A comparison of theoretical and experimental methods of calibrating the electrical potential drop technique for crack length determination

1982 ◽  
Vol 20 (2) ◽  
pp. 91-101 ◽  
Author(s):  
M. A. Hicks ◽  
A. C. Pickard
Keyword(s):  
Crack Length ◽  
Electrical Potential ◽  
Potential Drop ◽  
Experimental Methods ◽  
Length Determination ◽  
Drop Technique

Influence of crack length on crack depth measurement by an alternating current potential drop technique

2010 ◽  
Vol 21 (10) ◽  
pp. 105702 ◽  
Author(s):  
Manoj K Raja ◽  
S Mahadevan ◽  
B P C Rao ◽  
S P Behera ◽  
T Jayakumar ◽  
...  
Keyword(s):  
Crack Length ◽  
Crack Depth ◽  
Potential Drop ◽  
Alternating Current ◽  
Depth Measurement ◽  
Crack Depth Measurement ◽  
Drop Technique ◽  
Current Potential

Application of the Electrical Potential Drop Technique to the Pipe Wall Thinning Monitoring in Thermal Power Plants

2008 ◽  
Author(s):  
Shin Yoshino ◽  
Seiichi Hamada ◽  
Manabu Hayakawa
Keyword(s):  
Power Plants ◽  
Pipe Wall ◽  
Thermal Power ◽  
Electrical Potential ◽  
Potential Drop ◽  
Thermal Power Plants ◽  
Technical Requirements ◽  
Wall Thinning ◽  
On Line ◽  
Drop Technique

The electrical potential drop technique is one of the promising methods for monitoring the pipe wall thinning. In order to verify this method, preliminary thickness measurements were conducted for uniform and local thinning created on plate specimens. The result showed the electrical potential drop technique had a good performance equal to the ultrasonic testing method. The success in the preliminary tests allowed this technique to be applied to some pipes in thermal power plants in order to monitor the wall thinning and this on-line monitoring has continued for two to three years. It was confirmed that this technique was valid in terms of a long-term durability. Following these results, technical requirements on the potential drop technique were proposed to the JSME (the Japan Society of Mechanical Engineers) Rules on Pipe Wall Thinning Management for Thermal Power Generation Facilities (JSME S TB1-2006) and stipulated in those rules. In this paper, these rules are simply introduced and the on-line monitoring of the pipe wall thinning by means of the electrical potential drop technique is discussed through the results in the plate-specimen-tests and the real-pipe-tests in operating thermal power plants.

Application of Potential Drop Technique to the Inspection of Welded Boiler Pressure Parts

2004 ◽  
Author(s):  
Seiichi Hamada ◽  
Yasuki Ogawa ◽  
Hideo Iida ◽  
Tomoki Kuroiwa ◽  
Masahiko Kuroki ◽  
...  
Keyword(s):  
Direct Current ◽  
Electrical Potential ◽  
Creep Damage ◽  
Potential Drop ◽  
Burst Test ◽  
Technical Requirements ◽  
Pulsed Direct Current ◽  
Drop Technique ◽  
Direct Current Potential Drop ◽  
Current Potential

In this paper, a practical method using the electrical potential drop technique was discussed to evaluate the creep damage accumulated in the welded power piping such as main steam pipe and hot reheat pipe. Round robin experimental measurements conducted by the authors et al. as academic activities in the Japanese Society for Non-destructive Inspection showed that the potential drop technique is effective for the application to the inspection of welded boiler pressure parts. The authors have conducted additional experimental and numerical studies for verification focusing on the application of the pulsed direct current potential drop technique. The authors have proposed technical requirements on the potential drop technique for the application to the inspection of welded power piping to be implemented in JSME Codes for Thermal Power Generation Facilities (2003 Edition) as a non-mandatory appendix JA. And the practical on-line measurement in the high temperature and high pressure burst test using the repair-welded power piping has been conducted. In this burst test, Tokyo Electric Power Company has tried to monitor the creep damage accumulated in the seam-welded area using the commercialized tool based on pulsed direct current potential drop technique.

Accuracy Comparison of the Electrical Potential Drop Technique and Ultrasonic Testing for the Pipe Wall Thinning in the Thermal Power Plant

2010 ◽  
Author(s):  
Shin Yoshino ◽  
Seiichi Hamada ◽  
Yoshi Kaieda
Keyword(s):  
Ultrasonic Testing ◽  
Power Plants ◽  
Pipe Wall ◽  
Thermal Power ◽  
Electrical Potential ◽  
Potential Drop ◽  
Severe Condition ◽  
The Real ◽  
Wall Thinning ◽  
Drop Technique

The electrical potential drop technique is one of the promising methods for monitoring the pipe wall thinning. In the previous paper [1], it was reported that this technique had a good performance equal to the ultrasonic testing in the preliminary test and that it had a long-term durability under a severe condition on the real pipes in operating thermal power plants. This time one of these pipes was replaced because its thickness approached the threshold. The removed pipe was cut in many pieces and its thickness was measured with calipers at several locations corresponding to where the electrical potential drop technique was applied. This result was compared with the thickness resulted from this technique and the conventional ultrasonic testing that were conducted just before the pipe removal. This comparison led to the conclusion that the accuracy in the electrical potential drop technique was almost equivalent to that in the ultrasonic testing even in the real pipe under a severe condition. In this paper, the accuracy in the electrical potential drop technique is mainly discussed.

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