Patent ID: 7222744

Claim:
A tank comprising: a partially substantially cylindrical body; a substantially cylindrical extension of smaller diameter than the substantially cylindrical body; a tapered junction extension positioned between the body and the extension; and an internal reinforcement structure for providing tank reinforcement to the interior of the tank only with no exterior reinforcement means, the internal reinforcement structure comprising: a plurality of internal reinforcement rings integral with an internal surface of the extension; a longitudinal reinforcement brace connected to the internal surface of the extension and an internal surface of the body and extending generally along the internal surface of the extension, the internal surface of the junction extension and the internal surface of the body; another longitudinal reinforcement brace extending substantially parallel to the longitudinal reinforcement brace and connected to the internal surfaces; and at least one crosspiece connected between the longitudinal braces; wherein the longitudinal reinforcement braces are welded on the internal reinforcement rings.