Hydraulic fluid flows from the reservoir into the inlet port, continues through the low delta P element and through the outlet port. When the element becomes contaminated, your system is protected against possible wash-off of collected contaminant. Unlike other systems where the bypass flow is forced over the dirt-clogged element, the multi-port filter features a unique bypass valve which is self-contained and isolated in the filter head, and does not depend on the mechanical movement of the sludge covered element. Bypassing fluid flows from the inlet port directly to the outlet port, completely ignoring the dirty element and eliminating the possibility of dumping dirt downstream.