Abstract:An adjustable overpressure relief valve, which was composed of a valve body, a selflocking screw plug, a guide rod, a spring and a steel ball, was designed for automobile hydraulic power steering. There was a volume chamber set in the valve body which was respectively communicated with a pressure sensing hole and an overflow hole on the valve body. The spring was sheathed on the guide rod, and each ends of the spring were abutted on the selflocking screw plug and the steel ball which could be close to the pressure sensing hole. Through the use of the relief valve, the hydraulic power steering was protected from damage when the oil pressure of the hydraulic system elevated abnormally.