475STDA OSY - 4"

Designed for drop in replacement of competitor valves and new installation on water lines in fire  protection systems to protect against both backsiphonage and backpressure of contaminated water into the potable water supply. The Model 475STDA shall provide protection where a potential health hazard exists.  The Model 475STDA is approved for applications requiring flow vertical up and vertical down (standard) or flow vertical up and vertical up (V option). Incorporates metered by-pass to detect leaks and unauthorized water use.