Bosch Rexroth SL30PA3-4X/V pilot-operated check valve

SL30PA3-4X/V, manufacturer material number R900518694, is a Bosch Rexroth SL size 32 hydraulically pilot-operated check valve for subplate mounting to ISO 5781. It uses external pilot-oil drain through Y, FKM seals and a decompression stage that opens before the main poppet to reduce the decompression pressure shock.

Flow is free from A to B. Reverse B-to-A flow is blocked until pressure at X opens the poppet. Opening-pressure code 3 corresponds to a forward opening-pressure class of 8 bar in the original manufacturer table. This class is distinct from the pilot pressure needed to release a loaded circuit. Required pilot pressure depends on load and return pressure, and must be read from the applicable control-pressure/load-pressure curves.

The technical reference is the original manufacturer publication RE21468, edition 2024-02. Its size-specific component operating-pressure limit is 315 bar, with a catalog control range of 5–315 bar; 5 bar is not a universal pilot-opening requirement. No independent unrestricted Y-port pressure rating or application safety certification is established by these data. The external Y connection separates the pilot-spool annular area from A; A pressure still acts on control area A4.

The FKM fluid and ambient range in this reference is −15 to +80 °C, with viscosity 2.8–500 mm²/s and ISO 4406 cleanliness class 20/18/15. The pressure-drop and pilot-pressure curves use HLP46 at 40 ± 5 °C. The subplate and mounting screws are separately ordered. Representative manufacturer SV/SL subplate-mounting drawing. The Y connection applies to SL and is plugged on SV; the exact size and opening-pressure version are defined separately.