The 1" Double Check Backflow Preventer with Union Ball Valve includes top access check covers for easy maintenance access, is utilized in low health hazard non-potable water applications, and is suitable for below grade installation in standard valve boxes. The 950XLT protects against both backsiphonage and backpressure while the test cock plug protects against fouling caused by insects, dirt, and debris. It includes corrosion-resistant stainless steel springs, fasteners, and ball valve handles. Features of the 950XLT include a maximum working water pressure of 175 psi, hydrostatic test pressure of 350 psi, and a maximum working water pressure of 180°F.