SL10PA4-4X/

The SL10PA4-4X/ valve belongs to the Hy-Check Valves series and is manufactured by Bosch Rexroth for hydraulic automation circuits that need controlled reverse flow blocking and pilot-assisted release. It is built for subplate mounting, so installation uses a standardized base rather than threaded ports. The porting pattern conforms to ISO 5781-06-07-0-16, allowing alignment with common manifolds in size 10 circuits. With a nominal size of 10, flow capacity suits medium-scale actuators without excessive pressure drop. The valve withstands operating pressures up to 350 bar, so it can be placed in high-pressure lines of mobile or industrial machinery. A cracking pressure of 10 bar sets the point at which the check element begins to open under upstream pressure, while a minimum pilot pressure of 5 bar is required to fully release the poppet through the auxiliary control line. Control areas of 1.33 cm² on side A1 and 0.33 cm² on side A2 define the hydraulic force balance that acts on the internal spool during pilot operation. The specified cleanliness class of ISO 4406 20/18/15 establishes the maximum particle level permitted in the working fluid to prevent wear.

An additional control surface of 3.80 cm² at area A3 increases pilot efficiency when the valve is used for rapid venting, while the 0.79 cm² area at A4 supports stable closing after the pilot signal is removed. Pilot oil is returned externally, so the drain line must be routed back to tank at low pressure to avoid back-pressure that could delay reseating. The pilot cavity at port X holds 2.5 cm³ of oil, and port Y holds 2.0 cm³; these volumes affect the response time because they determine how quickly pressure can build and decay. The design includes a pre-opening feature that creates a small initial gap before full lift, reducing pressure shocks when the main flow is enabled. At 1.8 kg, the assembly is light enough for manifold blocks where space and weight are limited yet heavy enough to resist vibration. Together these characteristics tailor the valve for consistent, low-leakage blocking and reliable pilot release in servo or proportional controlled hydraulic systems.