A pipe is inserted into a recessed area of a valve or fitting. At the bottom of the socket is the gap, which compensates for expansion when the weld is made. According to ANSI 31.1, Section III, ASME US Navy and Military Codes, a 1/16″ minimum gap must be provided between the pipe end and the socket. This gap is required because if the pipe carries hot fluid, differential thermal expansion between the pipe and the fitting may add significant stress to the weld. The weld is then made on the outer surface of the pipe and fitting. Aquasol’s Solugap and SteelSpace provide and maintain the required minimum gap during socket welding.