Sacrificial Anode Required by Client for Pipes Coated With Phenolic Epoxy

"basic criteria to provide sacrificial anode in buried condition?"

Find a substance that will corrode//rust/decompose more readily than the primary material of construction. Zinc seems to be popular. The polymer coating is not important.

You should hire an engineer with some corrosion experience.

Thanks Mr. lyn to know about the criteria limited to buried only,

Maybe one of these will help.

• Buried pipe design - Alma P. Moser - Google Books
• BS 9295:2010 Guide to the structural design of buried pipelines
• Buried Pipe Design (2nd Edition)

Why do you need sacrificial anode at all?

Coated pipes, properly protected with epoxy, fitted with appropriate jointing techniques and fasteners have high lifetime reliability.

Plastic wrapping (or alternatively DENSO wrapping) provide high reliability systems for burried pipes by stopping Oxygen transfer and so corrosion stops once the enclosed Oxygen is depleted. This system is used in water/sewer industry, protection for underwater components of wharves and bridges in fresh and seawater.

Ask the pipe/fitting supplier for their recommended practices and don't take shortcuts.

If you already have epoxy coating, then the joints are where the protection is required, unless the epoxy has been damaged.

Thanks but those pipes being used for close drain lines have already been painted with above said paint, This relevant pipes painted in workshop and shifted to site after 100% holiday test by sponge method except the area of weld girth and identification mark of pipes and now responsibility of painting & testing for balance area (weld girth+ identification mark) goes to site people,

As i am a representative of contractor and installation of sacrificial anode was not decided from contractor but client proposes to install because of condition is buried

Why anonymous ?

Join Us.

of course and thanks

The starting point just has to be: what's in the pipe, its temperature and pressure?

• Service : Hydrocarbon,
• Operating Pressure: 0.8barg,
• Operating temperature: 43 deg.C and some line 170 deg.C

(Painted pipes going to use for hydrocarbon drain which has to be connected to sump)

(with) respect given to Post9, the importance of the information given (Post10) lies primarily in the fact that lines carrying gas, oil, and hazardous liquids fall under the jurisdiction of different Codes than lines carrying water (for example).

In the U.S. (and many other countries), "API" lines must (in-addition-to protective coatings) maintain cathodic potentials ... often referred-to as pipe-to-soil potentials ... of -850mV with respect to a Cu/CuSO₄ reference cell.

Information in books of the sort referenced above should be a MANDATORY starting place for you. This 'task' is not the sort of easy / cut-and-dried scenario that many persons would like to believe (and some would even suggest!). Peabody's Guide (see "References" HERE) has been one of the 'defacto_standards' for many years, to those involved with NACE (National Association of Corrosion Engineers International).

Step one is to determine the electrical characteristices of the line and to perform a Current Requirement Survey (to know how much current will be required in order to achieve/deliver the desired potential).

NO coating system is ever going to be totally and completely holiday free following installation. CP will afford protection to THOSE areas (it achieves *nothing* where the coating remains intact).

Sand typically exhibits an extraordinarily high resistivity, and thus, does not lend itself (as an electrolyte environment) to adequate protection via sacrificial anodes, as opposed to impressed current systems. That is, of course, unless the sand lies in a thoroughly soaked riverbed or swamp. MUCH more needs to be taken into consideration, before you dive into this project of providing cathodic protection.

Where is the line, and what systems are employed on similar lines in the area...?

Wishing you success ~

Thanks to all, this line is in saudi with saudi aramco total refining project and I have already been suggested to my head of department to install sacrificial anode after getting reply of Mr.lyn

Thanks again

Lyn's *best* advice to you was in his 'Post#1'... "You should hire an engineer with some corrosion experience."

Sacrificial anodes are unlikely to work at all in the arid environment.

Before spending 'dime number one' going any further, you ought to sign-up (free) for the Corrosion Forum (ListServer) at the NACE website: HERE

Ask the experts (of whom there are NUMEROUS from your area participating) just what will work best. You are guaranteed to get the most-experienced advice from the people who work in this field daily.....and share with each other, as well as 'newcomers'.

Wishing you the best ~

If the customer wants it and is willing to pay for it then oblige them.

Make sure you include the cost of a corrosion mitigation specialist's time.

Thank you very much Mr.Ndt-tom to help me to join Nace forum as well as give us precious time for subject matter