spool hydraulic directional control valve / cartridge
Series SDRB...−6 stack valves are used as pressure reducing valves in the P−, A− or B lines. They are equipped with the two−stage pressure reducing cartridge type DRPA−5−10... as shown on data sheet D−4.36 − the pilot stage is drained to port T. While the pressure in P1 (A1, B1) remains below the valve setting, the connection P−P1 (A−A1, B−B1) remains fully open. As soon as the pressure in P1 (A1, B1) rises above the setting, the pressure reducing function becomes active. The control spool holds the pressure in P1 (A1, B1) at the valve setting, independently of the primary pressure at P (A, B). Pilot flow occurs only while the reducing function is active and is approximately 300 cc/min (see Performance Data). The bypass check valve in models SDRB−AR−6... and SDRB−BR−6... allows reverse flow from A1 to A, or B1 to B. The screw−in design of the cartridge valve provides for straight−forward, trouble−free maintenance. Interface sealing is by means of O−rings which are retained in counterbores in the valve body.