Cathodic protection snapshot

Name of technique

Cathodic protection

Use

Prevent corrosion
Complement protection given by coatings

Definition

A technique where an ionic current towards the structure from the electrolyte is used to counter the corrosion current flowing out of the structure.

CP criteria

CP potential of -850 mV vs. CSE
An instant off potential of at least -850 mV vs CSE
A minimum 100 mV polarization post instant off

CP measurement techniques

Soil resistivity
CIPS
DCVG
Line current

Factors affecting CP requirements

pH
velocity
ionic type
ionic concentration
temperature

Issues with CP

Stray current corrosion
Insufficient CP potential
Insufficient CP current
Electrical shorting

I will discuss all these with examples in this major course, where you can prepare for the basics for your certification course!

Check out the introductory video for the brand new course and click on the link to access!

https://corrospective.com/courses/basics-of-cathodic-protection-cp-in-oil-and-gas-industry

Practice your CP knowledge here! Check out Quiz 1!

😀Happy learning!😀

Comments

Corrosion risk planning - 2 - Above ground storage tanks - oil and gas- PART 1

Above ground storage tanks 1. Inner walls Coating degradation Corrosion due to water/dissolved oxygen insufficient/damaged cathodic protection system dissolved sacrificial anodes 2. Outer walls/roof Atmospheric corrosion coating degradation due to moisture + UV radiation + temperature Erosion and wear due to wind and dust particles biological growth at the bottom areas near soil soil corrosion near the bottom 3. Pipes Atmospheric corrosion Coating degradation mechanical failure internal corrosion due to water/dissolved oxygen crevice corrosion in areas facing away from atmosphere corrosion at welds and joints microbial corrosion at 6 o' clock positions erosion corrosion at bends 4. Railing Coating degradation Wrong coating selection based on pure aesthetics coating damage at joints and bends corrosion at welds in the railing crevice corrosion at fixtures pitting corrosion 5. Breather valve uniform corrosion/pitting depending on whether it is made up of carbon steel/stainless steel...

What is a Corrosion Loop - PART 1 - CONCEPT

Corrosion loop is used to simplify inspection procedures in refining processes. Corrosion loop is defined as a group of components with common materials, processes, and operating parameters. Source: Rachman, A. and Ratnayake, R.M.C. (2020), "Corrosion loop development of oil and gas piping system based on machine learning and group technology method", Journal of Quality in Maintenance Engineering, Vol. 26 No. 3, pp. 349-368. https://doi.org/10.1108/JQME-07-2018-0058 It is needed when the scenario has - 1. Complex process 2. Several variables such a materials of construction, process parameters, functions 3. Multiple damage mechanisms WATCH THE VIDEO FOR A DETAILED EXPLANATION - Click here for part 2 ! https://corrospective.com/ 😀Happy learning! 😀

What is a Corrosion Loop - PART 2 - EXAMPLE

How to prepare a corrosion loop? To prepare a corrosion loop, the person in charge will look at the overall picture and answer the following questions - 1. What is the process? 2. What are the components? 3. What are the materials for each component? 4. What are the common features among them? 5. Where does the commonality end? - This is important as that will mark the beginning of a new corrosion loop. 6. Can I use the same inspection procedure for all of them? 7. Do they corrode/get damaged in the same manner due to the same reasons? WATCH THE VIDEO FOR A DETAILED EXPLANATION - Read part 1 here! https://corrospective.com/ 😀Happy learning! 😀

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