【Weekly Topic】Corrosion and Protection: Talking about Things at Work (2011.9.5-2011.9.11)
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This post was last edited by Litaol1314 on 2011-9-19 08:55. Dear colleagues: Corrosion is a common issue in our chemical enterprises, and it is essential to carry out proper protection measures. Please share what work related to corrosion and protection was done in your companies over the past week. We also welcome suggestions for good practices so that we can learn from each other and improve our efforts in preventing corrosion. Notes: 1. It is preferable to provide examples that occurred this week; a single incident can be described, such as: gum damage in xxx location, which was repaired by replacement ； It is also possible to conduct a deeper analysis of the reasons: such as aging over time, or the presence of organic solvents in the medium ； 2. It must be related to corrosion and protection ； 3. I hope everyone will participate actively.
On Saturday and Sunday, spark testing was conducted on the newly completed internal anti-corrosion coating of the two tanks; the construction method used was five layers of oil and three layers of fabric, along with epoxy resin. Some points showed missing detections, which triggered an alarm from the instrument; repairs were carried out today. Then perform the installation check again. The newly installed buried pipes have been treated for corrosion prevention by applying asphalt paint. After some testing, it has been found that asphalt paint works best when used on steel platforms designed for environmentally friendly use.
Yesterday, a re-inspection was conducted on the repaired lining, and the results were unsatisfactory; further corrections are being made. There are issues: at the joint area and at the welds. By the way, regarding the three-layer five-coat coating, is a spark testing voltage of 9 KV sufficient?
Reply to 3# yuchenchf: What kind of medium is it? Why isn’t direct lining with rubber considered?
The tank has a diameter of 10 meters and a height of 25 meters; it contains wastewater that is highly corrosive. The interior is lined with glass cloth, using a three-layer cloth with five layers of oil coating.
Another inspection of the large tank yielded unsatisfactory results. The most important thing when lining is to prepare the base surface properly; otherwise, it will be difficult for the lining layer to achieve good results.
Starting today, the anti-corrosion work for 40-meter buried pipes will begin, using a three-layer fabric and five layers of coating system, bituminous fabric for sealing, and robotic grinding wheels for rust removal. Personally, I think asphalt paint is a great option – it’s inexpensive and effective.
Construction on the new foundation has begun; a 100 MM layer of asphalt sand is planned to be laid on top of the foundation to prevent corrosion starting from the bottom of the tank.
This morning, I inspected a tank with an inner diameter of 10 meters and a height of 20 meters; only 6 spots were found on the lining (spots that were not detected by the ultrasonic testing). Not bad.