Centrifugal pump bearing oil tank level
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What is the appropriate level of oil in the bearing oil tank of a centrifugal pump? Should it reach halfway up the bearings, or should it cover the bearings entirely?
There’s no need to submerge the bearing; half of it is sufficient so that the oil level can be displayed at that level.
Our company stipulates that the liquid level in the bearing housing should be at 1/2–1/3
Theoretically, the oil level should be above the middle position of the balls. However, some bearings do not have oil seals; they only have labyrinth-type bearing caps. If the oil level is too high, oil will leak out instead.
Adding too much oil can also cause friction between the bearing and the lubricant, generating heat that leads to overheating of the bearing!
The lubricating oil level should generally be at the middle of the bearing balls; if there is an oil sight glass, it should be filled to 1/2 of its capacity. Centrifugal pumps are mostly equipped with labyrinth seals; a small number use oil seals or other types of seals. Excessive lubricating oil can cause leaks.
The oil level in the bearing housing should be above 1/3 of its capacity and below the oil seal at the bearing end cover; otherwise, oil leakage is likely to occur from the oil seal.
The bearing housing should have an oil sight glass; fill it to two-thirds of the sight glass’s capacity. If too much oil is added, it will be drained away by the oil seal, and the bearing temperature will remain high