Corrosion resistant tube and method of manufacture

A corrosion resistant tube comprising:

• a tubular low carbon steel body having an inside surface and an outside surface;
• a corrosion resistant metal coating on the inside surface;
• a first corrosion resistant metal coating on the outside surface;
• a second corrosion resistant metal coating applied to the first corrosion resistant metal coating;
• and
• a polymer layer applied over the second corrosion resistant metal coating,
• wherein the low carbon steel body has approximate mechanical properties including a tensile strength of 40,000 psi, a yield strength of 29,000 psi, and elongation of about 50.3%.

A method of manufacturing a corrosion resistant tube, said method comprising:

• providing a strip of low carbon steel, said strip having top and bottom primary surfaces, and longitudinal edges connecting the top and bottom primary surfaces along longitudinal edges of said strip;
• applying a corrosion resistant metal coating to at least the top and bottom primary surfaces of said strip;
• forming the strip into a tube with the longitudinal edges of the strip adjacent to each other;
• and
• welding the longitudinal edges of the strip to form a tubular body of the corrosion resistant tube, said tubular body having an inside surface and an outside surface corresponding to the top and bottom primary surfaces, said weld having an inside lateral span at said inside surface less than an outside lateral span of said weld at said outside surface,
• wherein the corrosion resistant metal coating on the inside surface of the tubular body is heated during welding and flows across and covers the inside lateral span of said weld.