MIL-V-24694, MILITARY SPECIFICATION: VALVE, HYDRAULIC RELIEF, 1.5 - 35 BARS (22 -500 POUNDS PER SQUARE INCH) CARTRIDGE TYPE, GENERAL SPECIFICATION (28 OCT 1987)., This specification covers the requirements for cartridge-type relief valves for use in hydraulic systems with a maximum operating pressure of 35 bars (500 pounds per square inch (lb/in2)).