The 4 in 475V Reduced Pressure Principle Backflow Preventer is utilized in high health hazard, potable water applications to protect against both backsiphonage and backpressure of contaminated water into the potable water supply. The Model 475V is shaped in the z-Pattern and is installed in vertical flow up applications, often for new or retrofit installations in compact spaces. Its single access cover reduces maintenance downtime and repair costs and is equipped with the patented, center-stem guided Compound Check for low headloss, superior reliability and unmatched performance.