The 1" Dual Check Valve 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 is available in a variety of inlet and outlet sizes, connection types, and thread types, and comes standard with a union inlet connection and integral body outlet connection. Simply confirm the inlet connection, outlet connection, and location of the union, then select from our configuration options for easy installation. The 700XL can be installed horizontally or vertically so long as no part of the unit is submerged.