Corrosion issues in shielded pumps
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Significant uniform corrosion occurred on the impeller, shield, and shaft monitor of the canned pump. The stator surface has corroded to give a matte, frosted appearance. The shell surface shows corrosion in the form of grain-like patterns. A portion of the front end of the shaft has corroded and peeled off, while the rear end of the shaft exhibits uniform corrosion. At the area where the rear end of the shaft contacts the bearing, there are corrosion patterns similar to grains. Medium: mainly chlorobenzene, about 1% esters, around 100 ppm water, and about 500–1000 ppm HCl. Strangely enough, there were very noticeable signs of uniform corrosion inside the pump, but the inlet and outlet pipes did not show any significant thinning. Another interesting point is that a grain-like morphology appeared in the bearing housing behind the pump. Has anyone encountered a similar situation? We can discuss it.
The information is very useful; I’ve learned a lot. Thank you so much:D
High flow velocity plus corrosive media can cause erosion, but there is no significant thinning in the wall thickness of the pipeline at the pump outlet. It feels kind of strange.
The elbows in the pump inlet pipeline were checked, and no significant thinning was detected
Spectral testing should be conducted on the pump body material.
The pump body is made of 304 or 316L, and the shaft monitor is 316L. A new shaft monitor was replaced in the middle. It can be said that at this flow rate within the pump body, the medium is at least quite corrosive to 316L.
Then give priority to cavitation, that is, the issue of matching your allowable temperature with the vacuum level
I can provide information on corrosion-resistant seals