Centrifugal pump selection
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There is a need to transport existing trichloroethylene and tetrachloroethylene materials; the purity of these substances is over 90%, with the remaining components being organic chlorinated aromatics. The acidity of these materials is around 1%, and they may contain some chloride salts as well. Previously, fluoroplastic centrifugal pumps were used, but they were later replaced by stainless steel centrifugal pumps – the main problem being frequent leaks in the mechanical seals. I would like to ask experts how this situation can be improved
Trichloroethylene and tetrachloroethylene are organic compounds, while chlorides contain chloride ions. Stainless steel can be corroded by these chloride ions; using a fluoroplastic pump should be a solution to this problem. Why is there a need for a change?
What material is used for the mechanical seal? What is the medium temperature? Neither steel components nor springs can withstand corrosion by the medium; it is still recommended to use fluoroplastic centrifugal pumps, with K-type seals for shaft sealing, which should resolve the issue
Fluoroplastic pumps are equipped with mechanical seals made of PTFE, and their sealing surfaces are made of silicon carbide; however, chlorides cause significant wear on these sealing surfaces. Stainless steel pumps are used, and the mechanical seals are double-end face seals made of 316L material; however, wear caused by chlorides can also lead to damage to these seals. Are there any types of mechanical seals that can withstand dissolution by trichloroethylene, as well as wear and mild corrosion caused by chlorides? Can magnetic pumps be used?
There is no issue with the material of the pump; fluoroplastic can still be used. The mechanical seal should be improved – instead of the current WB2 single-face design, a double-face design with flushing capabilities should be employed, which will provide effective protection and extend the seal’s lifespan.
If there are no impurities, a fluoroplastic magnetic pump is an excellent choice; be careful not to run it without load.
It is better to choose a fluorinated magnetic pump; for the shaft and bearings, SSIC should be used