Hydraulic system pressure-relief valve - has tappet protruding beyond plug into back-pressure chamber in housing

摘要

The hydraulic system pressure-relief valve has a plug forming part of a guide tappet and spring-loaded against a seat, and working in the axial passage in the housing, which has an expansion chamber with outet. The plug has a lengthwise groove extending as far as the seat. The tappet (11) works in a bush (8) detachably inserted in the valve housing (1), and protrudes beyond the plug (10) into a back-pressure chamber (33) in the housing. It also has an axial drilling (35) right the way through it. The resetting face (32) in the back-pressure chamber subjected to the shutting pressure can be of smaller area than the face (22) on the plug subjected to the opening pressure.