Shop Nilight RV Hi-Flow Water Regulator for Camper, Lead-Free Brass Water Hose Pressure Reducer Valve with Filter Screen 3/4 Inch Thread for Camper Trailer RV Plumbing System Water Hose, 40-50 psi in high quality. keep the outlet side opening and just swith the knob counterclockwise to set pressure lower, then close the outlet side to observe the pressure, if the pressure is still higher than you need, repeat the above steps to reduce the pressure until you get the pressure you want.