Causes of corner corrosion at the bottom of oil storage tanks and how to repair it?

Thank you for sharing. I often see the photos from the sites you post; they are very inspiring to me and also help me gain a better understanding of various types of corrosion

This post was last edited by “IAskYouAnswer” on December 2, 2024, at 09:57. The insulated base is not sealed to prevent moisture absorption； The two materials have different potentials, resulting in electrochemical corrosion in the electrolyte (water)

The causes of corner corrosion at the bottom of oil storage tanks are usually related to the following factors: 1. Water accumulation: When crude oil is stored at the bottom of the tank, water and other impurities may settle there, increasing the humidity in that area and thereby triggering corrosion. 2. Microbial activity: Microorganisms such as sulfate-reducing bacteria (SRB) are active in aquatic environments, and the metabolites they produce, such as hydrogen sulfide, can accelerate metal corrosion. 3. Material defects or design issues: Insufficient material quality or design of the tank may also make certain parts more susceptible to corrosion. Methods for repairing bottom corrosion of tanks include: 1. Cleaning and drying the tank bottom: Thoroughly remove deposits from the tank bottom, especially water and impurities, and keep it dry to reduce the corrosive environment. 2. Use anti-corrosion coatings: Apply special anti-corrosion paints to the bottom of the tank to prevent corrosive substances from coming into direct contact with the metal surface. 3. Replace the damaged portion: In cases of severe corrosion, it may be necessary to remove the damaged metal sections and weld in new steel plates to repair the bottom of the tank. 4. Install a cathodic protection system: Slow down or prevent tank corrosion by using sacrificial anodes or applying an external current. .

Engineer Wang, why do I feel it’s just CUI?

Cause of corrosion: Water accumulation: Water tends to accumulate in the corners at the bottom of the tank, and the oxygen and impurities dissolved in the water accelerate corrosion. Sediments: Impurities and moisture in the oil settle at the bottom of the tank, creating an environment conducive to corrosion. Electrochemical corrosion: Differences in various metals or the surface conditions of metals lead to electrochemical corrosion. Microbial corrosion: Certain microorganisms reproduce at the bottom of the tank, producing corrosive metabolites. Coating failure: The protective coating ages or gets damaged, losing its protective function. Repair method: Clean the surface: Remove rust and deposits from the corroded areas to ensure a clean surface. Local repair: Grind the corroded area, perform patch welding, or replace the steel plate. Coating protection: Reapply anti-corrosion coatings such as epoxy resin or polyurethane. Cathodic protection: Install sacrificial anodes or impressed current systems to prevent electrochemical corrosion. Drainage system improvement: Optimize drainage design to reduce water accumulation. Regular inspections: Periodically check for corrosion at the bottom of the tank and carry out maintenance promptly. Precautions: Regular maintenance: Clean the sediment at the bottom of the tank regularly to keep it dry. Coating maintenance: Regularly inspect and repair the protective coating. Water quality management: Control the moisture and impurity content in oils. Microbial control: Use fungicides to inhibit microbial growth. Through these measures, corrosion at the bottom corners of oil storage tanks can be effectively repaired and prevented.