The PVC Compact True Union Spring Check Valve, 2 in. IPS S X S is compact to make installation easier for applications with limited space in their pipelines. Allow water to flow one-way through pipe and prevent backflow with this check valve. The 1/2 lb. spring lifts when the water pressure exceeds the spring weight to let water through and closes to prevent water from going the wrong way through the irrigation system. This easy-fit check valve connects two 2 in. slip end pipes as a part of a complete irrigation or other pressurized system. Prevents costly property damage, pipe corrosion, and system issues. Durable check valve is made of PVC plastic. Pressurized Spring is made of stainless steel. Washer and O-Ring are made of EPDM. Use fittings and other valves to set up a new irrigation system, expand an existing system, or make repairs.