How did Nace let this mess get this far? Let's go back to basics. Since when is any Nace document 100% technically correct. Engineering is applied science. We take scientific principles we learn in a controlled environment, such as a lab, and apply them as best we can to the "real" world environment.
I believe we learned in the lab a long time ago, that all we need to minimize corrosion is a shift of 100 millivolts. Reading Potentials of -0.85 volts On or Off is simply a shortcut that has worked for us in 99% of the cases. In other words, the -0.85 Volt Off Criteria just has a bigger safety factor built in to it than the -0.85 Volt On Criteria, taking reading errors into account. It is economical and they have proven to work by digging up the pipes and examining them. From what I keep hearing, almost all of the corrosion or problems found have been due to Interference or Shielding under disbonded tape or coatings. This is not going to change. In fact by insisting on a -0.85 volt Off Criteria, there will be a type of "current wars" and incidences of Interference damage will only increase. There may be even more disbonding, and thus more corrosion due to Shielding. Insisting on a -0.85 Volt Off Criteria will lead to more problems; not less.
With the emergence of ECDA programs in more and more companies, we should be gathering the data from all of these Direct Assessments and comparing them to the CP readings that have been taken and the Criteria that was used. This is empirical data that is just as useful as theoretical data.
The Nace Committee working on this document has a cancer in it, in the form of obstinance; and it is time that Nace cuts it out and lets the body heal.
Thank you,
Tom Laundrie
Sr. Materials Engineering Specialist
NACE Cathodic Protection Specialist
Tuesday, August 24, 2010
Sunday, August 22, 2010
Comment from Joe Pikas
And Now the Rest of the Story – SP0169
NACE Central Area Conference, Corpus Christi, TX – 10-17-10
From the NACE Beginning
Let’s start with the history behind this legendary first standard produced by NACE in January, 1969. No let’s start a lot earlier in 1943 when NACE was formed in Houston, TX. Why 1943 in the middle of World War II and why Houston, TX. We could all agree that chemicals produced, pipelines serving the war effort, the Gulf environment above and below ground, operating temperatures, lack of industry standards, and did I mention the number of leaks and failures which brought this group together. “The perfect storm or the perfect venue; take your choice. Even during this massive war effort and the hiring of over 50,000 engineers, technicians and laborers to build atomic facilities to produce plutonium around the country; there were a number of smart guys who decided it was the time to start a corrosion society in this time of distress in our country. It was truly amazing that this occurred.
War is over and no standards?
What happened to NACE from 1943 to 1969? What happened to your “I Like Ike” political buttons as he fell asleep at the wheel and played golf in the early 50’s? NACE held annual conferences almost every year except during the early beginning due to the war effort. Where did all the smart guys go or do for a quarter of a century? Were we still celebrating the big ONE? What about the Korean conflict. We built the Little & Big Inch pipelines from the Gulf Coast to the Northeast only to be followed by many other others, by the way which are still in existence. Why 1969, we were still celebrating largest hippie gathering in Woodstock, NY? What more leaks and failures? Where were the standards? Were NACE and IKE on the same agenda? No wonder the flower power people took over.
Yes it took an act of Congress called the “Pipeline Safety Act” to get the wheels in motion. Was Congress finally doing their job? NACE is finally called to the rescue and to produce a standard by an organization called the Department of Transportation – Office of Pipeline Safety - Wow. How good can it get?
It’s Time to Start Your Engines
With a little nudge from DOT in preparing the Pipeline Safety Act for natural gas lines and certain companies like Transco and Tennessee Gas experiencing SCC failures back in the 60’s, NACE was encouraged to come up with a set of criteria for cathodic protection in a standard. A group of industry leaders including one of my old bosses Sal Bellasai were on the original committee to write this standard. Using their experiences and what worked in the field, they came up with a set of (field) criteria consisting of:
• -850 mV with the protective current applied (IR drop considered)
• 100 mV of polarization
• 300 mV shift
• Net protective current
• E-Log-I
Did these criteria complement each other? Yes. Did they oppose each other? Yes How can that be?
However, today, we have 3 criteria consisting of:
• -850 mV with the protective current applied (IR must be considered)
• -850 mV polarized
• 100 mV of polarization
Yes they also compliment and oppose each other just as the five criteria. But now we deleted 3 and added another -850 criterion (dueling criteria). How can that be? It goes back to the NACE Las Vegas Conference and what goes on in Vegas stays in Vegas. As you know the fight never ended back in the 60’s or the mid 90’s i.e. similar to the Korean Conflict. But somehow we were able to compromise and come up with solution after years of infighting. I cannot put this in words how this came about, but it resulted in some backdoor political compromises in the Frank Sinatra room. Just like Frank’s NY, NY; NACE makes it to Broadway with dueling -850s.
If each of these supposed criterion can oppose each other, then there must be other factors that are influencing the results. Yes, we all heard of shielding, disbondment, AC and DC interference, MIC, temperature, age, type and condition of coating, corrosive soil and electrolytes and other environmental factors. Then one must postulate that none of these criterion has an confidence level since most of the unknowns were not taken into consideration as shown in these limited number of examples.
1. A pipeline in NC exhibited a -1400 mV ON and -1100 mV OFF with several hundred millivolts of polarization yet continued to experience leaks. The coating was a single wrap of cold applied tape with minimal primer, experienced soil stress, experienced poor application and the pipe was pre-70 ERW. Yet the operator concluded and continued to state that the line was fully protected even after each of the leaks occurred.
a. Did the operator meet the criteria for cathodic protection, Yes? Was the line protected, No.?
2. A pipeline in AL exhibited a -1300 mV ON and -1050 mV OFF with several hundred millivolts of polarization, yet a catastrophic failure occurred 2 months after a close interval survey was taken. The coating was a coal tar enamel over the ditch application, experienced soil stress, never had CP for the first 5 to 6 years, was in a low spot with poor drainage and had a history of SCC. This operator continued to show that the line was fully protected even though there was a history of SCC and no CP for five years. Everyone thought that it was SCC; however, the failure was attributed to MIC.
a. Did the operator meet the criteria for cathodic protection, Yes? Was the line protected, No.?
3. A pipeline in North TX exhibited -1200 mV ON and -1000 mV OFF with several hundred millivolts of polarization, yet they were experiencing leaks in less than 10 years of operation. The coating was FBE, with hot applied sleeves, soil stress and poor drainage. The choice of sleeves was poor along with some application issues, but the weak link was wrinkling due to soil stresses.
a. Did the operator meet the criteria for cathodic protection, Yes? Was the line protected, No.?
4. A new pipeline in Gulf region of TX exhibited structure to electrolyte potentials of -1400 mV ON and -1100 mV OFF with several hundred millivolts of polarization, yet the operator was experiencing indications from the in-line-inspection results of pitting. The line and joints were coated with FBE and installation of the pipe was excellent. The coating was inspected in several areas and there was some minor pinholes, minor blisters with high pH and everything appeared to be in accordance to industry standards. Why the pitting? It was near an AC high voltage line. This line was in a rights of way with many other pipelines, but they were not experiencing this issue. The soil resistivity was in the order of 250 ohm cm and it only takes several volts of AC to start AC corrosion on a FBE coated line.
a. Did the operator meet the criteria for cathodic protection, Yes? Was the line protected, No.?
5. Conversely, let’s take a pipeline in South Texas where the structure to electrolyte potentials of -750 mV ON and -600 mV OFF. The coating was an asphalt enamel and was in poor condition and current requirements were extremely high. Everything about this line was as bad as it gets including some rock in the backfill. A direct examination revealed minor corrosion of less than 30 mils. Did I fail to mention the static potential was -250 mV and this line had several hundred millivolts of polarization, it was a dry environment and was 55 years old?
a. Did the operator meet the criteria for cathodic protection, Not in accordance to PHMSA? Was the line protected, Yes
b. It experienced less than 1 mil of pitting per year. Did it look and smell bad, Yes. However, the pipe had integrity, with little or no corrosion.
I can give hundreds more if not thousands of everyday examples of how pipelines operate with similar problems Criteria were designed to be guidelines not harden rigid rules. Why, because there are too many factors and unknowns that should be taken into consideration but are not. Basic tribal knowledge about the pipeline and its environment needs to be known. It is like driving your car in the rain with bald tires. We cannot use a criterion such as the dual -850s without knowing what is underneath the ground like the conditions of the tires. Does the pipe have any tread (coating) left. Has anyone kicked the tires or bent over to look in the ditch to see what is going on. There are companies who refuse to look deep into their systems and come to understand that shielding, MIC, interference; aged coating systems, corrosive soils, etc. are the issues and not the criteria. Then they make the bold statement, we are just going to move to -850 mV polarized criterion to make the material suppliers, contractors and others happy. What they don’t understand is that problem will not be solved. A lot of investment but little improvement in safety.
The SP0169 committee needs to recognize that these field guidelines called criteria are only as good as they fully understand the factors that really impact the integrity of the pipeline. If integrity issues are not part of the criteria, then how could we protect these lines? Any criterion will work as long as the tribal knowledge exists about the pipeline and its environment.
Recommendations:
• Get away from the simple single criterion values or numbers
• Set up system consisting of Confidence Factors (CF) or Risk Assessment (RA) Weighting
o A factor of 1.0 would be a verified laboratory test of a pipe specimen with a specific environment.
o Example of Factors that would influence readings – You the operator would set the weighting factors based on experience, environment, history for the specific pipe segment or plant setting:
Type, condition and age of coating
Isolated or grounded to power neutral or plant
When CP was first applied (within 1 year, 2 years, etc.)
How many lines in rights of way (1, 5, 25, 100, 150, etc.)
• Bonded, separation distance, stacked, etc.
Number bonds and current drain to foreign lines
Current Density to protect pipeline(s) for a specific coating, pipe diameter, length, etc.
AC/DC interference issues
Shorted to ground neutral, plant piping, casings etc.
Type of CP – Impressed, Galvanic, etc.
Environmental – resistivity, corrosivity, pH, temperature, MIC, etc.
Plant environments
• Grounding
• Mixed metals such as copper, galvanized and stainless
• Other nearby structures
o Conduit, Rebar, Tubing, Piping Runs, etc.
History of leaks or failures
Other – specific to this pipe segment or plant piping
• Get Out of Jail Free Card to offset Confidence or Risk Factors
o Pigging runs with little or no corrosion
o Other technologies such as guided wave with no corrosion
o Direct Examinations at areas of concern that validated structure to electrolyte readings
• Fully understand the integrity of the pipeline system and integrate this tribal knowledge with Corrosion Control Activities and
o History
o Construction and installation
Inspection records
Hydro test
o Coatings (Line pipe , Girth welds and fabrication piping)
Type
Condition
o CP levels
o Type of Pipe, WT, SMYS, Toughness, etc.
o Operations
Temperatures
Pigging Operations(Smart and Cleaning)
Patrolling Activities
Excavations
o Get out of the chair and get back in the ditch and really find out what is going on - involvement
o Let’s end the conflict and polarize the pipe not each other.
o No excuses, just old fashioned progress
PS
Did I fail to mention that DOT did not reference the original NACE RP0169 into the Pipeline Safety Regulations 49 CFR 192 Gas Regulations Appendix A back in 1970? ASME, API, ASTM and others were referenced but not NACE. However, DOT did create an Appendix D to Part 192 “Criteria for Cathodic Protection and Determination of Measurements”. The criteria were taken from then RP0169 along with the accepted measurement practices but no mention of NACE.
Does any know why?
If you were not at the NACE Central Area Panel Discussion in Corpus Christi, TX, the answer is that this was NACE’s first document after 26 years in existence with a little government prodding to get NACE to produce RP0169. However, it was not without controversy even at that time (IR drop is nothing new). Now we now understand this situation due to the many variables that are encountered in the right of way or the plant environment to achieve an indirect measurement to meet one of the criteria. In addition, API, ASME, ASTM was already established and had credibility, whereas NACE was finally taking their first baby step to establish standards. We have come a long way by the number of standards produced.
Note:
The above does not represent the view of any of my present or past employers (either operators or corrosion engineering companies), clients, or peers within the industry. These view points are based my 44 years of experience and findings on the many pipelines that I worked, studied and analyzed throughout the USA and the world.
Thank you,
Joe Pikas
Mobile - 832 758-0009
E-mail - jpikas@schiffassociates.com
NACE Central Area Conference, Corpus Christi, TX – 10-17-10
From the NACE Beginning
Let’s start with the history behind this legendary first standard produced by NACE in January, 1969. No let’s start a lot earlier in 1943 when NACE was formed in Houston, TX. Why 1943 in the middle of World War II and why Houston, TX. We could all agree that chemicals produced, pipelines serving the war effort, the Gulf environment above and below ground, operating temperatures, lack of industry standards, and did I mention the number of leaks and failures which brought this group together. “The perfect storm or the perfect venue; take your choice. Even during this massive war effort and the hiring of over 50,000 engineers, technicians and laborers to build atomic facilities to produce plutonium around the country; there were a number of smart guys who decided it was the time to start a corrosion society in this time of distress in our country. It was truly amazing that this occurred.
War is over and no standards?
What happened to NACE from 1943 to 1969? What happened to your “I Like Ike” political buttons as he fell asleep at the wheel and played golf in the early 50’s? NACE held annual conferences almost every year except during the early beginning due to the war effort. Where did all the smart guys go or do for a quarter of a century? Were we still celebrating the big ONE? What about the Korean conflict. We built the Little & Big Inch pipelines from the Gulf Coast to the Northeast only to be followed by many other others, by the way which are still in existence. Why 1969, we were still celebrating largest hippie gathering in Woodstock, NY? What more leaks and failures? Where were the standards? Were NACE and IKE on the same agenda? No wonder the flower power people took over.
Yes it took an act of Congress called the “Pipeline Safety Act” to get the wheels in motion. Was Congress finally doing their job? NACE is finally called to the rescue and to produce a standard by an organization called the Department of Transportation – Office of Pipeline Safety - Wow. How good can it get?
It’s Time to Start Your Engines
With a little nudge from DOT in preparing the Pipeline Safety Act for natural gas lines and certain companies like Transco and Tennessee Gas experiencing SCC failures back in the 60’s, NACE was encouraged to come up with a set of criteria for cathodic protection in a standard. A group of industry leaders including one of my old bosses Sal Bellasai were on the original committee to write this standard. Using their experiences and what worked in the field, they came up with a set of (field) criteria consisting of:
• -850 mV with the protective current applied (IR drop considered)
• 100 mV of polarization
• 300 mV shift
• Net protective current
• E-Log-I
Did these criteria complement each other? Yes. Did they oppose each other? Yes How can that be?
However, today, we have 3 criteria consisting of:
• -850 mV with the protective current applied (IR must be considered)
• -850 mV polarized
• 100 mV of polarization
Yes they also compliment and oppose each other just as the five criteria. But now we deleted 3 and added another -850 criterion (dueling criteria). How can that be? It goes back to the NACE Las Vegas Conference and what goes on in Vegas stays in Vegas. As you know the fight never ended back in the 60’s or the mid 90’s i.e. similar to the Korean Conflict. But somehow we were able to compromise and come up with solution after years of infighting. I cannot put this in words how this came about, but it resulted in some backdoor political compromises in the Frank Sinatra room. Just like Frank’s NY, NY; NACE makes it to Broadway with dueling -850s.
If each of these supposed criterion can oppose each other, then there must be other factors that are influencing the results. Yes, we all heard of shielding, disbondment, AC and DC interference, MIC, temperature, age, type and condition of coating, corrosive soil and electrolytes and other environmental factors. Then one must postulate that none of these criterion has an confidence level since most of the unknowns were not taken into consideration as shown in these limited number of examples.
1. A pipeline in NC exhibited a -1400 mV ON and -1100 mV OFF with several hundred millivolts of polarization yet continued to experience leaks. The coating was a single wrap of cold applied tape with minimal primer, experienced soil stress, experienced poor application and the pipe was pre-70 ERW. Yet the operator concluded and continued to state that the line was fully protected even after each of the leaks occurred.
a. Did the operator meet the criteria for cathodic protection, Yes? Was the line protected, No.?
2. A pipeline in AL exhibited a -1300 mV ON and -1050 mV OFF with several hundred millivolts of polarization, yet a catastrophic failure occurred 2 months after a close interval survey was taken. The coating was a coal tar enamel over the ditch application, experienced soil stress, never had CP for the first 5 to 6 years, was in a low spot with poor drainage and had a history of SCC. This operator continued to show that the line was fully protected even though there was a history of SCC and no CP for five years. Everyone thought that it was SCC; however, the failure was attributed to MIC.
a. Did the operator meet the criteria for cathodic protection, Yes? Was the line protected, No.?
3. A pipeline in North TX exhibited -1200 mV ON and -1000 mV OFF with several hundred millivolts of polarization, yet they were experiencing leaks in less than 10 years of operation. The coating was FBE, with hot applied sleeves, soil stress and poor drainage. The choice of sleeves was poor along with some application issues, but the weak link was wrinkling due to soil stresses.
a. Did the operator meet the criteria for cathodic protection, Yes? Was the line protected, No.?
4. A new pipeline in Gulf region of TX exhibited structure to electrolyte potentials of -1400 mV ON and -1100 mV OFF with several hundred millivolts of polarization, yet the operator was experiencing indications from the in-line-inspection results of pitting. The line and joints were coated with FBE and installation of the pipe was excellent. The coating was inspected in several areas and there was some minor pinholes, minor blisters with high pH and everything appeared to be in accordance to industry standards. Why the pitting? It was near an AC high voltage line. This line was in a rights of way with many other pipelines, but they were not experiencing this issue. The soil resistivity was in the order of 250 ohm cm and it only takes several volts of AC to start AC corrosion on a FBE coated line.
a. Did the operator meet the criteria for cathodic protection, Yes? Was the line protected, No.?
5. Conversely, let’s take a pipeline in South Texas where the structure to electrolyte potentials of -750 mV ON and -600 mV OFF. The coating was an asphalt enamel and was in poor condition and current requirements were extremely high. Everything about this line was as bad as it gets including some rock in the backfill. A direct examination revealed minor corrosion of less than 30 mils. Did I fail to mention the static potential was -250 mV and this line had several hundred millivolts of polarization, it was a dry environment and was 55 years old?
a. Did the operator meet the criteria for cathodic protection, Not in accordance to PHMSA? Was the line protected, Yes
b. It experienced less than 1 mil of pitting per year. Did it look and smell bad, Yes. However, the pipe had integrity, with little or no corrosion.
I can give hundreds more if not thousands of everyday examples of how pipelines operate with similar problems Criteria were designed to be guidelines not harden rigid rules. Why, because there are too many factors and unknowns that should be taken into consideration but are not. Basic tribal knowledge about the pipeline and its environment needs to be known. It is like driving your car in the rain with bald tires. We cannot use a criterion such as the dual -850s without knowing what is underneath the ground like the conditions of the tires. Does the pipe have any tread (coating) left. Has anyone kicked the tires or bent over to look in the ditch to see what is going on. There are companies who refuse to look deep into their systems and come to understand that shielding, MIC, interference; aged coating systems, corrosive soils, etc. are the issues and not the criteria. Then they make the bold statement, we are just going to move to -850 mV polarized criterion to make the material suppliers, contractors and others happy. What they don’t understand is that problem will not be solved. A lot of investment but little improvement in safety.
The SP0169 committee needs to recognize that these field guidelines called criteria are only as good as they fully understand the factors that really impact the integrity of the pipeline. If integrity issues are not part of the criteria, then how could we protect these lines? Any criterion will work as long as the tribal knowledge exists about the pipeline and its environment.
Recommendations:
• Get away from the simple single criterion values or numbers
• Set up system consisting of Confidence Factors (CF) or Risk Assessment (RA) Weighting
o A factor of 1.0 would be a verified laboratory test of a pipe specimen with a specific environment.
o Example of Factors that would influence readings – You the operator would set the weighting factors based on experience, environment, history for the specific pipe segment or plant setting:
Type, condition and age of coating
Isolated or grounded to power neutral or plant
When CP was first applied (within 1 year, 2 years, etc.)
How many lines in rights of way (1, 5, 25, 100, 150, etc.)
• Bonded, separation distance, stacked, etc.
Number bonds and current drain to foreign lines
Current Density to protect pipeline(s) for a specific coating, pipe diameter, length, etc.
AC/DC interference issues
Shorted to ground neutral, plant piping, casings etc.
Type of CP – Impressed, Galvanic, etc.
Environmental – resistivity, corrosivity, pH, temperature, MIC, etc.
Plant environments
• Grounding
• Mixed metals such as copper, galvanized and stainless
• Other nearby structures
o Conduit, Rebar, Tubing, Piping Runs, etc.
History of leaks or failures
Other – specific to this pipe segment or plant piping
• Get Out of Jail Free Card to offset Confidence or Risk Factors
o Pigging runs with little or no corrosion
o Other technologies such as guided wave with no corrosion
o Direct Examinations at areas of concern that validated structure to electrolyte readings
• Fully understand the integrity of the pipeline system and integrate this tribal knowledge with Corrosion Control Activities and
o History
o Construction and installation
Inspection records
Hydro test
o Coatings (Line pipe , Girth welds and fabrication piping)
Type
Condition
o CP levels
o Type of Pipe, WT, SMYS, Toughness, etc.
o Operations
Temperatures
Pigging Operations(Smart and Cleaning)
Patrolling Activities
Excavations
o Get out of the chair and get back in the ditch and really find out what is going on - involvement
o Let’s end the conflict and polarize the pipe not each other.
o No excuses, just old fashioned progress
PS
Did I fail to mention that DOT did not reference the original NACE RP0169 into the Pipeline Safety Regulations 49 CFR 192 Gas Regulations Appendix A back in 1970? ASME, API, ASTM and others were referenced but not NACE. However, DOT did create an Appendix D to Part 192 “Criteria for Cathodic Protection and Determination of Measurements”. The criteria were taken from then RP0169 along with the accepted measurement practices but no mention of NACE.
Does any know why?
If you were not at the NACE Central Area Panel Discussion in Corpus Christi, TX, the answer is that this was NACE’s first document after 26 years in existence with a little government prodding to get NACE to produce RP0169. However, it was not without controversy even at that time (IR drop is nothing new). Now we now understand this situation due to the many variables that are encountered in the right of way or the plant environment to achieve an indirect measurement to meet one of the criteria. In addition, API, ASME, ASTM was already established and had credibility, whereas NACE was finally taking their first baby step to establish standards. We have come a long way by the number of standards produced.
Note:
The above does not represent the view of any of my present or past employers (either operators or corrosion engineering companies), clients, or peers within the industry. These view points are based my 44 years of experience and findings on the many pipelines that I worked, studied and analyzed throughout the USA and the world.
Thank you,
Joe Pikas
Mobile - 832 758-0009
E-mail - jpikas@schiffassociates.com
Friday, August 20, 2010
Criteria in Crisis
CRITERIA IN CRISIS
From all that I can gather from the TG 360 committee, there is apparently a stalemate on the committee. This is very disappointing. From what I have heard, the problem is still the refusal of some on the committee to allow the use of the “ON” -850 mV criterion in the new document. They simply want to completely do away with this criterion, no matter what others have presented, proven or experienced.
The plan was to have another vote before CTW so the results could be discussed, etc. Now it appears this is not going to happen. Why? I am sure Jim will explain it to us and we will know what they are planning for the future.
I feel that there is a movement by some to stall the document in an attempt to force NACE to withdraw the SP0169 altogether and force the use of the ISO standard onto the world. The SP0169 is the first document every published by NACE and it will be an injustice to NACE and NACE membership to allow this to happen! This standard has been and is still used around the world today as the referenced industry standard in nearly all the others that are used. Do we as NACE want to allow this to go away or do we stand up and start the process in a direction to get it resolved?
What is amazing to me is the fact that the straw poll from this summer showed that almost 80% of those who voted in the poll would vote yes for the SP0169 if they would just leave the criterion as stated in the SP0169-2007, yet some on the committee are bound and determined to force their views or else. NACE documents are compromise documents that allow all who want to vote and comment to do so. I do not know of any standards that everyone totally agrees with.
The time has come for all who are interested in this document to take a stance! We have a choice:
1. Let it die and start using the ISO standard ( which I do not agree with and will explain later)
2. Force the committee to bring the document to vote with SP0169-2007 wording for criteria
3. Disband the TG 360 and start over
4. Replace some on the committee and move forward
#1
The problem with the ISO standards is that they are developed by a few folks and voted on and controlled by a select committee. Most of us would never get to voice an opinion or vote on these documents. NACE at least allows anyone to vote (if you sign up on the voting ballot list) and then to provide input and comments to defend your position. As with most things in life, this is not a perfect system, but I think offers a much better way of producing a document that is the best overall for our industry. When only a few select folks (who may have certain agendas) are allowed to produce these standards we are limited to their views and experiences only. If they are elitist in attitude, then the rest of us do not count.
#2
I think we need take the SP0169 – 2007 version of the criteria with most of the other changes and allow it to go to vote. Why did they even do the Straw Poll if they are not going to use the information! Folks have become accustom too this version of the criteria and are willing to move forward. There are those who insist that we no longer have an “ON” criterion in the SP0169, therefore they are right and everyone else is wrong.
#3
Maybe it is time to disband the committee that we now have and start over. Apparently, there are those who will not compromise and refuse to allow the document to go forward unless they get their way. I think most of us have been willing to listen, learn and in some case compromise to move the document forward. I am not the expert on laws of NACE committees, but something must be done to break this stalemate.
#4
Maybe it is time for Jim Chmilar to replace some on the committee to allow the document to go forward. Certainly these folks will vote negative if the document passes with the criteria as in the 2007 version, but if we can get the 66 2/3 vote, then we can at least move forward and address the negatives and try to get these resolved.
I also believe that some are hoping that we get tired and just give up. Please do not do this! This is too critical of a standard for us to allow to die or to not get the best document possible. Keep up the work and the commitment to providing the industry with a NACE document that will for all to us and provide efficient, effective and economical external corrosion control to our pipelines around the world!
I strongly encourage all to who are concerned as I am with this issue to please e-mail those at NACE and those on the committee with your thoughts and concerns. I am providing e-mails for the ones that you should contact. Some of these may not be on the committee any more, but this is the list that is posted on the NACE website. I will also include those at NACE that are important in the resolving this issue.
If you have any say in this process, no matter how you voted or even if you voted, please forward you comments and concerns to the committee and NACE! Pass this along to others in your company, who may need the information, want to comment or have clout to help this document along!
NACE contacts
Linda.Goldberg@nace.org
daniela.matthews@nace.org
Technology Coordinator
Ernest Klechka - eklechka@schiffassociates.com
STG 35 Chair
Steve Biagiotti, Jr. – sbiagiotti@structint.com
STG 35 Vice Chair
Roy Fultineer - rfultineer@eQt.com
If any of you know of others who need to be contacted please pass the information along to the rest of us. I will post this information on SP0169.com blog site for all to have access too.
There are a few of the TG 360 committee members that I do not have e-mail addresses for at this time. If any of you have contact e-mails for these folks please pass these along.
Name Title Member Since
Mark Brogger
Member 9/24/2007
James Chmilar jimchm@telus.net
Chair 10/17/2006
Robert Gummow bgummow@correng.com
Member 10/17/2006
Kimberly-Joy Harris kimberly.harris@enbridge.com
Member 10/18/2006
Gerald Holton Jr jerry@spc-net.com
Member 7/14/2008
Naeem Khan
Member 10/18/2006
David Kroon
Member 10/17/2006
Mark Lauber mlauber@lacledegas.com
Member 10/18/2006
Joseph Mataich joseph.mataich@dot.gov
Member 8/20/2007
Matt Matlas
Member 1/7/2010
David McQuilling David.McQuilling@sug.com
Member 1/7/2010
Richard Mielke, P.E. rmielke@nwpipe.com
Member 12/11/2007
Norman Moriber norm.moriber@mears.net
Member 10/17/2006
Richard Newell rnewell@wsscwater.com
Member 1/7/2010
Paul Nichols paul.r.nichols@shell.com
Member 10/17/2006
Frank Perry
Member 10/18/2006
Marcel Roche marcel.roche@orange.fr
Member 10/18/2006
Travis Sera tsera@semprautilities.com
Vice Chair 7/14/2008
Neil Thompson Neil.Thompson@dnv.com
Member 10/18/2006
Robert Vail
Member 10/17/2006
Brian Wyatt
Member 10/17/2006
This has become an urgent matter that needs to be addressed. Please post your thoughts on the blog site for all to view as well as e-mailing them to those on the committee and NACE. I urge all to do so. We need reasons and comments from all sides so we can arrive at the best overall document possible for our industry and that takes everyone’s input.
Thanks for the participation and time. DO NOT GIVE UP ON THIS PROCESS OR THE DOCUMENT. I hope the committee can move forward with our help and comments.
Richard Norsworthy
Polyguard Products, Inc.
From all that I can gather from the TG 360 committee, there is apparently a stalemate on the committee. This is very disappointing. From what I have heard, the problem is still the refusal of some on the committee to allow the use of the “ON” -850 mV criterion in the new document. They simply want to completely do away with this criterion, no matter what others have presented, proven or experienced.
The plan was to have another vote before CTW so the results could be discussed, etc. Now it appears this is not going to happen. Why? I am sure Jim will explain it to us and we will know what they are planning for the future.
I feel that there is a movement by some to stall the document in an attempt to force NACE to withdraw the SP0169 altogether and force the use of the ISO standard onto the world. The SP0169 is the first document every published by NACE and it will be an injustice to NACE and NACE membership to allow this to happen! This standard has been and is still used around the world today as the referenced industry standard in nearly all the others that are used. Do we as NACE want to allow this to go away or do we stand up and start the process in a direction to get it resolved?
What is amazing to me is the fact that the straw poll from this summer showed that almost 80% of those who voted in the poll would vote yes for the SP0169 if they would just leave the criterion as stated in the SP0169-2007, yet some on the committee are bound and determined to force their views or else. NACE documents are compromise documents that allow all who want to vote and comment to do so. I do not know of any standards that everyone totally agrees with.
The time has come for all who are interested in this document to take a stance! We have a choice:
1. Let it die and start using the ISO standard ( which I do not agree with and will explain later)
2. Force the committee to bring the document to vote with SP0169-2007 wording for criteria
3. Disband the TG 360 and start over
4. Replace some on the committee and move forward
#1
The problem with the ISO standards is that they are developed by a few folks and voted on and controlled by a select committee. Most of us would never get to voice an opinion or vote on these documents. NACE at least allows anyone to vote (if you sign up on the voting ballot list) and then to provide input and comments to defend your position. As with most things in life, this is not a perfect system, but I think offers a much better way of producing a document that is the best overall for our industry. When only a few select folks (who may have certain agendas) are allowed to produce these standards we are limited to their views and experiences only. If they are elitist in attitude, then the rest of us do not count.
#2
I think we need take the SP0169 – 2007 version of the criteria with most of the other changes and allow it to go to vote. Why did they even do the Straw Poll if they are not going to use the information! Folks have become accustom too this version of the criteria and are willing to move forward. There are those who insist that we no longer have an “ON” criterion in the SP0169, therefore they are right and everyone else is wrong.
#3
Maybe it is time to disband the committee that we now have and start over. Apparently, there are those who will not compromise and refuse to allow the document to go forward unless they get their way. I think most of us have been willing to listen, learn and in some case compromise to move the document forward. I am not the expert on laws of NACE committees, but something must be done to break this stalemate.
#4
Maybe it is time for Jim Chmilar to replace some on the committee to allow the document to go forward. Certainly these folks will vote negative if the document passes with the criteria as in the 2007 version, but if we can get the 66 2/3 vote, then we can at least move forward and address the negatives and try to get these resolved.
I also believe that some are hoping that we get tired and just give up. Please do not do this! This is too critical of a standard for us to allow to die or to not get the best document possible. Keep up the work and the commitment to providing the industry with a NACE document that will for all to us and provide efficient, effective and economical external corrosion control to our pipelines around the world!
I strongly encourage all to who are concerned as I am with this issue to please e-mail those at NACE and those on the committee with your thoughts and concerns. I am providing e-mails for the ones that you should contact. Some of these may not be on the committee any more, but this is the list that is posted on the NACE website. I will also include those at NACE that are important in the resolving this issue.
If you have any say in this process, no matter how you voted or even if you voted, please forward you comments and concerns to the committee and NACE! Pass this along to others in your company, who may need the information, want to comment or have clout to help this document along!
NACE contacts
Linda.Goldberg@nace.org
daniela.matthews@nace.org
Technology Coordinator
Ernest Klechka - eklechka@schiffassociates.com
STG 35 Chair
Steve Biagiotti, Jr. – sbiagiotti@structint.com
STG 35 Vice Chair
Roy Fultineer - rfultineer@eQt.com
If any of you know of others who need to be contacted please pass the information along to the rest of us. I will post this information on SP0169.com blog site for all to have access too.
There are a few of the TG 360 committee members that I do not have e-mail addresses for at this time. If any of you have contact e-mails for these folks please pass these along.
Name Title Member Since
Mark Brogger
Member 9/24/2007
James Chmilar jimchm@telus.net
Chair 10/17/2006
Robert Gummow bgummow@correng.com
Member 10/17/2006
Kimberly-Joy Harris kimberly.harris@enbridge.com
Member 10/18/2006
Gerald Holton Jr jerry@spc-net.com
Member 7/14/2008
Naeem Khan
Member 10/18/2006
David Kroon
Member 10/17/2006
Mark Lauber mlauber@lacledegas.com
Member 10/18/2006
Joseph Mataich joseph.mataich@dot.gov
Member 8/20/2007
Matt Matlas
Member 1/7/2010
David McQuilling David.McQuilling@sug.com
Member 1/7/2010
Richard Mielke, P.E. rmielke@nwpipe.com
Member 12/11/2007
Norman Moriber norm.moriber@mears.net
Member 10/17/2006
Richard Newell rnewell@wsscwater.com
Member 1/7/2010
Paul Nichols paul.r.nichols@shell.com
Member 10/17/2006
Frank Perry
Member 10/18/2006
Marcel Roche marcel.roche@orange.fr
Member 10/18/2006
Travis Sera tsera@semprautilities.com
Vice Chair 7/14/2008
Neil Thompson Neil.Thompson@dnv.com
Member 10/18/2006
Robert Vail
Member 10/17/2006
Brian Wyatt
Member 10/17/2006
This has become an urgent matter that needs to be addressed. Please post your thoughts on the blog site for all to view as well as e-mailing them to those on the committee and NACE. I urge all to do so. We need reasons and comments from all sides so we can arrive at the best overall document possible for our industry and that takes everyone’s input.
Thanks for the participation and time. DO NOT GIVE UP ON THIS PROCESS OR THE DOCUMENT. I hope the committee can move forward with our help and comments.
Richard Norsworthy
Polyguard Products, Inc.
Friday, July 23, 2010
TG 360 Straw Poll - Final Results
Original source of information was taken from the TG 360 Straw Poll.pdf file that can be found on the NACE International website (Proposed Revision to NACE SP0169 -2007). Under the “SUMMARY AND STATUS” heading, click on the bullet that says “Straw Poll for Section 6.”
Version 1 (CORROSION 2010)
A cathodic voltage of –850 mV or more negative across the structure to electrolyte boundary as measured with respect to a saturated copper/copper sulfate (CSE)reference electrode.
Version 1: What is the definition of Cathodic Voltage? This term does not appear in the SP0169 versions I have.
1. Fails to address IR drop.
Version 1 is from 1969, and is no longer valid for modern pipelines given our understanding of sources of measurement error with well coated pipeliens.
The remaining versions are more or less acceptable, but the wording requires the CP practitioner to 'correct' or 'consider' IR drops. I think this is a messier way to treat the criteria issue, as 'correction' implies some mathematical treatment, and 'consideration' is subject to interpretation.
While I agree Version 1 is technically correct and simple, I think more information is necessary such as in versions 4 and 5.
V1 –agree
Version 1 - cannot measure the potential reasonably as stated.
Version1, is inpractical.
(2) A negative polarized potential (see definition in Section 2) of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
COMMENTSVersion 2: Just the (2)
2. (1) Fails to address IR drop.
2. (2) Is an excellent criteria and scientifically defensible.
Version 2 is most agreeable to me because it allows virtually any empirically supported CP criterion to be used - and it places the burden of proof on the owner. This is consistent with CSA OCC-1.
I really like Ver.2. It is concise and well written. However I can see some pipelines owners/operators trying to abuse of criterion #1.Maybe NACE should emphasize that the owner shall used proper skilled and trained personnel in the CP area. And that the effectiveness of the current-applied potential criterion value selected will be owner responsibility only.
Should have been maybe added to the choices. I hate to be like the ones that vote yes but i want some changes made. Version #2 and #3 are not bad but could not vote for them as they are written. Thanks for going the extra mile to make it right. I would like to be alble to support it this time.
V2,3,4 – disagree
Version 2 - This is a start, but needs more information for ON. Why would the polarized not have to meet the corrosion control objectives of the owner?
Version 2 would be a nightmare to comply and enforce.
Version 2, To what detail the Empirical evidence needs to be supported? Sometimes a collection of all data, ie, leak survey, cp reads and history, all taken together will suffice. The devil is in the detail.
In version 2 the use of empirical evidence is too broad and therefore is not as helpful/informative as the other options.
(1) A negative (cathodic) voltage of at least 0.85 volt as measured between the structure surface and a saturated copper-copper sulfate half cell contacting the electrolyte. Determination of this voltage is to be made with the protective current applied. The Corrosion Engineer shall consider voltage (IR) drops other than those across the structure-electrolyte boundary for valid interpretation of the voltage measurement.
(2) A negative polarized potential (see definition in Section 2) of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
COMMENTS3. (1) Better but not scientifically defensible.
Version 3 would have been my top selection but I do not like that they have used the title "Corrosion Engineer". It should read "Responsible Corrosion Person". I do not like that they specified that a Corrosion Engineer should make the determination. I have met several Corrosion Engineers that I was amazed how little they understood about CP. Conversely, I have met many Corrosion Technicians that put these engineers to shame. I would vote yes on version 3 if the term "Corrosion Engineer" were replaced with "Responsible Corrosion Person" or something similar.
Since Corrosion Engineer is capitalized in the wording I presume that means NACE certified corrosion engineer.
Sentence 2 of version 3 contains the destination of a Corrosion Engineer as the one to consider voltage drop. Is that on purpose or are other professionals able to "consider" voltage drop?
I would vote for version 3 and strongly agree with it if the destination of "Corrosion Engineer" was changed to reflect field personnel. This seems to say that a person with even as high as a CP3 certification is not qualified to consider voltage drop and we must consult a corrosion engineer to get IR drop measurements.
Version 3 - Rephrase to take corrosion engineer out. There is no definition for this professional in many countries. A technician or any other qualified person can make this consideration. 3 and 4 with affirmative with comments.
V3 could be improved by deleting the second sentence and add "with IR drop considered" to the end of the first sentence.
Version 3 - Does not give guidance as to ways to consider IR drop.
(1) A negative (cathodic) voltage of at least 0.85 volt as measured between the structure surface and a saturated copper-copper sulfate half cell contacting the electrolyte. Determination of this voltage is to be made with the protective current applied. The Corrosion Engineer shall consider voltage (IR) drops other than those across the structure-electrolyte boundary for valid interpretation of the voltage measurement. NOTE: Consideration is understood to mean the application of sound engineering practice in determining the significance of voltage drops by methods such as:
• Measuring or calculating the voltage drop(s);
• Reviewing the historical performance of the CP system;
• Evaluating the physical and electrical characteristics of the pipe and its environment; and
• Determining whether or not there is physical evidence of corrosion.
(2) A negative polarized potential (see definition in Section 2) of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
Version 4 appears to leave Section 6 of the SP 0169 standard as is. I am in favor of this not only for the referenced criteria but for the section as a whole. Please see my detailed response for all the issues of concern within Section 6 provided during the last round of voting.
I like Version 4 but prefer using the .850 volt designation instead of 850 mV.
As no criteria can or should be an "absolute" for all situations, NACE should provide the best practical advice for an owner/operator to follow. I believe Version 4 accomplishes this and allows for good engineering practice to evaluate many highly variable environmental and field specific situations.
4. (1) Fails to define "considered" at all and thus is not scientifically defensible.
I feel that both the "CP On" and the "Polarized potential" should be in there own statements. I also like that in the Version 4 some guideance is given in "what must be considered for valid voltage drops"
Please consider the physical and electrical characteristics of the pipes coating in version #4.
In Version #4, bullet #3 the word pipe needs to be changed to structure.
In version 4 the integrity of application of the On criterion puts the emphasis squarely on the company's procedure. The proper aplication of a proper procedure is the key to any criterion, CP is no exception.
Version 4 I agree with the following reservation. With the current IMP regulations in the U.S. there is much useful data with regards to corrosion coming from metal loss smart pig runs. We should take advantage of this information when making decisions regarding "physical evidence of corrosion". I would suggest this data can be used to fulfill this caveat in Version 4.
Version 4 is a soft option for poorly designed systems. It is possible as it specifically draws the users attention to the issues required for consideration.
Version 4 - I would remove "Reviewing the historical performance of the CP system". This will be interpretated as a leak detection criteria that is really dangerous.
I would prefer to leave the criteria section the same as the current version - I believe that is V4.
Version 4 appears to leave Section 6 of the SP 0169 standard as is. I am in favor of this not only for the referenced criteria but for the section as a whole.
Version 4 - This version gives some guidance as to how to consider IR drop
Version 4 of the criteria represents no change from the existing standard SP0169 with regard to the -0.850 V criteria and I am in agreement with leaving Section 6 as currently written.
As stated above, cosideration of cathodic protection is already appropriately addressed in the existing standard. Version 4 appears to make no chage to the existing standard.
There should be a maybe. With some enhancement I could vote yes for version 2. Version 4 I could compromise and vote yes for it. Thanks for asking!
Version 4 appears to provide the broadest range of options, and provides detail regarding the interpretation of the work consider. It also recognizes the application of the polarized criteria.
Versions 4 and 5 are the most informative in my opinon.
Version 4 best represents my view.
A cathodic voltage of –850 mV or more negative as measured with respect to a saturated copper/copper sulfate (CSE) reference electrode. This potential may be either a direct measurement of the instant-off potential, or a current-applied potential. Interpretation of a current-applied measurement requires correction for voltage drops in the earth or metallic paths.
NOTE: Correction is understood to mean the application of sound engineering practice in the determination of the magnitude and significance of voltage drops by methods such as:
• Measuring or calculating the voltage drop(s); or
• Determining whether or not there is physical evidence of corrosion.
5. First bullet: A scientific method of "calculating the voltage drop(s)" must be provided. Second bullet: There is no practical method of "Determining whether or not there is physical evidence of corrosion".
Version 5 would be better if instant-off was changed to polarized.
To much can be miss understood with the On and Off criteria in version 5. Regulators can go off in a tangent and require the Off potential.
Version 5 would be "neutral" & "yes" if "correction" was changed to "consideration".
We've got to stay with the word "considered" and stay away from "corrected". No way on Version 5.
Version 5 - Correction means off potential. There is no other way. "Determining whether or not there is physical evidence of corrosion" does not mean correction. Ohmic drop can be big, but soil corrosion rate is negligible.
V5 - neutral
Version 5 - basically the same as the polarized potential since you must "correct" for IR drop.
I favour somewhere between versions 4 and 5 such as version 5 with the 4 points itemized in version 4. The other 3 versions can only be valid if they have been validated at leats once using my modification of version 5 suggested above. That being said then version 5 is the most acceptable. In version 5 we do not feel we can support the term corrected at this time.
This doesnt seem like a fair poll. Did everyone on the TG agree with this, or just a few individuals?
need to omit having two criteria that both say 850 is the magic number but each 850 is defined differental, this can not be correct. Just state control is achieved at some degree of polarization depending on environmental conditions... (period)
I agree with all so interpret the rankings as 1 = least prefer to 5 = most prefer
IN GENERAL: there is not even one of the proposals strongly asking for the negative polarized potentials as only possibility (of course including also the 100 mV of cathodic polarization). This will be the criterion that I will vote for. Meanwhile we are giving the chance for interpretations of the measured values beyond the simple measurement, people can use these
interpretations to their convinience.
Can only do the first part, not the second part.
Voltage applied - can do.
Voltage off - no can do
All of the above criteria are meaningless unless the temperature of the reference electrode is specified.
Guidance for correction of the reference electrode potential given elsewhere in previous drafts gave method for this correction but did not give a temperature that the potentials should be corrected to.
Why not simply define "polarzed potential" as:
Polarized Potential = A pipe-to-soil potential (excluding all IR or other possible sources of error in the measurement) more negative than -850 mV CSE.
Then the criteria becomes:
Protection is determined by demonstrating a polarized potential of more negative than -850 mV CSE.
Note that I used one choice for each ranking and didn't repeat any of them.
It seems to me that potential readings are essentially a conservative way of being reasonably confident about the structural integrity of a pipe without seeing it or otherwise testing it. It seems there should be an alternative such as sufficient visual inspection or testing that adequately proves there is no damage of sufficient size to compromise the structural integrity of the pipe before the next inspection or test. This alternative would say that any level of cathodic protection, or even leaving off cp, is adequate since service life can be safely
anticipated.
Over the years, on pipeline systems that I maintain, I have come to find that as long as there are no foreign cathodically protected structures in the near vicinity that the negative 850 millivolt "on potential" will result in a greater than 100 millivolt shift in cathodic protection current. This has been substantiated with many miles of close interval survey data. I have maintained lines in several of the western states and this has been true on all that I have been in charge of. Foreign cathodically protected structures nearby to my structures have been a concern due to interferance and groundbed gradients.
I strongly disagree with all statements as presented and believe the move should be made completely away from voltage potential measurements for "protective criteria". We all understand that -850 mV does not work in all cases and in fact we should be further focusing on applied current to prove that in fact we are protecting a structure. In the past voltage potential was an easy available way to prvide some proof that current might flow to the structure (emphasis on the might) and was in no way meant to be what it is today. Methods of measuring current (not voltage) must be included in criteria today. Once it can be demonstrated that current is in fact flowing to the structure, then a voltage potential measurement can be useful in montioring the situation. A voltage potential by itself can mean nothing at times without knowing about the current flow.
I'm not sure why the negative comments aren't being looked at. This seems like a way to push through a change that isn't wanted. Can you please add teh poll question: Do you feel additional requirements to SP0169 are being pushed by people who would profit from the changes? Do you feel this is right?
Please see my detailed response provided in the last round of voting that details the rationale for the negative response. I would vote affirmatively only if all the issues identified in my negative response were addressed appropriately. Version 4 of the criteria represents no change from the existing standard approved SP0169 standard with regard to the -0.850 V criteria and I am in agreement with leaving Section 6 as is.
Any criteria that is published must be based in the scientific method. Otherwise, failures will result and damage infrastructure, lives, and the reputation of NACE and our engineers.
Alterntaly why not adopt criteria given in ISO 15589-1 that is
(a) Protection potential applies at the metal/electrolyte interface, i.e. a potential which is free from the IR drop in the corrosive environment (IR-free potential)
(b) Prtoection potential is dependent on soil type / resistivity, as follows:
anerobic conditions or < -950 mV high resisitivty soils (10 to 100 kohm.cm) -750 mV very high resisitivty soils (> 100 kohm.cm) -650 mV
As you mentioned the wording of the above can be changed. So actually an affirmative volt depends on the wording. The no's on this questions is a maybe depending on the wording, but you did not give that choise.
My company, one of the largest energy transmission companies in North America, will continue to use the -850 polarized OFF potential regardless of how weakened the standard becomes through the lobbying efforts of certain individuals.
In canada, we are entitled to use alternate criteria where we can demonstrate the objective of corrosion prevention has been achieved (but we need to support it empirically).
To reiterate my position, voltage potential by itself should not be allowed as a criteria. One must prove out the current flow in the system and that it is in fact enough current to the steel to be cathodically protective. Until that occurs, voltage potential is only a hopeful way of measuring what might occur. I know some may think this is radical but today's technology (along with older technology) allows one to measure direct current on a pipeline (both through direct measurements and measurements from above the ground without touching the pipeline). Until NACE members recognize the failure of a voltage only criteria, we will not make progress in our world of cathodic protection. We must start measuring current again to prove if a structure is cathodically protection.
The format and content of this poll is a waste of time. If SurveyMonkey and hence NACE thinks that this survey "Surveys Made Simple" then this is all monkey business and belongs in a zoo. And, we need to rethink about NACE leadership qualifications and where it is taking us. This poll is worthless.
It is my opinion that the existing version of Section 6 of SP 0169 adequately addresses cathodic protection measurement and interpretation.
While I am not sure that we need to eliminate current applied measurements, I think the format presented actually would encourage that.
Version 1 (CORROSION 2010)
A cathodic voltage of –850 mV or more negative across the structure to electrolyte boundary as measured with respect to a saturated copper/copper sulfate (CSE)reference electrode.
COMMENTS
Version 1 is the only technically corrrect version of the 850 criterion. Versions 2,3 and 4 do not eliminate the ambiguity between current-applied and polarized potential critera that the committee was charged to accomplish. Version 5 is better than versions 2, 3 and 4 but it is still technically incorrect because you can not correct for voltage drops by "Determining whether or not there is physical evidence of corrosion".Version 1: What is the definition of Cathodic Voltage? This term does not appear in the SP0169 versions I have.
1. Fails to address IR drop.
Version 1 is from 1969, and is no longer valid for modern pipelines given our understanding of sources of measurement error with well coated pipeliens.
The remaining versions are more or less acceptable, but the wording requires the CP practitioner to 'correct' or 'consider' IR drops. I think this is a messier way to treat the criteria issue, as 'correction' implies some mathematical treatment, and 'consideration' is subject to interpretation.
While I agree Version 1 is technically correct and simple, I think more information is necessary such as in versions 4 and 5.
V1 –agree
Version 1 - cannot measure the potential reasonably as stated.
Version1, is inpractical.
Version 2 (Committee E-mail Suggestion)
(1) A structure-to-electrolyte potential measured with the cathodic protection current applied. The current-applied potential criterion value shall be established by the owner through sound engineering practice and supported by empirical evidence that demonstrates the corrosion control objective of the owner is achieved.(2) A negative polarized potential (see definition in Section 2) of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
COMMENTS
2. (1) Fails to address IR drop.
2. (2) Is an excellent criteria and scientifically defensible.
Version 2 is most agreeable to me because it allows virtually any empirically supported CP criterion to be used - and it places the burden of proof on the owner. This is consistent with CSA OCC-1.
I really like Ver.2. It is concise and well written. However I can see some pipelines owners/operators trying to abuse of criterion #1.Maybe NACE should emphasize that the owner shall used proper skilled and trained personnel in the CP area. And that the effectiveness of the current-applied potential criterion value selected will be owner responsibility only.
Should have been maybe added to the choices. I hate to be like the ones that vote yes but i want some changes made. Version #2 and #3 are not bad but could not vote for them as they are written. Thanks for going the extra mile to make it right. I would like to be alble to support it this time.
V2,3,4 – disagree
Version 2 - This is a start, but needs more information for ON. Why would the polarized not have to meet the corrosion control objectives of the owner?
Version 2 would be a nightmare to comply and enforce.
Version 2, To what detail the Empirical evidence needs to be supported? Sometimes a collection of all data, ie, leak survey, cp reads and history, all taken together will suffice. The devil is in the detail.
In version 2 the use of empirical evidence is too broad and therefore is not as helpful/informative as the other options.
Version 3 (RP0169-1969)
(1) A negative (cathodic) voltage of at least 0.85 volt as measured between the structure surface and a saturated copper-copper sulfate half cell contacting the electrolyte. Determination of this voltage is to be made with the protective current applied. The Corrosion Engineer shall consider voltage (IR) drops other than those across the structure-electrolyte boundary for valid interpretation of the voltage measurement.
(2) A negative polarized potential (see definition in Section 2) of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
COMMENTS
Version 3 would have been my top selection but I do not like that they have used the title "Corrosion Engineer". It should read "Responsible Corrosion Person". I do not like that they specified that a Corrosion Engineer should make the determination. I have met several Corrosion Engineers that I was amazed how little they understood about CP. Conversely, I have met many Corrosion Technicians that put these engineers to shame. I would vote yes on version 3 if the term "Corrosion Engineer" were replaced with "Responsible Corrosion Person" or something similar.
Since Corrosion Engineer is capitalized in the wording I presume that means NACE certified corrosion engineer.
Sentence 2 of version 3 contains the destination of a Corrosion Engineer as the one to consider voltage drop. Is that on purpose or are other professionals able to "consider" voltage drop?
I would vote for version 3 and strongly agree with it if the destination of "Corrosion Engineer" was changed to reflect field personnel. This seems to say that a person with even as high as a CP3 certification is not qualified to consider voltage drop and we must consult a corrosion engineer to get IR drop measurements.
Version 3 - Rephrase to take corrosion engineer out. There is no definition for this professional in many countries. A technician or any other qualified person can make this consideration. 3 and 4 with affirmative with comments.
V3 could be improved by deleting the second sentence and add "with IR drop considered" to the end of the first sentence.
Version 3 - Does not give guidance as to ways to consider IR drop.
Version 4 (SP0169-2007)
(1) A negative (cathodic) voltage of at least 0.85 volt as measured between the structure surface and a saturated copper-copper sulfate half cell contacting the electrolyte. Determination of this voltage is to be made with the protective current applied. The Corrosion Engineer shall consider voltage (IR) drops other than those across the structure-electrolyte boundary for valid interpretation of the voltage measurement. NOTE: Consideration is understood to mean the application of sound engineering practice in determining the significance of voltage drops by methods such as:
• Measuring or calculating the voltage drop(s);
• Reviewing the historical performance of the CP system;
• Evaluating the physical and electrical characteristics of the pipe and its environment; and
• Determining whether or not there is physical evidence of corrosion.
(2) A negative polarized potential (see definition in Section 2) of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
COMMENTS
Version 4: Just the (2)Version 4 appears to leave Section 6 of the SP 0169 standard as is. I am in favor of this not only for the referenced criteria but for the section as a whole. Please see my detailed response for all the issues of concern within Section 6 provided during the last round of voting.
I like Version 4 but prefer using the .850 volt designation instead of 850 mV.
As no criteria can or should be an "absolute" for all situations, NACE should provide the best practical advice for an owner/operator to follow. I believe Version 4 accomplishes this and allows for good engineering practice to evaluate many highly variable environmental and field specific situations.
4. (1) Fails to define "considered" at all and thus is not scientifically defensible.
I feel that both the "CP On" and the "Polarized potential" should be in there own statements. I also like that in the Version 4 some guideance is given in "what must be considered for valid voltage drops"
Please consider the physical and electrical characteristics of the pipes coating in version #4.
In Version #4, bullet #3 the word pipe needs to be changed to structure.
In version 4 the integrity of application of the On criterion puts the emphasis squarely on the company's procedure. The proper aplication of a proper procedure is the key to any criterion, CP is no exception.
Version 4 I agree with the following reservation. With the current IMP regulations in the U.S. there is much useful data with regards to corrosion coming from metal loss smart pig runs. We should take advantage of this information when making decisions regarding "physical evidence of corrosion". I would suggest this data can be used to fulfill this caveat in Version 4.
Version 4 is a soft option for poorly designed systems. It is possible as it specifically draws the users attention to the issues required for consideration.
Version 4 - I would remove "Reviewing the historical performance of the CP system". This will be interpretated as a leak detection criteria that is really dangerous.
I would prefer to leave the criteria section the same as the current version - I believe that is V4.
Version 4 appears to leave Section 6 of the SP 0169 standard as is. I am in favor of this not only for the referenced criteria but for the section as a whole.
Version 4 - This version gives some guidance as to how to consider IR drop
Version 4 of the criteria represents no change from the existing standard SP0169 with regard to the -0.850 V criteria and I am in agreement with leaving Section 6 as currently written.
As stated above, cosideration of cathodic protection is already appropriately addressed in the existing standard. Version 4 appears to make no chage to the existing standard.
There should be a maybe. With some enhancement I could vote yes for version 2. Version 4 I could compromise and vote yes for it. Thanks for asking!
Version 4 appears to provide the broadest range of options, and provides detail regarding the interpretation of the work consider. It also recognizes the application of the polarized criteria.
Versions 4 and 5 are the most informative in my opinon.
Version 4 best represents my view.
Version 5 (current draft)
A cathodic voltage of –850 mV or more negative as measured with respect to a saturated copper/copper sulfate (CSE) reference electrode. This potential may be either a direct measurement of the instant-off potential, or a current-applied potential. Interpretation of a current-applied measurement requires correction for voltage drops in the earth or metallic paths.
NOTE: Correction is understood to mean the application of sound engineering practice in the determination of the magnitude and significance of voltage drops by methods such as:
• Measuring or calculating the voltage drop(s); or
• Determining whether or not there is physical evidence of corrosion.
COMMENTS
Version 5: What is the definition of Cathodic Voltage?5. First bullet: A scientific method of "calculating the voltage drop(s)" must be provided. Second bullet: There is no practical method of "Determining whether or not there is physical evidence of corrosion".
Version 5 would be better if instant-off was changed to polarized.
To much can be miss understood with the On and Off criteria in version 5. Regulators can go off in a tangent and require the Off potential.
Version 5 would be "neutral" & "yes" if "correction" was changed to "consideration".
We've got to stay with the word "considered" and stay away from "corrected". No way on Version 5.
Version 5 - Correction means off potential. There is no other way. "Determining whether or not there is physical evidence of corrosion" does not mean correction. Ohmic drop can be big, but soil corrosion rate is negligible.
V5 - neutral
Version 5 - basically the same as the polarized potential since you must "correct" for IR drop.
I favour somewhere between versions 4 and 5 such as version 5 with the 4 points itemized in version 4. The other 3 versions can only be valid if they have been validated at leats once using my modification of version 5 suggested above. That being said then version 5 is the most acceptable. In version 5 we do not feel we can support the term corrected at this time.
Other Comments (General):
Part of your problem is wording. How many ways can you basically say the same thing. It seems you are just word-smithing to cover all the bases. Say it one way and let that be it - don't confuse people. For instance the first sentence in item (1) for each version. Look at the different ways you say the same thing.This doesnt seem like a fair poll. Did everyone on the TG agree with this, or just a few individuals?
need to omit having two criteria that both say 850 is the magic number but each 850 is defined differental, this can not be correct. Just state control is achieved at some degree of polarization depending on environmental conditions... (period)
I agree with all so interpret the rankings as 1 = least prefer to 5 = most prefer
IN GENERAL: there is not even one of the proposals strongly asking for the negative polarized potentials as only possibility (of course including also the 100 mV of cathodic polarization). This will be the criterion that I will vote for. Meanwhile we are giving the chance for interpretations of the measured values beyond the simple measurement, people can use these
interpretations to their convinience.
Can only do the first part, not the second part.
Voltage applied - can do.
Voltage off - no can do
All of the above criteria are meaningless unless the temperature of the reference electrode is specified.
Guidance for correction of the reference electrode potential given elsewhere in previous drafts gave method for this correction but did not give a temperature that the potentials should be corrected to.
Why not simply define "polarzed potential" as:
Polarized Potential = A pipe-to-soil potential (excluding all IR or other possible sources of error in the measurement) more negative than -850 mV CSE.
Then the criteria becomes:
Protection is determined by demonstrating a polarized potential of more negative than -850 mV CSE.
Note that I used one choice for each ranking and didn't repeat any of them.
It seems to me that potential readings are essentially a conservative way of being reasonably confident about the structural integrity of a pipe without seeing it or otherwise testing it. It seems there should be an alternative such as sufficient visual inspection or testing that adequately proves there is no damage of sufficient size to compromise the structural integrity of the pipe before the next inspection or test. This alternative would say that any level of cathodic protection, or even leaving off cp, is adequate since service life can be safely
anticipated.
Over the years, on pipeline systems that I maintain, I have come to find that as long as there are no foreign cathodically protected structures in the near vicinity that the negative 850 millivolt "on potential" will result in a greater than 100 millivolt shift in cathodic protection current. This has been substantiated with many miles of close interval survey data. I have maintained lines in several of the western states and this has been true on all that I have been in charge of. Foreign cathodically protected structures nearby to my structures have been a concern due to interferance and groundbed gradients.
I strongly disagree with all statements as presented and believe the move should be made completely away from voltage potential measurements for "protective criteria". We all understand that -850 mV does not work in all cases and in fact we should be further focusing on applied current to prove that in fact we are protecting a structure. In the past voltage potential was an easy available way to prvide some proof that current might flow to the structure (emphasis on the might) and was in no way meant to be what it is today. Methods of measuring current (not voltage) must be included in criteria today. Once it can be demonstrated that current is in fact flowing to the structure, then a voltage potential measurement can be useful in montioring the situation. A voltage potential by itself can mean nothing at times without knowing about the current flow.
I'm not sure why the negative comments aren't being looked at. This seems like a way to push through a change that isn't wanted. Can you please add teh poll question: Do you feel additional requirements to SP0169 are being pushed by people who would profit from the changes? Do you feel this is right?
Please see my detailed response provided in the last round of voting that details the rationale for the negative response. I would vote affirmatively only if all the issues identified in my negative response were addressed appropriately. Version 4 of the criteria represents no change from the existing standard approved SP0169 standard with regard to the -0.850 V criteria and I am in agreement with leaving Section 6 as is.
Any criteria that is published must be based in the scientific method. Otherwise, failures will result and damage infrastructure, lives, and the reputation of NACE and our engineers.
Alterntaly why not adopt criteria given in ISO 15589-1 that is
(a) Protection potential applies at the metal/electrolyte interface, i.e. a potential which is free from the IR drop in the corrosive environment (IR-free potential)
(b) Prtoection potential is dependent on soil type / resistivity, as follows:
anerobic conditions or < -950 mV high resisitivty soils (10 to 100 kohm.cm) -750 mV very high resisitivty soils (> 100 kohm.cm) -650 mV
As you mentioned the wording of the above can be changed. So actually an affirmative volt depends on the wording. The no's on this questions is a maybe depending on the wording, but you did not give that choise.
My company, one of the largest energy transmission companies in North America, will continue to use the -850 polarized OFF potential regardless of how weakened the standard becomes through the lobbying efforts of certain individuals.
In canada, we are entitled to use alternate criteria where we can demonstrate the objective of corrosion prevention has been achieved (but we need to support it empirically).
To reiterate my position, voltage potential by itself should not be allowed as a criteria. One must prove out the current flow in the system and that it is in fact enough current to the steel to be cathodically protective. Until that occurs, voltage potential is only a hopeful way of measuring what might occur. I know some may think this is radical but today's technology (along with older technology) allows one to measure direct current on a pipeline (both through direct measurements and measurements from above the ground without touching the pipeline). Until NACE members recognize the failure of a voltage only criteria, we will not make progress in our world of cathodic protection. We must start measuring current again to prove if a structure is cathodically protection.
The format and content of this poll is a waste of time. If SurveyMonkey and hence NACE thinks that this survey "Surveys Made Simple" then this is all monkey business and belongs in a zoo. And, we need to rethink about NACE leadership qualifications and where it is taking us. This poll is worthless.
It is my opinion that the existing version of Section 6 of SP 0169 adequately addresses cathodic protection measurement and interpretation.
While I am not sure that we need to eliminate current applied measurements, I think the format presented actually would encourage that.
Wednesday, July 7, 2010
Update to SP0169 Revision July 7, 2010
Another vote likely in August 2010!!
Another version of the SP0169 is in the works. I think everyone is hopeful for resolution of the key issues on this document so we can move forward. The committee is working to address many of the negatives and comments from the last vote. Even though they do not have to resolve the negatives (because the ballot failed), they are trying to see where the main issues are and how they might resolve them before the next vote.
I have no idea of where they are at this time or what changes have been made, but it is time we get this document out to our members and others that need this standard around the world.
Those on the voting list did receive a poll recently addressing the criteria section and what would be acceptable to them as far as the criteria section. I was hoping the committee would release these results to see how the voters responded. Since this is the critical issue for most voters, it would be nice to know where the committee is focusing their changes, if any, in this section before the balloting process. As far as I can tell there is nothing on the NACE website under the TG 360 committee that addresses the recent poll.
The last word I had was that another version of the revision will be out for vote in August 2010. To vote, you will have had to signed up on the original voting ballot list which was in July 2009. If you are not on this list you can not vote, but you can make your views known by posting them on the SP0169.com blog site and by passing them along to those who are voting, especially those in your company. That way others who will be voting can get information from anyone who posts their views on the blog in order to help them make a more informed decision.
It has been interesting to me that those who favor changes to the criteria section rarely post their concerns, reasons and information on the topic. Why not allow everyone to get as much information as possible so they can reason the best choices for this document. We learn from every ones comments derived from their experiences, knowledge and education. Those who chose not to inform others of their views on this subject are not allowing for an open forum to discuss these very important and critical issues. Please provide you insight into these issues no matter where your experiences have taken you.
Get ready for another ballot soon! And please vote if you are on the balloting list! Take some time to read the document and comment as you see places that may need some changes or improvements. You can choose to vote for or against or abstain. If voting for this version you do not have comment, but are welcome to. If you vote against the document, you must give the committee valid reasons why you voted negative. You will need to define the particular section and give reasoning why you voted negative on that part, as well as giving a valid resolution to the committee. This is where the information mentioned above becomes very important.
The committee has spent many long hours and much effort in this matter and like the rest of us is tired of the battle, but in order to give the industry the best possible document, we have to keep working together! Do not give up! And do not just give in to get it over with. Compromise is the only way we will get this document out, but it must happen on both sides.
Thanks for the support of the SP0169.com blog site. Please continue to provide comments and any other information (especially case histories) that will help with this effort!
Richard Norsworthy
Polyguard Products, Inc.
Another version of the SP0169 is in the works. I think everyone is hopeful for resolution of the key issues on this document so we can move forward. The committee is working to address many of the negatives and comments from the last vote. Even though they do not have to resolve the negatives (because the ballot failed), they are trying to see where the main issues are and how they might resolve them before the next vote.
I have no idea of where they are at this time or what changes have been made, but it is time we get this document out to our members and others that need this standard around the world.
Those on the voting list did receive a poll recently addressing the criteria section and what would be acceptable to them as far as the criteria section. I was hoping the committee would release these results to see how the voters responded. Since this is the critical issue for most voters, it would be nice to know where the committee is focusing their changes, if any, in this section before the balloting process. As far as I can tell there is nothing on the NACE website under the TG 360 committee that addresses the recent poll.
The last word I had was that another version of the revision will be out for vote in August 2010. To vote, you will have had to signed up on the original voting ballot list which was in July 2009. If you are not on this list you can not vote, but you can make your views known by posting them on the SP0169.com blog site and by passing them along to those who are voting, especially those in your company. That way others who will be voting can get information from anyone who posts their views on the blog in order to help them make a more informed decision.
It has been interesting to me that those who favor changes to the criteria section rarely post their concerns, reasons and information on the topic. Why not allow everyone to get as much information as possible so they can reason the best choices for this document. We learn from every ones comments derived from their experiences, knowledge and education. Those who chose not to inform others of their views on this subject are not allowing for an open forum to discuss these very important and critical issues. Please provide you insight into these issues no matter where your experiences have taken you.
Get ready for another ballot soon! And please vote if you are on the balloting list! Take some time to read the document and comment as you see places that may need some changes or improvements. You can choose to vote for or against or abstain. If voting for this version you do not have comment, but are welcome to. If you vote against the document, you must give the committee valid reasons why you voted negative. You will need to define the particular section and give reasoning why you voted negative on that part, as well as giving a valid resolution to the committee. This is where the information mentioned above becomes very important.
The committee has spent many long hours and much effort in this matter and like the rest of us is tired of the battle, but in order to give the industry the best possible document, we have to keep working together! Do not give up! And do not just give in to get it over with. Compromise is the only way we will get this document out, but it must happen on both sides.
Thanks for the support of the SP0169.com blog site. Please continue to provide comments and any other information (especially case histories) that will help with this effort!
Richard Norsworthy
Polyguard Products, Inc.
Tuesday, May 25, 2010
Anonymous comments
I, like many others, are weary of the battle between those for and against the -0.850V "ON" criteria (yes yes with reference to a CuCuSO4 reference cell).
I do lean towards the science side of the debate, but also recognize that a lab is not the same as in the field, and practical measures are required in the field.
IMHO, a -0.85V "ON" criteria specifically for galvanic anode CP systems in soils above some soil resistivity (pick a number based on science 2000? 5000? ohm-cm)will protect the pipe. The amount of current an anode can generate would not be able to produce a significant IR drop, hence by default "considers" those drops other than those across the electrolye boundary.
Providing a sound basis that allows the operator to use the -0.85V "ON" criteria addresses the concerns I hear at the meetings. It provides the operator a safe criteria, supported by sound science, and give a valid/supported stance to take with a regulator. Most importantly, it provides for a procedure that can be performed cost effectively, repeatably, correlates with the historical data.
This is no different than what I hear others say they do. It just documents the process, brings some consensus and consistancy to the approach, and moves us forward on this standard.
Why is this important to some many operators? The practical issue, as I see it, are associated with trying to measure an "instant off" value on a pipeline that is protected by galvanic anodes that are cad welded to the pipeline. This is very imparactical to interrupt. Even if they the anodes came up into a test station, just the vast numbers of anodes involved make it an impractical test procedure to perform (how many interrupters would it take?). In many cases, we wouldn't even be allowed to dig down just to break the anode wire connection.
Besides the impractical nature, it is not warranted in these low current situations.
I propose a study to establish some norms for when the -0.85 ON criteria would be acceptable. Tables could be generated that might correlate soil resistivity, "typical" anode current flow, and "expected" IR drops associated with those currents. This should meet the concerns of most folks. Guidance could be provided if an operators system were outside of those norms.
Of course this is not 100% iron clad. There could be scenarios where interference could be involved, thus the "ON" reading might not be real, but this is no less true of any CP system, even with "instant off" readings. No criteria eliminates the need for knowledgeable CP personnel to monitor and interpret the results.
Standards of any kind do not lend themselves to performing a task in the most precise way, but takes complicated processes and builds in enough of a safety factor that it becomes a practical rule book to use in most cases. We always depend on knowledgeable folks to know when the "rules" or standards are applicable for a given situation.
I do lean towards the science side of the debate, but also recognize that a lab is not the same as in the field, and practical measures are required in the field.
IMHO, a -0.85V "ON" criteria specifically for galvanic anode CP systems in soils above some soil resistivity (pick a number based on science 2000? 5000? ohm-cm)will protect the pipe. The amount of current an anode can generate would not be able to produce a significant IR drop, hence by default "considers" those drops other than those across the electrolye boundary.
Providing a sound basis that allows the operator to use the -0.85V "ON" criteria addresses the concerns I hear at the meetings. It provides the operator a safe criteria, supported by sound science, and give a valid/supported stance to take with a regulator. Most importantly, it provides for a procedure that can be performed cost effectively, repeatably, correlates with the historical data.
This is no different than what I hear others say they do. It just documents the process, brings some consensus and consistancy to the approach, and moves us forward on this standard.
Why is this important to some many operators? The practical issue, as I see it, are associated with trying to measure an "instant off" value on a pipeline that is protected by galvanic anodes that are cad welded to the pipeline. This is very imparactical to interrupt. Even if they the anodes came up into a test station, just the vast numbers of anodes involved make it an impractical test procedure to perform (how many interrupters would it take?). In many cases, we wouldn't even be allowed to dig down just to break the anode wire connection.
Besides the impractical nature, it is not warranted in these low current situations.
I propose a study to establish some norms for when the -0.85 ON criteria would be acceptable. Tables could be generated that might correlate soil resistivity, "typical" anode current flow, and "expected" IR drops associated with those currents. This should meet the concerns of most folks. Guidance could be provided if an operators system were outside of those norms.
Of course this is not 100% iron clad. There could be scenarios where interference could be involved, thus the "ON" reading might not be real, but this is no less true of any CP system, even with "instant off" readings. No criteria eliminates the need for knowledgeable CP personnel to monitor and interpret the results.
Standards of any kind do not lend themselves to performing a task in the most precise way, but takes complicated processes and builds in enough of a safety factor that it becomes a practical rule book to use in most cases. We always depend on knowledgeable folks to know when the "rules" or standards are applicable for a given situation.
Straw Poll
Comments on Straw Poll concering criteria for SP0169
The recent straw poll sent by the TG 360 committee gives you a chance to provide the committee with your thoughts and potential compromises. They have provided 5 versions to choose. Also, you are to rank each one as to whether you strongly agree to strongly disagree. Then you are asked if you would vote yes or no on each version.
The 100 mV polarization criterion would be common to each version so is not included.
Here is what I think:
Version 1
A cathodic voltage of -850 mV or more negative across the structure to electrolyte boundary as measured with respect to a saturated copper/copper sulfate (CSE) reference electrode.
MY COMMENTS: (Disagree)
The major problem with this version is that there is no “real” way to perform this in the field. Theoretically, this is what we are trying to accomplish, but in the real world, I do not think we can do it with enough consistent accuracy to be viable. The cost of performing these type surveys can be high and the extra cost does not provide much value for amount it could cost. Therefore, I could not agree with this being the only criterion besides the 100 mV.
Interpretation of the way to measure the potentials in this criterion would lead to much confusion and possible problems that could be a major issue for those trying to use such a criterion. The test method committee for TM-0497 would have to come up the ways to measure this version and that may take longer than revising the SP0169!
Version 2
(1) A structure-to-electrolyte potential measured with the cathodic protection current applied. The current-applied potential criterion value shall be established by the owner through sound engineering practice and support by empirical evidence that demonstrates the corrosion control objective of the owner is achieved.
(2) A negative polarized potential of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
MY COMMENTS: (Has potential, but needs some re-wording)
I like much about this version, but am concerned about the definitions of “empirical evidence” and “objective of the owner”. If these are defined satisfactorily in the document, then possibly I could “strongly agree” with this version. At this time I would say it is a definite “maybe”.
This would leave it up to the owner to determine what “ON” potential they will use at each test site. This could be determined by several methods that should be spelled out in the test method document.
Also, why is it important to establish “by the owner through sound engineering practice and support by empirical evidence that demonstrates the corrosion control objective of the owner is achieved” for the “ON” potential, but if you take an “instant off” you do not have to meet the owner’s objective? Seems like every criterion should meet the owner’s objectives and if we mention it in one we need to mention it in all or make a generic statement as such in the document and not apply it to each separate criterion.
Version 3
(1) A negative (cathodic) voltage of at least 0.85 volt as measured between the structure surface and a saturated copper-copper sulfate half cell contacting the electrolyte. Determination of this voltage is to be made with the protective current applied. The Corrosion Engineer shall consider voltage (IR) drops other than those across the structure-electrolyte boundary for valid interpretation of the voltage drop.
(2) A negative polarized potential of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
MY COMMENTS (Disagree at this time)
This was almost good. Had they not included the wording “Corrosion Engineer” and “shall consider”. Not sure how we define a corrosion engineer these days. Not even sure we can get a corrosion engineering degree as such in most places around the world. There are “degreed engineers” that work in the discipline of corrosion, but not many who actually have a degree in corrosion. There are also more of us working corrosion that do not have an engineering degree than those with one. So how do we define that?
I know “must” is used in Version 4, but at least they allow for some ways of considering the voltage drops.
Version 4
(1) A negative (cathodic) potential of at least 850 mV with the CP applied. This potential is measured with respect to a saturated copper/copper sulfate reference electrode contacting the electrolyte. Voltage drops other than those across the structure to-electrolyte boundary must be considered for valid interpretation of this voltage measurement.
NOTE: Consideration is understood to mean the application of sound engineering practice in determining the significance of voltage drops by methods such as:
- Measuring or calculating the voltage drop(s);
- Reviewing the historical performance of the CP system;
- Evaluating the physical and electrical characteristics of the pipe and its environment; and
- Determining whether or not there is physical evidence of corrosion.
(2) A negative polarized potential of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
MY COMMENTS (Agree overall)
These are the same two criterion in the SP-0169 – 2007 and is the same as has been used since 1992 (I believe). We have been able to make this work and I can vote for the document (if a few other areas are corrected) with the criteria as is at present.
I personally could do without the “must” before “be considered” and would prefer “should”, but can live with “must” as a compromise.
Version 5
A cathodic voltage of – 850 mV or more negative as measured with respect to a saturated copper/copper sulfate (CSE) reference electrode. This potential may be either a direct measurement of the instant off potentials, or a current applied potential. Interpretation of a current applied measurement requires correction for voltage drops in the earth or metallic paths.
Note: Correction is understood to mean the application of sound engineering practice in the determination of the magnitude and significance of the voltage drops by methods such as:
- Measuring or calculating the voltage drop(s); or
- Determining whether or not there is physical evidence of corrosion.
MY COMMENTS: (Strongly disagree)
This is the same criterion that was in the most recent revision. The term “correction” concerns many because it means you must determine the “instant off” for each reading when using an “ON” reading. The term “with current applied” is useless, because you have to “correct” for voltage drop by doing an “instant off”. Even though it does give some help with “evidence of corrosion” statement, I could not support this criterion.
FINAL COMMENTS:
Only those on the voting list got the opportunity to vote in this straw poll, but I encourage all those who have interest and want to express their opinion please do so through contacting the TG 360 committee or you can voice it through the blog site. You may have the best wording of the criteria so let us know.
I do hope the committee will take our words and comments as constructive and work to get us a document that gives the industry a valuable tool that can be used reasonably in the field to provide us with the data needed to determine when we have achieved the goal of providing adequate external corrosion control to the industries pipelines around the world. We will never reach 100%, but we can get very close and keep the effort affordable and reasonable. There have been many improvements and updates in the document, now let us compromise and move forward.
Again, I want to thank the committee and everyone else for hard work and effort. Though we may disagree at times, we all want the same thing. This is a critical document to the industry and we all want the best standard possible to provides guidance to the pipeline industry around the world.
I think this is a great opportunity to provide input to the committee. Please respond to best of your knowledge. You do not have to agree or disagree with me or the committee, but we do need to resolve this standard and get it out.
Thanks for your help and time,
Richard Norsworthy
The recent straw poll sent by the TG 360 committee gives you a chance to provide the committee with your thoughts and potential compromises. They have provided 5 versions to choose. Also, you are to rank each one as to whether you strongly agree to strongly disagree. Then you are asked if you would vote yes or no on each version.
The 100 mV polarization criterion would be common to each version so is not included.
Here is what I think:
Version 1
A cathodic voltage of -850 mV or more negative across the structure to electrolyte boundary as measured with respect to a saturated copper/copper sulfate (CSE) reference electrode.
MY COMMENTS: (Disagree)
The major problem with this version is that there is no “real” way to perform this in the field. Theoretically, this is what we are trying to accomplish, but in the real world, I do not think we can do it with enough consistent accuracy to be viable. The cost of performing these type surveys can be high and the extra cost does not provide much value for amount it could cost. Therefore, I could not agree with this being the only criterion besides the 100 mV.
Interpretation of the way to measure the potentials in this criterion would lead to much confusion and possible problems that could be a major issue for those trying to use such a criterion. The test method committee for TM-0497 would have to come up the ways to measure this version and that may take longer than revising the SP0169!
Version 2
(1) A structure-to-electrolyte potential measured with the cathodic protection current applied. The current-applied potential criterion value shall be established by the owner through sound engineering practice and support by empirical evidence that demonstrates the corrosion control objective of the owner is achieved.
(2) A negative polarized potential of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
MY COMMENTS: (Has potential, but needs some re-wording)
I like much about this version, but am concerned about the definitions of “empirical evidence” and “objective of the owner”. If these are defined satisfactorily in the document, then possibly I could “strongly agree” with this version. At this time I would say it is a definite “maybe”.
This would leave it up to the owner to determine what “ON” potential they will use at each test site. This could be determined by several methods that should be spelled out in the test method document.
Also, why is it important to establish “by the owner through sound engineering practice and support by empirical evidence that demonstrates the corrosion control objective of the owner is achieved” for the “ON” potential, but if you take an “instant off” you do not have to meet the owner’s objective? Seems like every criterion should meet the owner’s objectives and if we mention it in one we need to mention it in all or make a generic statement as such in the document and not apply it to each separate criterion.
Version 3
(1) A negative (cathodic) voltage of at least 0.85 volt as measured between the structure surface and a saturated copper-copper sulfate half cell contacting the electrolyte. Determination of this voltage is to be made with the protective current applied. The Corrosion Engineer shall consider voltage (IR) drops other than those across the structure-electrolyte boundary for valid interpretation of the voltage drop.
(2) A negative polarized potential of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
MY COMMENTS (Disagree at this time)
This was almost good. Had they not included the wording “Corrosion Engineer” and “shall consider”. Not sure how we define a corrosion engineer these days. Not even sure we can get a corrosion engineering degree as such in most places around the world. There are “degreed engineers” that work in the discipline of corrosion, but not many who actually have a degree in corrosion. There are also more of us working corrosion that do not have an engineering degree than those with one. So how do we define that?
I know “must” is used in Version 4, but at least they allow for some ways of considering the voltage drops.
Version 4
(1) A negative (cathodic) potential of at least 850 mV with the CP applied. This potential is measured with respect to a saturated copper/copper sulfate reference electrode contacting the electrolyte. Voltage drops other than those across the structure to-electrolyte boundary must be considered for valid interpretation of this voltage measurement.
NOTE: Consideration is understood to mean the application of sound engineering practice in determining the significance of voltage drops by methods such as:
- Measuring or calculating the voltage drop(s);
- Reviewing the historical performance of the CP system;
- Evaluating the physical and electrical characteristics of the pipe and its environment; and
- Determining whether or not there is physical evidence of corrosion.
(2) A negative polarized potential of at least 850 mV relative to a saturated copper/copper sulfate reference electrode.
MY COMMENTS (Agree overall)
These are the same two criterion in the SP-0169 – 2007 and is the same as has been used since 1992 (I believe). We have been able to make this work and I can vote for the document (if a few other areas are corrected) with the criteria as is at present.
I personally could do without the “must” before “be considered” and would prefer “should”, but can live with “must” as a compromise.
Version 5
A cathodic voltage of – 850 mV or more negative as measured with respect to a saturated copper/copper sulfate (CSE) reference electrode. This potential may be either a direct measurement of the instant off potentials, or a current applied potential. Interpretation of a current applied measurement requires correction for voltage drops in the earth or metallic paths.
Note: Correction is understood to mean the application of sound engineering practice in the determination of the magnitude and significance of the voltage drops by methods such as:
- Measuring or calculating the voltage drop(s); or
- Determining whether or not there is physical evidence of corrosion.
MY COMMENTS: (Strongly disagree)
This is the same criterion that was in the most recent revision. The term “correction” concerns many because it means you must determine the “instant off” for each reading when using an “ON” reading. The term “with current applied” is useless, because you have to “correct” for voltage drop by doing an “instant off”. Even though it does give some help with “evidence of corrosion” statement, I could not support this criterion.
FINAL COMMENTS:
Only those on the voting list got the opportunity to vote in this straw poll, but I encourage all those who have interest and want to express their opinion please do so through contacting the TG 360 committee or you can voice it through the blog site. You may have the best wording of the criteria so let us know.
I do hope the committee will take our words and comments as constructive and work to get us a document that gives the industry a valuable tool that can be used reasonably in the field to provide us with the data needed to determine when we have achieved the goal of providing adequate external corrosion control to the industries pipelines around the world. We will never reach 100%, but we can get very close and keep the effort affordable and reasonable. There have been many improvements and updates in the document, now let us compromise and move forward.
Again, I want to thank the committee and everyone else for hard work and effort. Though we may disagree at times, we all want the same thing. This is a critical document to the industry and we all want the best standard possible to provides guidance to the pipeline industry around the world.
I think this is a great opportunity to provide input to the committee. Please respond to best of your knowledge. You do not have to agree or disagree with me or the committee, but we do need to resolve this standard and get it out.
Thanks for your help and time,
Richard Norsworthy
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