Patent ID: 6769719
Filing Date: 2004-08-03
Classification: B29C,F16L

Abstract:
A tube having at least one end to be butt welded and for conveyance of a fluid producing a drop in mechanical resistance, said tube comprisingan external layer made of weldable plastic, an internal protective layer located inside the external layer for protection of the external layer from contact with the fluid conveyed, a terminal section of the external layer adjoining said at least one end to be butt welded, said internal protective sleeve extending up to said terminal section and stopping short of the at least one end to be butt welded, and an external reinforcing sleeve covering said external layer at said at least one end to be butt welded, said external reinforcing sleeve being made of said weldable plastic to participate in the butt welding of the at least one end with the external reinforcing sleeve having a thickness such as to make a mechanical resistance of a tube section of said external layer nearest the at least one end when in contact with the fluid in a welding zone without the internal protective layer at least equal to mechanical resistance of the external layer not in contact with the fluid.