Search


Information
ICMST-Tohoku 2018
Oct. 23 - 26, 2018
Sendai, Japan
ICMST-Shenzhen 2016
Nov 1 - 4, 2016
Shenzhen, China
(EXIT THIS PAGE)
ICMST-Kobe 2014
Nov 2(Sun) - 5(Wed), 2014
Kobe, Japan
Nuclear Regulation Authority Outline of the New Safety Standards for Light Water Reactors for Electric Power Generation
For Public Comment
Outline of New Safety Standard (Design Basis)
For Public Comment
New Safety Standards (SA) Outline (Draft)
For Public Comment
Outline of New Safety Standard(Earthquake and Tsunami)(DRAFT)
Issues
 

Vol.10 No.2(Aug)
Vol.10 No.1(May)
Vol.9 No.4(Feb)
Vol.9 No.3(Nov)
< Other Issues

 

Occasional Topics
OTjapan Measures for Tsunami Striking Nuclear Power Station in Japan
Special Article: The Great Tohoku Earthquake (1)
OTjapan The Tragedy of “To Be” Principle in the Japanese Nuclear Industry
EJAMOT_CN3_Figure1_The_outside_view_of_CEFR OTChinaPlanning and Consideration on SFR R&D Activities in China
< All Occasional Topics

Featured Articles
EJAM7-3NT72 A New Mechanical Condition-based Maintenance Technology Using Instrumented Indentation Technique
EJAM7-3NT73 Survey robots for Fukushima Daiichi Nuclear Power Plant

JSM
Contacts
(EJAM): ejam@jsm.or.jp
(JSM): secretariat@jsm.or.jp
HP: http://www.jsm.or.jp
(in English)

 
Vol.1 No.3 previous GA 8 - 9 - 10 - AA 10 - NT 14 - 15 - 16 - 17- 18 next Vol.2 No.1
Vol.1, No.4, NT16 EJAM (1-4-NT16) - Wall thinning inspection technique for large-diameter piping by a partially attached-type guided wave sensor

Wall thinning inspection technique for large-diameter piping by a partially attached-type guided wave sensor
 
Hitachi, Ltd.
Hitachi-GE Nuclear Energy, Ltd.
 

KEYWORDS：
Guided wave inspection, piping, large-diameter piping, wall thinning, partially attached-type guided wave sensor
 
1. Technical summary
 
Classification
(I: Inspection, II: Repair, III: Replacement, IV: Preventive Maintenance, V: Others)
 
Guided wave inspection by an ultrasonic wave propagated towards an axial direction is applied to detect the locations and cross section area of wall thinning in structures suck as piping (Fig.1). Over several dozen meters can be inspected at one time by attaching the sensor to part of the piping. Therefore, the inspection procedures can be rationalized by cancelling such incidental tasks like the heat insulator removal or installation of scaffolding to better access the piping. In particular, a partially attached-type guided wave sensor offers a great benefit for the rationalization, in the case of inspecting large structures like large-diameter piping.
EJAM1-4NT16-Fig.1_Schematic_of_guided_wave_inspection
Fig.1 Schematic of guided wave inspection
 
2. Scope

(1) Components
Large-diameter piping (diameter: over 500 A (20 B)), cylindrical structures such as tanks

(2) Materials
Carbon steel, stainless steel, etc.

(3) Condition
Removal and later re-attachment of the heat insulator is needed, but to a limited extent of the sensor attachment
 
3. Features

・No needs of large sensor for all around the piping
・Partially attached-type guided wave sensor is deformable to depend on piping curvature (Fig.2)
・Portable-type guided wave inspection system for partially attached-type sensor has been prepared. (Fig.3)

EJAM1-4NT16-Fig.2_Partially_attached-type_guided_wave_sensor_Attached_on_1100_A_piping
Fig.2 Partially attached-type guided wave sensor (Attached on 1100 A piping)

EJAM1-4NT16-Fig.3_Guided_wave_inspection_system
Fig.3 Guided wave inspection system
 
4. Examples of Application
・Guided wave inspection adopting the partially attached-type guided wave sensor can detect wall thickness. The wall thinning position can be detected by moving the sensor circumferentially. A typical test result is shown in Fig.4
・No experience of application to actual plant piping inspection so far.
EJAM1-4NT16-Fig.4_(a)_Location_of_wall_thinning_area_and_sensor_Circumferential_projection_of_piping
(a) Location of wall thinning area and sensor (Circumferential projection of piping)
EJAM1-4NT16-Fig.4_(b)_Inspection_results_depending_on_the_sensor_position
(b) Inspection results depending on the sensor position
Fig.4 Inspection example (500A piping, 9.5mm thickness, carbon steel)
 
5. Reference

M.Miki, Y.Nagashima, M.Endou, K.Kodaira, and K.Maniwa; “Wall Thinning Inspection Technique for Large-Diameter Piping using Guided Wave”, Proceedings of the 6th Annual Meeting, Japan Society of Maintenology, 2009 (in Japanese)
 
6. Contact
Japan Society of Maintenology (ejam@jsm.or.jp)