Method of continuously producing a twin-wall pipe with a ventilation zone between a socket and an adjacent elevation

摘要

A twin-wall pipe comprises an internal pipe and an external pipe. The external pipe is corrugated, having elevations and troughs. The twin-wall pipe is further provided with a socket. In a transition portion towards the twin-wall pipe and the socket, provision is made for at least one overflow passage which interconnects the clearance between the external pipe and internal pipe in the vicinity of the transition portion and an adjacent elevation.