The 350 Double Check Valve Backflow Assembly, with NRS gate valves, is used on potable water lines in all low health hazard applications for protection against both backsiphonage and backpressure. Its convenient single access cover saves you unnecessary maintenance costs and repair time, and the patented compound check guarantees reliable performance and improved flow characteristics. The epoxy-coated ductile iron body provide corrosion-resistance, and the multiple shut-off and end connection options increase the installation versatility of the 350.