Apparatus for forming in continuous a spiral seamed conduit, forming process and spriral conduit

Abstract

Apparatus () for forming in continuous a spiral seamed conduit () from a metallic strip () comprising a feeding plane () for said metallic strip (); a forming head (') rotating about a forming axis (A) substantially parallel to the feeding plane () and tilted by a forming angle (a) with respect to a direction orthogonal () to a feeding direction (F) of the metallic strip, wherein the forming head (′) is adapted to drive in rotation said metallic strip () for defining a spiral conduit (); a lock-seaming device () configured to lock in continuous two portions of said metallic strip () along opposite profiles for forming said spiral seamed conduit (); wherein said forming head (′) is provided with one or more forming elements () arranged and configured so to define a substantially polygonal shape for the section of said spiral conduit () during the drive in rotation of said metallic strip (); wherein said lock-seaming device () is configured to move along a seaming direction (G) so to lock said two portions along a side of said conduit (); and wherein said apparatus () further comprises means configured to move the forming head (′) according to a plurality of axes. The present invention also relates to a process for forming in continuous a spiral conduit () having a substantially polygonal section and a spiral conduit () having a substantially polygonal section and four flat sides.