SF80A1-1-1X/12

The SF80A1-1-1X/12 valve is produced by Bosch Rexroth for the SF Prefill Valves series and is intended to manage rapid filling and discharge in hydraulic cylinders. It can be mounted in any position, which allows flexible placement inside power units or manifold blocks. The A port uses a DN76 interface according to ISO 6162-1 so it matches large-bore pipework between the cylinder and tank. Supply to port P is made through a G3/4 thread, providing a standard line for pilot oil or auxiliary functions. A G1/2 connection is provided at port X for external pilot control lines. The maximum operating pressure is limited to 16 bar at port A to protect the low-pressure side during cylinder charging. Port B, also designated as P, tolerates up to 350 bar so the unit can withstand high system pressure when closed. Pilot port X operates safely up to 150 bar, ensuring reliable actuation without overstressing the control passages. To prevent leakage under these loads, the housing screws must be tightened to 1400 Nm. Hydraulic cleanliness must be maintained at ISO 4406 class 20/18/15 to keep the sealing surfaces free of wear.

The main poppet has an effective area of 49.02 cm², enabling large flow rates while maintaining low pressure drop during cylinder filling. Its stroke is 17 mm, giving enough lift to uncover the seat fully when the valve is commanded open. A separate control spool with an area of 10.18 cm² modulates pilot oil so that opening force is balanced and response is predictable. The spool travels 13 mm, allowing precise metering of pilot flow before the poppet moves. Opening requires 13.20 cm³ of pilot oil, a volume that determines the response time of the valve in automated cycles. A 1.0 mm nozzle insert restricts this pilot flow, preventing pressure spikes and damping the opening movement. These internal dimensions coordinate to deliver stable operation during high-speed prefill sequences without cavitation.