I couldn’t disagree more.
There are subtle but significant changes to TM0497 that weaken this document and constitute technical not editorial changes. NACE by-laws do not allow reaffirmation of standards if technical changes have been made.
I have requested that NACE suspend balloting and am awaiting a decision on this matter.
Some have requested that NACE postpone any changes to TM0497 until SP0169 is resolved. I support this effort, as the documents are complimentary. If TM0497 is to be reaffirmed, it should be done without changes in the same manner that SP0169 was reaffirmed.
Monday, December 8, 2008
Jim Chmilar comments
Richard, IF you do not agree with the “document as is” then I do not understand how you can vote to re-affirm?
I, myself believe the document needs to be improved TODAY and will be voting to not re-affirm it, because it needs additional information on measurement techniques and that does not depend on the state of SP0169.
The present draft version of the revisions to SP0169 (which is still in TG 360 committee draft stage as everyone knows) I believe does expand the criteria to include the new one that some are proposing, ie a potential valve of –850 mV without consideration or correction for IR drop. Please read all of section 6.2.3.1 which includes a listing of FOUR criteria in 6.2.3.1.1 to 6.2.3.1.4 and in particular 6.2.3.1.3 which is proposed to say “Criteria that have been shown to successfully control corrosion on piping systems can continue to be used on those piping systems” and 6.2.3.1.4 “Other criteria that can be demonstrated to achieve the corrosion control objectives of the operator.” Do these two criteria not allow all those who have been using 850 ON without any correction, or 300 Millivolt shift, or E log I to be in-compliance with the standard?? No need to answer this now, I am sure I will be hearing it when the SP0169 ballot comes out.
It is time for well wishes and hope everybody enjoys the coming Christmas Season.
Cheers
Jim Chmilar
I, myself believe the document needs to be improved TODAY and will be voting to not re-affirm it, because it needs additional information on measurement techniques and that does not depend on the state of SP0169.
The present draft version of the revisions to SP0169 (which is still in TG 360 committee draft stage as everyone knows) I believe does expand the criteria to include the new one that some are proposing, ie a potential valve of –850 mV without consideration or correction for IR drop. Please read all of section 6.2.3.1 which includes a listing of FOUR criteria in 6.2.3.1.1 to 6.2.3.1.4 and in particular 6.2.3.1.3 which is proposed to say “Criteria that have been shown to successfully control corrosion on piping systems can continue to be used on those piping systems” and 6.2.3.1.4 “Other criteria that can be demonstrated to achieve the corrosion control objectives of the operator.” Do these two criteria not allow all those who have been using 850 ON without any correction, or 300 Millivolt shift, or E log I to be in-compliance with the standard?? No need to answer this now, I am sure I will be hearing it when the SP0169 ballot comes out.
It is time for well wishes and hope everybody enjoys the coming Christmas Season.
Cheers
Jim Chmilar
Friday, December 5, 2008
TM0497 and SP0169 comments
It would seem that Jim Chmilar (TG-360 Chairman) intends to go out for ballot on the proposed/revised SP0169, before CORROSION 2009. There are many who do not believe in Jim’s version of what the “FOUR criteria” will allow. Those individuals believe the facts remain that the -850 mV “On” criterion has been removed, only the -850 mV “polarized” (actually instant-off) and the 100 mV polarization criteria remain in black and white, the regulators and other auditors will only want to deal with black and white, and other wording (and lack of wording) within the proposed/revised SP0169, as well as the yet-to-be-created proposed/revised TM0497, along with the most likely perceived ambiguity of the 3rd and 4th “criteria” in the proposed/revised SP0169, will almost certainly make it virtually impossible to ever utilize the -850 mV “On” criterion or any other alternative criterion. In other words, there are many who believe that only the -850 mV “polarized” and the 100 mV polarization criteria will end up being allowed.
Everyone does need to read the proposed/revised SP0169 very, very carefully. It is the belief of a number of individuals that everyone needs to formally insist the PRCI studies be completed, fully reviewed and incorporated, before the proposed/revised SP0169 goes to ballot. In addition, they believe that everyone should formally insist that the proposed/revised SP0169 and proposed/revised TM0497 go to ballot simultaneously, once both of these proposed revisions have been completed and appropriate changes/incorporations have been made to both based on the PRCI studies, as well as the consensus determinations of the industries most affected by these documents. These are both supposed to be consensus documents. It appears there are many who believe that objective is not truly being achieved.
Everyone does need to read the proposed/revised SP0169 very, very carefully. It is the belief of a number of individuals that everyone needs to formally insist the PRCI studies be completed, fully reviewed and incorporated, before the proposed/revised SP0169 goes to ballot. In addition, they believe that everyone should formally insist that the proposed/revised SP0169 and proposed/revised TM0497 go to ballot simultaneously, once both of these proposed revisions have been completed and appropriate changes/incorporations have been made to both based on the PRCI studies, as well as the consensus determinations of the industries most affected by these documents. These are both supposed to be consensus documents. It appears there are many who believe that objective is not truly being achieved.
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
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
Monday, November 3, 2008
Reminder to Ballot
Reminder to Ballot TMO497-2002:
Just a reminder that there is a ballot being sent out soon for the reaffirmation of the TMO497-2002, “Measurement Techniques Related to Criteria for Cathodic Protection on Underground or Submerged Metallic Piping Systems”. If you are interested in voting on this TG 020 document you must go to the NACE Website and follow the instructions as shown below. This will have to be done by November 7, 2008.
This will be good practice for the SP0169-2002 revision when it comes out for vote (maybe later this year). You must first join the STG 05 or 35 committee, then sign up to vote (as shown below). Then you wait for NACE to send the revised or reaffirmation document to vote on. Again, there is a need for voters that are not in the “user/consumer” classification, so if possible sign up in another group of voters.
STEP 1: Please review the abstract by going to http://web.nace.org/ where you will view the NACE login page. You will be prompted to enter your user name and password. Once you have done so and are logged in, click on the tab in the upper right-hand corner titled “Committees.” Then, click on “Online Balloting” (on the right-hand column on this page). The next page you will see offers you Action Items, Results and a Logout option.
------------------------------------------------------------------------
STEP 2: The next page you will see is TCC Balloting Home.
To join a voting list, click on the Action Items button. This will take you to a listing of open Ballots, Reballots, Review and Comments, and voting lists.
Under the heading “Join Ballot Voting Lists,” find the appropriate TG number and click “Respond.”
STEP 3: To review the abstract prior to responding, click on the document title link at the top of the page.
The abstract is in Adobe Acrobat PDF format, which means you will need Acrobat Reader software on your computer. If you do not have it, you may download it FREE from the Adobe Web site,
http://www.adobe.com/products/acrobat/readstep.html
STEP 4: After reviewing the abstract, you may join the voting list or decline to join by clicking the “Back” button at the top left corner of the screen and choosing “yes” or “no” on the TCC Ballot Response page. Please remember to indicate your classification.
Be sure to click on the SUBMIT RESPONSE button at the bottom of the page to submit your response.
After you have submitted your response, the TCC Response Confirmation page will appear stating that your response has been recorded. In addition, you will receive an e-mail confirmation of your response.
Contact Daniela with any questions or problems with getting signed up to vote on this document.
Daniela Matthews
Technical Liaison/Editor
NACE International
Toll Free 1-800 797 NACE (6223)
Direct Tel: (281) 228-6287
Fax: (281) 228-6387
email: daniela.matthews@nace.org
Thank you for help and attention to this matter. Please pass this information on to others!! Also we need comments on the SP0169.com blog site from all sides of the issue so we can all learn and challenge each other to be sure we get the best document possible!
Richard Norsworthy
Polyguard Products, Inc.
214-912-9072
Just a reminder that there is a ballot being sent out soon for the reaffirmation of the TMO497-2002, “Measurement Techniques Related to Criteria for Cathodic Protection on Underground or Submerged Metallic Piping Systems”. If you are interested in voting on this TG 020 document you must go to the NACE Website and follow the instructions as shown below. This will have to be done by November 7, 2008.
This will be good practice for the SP0169-2002 revision when it comes out for vote (maybe later this year). You must first join the STG 05 or 35 committee, then sign up to vote (as shown below). Then you wait for NACE to send the revised or reaffirmation document to vote on. Again, there is a need for voters that are not in the “user/consumer” classification, so if possible sign up in another group of voters.
STEP 1: Please review the abstract by going to http://web.nace.org/ where you will view the NACE login page. You will be prompted to enter your user name and password. Once you have done so and are logged in, click on the tab in the upper right-hand corner titled “Committees.” Then, click on “Online Balloting” (on the right-hand column on this page). The next page you will see offers you Action Items, Results and a Logout option.
------------------------------------------------------------------------
STEP 2: The next page you will see is TCC Balloting Home.
To join a voting list, click on the Action Items button. This will take you to a listing of open Ballots, Reballots, Review and Comments, and voting lists.
Under the heading “Join Ballot Voting Lists,” find the appropriate TG number and click “Respond.”
STEP 3: To review the abstract prior to responding, click on the document title link at the top of the page.
The abstract is in Adobe Acrobat PDF format, which means you will need Acrobat Reader software on your computer. If you do not have it, you may download it FREE from the Adobe Web site,
http://www.adobe.com/products/acrobat/readstep.html
STEP 4: After reviewing the abstract, you may join the voting list or decline to join by clicking the “Back” button at the top left corner of the screen and choosing “yes” or “no” on the TCC Ballot Response page. Please remember to indicate your classification.
Be sure to click on the SUBMIT RESPONSE button at the bottom of the page to submit your response.
After you have submitted your response, the TCC Response Confirmation page will appear stating that your response has been recorded. In addition, you will receive an e-mail confirmation of your response.
Contact Daniela with any questions or problems with getting signed up to vote on this document.
Daniela Matthews
Technical Liaison/Editor
NACE International
Toll Free 1-800 797 NACE (6223)
Direct Tel: (281) 228-6287
Fax: (281) 228-6387
email: daniela.matthews@nace.org
Thank you for help and attention to this matter. Please pass this information on to others!! Also we need comments on the SP0169.com blog site from all sides of the issue so we can all learn and challenge each other to be sure we get the best document possible!
Richard Norsworthy
Polyguard Products, Inc.
214-912-9072
Sunday, September 28, 2008
SP0169 updates and voting!
There are several points that must be questioned and answered before this document goes to ballot. At this time, I am not sure they will be answered before the first ballot is sent to the voters.
Those of you who want to vote on this document must pay attention to the new voting process for NACE document approval. Request a copy of the Technical Committee Publications Manual for all the details.
1. Be sure you are a member of the STG 35 group. This can be accomplished over the internet by going to the NACE International website and following the process for becoming a member of that STG group. You should then receive a copy of the ballot when sent out for vote. We are not sure when the draft will be sent out for vote, but some think it will be before the end of the year.
2. Once you receive the ballot, you must indicate on the ballot what group you are voting in. Some of these groups are:
a. End user
b. Consultant
c. Manufacturer/producer
d. Not sure of the other groups, but I think there are 7 categories
3. It is important to understand that the group you vote in is very critical. If more than 50% of the votes are from one group, NACE has to find more voters to fill in so that the majority voters are from more than one group. Of course the problem is that these (fill in) voters may not be knowledgeable of the document and the concerns that may exist. Since many votes will be from end-users, that group could easily be over 50% of the total votes. If you can legitimately be in another group, please sign up as so. Fro example, if you are an end user, but your job function is a consultant to the field techs, then I think you could sign up as a consultant.
4. If you do not vote on the first ballot you will not be able to vote on any further revisions or re-ballots of this particular version.
5. If you vote negative you must provide the committee with a perceived technical inaccuracy or omission or address points dealing with perceived ambiguity or lack of clarity.
The negative must be accompanied by a written comment with a technical explanation and justification statement. A suggested revision or an action that serves to resolve the negative should also be included. Without these the committee does not have to consider the negative.
As you can see it is rather complicated, but the first thing is to be sure you are member of the STG 35 group before the ballot comes out. Please let me know if I can help with any of these issues above.
DISCUSSION OF CTW MEETING – Draft Version #1e – July 2008
The import issues that come out this meeting from my perspective are:
There are several definitions the need to be corrected/changed.
Section #4 has some changes in wording that was worked on by the committee.
Section #5 addresses pipeline coatings and has not been completely revised. A representative from a rock shield company as well as myself have provide comments that have not been totally or correctly inserted at the time of this revision, but is being worked on.
Section # 6 has several issues, but here are the two big ones as far as I am concerned:
6.2.12. The two fundamental polarization criteria in this section have been proven empirically to reduce
the average corrosion rate of steel to less than 25 μm/y (1 mil/y) in soils and natural waters in the field
at ambient temperatures.3,4,5 Situations may exist in which a single criterion for evaluating the
effectiveness of CP may not be satisfactory for all conditions. A single criterion for evaluating the
effectiveness of CP may not be satisfactory for all locations along a structure.
The problem with this section is how does one apply this to a pipeline? How does one prove an average corrosion rate of less than 1 mil per year or less? Of course you can by installing coupons that measure the corrosion rate, but how does that really relate to a pipeline that travels through all kinds of terrains and situations with various coating conditions, etc? Coupons are great tools, but do not provide all the answers to these questions. We will continue to have external corrosion as long as we have coatings and other shielding effects along with interference (AC and DC).
This statement is used in the ISO document and perhaps some others, but the 25 µm/y (1 mil/y) is not a reasonable value for determining corrosion control on external surfaces of pipelines and most other structures. It may be a good definition for some purposes, but is not practical for pipelines.
6.2.3.1.1 A negative (cathodic) voltage of at least 850 mV as measured with respect to a
saturated copper/copper sulfate reference electrode. This potential may be either a direct
measurement of the polarized potential, or a current applied potential corrected for voltage
(IR) drops other than those across the structure/electrolyte boundary.
This criterion would no longer allow the owner to consider IR drop, but force you to only use a polarized potential, because the current applied “ON” potential must now be “corrected” for IR drops. How else can you correct it without using an instant off? The language does not leave much for consideration and use of other methods to prove what you are doing works. Of course, I am still waiting on an answer for the questions I have asked about why we do not have external corrosion on pipelines that use non-shielding coatings such as FBE and an “ON” -850 mV even with out considering IR drop. Most of us know why but this does not “fit” what we are being told must be done to protect our pipelines. Those of you who have this evidence must be putting it together to show the committee and prove the point that we do not need to have more stringent criterion. We need to continue to use the tools we have and better train our corrosion control employees how to recognize the problems that may need more work or investigation and apply the necessary control methods as needed.
Each section and part must be read and examined for accuracy. Remember the document presents procedures and practices for achieving effective control of external corrosion on buried or submerged metallic piping systems. In all NACE SPO’s the Forward says “This standard represents minimum requirements…”. The purposed version is far beyond minimum requirements. If passed as is it will represent the maximum requirements!
Please comment so we can all learn and work together to develop the best possible document that is practical and economical for companies around the world to use for effective external corrosion control on pipelines!
Those of you who want to vote on this document must pay attention to the new voting process for NACE document approval. Request a copy of the Technical Committee Publications Manual for all the details.
1. Be sure you are a member of the STG 35 group. This can be accomplished over the internet by going to the NACE International website and following the process for becoming a member of that STG group. You should then receive a copy of the ballot when sent out for vote. We are not sure when the draft will be sent out for vote, but some think it will be before the end of the year.
2. Once you receive the ballot, you must indicate on the ballot what group you are voting in. Some of these groups are:
a. End user
b. Consultant
c. Manufacturer/producer
d. Not sure of the other groups, but I think there are 7 categories
3. It is important to understand that the group you vote in is very critical. If more than 50% of the votes are from one group, NACE has to find more voters to fill in so that the majority voters are from more than one group. Of course the problem is that these (fill in) voters may not be knowledgeable of the document and the concerns that may exist. Since many votes will be from end-users, that group could easily be over 50% of the total votes. If you can legitimately be in another group, please sign up as so. Fro example, if you are an end user, but your job function is a consultant to the field techs, then I think you could sign up as a consultant.
4. If you do not vote on the first ballot you will not be able to vote on any further revisions or re-ballots of this particular version.
5. If you vote negative you must provide the committee with a perceived technical inaccuracy or omission or address points dealing with perceived ambiguity or lack of clarity.
The negative must be accompanied by a written comment with a technical explanation and justification statement. A suggested revision or an action that serves to resolve the negative should also be included. Without these the committee does not have to consider the negative.
As you can see it is rather complicated, but the first thing is to be sure you are member of the STG 35 group before the ballot comes out. Please let me know if I can help with any of these issues above.
DISCUSSION OF CTW MEETING – Draft Version #1e – July 2008
The import issues that come out this meeting from my perspective are:
There are several definitions the need to be corrected/changed.
Section #4 has some changes in wording that was worked on by the committee.
Section #5 addresses pipeline coatings and has not been completely revised. A representative from a rock shield company as well as myself have provide comments that have not been totally or correctly inserted at the time of this revision, but is being worked on.
Section # 6 has several issues, but here are the two big ones as far as I am concerned:
6.2.12. The two fundamental polarization criteria in this section have been proven empirically to reduce
the average corrosion rate of steel to less than 25 μm/y (1 mil/y) in soils and natural waters in the field
at ambient temperatures.3,4,5 Situations may exist in which a single criterion for evaluating the
effectiveness of CP may not be satisfactory for all conditions. A single criterion for evaluating the
effectiveness of CP may not be satisfactory for all locations along a structure.
The problem with this section is how does one apply this to a pipeline? How does one prove an average corrosion rate of less than 1 mil per year or less? Of course you can by installing coupons that measure the corrosion rate, but how does that really relate to a pipeline that travels through all kinds of terrains and situations with various coating conditions, etc? Coupons are great tools, but do not provide all the answers to these questions. We will continue to have external corrosion as long as we have coatings and other shielding effects along with interference (AC and DC).
This statement is used in the ISO document and perhaps some others, but the 25 µm/y (1 mil/y) is not a reasonable value for determining corrosion control on external surfaces of pipelines and most other structures. It may be a good definition for some purposes, but is not practical for pipelines.
6.2.3.1.1 A negative (cathodic) voltage of at least 850 mV as measured with respect to a
saturated copper/copper sulfate reference electrode. This potential may be either a direct
measurement of the polarized potential, or a current applied potential corrected for voltage
(IR) drops other than those across the structure/electrolyte boundary.
This criterion would no longer allow the owner to consider IR drop, but force you to only use a polarized potential, because the current applied “ON” potential must now be “corrected” for IR drops. How else can you correct it without using an instant off? The language does not leave much for consideration and use of other methods to prove what you are doing works. Of course, I am still waiting on an answer for the questions I have asked about why we do not have external corrosion on pipelines that use non-shielding coatings such as FBE and an “ON” -850 mV even with out considering IR drop. Most of us know why but this does not “fit” what we are being told must be done to protect our pipelines. Those of you who have this evidence must be putting it together to show the committee and prove the point that we do not need to have more stringent criterion. We need to continue to use the tools we have and better train our corrosion control employees how to recognize the problems that may need more work or investigation and apply the necessary control methods as needed.
Each section and part must be read and examined for accuracy. Remember the document presents procedures and practices for achieving effective control of external corrosion on buried or submerged metallic piping systems. In all NACE SPO’s the Forward says “This standard represents minimum requirements…”. The purposed version is far beyond minimum requirements. If passed as is it will represent the maximum requirements!
Please comment so we can all learn and work together to develop the best possible document that is practical and economical for companies around the world to use for effective external corrosion control on pipelines!
Sunday, September 7, 2008
Response to Ed Ondak and Roy Bash Comments
I first want to thank these two gentlemen for providing comments to the SP0169.com blog site. I encourage others to provide comments to help us all learn and grow in knowledge of the proper ways to control external corrosion on pipelines.
I do agree with Ed’s assessment of the section 3.2. We do not to write the SP0169 around regulations or regulators from what ever country or entity that may be regulating that industry. All NACE Standard should only be written to provide the industry with the most economically effective ways to prevent corrosion.
I do not agree with all of Ed’s assessment of the remainder of the document, but this is not the first time Ed and I have disagreed! Thanks, Ed.
Roy’s comments are also very good. I do agree with most of it; except for the comments on FBE not have a problem if CP is not available. With few exceptions, if the coating system’s adhesion is good, there cannot be corrosion, because the pipe is isolated from the electrolyte.
I have seen corrosion occur on an FBE coated pipe with no CP. This was not a case of interference problems, etc. Without CP the pipe can corrode at holidays just like any other coating system.
I agree with his comments of the water penetrating and being basically pure water, but there are other conditions that exist that allow corrosion to develop. When contaminants (various salts) remain on the pipe surface before the pipe is coated, the “pure water” that penetrates combines with the salts to form a conductive path for the CP current to provide protection to the pipe surface. Without CP this area would corrode by local cell action or by being anodic to other areas where disbondments and water penetration has occurred.
If Roy’s assumption is correct, the electrochemical reactions taking place would not cause the high pH values recorded under blistered and disbonded FBE. The high pH indicates the electrochemical process is the same as that taking place on bare steel areas exposed to the same electrolyte when adequate CP is available. Therefore the current is being allowed to protect the pipe surface it these areas of disbondment because the FBE is a non-shielding pipeline coating to CP current when disbondments occur and water penetrates between the coating and the pipe surface.
Cathodic protection can be effective if it can get to the pipe surface and is not shielded by coatings or other materials, etc. As long as the coating is adhered, the CP does not need to be effective, because there is no electrolyte to cause corrosion.
There have been many papers written on this topic that explain the processes of shielding by certain types of coating systems. FBE does not have this problem even when protected by using only the -850 mV criterion (without IR drop consideration). We must start understanding this process and putting 2 and 2 together to understand when we do not need to add more CP! We need to educate our engineers and others about shielding and the proper selection of coatings that will not shield CP current if and when disbondments occur.
DO NOT FORGET TO VOTE ON THE SP0169 REVISION. If you have not joined the STG 35 group, you may not be able to vote! If you do not vote the first time, you will not get the chance to vote on other revisions that may take place after the first ballot. I am not sure when it will be voted, but my guess is sometime this year or early 2009.
I do agree with Ed’s assessment of the section 3.2. We do not to write the SP0169 around regulations or regulators from what ever country or entity that may be regulating that industry. All NACE Standard should only be written to provide the industry with the most economically effective ways to prevent corrosion.
I do not agree with all of Ed’s assessment of the remainder of the document, but this is not the first time Ed and I have disagreed! Thanks, Ed.
Roy’s comments are also very good. I do agree with most of it; except for the comments on FBE not have a problem if CP is not available. With few exceptions, if the coating system’s adhesion is good, there cannot be corrosion, because the pipe is isolated from the electrolyte.
I have seen corrosion occur on an FBE coated pipe with no CP. This was not a case of interference problems, etc. Without CP the pipe can corrode at holidays just like any other coating system.
I agree with his comments of the water penetrating and being basically pure water, but there are other conditions that exist that allow corrosion to develop. When contaminants (various salts) remain on the pipe surface before the pipe is coated, the “pure water” that penetrates combines with the salts to form a conductive path for the CP current to provide protection to the pipe surface. Without CP this area would corrode by local cell action or by being anodic to other areas where disbondments and water penetration has occurred.
If Roy’s assumption is correct, the electrochemical reactions taking place would not cause the high pH values recorded under blistered and disbonded FBE. The high pH indicates the electrochemical process is the same as that taking place on bare steel areas exposed to the same electrolyte when adequate CP is available. Therefore the current is being allowed to protect the pipe surface it these areas of disbondment because the FBE is a non-shielding pipeline coating to CP current when disbondments occur and water penetrates between the coating and the pipe surface.
Cathodic protection can be effective if it can get to the pipe surface and is not shielded by coatings or other materials, etc. As long as the coating is adhered, the CP does not need to be effective, because there is no electrolyte to cause corrosion.
There have been many papers written on this topic that explain the processes of shielding by certain types of coating systems. FBE does not have this problem even when protected by using only the -850 mV criterion (without IR drop consideration). We must start understanding this process and putting 2 and 2 together to understand when we do not need to add more CP! We need to educate our engineers and others about shielding and the proper selection of coatings that will not shield CP current if and when disbondments occur.
DO NOT FORGET TO VOTE ON THE SP0169 REVISION. If you have not joined the STG 35 group, you may not be able to vote! If you do not vote the first time, you will not get the chance to vote on other revisions that may take place after the first ballot. I am not sure when it will be voted, but my guess is sometime this year or early 2009.
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