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:
Feb. 05, 2002
Filed:
Aug. 12, 1999
Kunio Enomoto, Tokai-mura, JP;
Katsuhiko Hirano, Hitachi, JP;
Eisaku Hayashi, Hitachi, JP;
Ren Morinaka, Hitachi, JP;
Sadato Shimizu, Hitachinaka, JP;
Satoshi Kanno, Hitachi, JP;
Shigeru Tanaka, Tokai, JP;
Tetsuya Ishikawa, Hitachi, JP;
Other;
Abstract
A preventive maintenance method and apparatus for a structural member in a reactor pressure vessel according to the present invention reduce a tensile residual stress on a surface of the structural member by impinging a water jet from a nozzle onto a plane surface of a deflector to thereby change direction of flow of the water jet, and impinging the water jet after being deflected onto the surface of the structural member. This method and apparatus are applicable to a narrow space portion, and can improve a residual stress on the surface of the structural member and can also prevent damage such as stress corrosion cracking.