Why can excessive seal oil injection and too low a specific gravity of the seal oil easily lead to cavitation in centrifugal pumps?
Thread Content
Why can excessive seal oil injection and too low a density of the seal oil easily lead to cavitation in centrifugal pumps?
Sealing oil has nothing to do with vacuuming.
Firstly, when the gas content in the medium is low, there are no issues with pumping using a centrifugal pump. The sealing oil contains certain light components; when an excessive amount of it is injected, more of these light components vaporize, making it easier for vacuum to occur. Naturally, oils with a lower specific gravity vaporize and lead to vacuum more easily. However, normal seal oil injection is equipped with a flow control orifice plate, so the amount of oil injected does not become excessive; this might be due to the low specific gravity of the seal oil.