SV20PB2-4X/

The SV20PB2-4X/ is produced by Bosch Rexroth for the Hy-Check Valves series and is applied in hydraulic automation circuits to block or allow flow based on pilot pressure. It is built for nominal size 20 passages, giving designers a clear guideline on flow capacity and compatible manifold cavities. A subplate mounting interface simplifies installation, while the porting pattern ISO 5781-08-10-0-16 matches widely used base plates for rapid exchange. To meet contamination limits, the component requires hydraulic fluid cleanliness of ISO 4406 20/18/15 so the seating elements are not damaged by particles. Internal pilot oil return removes the need for an external drain line and reduces plumbing. The pilot chamber holds 10.8 cm³ at port X, a volume that determines response time during actuation. Flow forces act on distinct control areas; area A1 is 3.46 cm² and area A2 is 0.70 cm², values that define the pressure differential needed to shift the poppet. The poppet starts to open at a cracking pressure of 5.0 bar, allowing predictable circuit sequencing without premature flow.

During operation the valve withstands a maximum operating pressure of 315 bar so it can be placed directly in high-pressure pump lines. The main poppet is influenced by a larger control area of 10.17 cm² at A3 and a secondary area of 1.13 cm² at A4; these surfaces balance hydraulic forces to secure the closed position until pilot pressure is applied. Pre-opening is absent, ensuring the passage remains fully blocked until the cracking value is reached, which avoids leakage in load-holding applications. The recommended medium is mineral oil of the HL or HLP type, a choice that guarantees compatibility with the internal seals and damping orifices. A calculated mean time to dangerous failure of 150 years indicates high functional safety for long-term duty cycles. Even with its pressure rating, the assembly weighs 4.7 kg when set on a subplate, a factor useful for manifold weight calculations and service handling. Together these parameters establish reliable shut-off behavior and straightforward integration in hydraulic power units.