Abstract: A corrugated spiral pipe with a coupling device comprises a pipe body 10, a pair of flanges 20, and a pair of binding bands 30. The pipe body 10 has a cylindrical shape and is prepared to have a spirally corrugated shape 11. The pair of the flanges 20 are formed in one body of outer circumferences of both end portions of said pipe body 10, each of the flanges 20 having a large outer diameter portion at an end portion of the flange 20 and a small outer diameter portion 21 at a longitudinally inside portion of the flange 20.

Abstract: A double-walled spiral pipe in accordance with the present invention is composed of an outer wall 10 having a cylindrical shape, which is prepared by winding spirally a coated steel plate 11 having corrugations 12; and an inner wall 20 having a cylindrical shape, which is contacted with the wave bottom of corrugations of said outer wall 10, and can contracted or elongated depending upon a change of the pitch of the corrugations of said outer wall 10. The inner wall 20 having a cylindrical configuration is installed to be contacted with the wave bottom of corrugations of the outer wall 10, and functions to drain a sewage, etc. The inner wall 20 has a semi-circular portion which is formed at the point of the wave bottom of the corrugations of the outer wall, and a plane surface is formed between the semi-circular portions.