A socket is a fitting that simply goes over the end of a pipe. A 1" socket end will fit on a 1" pipe. These are extremely common. Many PVC couplings have socketed ends. A commonly used abbreviation for "socket" is "soc."PVC pipe socketing machine is widely used in many industrial processes and applications. It is used in industries like irrigation, construction, water and underground hot water projects where PVC pipes are used.It is the plastic pipe commonly used for plumbing and drainage. PVC stands for Poly Vinyl Chloride, and it's become a common replacement for metal piping. PVC is a thermoplastic material that is molded into different shapes to create pipes, fittings, valves and other liquid handling supplies.