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:
Mar. 19, 1985
Filed:
Jun. 23, 1982
Applicant:
Inventors:
Isao Sugihara, Hitachi, JP;
Wataru Sagawa, Mito, JP;
Tsukasa Ikegami, Hitachi, JP;
Tasuku Shimizu, Hitachi, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C21D / ;
U.S. Cl.
CPC ...
148127 ; 266129 ; 219 1043 ; 219 1079 ;
Abstract
Herein disclosed are a method of heat-treating a weld zone of a piping system, in which the outer wall of a pipe is heated by means of a heating coil, while a coolant is present in said pipe, to establish a temperature difference between the inner and outer walls of said pipe thereby to prevent the weld zone of said pipe from corroding and cracking due to stress, and a heating coil therefor. The aforementioned heating coil is wound on the parent tube and the pipe welding desk generally concentrically thereof thereby to heat substantially uniformly all over the region of said weld zone.