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.
Patent No.:
Date of Patent:
May. 13, 1986
Filed:
Feb. 24, 1984
Kazuo Yoshida, Yokohama, JP;
Tadahiro Umemoto, Yokohama, JP;
Ishikawajima-Harima Jukogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A welding machine is used to heat the outer surface of a butt welded joint of pipe sections such that the weld heat input condition q/t.sup.2 (where q: heat input and t: the thickness of the wall of a pipe) is higher than approximately 0.01 and the relative heat transfer coefficient ht/.lambda. (where h: the heat transfer coefficient between a coolant and the inner surface of a pipe and .lambda.: the thermal conductivity of a pipe) is higher than approximately 2, whereby the residual stresses at the inner surface of the weld can be relieved by utilizing the temperature difference between the outer and inner surfaces of the pipe.