Mannesmann Rexroth Corporation

Gunter Fertig

Armin Stellwagen

Edmund Kraft

Herbert Blendinger

Walter Kirsch

The invention is a pipe rupture valve having an internal servovale that comprises a valve piston that, in a setting at a steering edge, blocks the connection between two internal pressure connections of the servovalve. At a distance axially to said steering edge the valve piston has an additional steering edge that separates, sealed against fluids, a pre-loaded spring of the valve piston (or a spring area accommodating this spring) from the pressure connections.

Pipe breakage safety valve

An apparatus for adjusting the pressure of working fluid provided to the load or user via a hydraulically actuatable control valve is provided. The apparatus includes a comparator that compares a given or desired control pressure for the control valve with the predominant present load pressure. The resulting pressure differential is used to re-adjust the control valve or to re-adjust a pressure compensator positioned upstream of the control valve with respect to the direction of the flow of working fluid flowing to the user.

Apparatus for adjusting the working fluid pressure

A directional control valve comprising a valve housing, tank-, user-, and pump-ports provided in said housing, a spool reciprocally mounted in said housing and adapted to connect and/or separate said ports, and a pilot controlled flow control valve within said directional control valve.

Growing community of inventors

Wertheim, Germany

Gunter Fertig