Welded piping joint structure

摘要

An object is to provide a piping joint structure (10;20;30;50) that enables welding without back shielding, and in which oxidized scale does not occur on the inner surface side of the pipe. In a piping joint structure in which an end of a first tubular material (12;24;32;52) and an end of a second tubular material (13;25;33;53), which is located adjacent to the first tubular material, are joined by butt welding, an inner fitting portion (14a;24a;34a;54a) is formed around the circumference on the end of the first tubular material, and a first bevel (14b;24b;34b;54b) is formed on the radial outside of the inner fitting portion around the circumference, an outer fitting portion, which is fitted to the radial outside of the inner fitting portion, is formed on the end of the second tubular material, and a second bevel (15b;25b;35b;B) is formed around the circumference at a location that is at the end of the outer fitting portion and that faces the first bevel.