The PVC Adjustable Spring Check Valve, 2 in. IPS S X S allows water to flow one-way through pipe with its adjustable spring that lifts when the water pressure exceeds the selected spring weight. This leak-resistant valve prevents backflow in your irrigation system. Connect two 2 in. slip end pipes with this check valve as 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.