Seeking help with centrifugal pump seal issues! ! !
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Horizontal centrifugal pump, double-end face back-to-back seal, for pumping sulfur slurry (containing some chelating agents and trivalent iron ions), 50°C, 54 flushing scheme. But the mechanical seal looked strange after it was removed; the sealing surfaces were intact, yet the O-rings on the stationary and rotating rings had melted. It’s a fluorine-coated ring. I need experts to help analyze and explain this! Thank you so much! ! !
I want to find the reason. Because the size of this fluorine-coated ring is different from that of the standard ring, it’s not easy to replace it either. It’s a new pump that was being tested for operation; it started leaking like this after less than three days of use! Don’t know how to explain it? ! ? The flushing water uses recycled water, and it remains on all the time. Even if it was forgotten to turn on, water was already transported inside earlier, so it definitely contains water.
That material cannot withstand high temperatures and corrosion; it is recommended to use graphite. Otherwise, seeing if it’s possible to modify it by using fillers might be an option
You say the fluorinated ring is not resistant to high temperatures and corrosion? Today I placed the removed damaged ring in a medium and heated it to 98°C; I left it there for half an hour, but nothing changed~
Are there any flanged fluorocarbon rings of substandard quality that cannot withstand certain temperatures? Generally, if the flushing fluid does not clean thoroughly, what temperature can be reached at the contact point between the stationary ring and the O-ring? As shown by the deteriorated ring, the coating of the ring dissolves first from the inside.
It’s probably due to the high temperature; it is recommended to try modifying the O-ring
Only the tetrafluoro outer layer remains; it must have melted due to the high temperature. Please check carefully the cooling water channels of the mechanical seal to see if they are unobstructed. The outer surface of the last image shows ring-shaped wear marks; there should be no relative movement at the location where the O-ring is sealed, and it is the frictional heat that has damaged the O-ring
It’s caused by high temperatures; was it emptied?
Theoretically it seems to work, but in practice it often doesn’t; just use the most corrosion-resistant one