Pipe conduit e.g. for exhaust duct or flue, has continuous inner pipe fitted inside alternately smooth and corrugated outer pipe

摘要

The corrugated pipe sections have a wall comprising multiple radially projecting annular corrugations (18). The pipe conduit includes an outer pipe with alternate smooth (12) and corrugated pipe sections (16) of constant inner diameter, and a coaxial continuous smooth inner pipe, e.g. made of soft plastics. The outer surface of the smooth inner pipe fits snugly against the inner surface of the cylindrical pipe sections (12) of the outer pipe.