where expertise comes together - since 1996

Web's Largest Portal of Nondestructive Testing (NDT)
Open Access Database (Conference Proceedings, Articles, News), Exhibition, Forum, Network

All Forum Boards
Technical Discussions >
Phased Array
Career Discussions
Job Offers
Job Seeks
Classified Ads
About NDT.net
Articles & News

AT-Automation Technology GmbH
AT -Automation Technology is a systems house for industrial image processing. AT offers thermographic ndt systems as well as high-speed 3D sensors.

07:35 Jan-12-2009
Navish M
Phased Array

Hello All,

Does it really require having Individual piping Blocks of thicknesses & diameters for demonstration/ ref calibration as per ASME CC 181 or we can use the range for specific diameters & thickness.


13:20 Jan-12-2009

Ed Ginzel

R & D, -
Materials Research Institute,
Joined Nov 1998
Re: Phased Array In Reply to Navish M at 07:35 Jan-12-2009 (Opening).

You are mixing two aspects of ASME CC181; i.e. calibration and demonstration. CC181 states that you are to follow the rules in Article 4 of Section V. Since CC181 is only addressing the permission to use an alternative acceptance criteria on pipe welds you are therefore required to use the piping calibration requirements. T-434.3 states that the calibration block shall be from a section of pipe of the same nominal size and schedule. So as for the "calibration" portion of your question the answer is no, you are not permitted to use a range.
The issue of demonstration is separate. This is not specified in the ASME CC181. However, EPRI has been for years "qualifying" techniques with a tolerance of about 6mm above and below that demonstrated on. For now, (until ASME defines this parameter) I would think that that should be a reasonable limit. A reasonable range of diameters addressed by the demonstration should also apply. Fig. T-434.1.7.2 provides a graph of curvatures limits used for curved "plate". Six diameters are identified on that image over the range of 1 to 20 inch diameter. I would suggest that this is a reasonable guide for the demonstration block diameter ranges.


© NDT.net - The Web's Largest Portal of Nondestructive Testing (NDT) ISSN 1435-4934

Open Access Database, |Conference Proceedings| |Articles| |News| |Exhibition| |Forum| |Professional Network|