The 700XL Dual Check Valve with 1 in. female union inlet x 1'''' female outlet is used in low hazard applications on potable water lines to protect against both backsiphonage 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 bronze body resist against corrosion. The valve is Safe Drinking Water Act compliant, ASSE Listed and CSA Certified.