FD12FA2X/B03V

The FD12FA2X/B03V check valve belongs to the FD Check Valves series and is manufactured by Bosch Rexroth to permit one-directional flow in hydraulic automation loops. Its nominal size 12 defines the passage area and makes it suitable for medium-capacity circuits. An SAE flange connection simplifies installation on manifold blocks and resists leakage under dynamic loads. A dedicated G1/4 control or measuring port lets designers attach test gauges or pilot lines without extra fittings. The valve handles line pressures up to 350 bar on ports A and X, while port B endures 420 bar, so it can sit directly in high-pressure pump or actuator branches. A separate pilot signal may act on port X to 350 bar, giving designers the option to force open the poppet when required. Flow from A to B starts once the poppet sees a cracking pressure of 2 bar, thereby minimizing energy loss during normal advance strokes. Reverse flow from B to A is restricted until 20 bar is reached, preventing unplanned motion when loads try to overrun the actuator.

An internal orifice of 0.3 mm meters pilot oil so the pre-opening sequence remains stable even with pressure spikes. The pre-opening area ratio of 1:20 further tunes this metering, allowing a small pilot flow to lift a larger poppet area for smooth transition to full flow. During full travel the valve passes up to 80 l/min, covering common feed rates for compact presses or tooling circuits. System cleanliness must be maintained at ISO 4406 class 20/18/15 to protect the sealing edges and avoid premature wear. Compatible hydraulic media are HL or HLP fluids according to DIN 51524, ensuring proper lubrication of the moving parts. Service temperature can rise to 80 °C, so installations must include coolers or reservoirs sized to keep oil below this limit. Sealing elements are made from FKM, improving resistance against heat and mineral oil aging. The assembled unit weighs 7 kg, which supports rigid mounting while still allowing manual handling during maintenance.