Create a watertight seal and stop backflow through pipe using the PVC Swing Check Valve, 2 in. IPS S X S with Viton™ O-Ring. Water is conveyed one-way through the valve when the flap opens. This easy-fit valve connects two 2 in. pipes in an irrigation or other pressurized system and prevents the backflow of water. Prevents costly property damage, pipe corrosion, and system issues. Durable check valve is made of clear PVC plastic. O-Ring is made of Viton™. Use fittings and other valves to set up a new irrigation system, expand an existing system, or make repairs.