REXROTH Types Z4WEH22 And Z4WH22 4/2 And 4/3 Directional Shut-off Valves, Internally Pilot Operated, Externally Pilot Operated

Component series 5X Maximum operating pressure 315 bar Maximum flow 650 l/min .Valves of type Z4WEH are directional spool valves with electrohydraulic actuation. They control the start and stop of a flow. These directional valves basically consist of the main valve with housing (1), main control spool (2), one or two return springs (3.1 and 3.2), as well as pilot valve (4). Main control spool (2) in the main valve is held by springs or through pressurization in the zero or initial position. In the initial position, the two spring chambers (6) and (7) are connected pressureless to tank via pilot channel (4). The pilot valve is supplied with pilot oil via pilot line (11). The supply can be provided internally or externally (externally via port X in the sandwich plate, see page 6). When the pilot valve is operated, e.g. solenoid “a“, the pilot spool (not shown on the drawing) is pushed to the left and spring chamber (7) is consequently pressurized to pilot pressure. Spring chamber (6) remains pressureless. The pilot pressure acts on the left side of main control spool (2) and pushes it against spring (3.1). In the main valve the ports are connected on the component side and on the plate side depending on the symbol