With the development of technology there is a fine line in the relationship between Manual Ultrasonic Testing, Time-of-flight diffraction (TOFD), Phased Array Ultrasonic Testing (PAUT) and other encoded methods in relation to Codes and the customers’ expectations of Ultrasonic Testing. Level III NDE Inspector Philly le Roux keeps us up to date on ‘Customers and codes versus New NDT methods…..
During the past decade Non-Destructive Testing (NDT) has evolved rapidly with new technology and/or methods being implemented in the NDT market. However certain questions still remain.
Do the International Codes relate to new NDE methods?
New technological developments made over the current decade are quite remarkable, particularly the American Society of Mechanical Engineers (ASME) Codes that have addressed much more techniques and produce progress on the various methods annually, while the Euro Norm and ISO codes have begun implementing these techniques, it still plays second fiddle to the advancement and progress of new technology in relation to ASME codes.
Do we comply with International Codes?
In most cases we currently comply with the relevant Codes. However in some instances it maybe an opinion or interpretation of the Code that varies from one individual to another. For example, ASME B31-1:2004 (Power Piping), already incorporated the recording of UT data during Ultrasonic Examination. According to ASME B31-1:2010/2012/2014 (Power Piping) section 136.4.6: The following criteria shall also be met when performing ultrasonic examinations:
The equipment used to perform the examination shall be capable of recording the UT data to facilitate the analysis by a third party and for the repeatability of subsequent examinations, should they be required. Where physical obstructions prevent the use of systems capable of recording the UT data, manual UT may be used with the approval of the owner.
Various customers and NDT personnel disregard or interpret the above statement differently. Some say Manual UT is permitted where others say TOFD, PAUT or other encoded methods must be applied to perform the encoding of data for review. Surely all parties need to agree that there can only be one conclusion to the above reference from ASME.
Do NDT customers have knowledge of new NDE methods?
Over the past few years it has become more and more evident that the South African market is not ready for change or possibly do not have the necessary know-how to implement these changes due to;
- People not being ready for change
- People being inadequately informed
- Internal processes blocking progress
- Outdated manufacturing Codes being used for new builds
- Cost factor, which should never out way quality or code compliance
The main concern from clients is that they believe new technology is more sensitive than basic NDT methods. Sensitivity is a questionable concept as Codes’ acceptance criteria guide compliance. Nonetheless one of the main advantages of new technology/methods is the probability of detecting discontinuities that is significant. The two main contributing factors are;
- Advance method capabilities
- Reducing the human factor that is considered experience in the NDE market.
There are additional factors that can influence the above statement and not only one NDE method can replace all other methods, as NDE methods supplement each other.
Phased Array Ultrasonic Encoded data scan of 1.6m on 40mm double bevel weld, Skew 90 and S270 at the same time, with sectorial setups to cover full range.
Phased Array Ultrasonic Encoded data scan of 1.6m, Skew 90 and S270 with A-Scan, S-Scan and B-Scan presentation