Allow water to flow one-way through pipe while preventing backflow, using the PVC Breakaway Coupling Valve, 1/2 in. IPS FPT X FPT in Orange. When water pressure exceeds a certain amount, internal mechanism is designed to break to block any fluid from going through the line or leaking. This high-quality valve connects two 1/2 in. MPT galvanized or iron pipes in an irrigation or other pressurized system and prevents the backflow of water. Prevents costly property damage, pipe corrosion, and system issues. Durable coupling is made of high-density polyethylene (HDPE). Use fittings and other valves to set up a new irrigation system, expand an existing system, or make repairs.