Gasket assembly for igniter tube non-welded to the chamber wall

The chamber has a sparkplug (3) with a body (2) having a free end in an opening (8) of a chamber wall (5) to compensate relative movements between a case and the wall. A sealing device (1) has an annular spark plug guide (10) mounted at a radial external end of an annular support (12). The support is integrated with a radial external part of a vapor tube (20) having a skirt in support against an internal side of the wall.