Verfahren zur Herstellung eines mit einem Abzweigstutzen versehenen luftspaltisolierten Abgasrohres

摘要

The manufacturing method has an inner pipe for exhaust gases fitted inside an outer pipe, with an air insulation gap between the inner and outer pipes. A common branch point is formed in the double-walled pipe using two internal pressure deforming tools, successively providing a double-walled pipe opening and sealing the edge of the outer pipe opening around the outside of the inner pipe opening.