PILOT-OPERATED PRESSURE LIMITATION VALVE FOR FLUID CIRCUITS UNDER PRESSURE

摘要

A pressure limiting valve has two pipe connections connectable to pipes at different pressures and a main piston axially movable in a sleeve in a housing. One end of the piston is closed and the other, free end is attached to an annular piston having two oppositely facing annular surfaces. One annular surface is exposed to the higher pressure through a fluid circuit portion including a changeover valve and the other annular surface is exposed to the pressure at one of the connections. The interior of the main piston is exposed to the lower pressure through a fluid circuit portion including a servocontrol valve. The resulting structure is a double-acting limiting valve having a very low mass piston and high response sensitivity.