Analysis of the causes of corrosion in the solvent pump outlet pipeline
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Analysis of the causes of corrosion in the outlet pipeline of the solvent pressure pump: The medium is a lean solution, with 30% MDEA and 70% water and other components. In addition, it contains 45 mg/L of heat-stable salts. The pump is a magnetic drive pump; the outlet pressure is 0.6 MPa and the temperature is around 90°C. The inlet pressure of the pump corresponds to the static pressure at the bottom of the regeneration tower, which is approximately 0.2 MPa. Based on the corrosion patterns shown in the images, I urge my colleagues to share their opinions and contribute their ideas.
Is your image showing corrosion and cracking? If so, it’s likely a problem with the material. If it’s just rust, then that’s normal – the liquid contains hydrogen sulfide; I’m not sure what the level of this substance is in your case
How long has your device been in use? Ours has been in use for over three years. During maintenance, we went inside the absorption tower and found that its inner walls were as smooth as mirrors; at the bottom, there were mainly deposits of impurities from the exhaust gases.
Could you introduce the material? Does it feel like a coating? Looking at the first and second images, there are characteristics of temperature differences, impact fracture, erosion by scouring, and cavitation.
The material is 20# steel, in accordance with GB9948 standard.
For reference: The media inside the amine regeneration tower of a certain oil project mainly include MDEA solution, acidic gas, and acidic water. The tower is constructed from Q245R material, with a design temperature of 150°C and a design pressure of 0.3 MPa. Coatings are used for corrosion protection. See attached figure.
How long ago was this problem discovered? Is it feasible to replace the pipeline directly? Is it a quality issue with the supplied materials?