A Socket Weld, abbreviated as SW, pipe fitting is one where the pipe is inserted into a recessed area of the fitting. To make a socket weld fitting, the pipe is inserted into the pipe before it is welded. In order to prevent damage to the pipe and fitting, the pipe is then backed out a minimum of 1/16” to allow for thermal expansion of the pipe during the welding procedure. If this clearance is not made, the weld can crack due to the pipe expanding against the fitting.

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Socket Weld Fitting sizes - 1/8" through 4"
	Cap - Round, ANSI Class 3000, FCS (in) Cap - Round, ANSI Class 6000, FCS (in)		Elbow - 90 Degree, ANSI Class 3000, FCS (in) Elbow - 90 Degree, ANSI Class 6000, FCS (in) Elbow - 90 Degree, ANSI Class 9000, FCS (in)
	Coupling - Full, ANSI Class 3000, FCS (in) Coupling - Full, ANSI Class 6000, FCS (in) Coupling - Full, ANSI Class 9000, FCS (in)		Lateral - ANSI Class 3000, FCS (in) Lateral - ANSI Class 6000, FCS (in) Lateral - ANSI Class 9000, FCS (in)
	Coupling - Half, ANSI Class 3000, FCS (in) Coupling - Half, ANSI Class 6000, FCS (in) Coupling - Half, ANSI Class 9000, FCS (in)		Reducer - ANSI Class 3000, FCS (in) Reducer - ANSI Class 6000, FCS (in) Reducer - ANSI Class 9000, FCS (in)
	Cross - Straight, ANSI Class 3000, FCS (in) Cross - Straight, ANSI Class 6000, FCS (in) Cross - Straight, ANSI Class 9000, FCS (in)		Tee - Straight, ANSI Class 3000, FCS (in) Tee - Straight, ANSI Class 6000, FCS (in) Tee - Straight, ANSI Class 9000, FCS (in)
	Elbow - 45 Degree, ANSI Class 3000, FCS (in) Elbow - 45 Degree, ANSI Class 6000, FCS (in) Elbow - 45 Degree, ANSI Class 9000, FCS (in)		Union - ANSI Class 3000, FCS (in) Union - ANSI Class 6000, FCS (in)