Talk:Cathodic protection

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Can we get a quick, easy to read diagram? I'd make it in MS Paint, but I don't know how this process works (hence the request :)) Bmunden 15:21, 11 April 2007 (UTC)

Done. I found one in the Commons, but is was not English, so I translated it and added it to this page. Cafe Nervosa (talk) 21:38, 7 June 2012 (UTC)

Remove section?[edit]

The electrolyte is the environment the structure is place in, so it is permanent just like the pipeline is permanent. For a pier at a ocean port, the electrolyte is the sea water on one side and soil on the back side. For an on shore pipeline, the electrolyte is the soil or special backfill material covering the pipeline. User:Cafe_Nervosa 28SEPT 2009

Galvanising section appears unnecessary. A single sentence with link to Galvanization, mentioning that galvanising has some aspects of CP would be better. Agreement? Fdac 04:59, 26 September 2006 (UTC)

I absolutly disagree. 12:05, 18 October 2007 (UTC)

I AGREE - Galvanizing just needs a cross reference or one sentence in CP. CP generally places the anode away from the structure. For 90% of the systems, the anodes are minimum 10 cm from the structure to be protected. Exception is bolt-on anodes for small boats. CP engineers have to deal with current distribution on the the surface and wires and structure-to-potential measurements. Galvanizing is coated directly onto the steel surface and they look at uniform material coverage, thickness. Galvanizing is sufficiently different from CP that it needs just needs a cross reference or one sentence in CP. User:Cafe_Nervosa 38SEPT2009

Cathodic protection, doesnt make sence to me. any explanations?

Yes. It makes sense. It is the most common and standard method of corrosion protection. The application of two common types are as follows: Sacrificial Anodes (use the ignoble material to protect more noble material by sacrifying the ignoble one) are usually applied to protect "offshore structures" and "offshore pipelines". It is also applied for onshore pipelines and structures but less compare to offshore. Impressed Current Cathodic Protection (ICCP) is the method of corrosion prvention by injecting a current which is stronger than the "corrosion current" into the pipeline through soil (electrolyte) then, corrosion can not occur. Remember, corrosion takes place at the place where the current "goes out" from the pipeline into "soil (electrolyte)". So if the current can not "go out" and only "enters" the pipeline, there will be no corosion). It is widely used in protection of onshore pipelines, structures and tanks. Please take note that Cathodic Protection can protect ONLY the EXTERNAL corrosion. Not internal. [10:00 16 August, 2006 Thet Htin Oo]

Sir, many water tank operator use CP to protect the internal surfaces of their tanks. The anodes are suspended from the roof and hang down into the water. In other applications, have inserted impressed current anodes through the wall of a chill water pipeline (36-inch diameter) to protect the internal surface of the pipe. User:Cafe_Nervosa 28 Sept 2009

Telluric Current Effect on CP System[edit]

The telluric current has substantial effect on CP system. The most obvious problem is substantial and rapid fluctuations in pipe-to-soil potential of onshore pipelines. Due to the mask of telluric, the true potential of pipeline can not be observed and the level of protection will be unknown. The phenomena of telluric effect is very unpredicatable. The amount of fluctuations or telluric effect depends on many parameters: - Size of pipeline (diameter) - Wall Thickness - Orientation (East-West oriented pipelines are more vulnerable) - Soil resistivity - Geographical area (different effect at equator and north pole) - Location (less effect when close to the sea) - Geometric configuration of pipeline (bends, etc) - Time of the day (different in day and night. Worse in the day) - Presence of other equipment (barred tees, insulating joints, etc.) - Lenght of pipeline (the longer the pipeline, the stronger the effect) etc. Up to now, there is no proven solution for this problem. And there are only a few books and publications about this topic in open literature.

This section should be discussed more widely. More comments and suggestions are welcome. 10:30 14 August, 2006 [Thet Htin Oo]

Sir, Well trained CP experts are aware of telluric effects on CP and the problems it introducs to the measurement of pipe-to-soil potential, however I disagree that "Up to now, there is no proven solution for this problem". My evidence is the undisputed successful application of CP when maintained in accordance with the industry standards. When CP does not work, it can almost always be traced back to improper engineering and maintenance by non-CP experts. Telluric current effects are real at many facilities, however, for most applications of CP, the structures are too small so that Telluric effects are not measurable and do not impact the CP system. Pipeline operators that may be affected by Telluric Current effects should not be referencing encyclopedia articles for engineer practice. It should be performed by professionals. Pipelines are expensive and the owners should pay experts to protect them. User:Cafe_Nervosa 28SPET 2009


Added a section on standards to connect it to the real world. List is going to be long if all international and national standards are added so some of the standards that have been added might have to be removed , and only the key standards kept. but it's a start —Preceding unsigned comment added by (talk) 15:06, 29 November 2007 (UTC)

I'm a bit confused[edit]

First I get the impression that cathodic protection is something physical (a liner) that fits the outside of the pipe. But then I'm reading that there is something electrical going on.

Could you please explain to me in words that a 5-year-old would understand?

Thank you. Kekkadean (talk) 22:29, 19 November 2008 (UTC) Kekkadean

I agree that the entry can be improved, and that is why is is continuously edited. No technically correct entry will be understood by 5-year old children unless the child has successfully finished high school and first year college chemistry. That is why cathodic protection and industrial maintenance it is left out of educational curriculum's until college. level. Here's a quickie explanation that is overly simplified. A bare piece of steel in water or buried in the soil will corrode freely because on the surface there are areas that are anodic to other areas (the cathodic areas). The surface areas are small, large and microscopic and the difference might be only a couple/few millevolts , but we have lots of time, so there is a driving force for the corrosion reaction (iron reacting with nearby oxygen and forming iron oxide RUST). Cathodic protection is the application of voltage to the steel (through the use of a galvanic anode or a impressed current CP system) to make the entire surface of the steel have a uniform voltage-potential. When the surface of the steel is uniform, the driving force for the corrosion reaction is now missing and corrosion does not occur. User:Cafe_Nervosa - September 28, 2009

I'm fixing a few typos in the table of material electrochemical potentials: silicium-bronze -> silicon-bronze, cupper -> copper, cuppernickel -> cupronickel, manganesebronze -> manganese-bronze. I'm also deleting the extra entry for cupper (sic) that says, -.24. The much bigger problem, though, is that all the values look extremely suspicious. For one thing, that table MUST list what it is using for the reference "zero" material. In a typical half-cell table, hydrogen is used as the reference. In that table copper would be +0.34 and zinc -.76. I could not locate the reference cited in footnote 3 to see what the author was referencing. Someone needs to fix this for the table to be correct. If for any reason, I'm wrong, fell free to revert. Jeremy (talk) —Preceding undated comment added 01:00, 27 January 2010 (UTC).

I don't think this table is relevant to this article, not in the present form. Most of those materials aren't used as anodes or have CP applied to them. Any objections if the table is cut down to the relevant materials, steels, aluminium, zinc, magnesium? Apau98 (talk) 06:34, 6 February 2010 (UTC)

Since there were no objections, I've reduced the table to the more common metals and moved it into the galvanic section, where it is more relevant. I also edited the section on the 'typical' pipeline cp system, which seemed a bit too specific. Apau98 (talk) 13:11, 31 October 2010 (UTC)


Should this be the title of that paragraph? The problem described is disbondment of coatings as I see it, and a reduction in effectiveness is the effect, not the problem. If there are no objections, I'll re-word it and revise the text slightly to make it more applicable to coating disbondment in general. 13:20, 4 April 2010 (UTC) —Preceding unsigned comment added by Apau98 (talkcontribs)


"Electrodes used in open circuit, such as pipeline cathodic protection monitoring, are not reference cells" : is that stricty true and if it is, is it relevant to that section?Apau98 (talk) 09:15, 27 August 2010 (UTC)

If no-one has any comments regarding that section, I plan to remove or edit the text that needs citationApau98 (talk) 09:35, 4 January 2011 (UTC)

American English[edit]

When did this article suddenly become written in American English? I seem to remember it was in British English for some time, certainly all my edits were... Apau98 (talk) 17:26, 11 June 2011 (UTC)

In fact, up to this point: [1] the article was in British English. Does anyone see any good reason for the changes? I don't wish to get into a bickering war with anyone, but since it had previously been in British English, shouldn't it remain so? See [2]WP:Retain Apau98 (talk) 12:41, 13 June 2011 (UTC)
Per WP:ENGVAR the deciding edit is: Wizard191 (talk) 21:40, 13 June 2011 (UTC)
Ah yes, I agree. Apau98 (talk) 12:17, 8 June 2012 (UTC)
I agree it should be English type English in conformance with my very early edits and native language. Cafe Nervosa (talk) 05:13, 5 September 2012 (UTC)
I think the consensus was that the original article was in American English, and per WP:ENGVAR, that was the deciding edit. Apau98 (talk) 10:02, 11 May 2013 (UTC)


Should the use of meters for testing be included? dcvg's and Swain Meters? There are many options are there not? for many applications? Icebreaker83 (talk) 15:20, 16 August 2011 (UTC)

I restored an article DCVG that might be merged here.--Tikiwont (talk) 20:43, 8 October 2011 (UTC)
Strictly speaking, DCVG only tests the coating for defects, not the cathodic protection. I would say merging wouldn't be a good idea Apau98 (talk) 12:14, 8 June 2012 (UTC)
I agree with Apau98. DCVG and CP are both corrosion control things but quite different. Cafe Nervosa (talk) 02:25, 31 July 2012 (UTC)

Suggest merge[edit]

Cathodic protection rectifier should be merged to this article to give it context; it's very short and the subject doesn't appear notable outside the context of cathodic protection. --Wtshymanski (talk) 15:32, 21 March 2012 (UTC)

I undid the merge[3]. The article, Cathodic protection rectifier can be expanded. There are different types of units: solar powered, gas powered, three phase AC, oil cooled, air cooled, automatic controlled output, constant voltage output, remote monitoring, etc. The rectifiers are distinct from the anode groundbeds of which there are many different types and distinct from the other components of a CP system. Cafe Nervosa (talk) 20:20, 22 June 2012 (UTC)
It would be very nice if Cathodic protection rectifier had grown any in the last few weeks. I recommend it be merged to Cathodic protection until there's enough material to support more than a stub article. It wasn't really an undo of the merge, because now the content is duplicated in both places. --Wtshymanski (talk) 14:40, 30 July 2012 (UTC)
Wtshymanski, please take to heart the criticism leveled in your direction regarding deleting the work of others.Cafe Nervosa (talk) 17:11, 31 July 2012 (UTC)
But isn't that what editing is about? It's a collabrative process - not every word that gets added needs to stay, and Wikiprose is typically awkwardly wordy. --Wtshymanski (talk) 18:10, 31 July 2012 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── Again, recommend a merge. Not every circlip and cotter pin is notable and the topic Cathodic protection rectifier is not notable outside the context of this article; the whole subject matter can be adequately described in a paragraph or two here. --Wtshymanski (talk) 03:45, 24 August 2012 (UTC)

I will work to keep these as separate articles. I am an expert the field and have contributed good material to both. Editting is good, but why piss off contributors? Cafe Nervosa (talk) 05:08, 5 September 2012 (UTC)
Can anyone (else) suggest any reason for two articles instead of one? --Wtshymanski (talk) 20:16, 5 October 2012 (UTC)

Outside layman's opinion: Cathodic protection rectifier certainly has the potential to be a good stand-alone article, but at the moment it isn't one. In its current state, it makes more sense as a subtopic of cathodic protection. Once it is expanded, it can then be made a separate article. Ego White Tray (talk) 21:24, 6 December 2012 (UTC)

Support I agree. The only purpose of a cathodic protection rectifier is to power an impressed current cathodic system. The rectifiers can be better explained in the context of the Cathodic protection article, unless the amount of material requires a separate article. Why make readers click over to a stub? --ChetvornoTALK 05:30, 22 January 2013 (UTC)
Support I also agree it should be kept as a subtopic on the basis that they are only used for CP. Apau98 (talk) 08:46, 3 January 2014 (UTC)

Chemical process(es) during impressed current cathodic protection[edit]

I am curious about what the chemical process is during cathodic protection. My limited understanding of chemistry suggests to me that the process should plate the cathode with whatever is the most abundant or mobile or electrochemically available? cation in the groundwater. I am thinking of a specific case where I know that the water that is causing the corrosion that is being protected against using CP has very high calcium levels; around 30,000 ppm. In this case I assume that Calcium metal is plating on the exterior of the cathode. — Preceding unsigned comment added by Dpdean (talkcontribs) 17:23, 4 October 2012 (UTC)


I'm sure there are safety concerns, but it seems to me that the section on Safety is just an advertisement for a commercial company (supplying TRs with 'Touch Safe technology'), so I've deleted it.Apau98 (talk) 21:51, 3 May 2013 (UTC)

What is being compared?[edit]

Interpretation of electrode potential measurements to determine the potential at the interface between the anode of the corrosion cell and the electrolyte requires training[41] and cannot be expected to match the accuracy of measurements done in laboratory work.

Are we comparing measurements in the field to lab work? (talk) 10:46, 15 February 2015 (UTC)

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