SV20GA2-4X//12

The SV20GA2-4X//12 valve is part of the Hy-Check Valves series from Bosch Rexroth and is intended to control directional flow and prevent back-pressure in hydraulic automation circuits. It connects to manifolds or line piping through a threaded connection that follows the UNF/UN profile defined in ANSI/ASME B1.1, simplifying interchange with standard North American fittings. Nominal size 20 (NG20) allows the component to match medium-flow passages without introducing excessive pressure drop, while the 5.4 kg mass supports rigid mounting without additional supports. Cleanliness requirements of ISO 4406 code 20/18/15 limit solid contamination so the sealing edges and control surfaces avoid premature wear. Installation can be oriented in any position, giving designers freedom in compact power units. Flow moves freely from port A to port B but is blocked in the reverse direction until the pilot stage opens, a behavior enabled by a control area A1 of 3.46 cm² that balances hydraulic forces during normal service.

Opening of the main poppet is assisted by a pre-opening feature, so small pilot flow initiates movement and reduces pressure shock when circuits shift. The element begins to lift at a cracking pressure of 5.0 bar and will stay seated until at least the minimum pilot pressure of 5 bar is applied to port X. Once actuated, the valve withstands pilot pressures up to 315 bar and an identical maximum operating pressure in the main line, aligning with typical industrial pump ratings. A larger control area A3 of 10.17 cm² ensures sufficient hydraulic force to keep the poppet fully open under high flow, and the 10.8 cm³ pilot volume in port X allows predictable response times in proportional control loops. Pilot oil returns internally, eliminating the need for an external drain hose and simplifying installation. Together these parameters let the SV20GA2-4X//12 perform consistent check and release functions in high-pressure mobile or industrial hydraulic systems.