PERMCO 1-QTY 40SR 1NPT GAGE/25PSIBP

The bypass valve on this unit is set at 25 PSI. That means once differential pressure across the filter hits that threshold, the bypass opens to keep flow moving even if the element is restricted. The port size is 1 inch NPT, which fits standard hydraulic reservoir return line fittings pretty well on most mid-size power units.