This tool is a PPR Pipe Welding Machine (often called a socket fusion welder). Its primary use is to permanently join plastic pipes and fittings together, most commonly PPR (Polypropylene Random Copolymer) pipes used in modern hot and cold water plumbing systems.Instead of using glue or threads, this machine uses high heat to melt the plastic surfaces so they chemically fuse into a single, leak-proof piece.