Unlike safety relief valves, pressure regulating valves operate more frequently. The Lee Company offers a “momentum-free” design concept for these applications. These valves compensate for momentum forces that upset the normal force balance of typical direct acting valves. The result is a valve that is stable throughout the operating range. These valves are available in 0.375 and 0.500 inch diameters with cracking pressures from 50-500 psid.