US 8,069,880 B2 · Pressure cast concrete or mortar lined steel pipes and methods of making the same

Abstract

Pressure cast lined steel pipes comprise an annular concrete or mortar liner along an inside diameter, and a metal shell surrounding the liner, wherein the liner is in direct contact with the metal shell. The wall thickness of the liner can be from 10 to 50 times the thickness of the metal shell. The pipe may be coated with a dielectric material. A mold assembly used to form the pipe includes an annular concrete or mortar composition chamber formed between the metal shell and an inner mold member. Pressurized water is used in the mold assembly to pressurize the concrete or mortar composition and exert a desired pressure force onto the metal shell while the composition cures in the mold. Once a desired degree of cure is achieved, the pressure is removed causing the metal shell to exert a desired compression force onto the cured liner.

Claims34

Dependent claims

A pressure cast lined steel pipe that is placed into fluid transport service, the pipe comprising:

an annular concrete or mortar liner forming an inside diameter of the pipe;
a metal shell surrounding the liner;
wherein the liner is in direct contact with an inside wall surface of the metal shell, wherein the liner is in a prestressed state by the metal shell in an initial state prior to the pipe being placed into fluid transport service, and wherein the prestress of the liner in a final state when placed into fluid transport service is essentially eliminated.

Dependencies are inferred from the claim text.

Pressure cast concrete or mortar lined steel pipes and methods of making the same

Life of this patent

Pressure cast concrete or mortar lined steel pipes and methods of making the same

Life of this patent

Abstract

Claims34