Mitsubishi Heavy Industries Limited

The Kansai Electric Power Co., Inc.

The Tokyo Electric Power Company, Incorporated

Chubu Electric Power Company, Inc.

The Chugoku Electric Power Co., Inc.

Tohoku Electric Power Company, Inc.

Electric Power Development Co., Ltd.

Kyushu Electric Power Co., Inc.

Hokkaido Electric Power Company, Inc.

Shikoku Electric Power Co., Inc.

Hokuriku Electric Power Company

The Japan Atomic Power Company

Itaru Muroya

Takahiro Ota

Yoichi Iwamoto

Koji Okimura

Ryoichi Kawakami

Kazuhiko Kamo

Kengo Shimamura

Hironori Onitsuka

Seiji Asada

Hisanori Watanabe

Kazuhiro Wakabayashi

A pipe expansion method capable of reducing an inspection range (area) of a heat-transfer pipe secured to a pipe plate and capable of shortening the time required for inspection is provided. In a pipe expansion method for securing a heat-transfer pipe inserted in a pipe hole of a pipe plate by expanding the pipe, after tightly fitting an outer circumferential surface of the heat-transfer pipe to an inner circumferential surface of the pipe hole from a primary-side end face to a secondary-side end face of the pipe plate, surface pressure between the heat-transfer pipe and the pipe plate is further increased in a predetermined range from the secondary-side end face, or close to the secondary-side end face, towards the primary-side end face.

Pipe expansion method

An object is to provide a method and an apparatus for improving a residual stress in a tubular body, which are enabled to improve the residual stress reliably by clearly defining controlling rage for treatment conditions without depending on an installation state and configuration of the tubular body. When a cylindrical tubular body () is improved in its residual stress by locally irradiating an outer-circumferential surface of a welded portion (C) of the tubular body () with laser beams () and by moving an irradiation area (s) in an circumferential direction, a plurality thermocouples () are installed on the tubular body () to be improved, a temperature history of the outer surface of the tubular body () by the irradiation of the laser beam () is managed by measuring the temperature history itself.

Method for improving residual stress in tubular body

Growing community of inventors

Takasago, Japan

Itaru Muroya