Pipe arrangement branching structure, method for working perforated pipe and method for working branch pipe

摘要

A pipe arrangement branching structure is provided with a perforated pipe having two holes partitioned by a partition wall and a plurality of branch pipes connected to the respective holes of the perforated pipe in an air-tight manner. The holes of the perforated pipe at an end thereof are formed to have shapes coincident with outer shapes of the respective branch pipes by plastic deformation work. The respective branch pipes are inserted into the holes formed by the plastic deformation work and the perforated pipe and the respective branch pipes are brazed.