The 700XL Dual Check Valve with 1 in female union inlet x 1 in female outlet is used in low hazard applications on potable water lines to protect against both back siphonage and backpressure of polluted water. A non-testable device, the 700XL can be installed horizontally or vertically so long as no part of the unit is submerged and will provide protection where a potential health hazard does not exist. The quality stainless steel springs and low-lead bronze body resist against corrosion and the valve is ASSE® Listed and CSA® Certified.