BUND FUER DOPPELWANDIGE ROHRE UND HERSTELLUNGSVERFAHREN.
摘要
The invention comprises a part forming a cylinder (4) extended in an inwards direction by a radial part (5), the part forming a cylinder (4) having at least one projection (6, 7) towards the exterior for fitting to at least one pipe and the radial part directed inwards being recessed. <IMAGE>