687 inch threaded configurations. They are constructed entirely of stainless steel and are available screened and unscreened. Built-in damping ensures quiet operation. Cracking pressures ranging from 20 to 5900 psid.

When traveling from the cold at an altitude of 30,000 feet to a runway in the desert, rapid temperature change can cause thermal expansion of fluids and potential damage within the system. Thermal relief valves are designed to relieve small volumes of fluid to protect against thermal expansion. Two models are available, the Lee TRI^® (Thermal Relief Insert) at 0.187-inch diameter and the High Pressure Lee TRI at 0.250 inch diameter. Due to the small passage size of thermal relief valves, they include an integral CRES low micron filter upstream of the valve seat to prevent internal silting due to ingested contamination.

These 0.281 and 0.375 inch diameter relief valves are designed for applications where operating pressures and pressure spikes are too severe for conventional relief valves. Such conditions can lead to instability, erosion, and structural damage of conventional relief valves. High Pressure Safety Relief Valve sizes are available in a range of cracking pressures for system pressures up to 5000 psi.