Valves Check Bosch check valves are manufactured to high quality manufacturing standards. These check valves have a maximum operating pressure of 3000 psi and 4600 psi depending on design. Bosch check valves consist of inline and sub-plate mounting both with fixed and adjustable poppet cracking pressure and pilot operated versions. Sizes available in 6 SAE to -32 SAE port size and DO3 (NG6) to D10 (NG10) sub-plate mounting. Pilot Operated 3000 PSI 3000 PSI to 80 GPM Inline Mounted 3000 PSI Subplate Mounted 4600 PSI Subplate Mounted D03/NG6 Check 3000 PSI SAE #6 - #32 Adjustable Resistance 4600 PSI NG10, NG25 Accessories