TUBULAR MEMBERS AND METHODS OF FORMING SAME

摘要

The present invention provides a tubular member (10) and method of formin g the same in which the tubular member (10) comprises one or more strips of self overlapping helically wound material (12) having corrugations with radi ally adjacent curves sharing the same origin of bend radius O formed therein and including a step portion or depression (22) which allows the edges (14) , (16) of each strip to lie within the profile of the combined strips. The s tructure is manufactured by helically winding said strip (12) in self overla pping manner such as to cause the edges (14), (16) to sit within the depress ion (22) whilst providing a multi-layer structure.