Flojet Water Booster System - 40 PSI - 4.5GPM - 12VWater Booster System 40 PSI 4. 5GPM 12V The Flojet 2840 Series Booster Systems are designed to provide constant water pressure of 0 to 40 psi (0. 7 to 2. 7 bar) and a maximum flow rate of 4. 5 GPM at 10 psi (0. 7 bar). The pump is fully automatic, with a built in inlet strainer, pressure switch, and check valve, and supplies smooth flow from trickle to full flow. Typical uses include applications where available water pressure is very low and