UNLOADER, 21GPM @ 4050PSI, GREEN SPRING Pacific Bay Equipment Sale! from $295.00 Qty. Add to Cart This item is currently on backorder but you can still purchase it now and we'll ship as soon as more become available. GPM: 21.0 Temperature: 200°F 1/2" FPT Inlet and Outlet Two 1/2" FPT Bypass Ports Forged-Brass Body Stainless-Steel Internals PSI: 4050 Rated Pressure: 4500 Max