Abstract: One box body is attached to an undercarriage of a trailer, and provided with a brazing area, a gastight testing area, and a finishing area aligned with one another in this order along a first side wall of the box body the brazing area, a plurality of members are bonded together by brazing to produce a half-finished product. In the gastight testing area, gas-tightness of the half-finished product is tested. In the finishing area, the half-finished product is covered with a thermal insulator to completely produce a pipe component. As a result, it becomes possible to properly dispose a working area, where the pipe component is produced, in the interior space of one box body without losing workability.

Abstract: Disclosed is one box body attached to an undercarriage of a trailer, and provided with a brazing area, a gastight testing area, and a finishing area aligned with one another in this order along a first side wall of the box body. In the brazing area, a plurality of members are bonded together by brazing to produce a half-finished product. In the gastight testing area, gas-tightness of the half-finished product is tested. In the finishing area, the half-finished product is covered with a thermal insulator to completely produce a pipe component. As a result, it becomes possible to properly dispose a working area, where the pipe component is produced, in the interior space of one box body without losing workability.