What is a Socket Weld Union Fitting exactly? It is a pipe made of metal and a fitting that is used for joining two pipes of the same or different diameters in a way that is secure, strong, and leak-proof. Unlike threaded fittings, the weld in the socket weld fittings is a fillet type which is at the pipe connection, thus, it is a permanent joint which is leak-proof. Hindco Steel and A... https://www.hindco.co.in/socket-weld-union-fitting-manufacturer-exporter-supplier-stockist.html