The Difference between Socket Welding and Butt Weld
Socket Weld (SW) fittings are defined in the ASME B16.11. As with socket weld, a pipe is inserted into a recessed area of the fitting. Both the pipe and the fitting are square cut, with no need for beveled end or preparation other than cleaning the outside, which allows easy welding and installation. Butt weld (BW) fittings are defined in the ASME B16.9. They are welded at their ends to pipe end, with the same thickness as pipes. The end of butt weld fittings shall be beveled. Application Socket weld (the fillet weld) resists around 1/2 the strength of butt welding. So it is mainly used for small pipeline (Small Bore Piping) with diameters NPS 2 or smaller. Butt weld keeps better strength, good for high pressure or high temperature pipelines. So it is used when a welded joint with strength not lower than that of the base metal itself is needed. Feature Socket weld is easy to ins...