Friday, December 5, 2008

TM0497-Reaffirmation

I strongly disagree with your position that proposed changes discussed in my original correspondence do not constitute technical changes to TM0497.



If the procedure to assess the adequacy of cathodic protection using the 850 mV Current Applied Criterion (Method 1) is modified as proposed, the tone / intent of TM0497 changes. In light of the ongoing debate within NACE over the 850 mV Current Applied Criterion and the omission of this verbiage from the working draft of SP0169, these changes would be proclaimed by some as a clear message that NACE no longer considers these techniques to be valid.



I agree with the proposal from Mark Brogger – let the dust settle on SP0169 and then let’s work on TM-0497. Until then, reaffirm as written.



Additional instances of technical changes are as follows.



· Section 8.6.3 (b) has been changed, but this change is not highlighted in the document. This omission is reason enough to pull the ballot, as members are only asked to review changes. It also raises the question as to how many other changes were not highlighted in the document.



The proposed text is as follows:



8.6.3 Cathodic protection shall be judged adequate at the test site if: (a) The pipe-to-electrolyte potential measurement is negative 850 mV, or more negative, with respect to a CSE; and (b) The significance of voltage drops has been considered by applying the principles described in Paragraphs 8.6.1 (reference Paragraph 1.3 for exceptions).



The current text is as follows:



8.6.3 Cathodic protection shall be judged adequate at the test site if: (a) The pipe-to-electrolyte potential measurement is negative 850 mV, or more negative, with respect to a CSE; and (b) The significance of voltage drops has been considered by applying the principles described in Paragraphs 8.6.1 or 8.6.2.



Paragraph 8.6.2 discusses physical evidence of corrosion which relates to Item (d) Determining whether there is physical evidence of corrosion contained in the Note in Section 8.1 and also in SP0169. Deletion of both is a major technical change to TM0497.



The most widespread impact of this change would relate to the use of ILI data to consider the significance of voltage drops in accordance with 8.6.2 (c). Section 8.6.3 of TM0497 currently allows an operator to judge CP as adequate when current applied potentials are more negative than 850 mV and the significance of voltage drops has been considered by verification of ILI metal loss indications in accordance with 8.6.2(c). The proposed technical changes would require additional steps to consider the significance of voltage drops.



· The addition of “Ductile Iron Pipe” throughout the document.



This was never a simple omission (and thus an editorial change).



· The addition of “non-mandatory” to Appendices B and C



TM0497 is a test method which by definition provides description of techniques to determine whether a specific criterion has been complied with at a test site. As the methods described in Appendices B and C are contained within SP0169, I can’t understand how a technically correct procedure that has been recognized by NACE for years could now be reclassified as non-mandatory.



Again, I request that NACE immediately stop balloting on TM0497. We can discuss the path forward in Atlanta .



As you can see, this individual and his company are very concerned. For those who “signed up” to vote, they may want to consider the possibility of sending NACE a similar note. They also need to remember that the voting deadline is December 9, 2008.



Thanks

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