A Control Valve Compensation System for producing both a pre-compensated and a post-compensated load sensing hydraulic directional control valve module, wherein both configurations use the same components except for a sliding compensating component. The Control Valve Compensation System generally includes a hydraulic directional control valve housing which is adapted to be easily-interchangeable between a load sensing pre-compensated pressure configuration and a load sensing post-compensated pressure configuration by simply removing and replacing a different compensator assembly within the housing. The compensator assembly is adapted to direct oil flow through the housing while simultaneously providing compensation for the valve function. Directional valve assemblies may be provided, with the valve assemblies functioning to provide post-compensated functions, pre-compensated functions, and mixed pre- and post-compensated functions. These directional valve functions can be re-configured in the field by simply swapping the compensator assemblies to produce the desired functionality of the end-user at that particular time.

An open-center valve device for operating machines includes: a first section and a second section, a high-pressure line configured in such a way as to be connected to a pump to supply an operating fluid flow rate to the sections, and a discharge line configured to be connected to an outlet of the operating fluid. Each of the sections includes a spool control element, configured in such a way as to send the fluid flow rate to the respective work ports. The valve device further includes one or more free flow segments, a series duct configured in such a way that, upon a movement from the neutral position of one of the control elements for operating one of the actuators, a return flow rate from a respective work port is supplied to a subsequent control element, progressively closing the respective free flow passage.

A working valve section for a sectional fluid control valve comprising a valve section housing having a substantially planar surface for being attached to an adjacent valve section housing; a main control spool bore (43) extending into the housing substantially parallel to the planar surface; a compensator spool bore (46) extending into the housing substantially parallel to the planar surface, the compensator spool bore being spaced from the main control spool bore; a first relief slot (49a) extending across the planar surface substantially coextensive with the main control spool bore; and a second relief slot (49b) extending across the planar surface substantially coextensive with the compensator spool bore.

An example pressure compensator valve includes: a compensator spool; a first piston coupled to a distal end of, and axially-movable with, the compensator spool; a second piston disposed at a proximal end of the compensator spool, wherein the compensator spool is axially movable relative to the second piston; and a compensator spring applying a biasing force on the compensator spool.