This Giant Adjustable Unloader, 3000 PSI, 13 GPM with Orange Spring (22913A) Designed for any pump that fits within the flow and pressure range of the unloader. The unloader regulates the flow in the system and maintains system pressure via an adjustable nut that controls the amount of tension on a pressure spring. When no flow is going out of the outlet port, all flow is diverted to the bypass port at virtually no pressure. The unloader is capable of handling one or more shut-off guns and should be run with no bypass (if the full flow from the pump is going through the unloader). It actuates at around 10% above the system pressure.