ASME B16.25 pdf download Buttwelding Ends 1 SCOPE 1.1 General This Standard covers the preparation of buttweldingends of piping components to be joined into a pipingsystem by welding. lt includes requirements for weldingbevels, for external and internal shaping of heavy-walcomponents,and for preparation of internal ends(including dimensions and tolerances). Coverageincludes preparation for joints with the following: (a) no backing rings (b)...