Twin=walled exhaust pipe - comprises two shanks joined by bend and inner pipe has two sections connected by sliding joint in one shank and inner pipe support is in bend

摘要

The exhaust gas pipe(2) consists of outer(4) and inner(6) pipes with an insulating air gap inbetween. The pipe(2) has two shanks(18,22) separated by a connecting bend(20) and the inner pipe(6) comprises two sections(12,14) connected by a sliding joint in a first position in the first shank(8). A radial support(26) for the inner pipe(6) is at a second position either in the bend(20) or the second shank. Also claimed is a waste gas pipe(2) with an air gap between the inner pipe sections(12,14). A distance piece fills the gap and has a radially inward facing stop at one end and a radially outward facing stop at the other end. The stops determining axial positions of the pipe sections (12,14) relative to each other. In the mfr. the inner pipe sections (12,14) are connected, inserted into the out pipe(4) and after filling space between them with fluid are bent. The radial support(26) may be inserted before or after bending. In a further process the inner tube sections(12,14) are polygonally calibrated and after insertion into one another are twisted relative to each other until contact is made between the sections(12,14). In another process a distance piece inserted into an air gap between the inner pipe section(12,14) ends is burnt away leaving the joint free to move.