The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Dec. 06, 2011

Filed:

Apr. 02, 2008
Applicants:

Ralph S. Friedrich, Hermosa Beach, CA (US);

Qizhong Sheng, Cerritos, CA (US);

Paul Kubat, La Mirada, CA (US);

Inventors:

Ralph S. Friedrich, Hermosa Beach, CA (US);

Qizhong Sheng, Cerritos, CA (US);

Paul Kubat, La Mirada, CA (US);

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16L 9/00 (2006.01); B28B 5/00 (2006.01);
U.S. Cl.
CPC ...
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.


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