Analyze the cause of the leak! Everyone, please share your opinions
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There is a leak at a elbow; the material used is 347H. The operating temperature is around 270 degrees. The media involved are vinyl chloride, hydrogen chloride, and dichloroethane, with a water content of less than 10PPM. The component has been in use for 16 years. I ask everyone to analyze and determine the cause of these cracks!
Thickness measurement showed no signs of corrosion or material accumulation
It means it’s old and can retire now.....
I hope everyone can share their opinions and express their views, which will also give me some inspiration
Could it be more specific? If that’s the case, don’t all the other elbows in the device need to be replaced as well?
Is this the outside of the elbow? Did it get scratched while moving things?
Personal opinion: Turbulence accelerates CP fatigue and thus leads to SCC cracking
It arises from the frequent effects of minor deformations in adjacent pipes caused by temperature fluctuations.
This issue shouldn’t be caused by vibrations or the medium used; in my opinion, it’s a problem with the raw materials. After all, over time, even a small issue can grow into something more serious.
1. It is not ruled out that defects existing in the base material itself during production could cause cracks to appear in the product. 2. Fittings are produced by high-frequency heating followed by drawing, and operational errors during the drawing process can also cause this problem. 3. Excessive pressure, or a large temperature difference; no heat treatment was applied during the production of the pipe fittings, resulting in excessive hardness. Suggestion: 1. Conduct a material analysis to check whether the materials match. 2 Conduct a hardness test. 3 Expand the crack to check whether it is an old fracture.