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, 2002
Filed:
Nov. 01, 1999
Applicant:
Inventors:
Jun Tang, Cambridge, CA;
Roderick J. McGregor, Montreal, CA;
Assignee:
Babcock & Wilcox Canada, Ltd., Cambridge, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21D 3/908 ;
U.S. Cl.
CPC ...
B21D 3/908 ;
Abstract
A method of hydraulically prestraining the tubes of a once-through steam generator by welding the tubes to their respective tubesheets prior to the application of hydraulic expansion to produce tensile stresses which shorten the tubes an equal and predetermined amount to increase the margin to buckling and increase the natural frequency of the tubes reducing flow induced vibration.