This article is to introduce three types of vacuum oils are supplied to vacuum pumps.
It is well known that engine oil cannot be used in a vacuum pump, but not many people are knowledgeable about the vacuum pump oil.
Nowadays, three types of vacuum oils are supplied to the vacuum pumps:
1. Mineral vacuum pump oil
The oil is made by refining crude oil and widely used in different oil-sealed vacuum pumps as standard and basic type.
The advantage of mineral oil: Cost effective compared with the other vacuum oil types. Therefore, it is used as default in many vacuum pump factories.
The disadvantages of mineral oil: Difficult to deliver consistent vacuum when the pump’s heat varies during operation; Frequent to replace oil because oil oxidization happens frequently; Easy to form sludge in the oil.
2. Semi-synthetic vacuum oil
This type is a mix of mineral and synthetic oil with some additives. Some performance of the vacuum pump can be enhanced.
The advantages of semi-synthetic oil: Moderate price; the stability of pump performance is improved during high temperature operation; Longer service life than mineral oil.
For some small-sized rotary vane pumps, it’s sufficient to ensure a good performance with such oil.
3. Synthetic vacuum oil
It’s made by advanced refining process with additional chemical compounds, also known as “additives”, to enhance the oil performance. It’s recommended to use synthetic oil only for vapory applications as mineral oil can be emulsified easily. For extreme working temperature, the performance is obviously much better than that of semi-synthetic vacuum oil. Some other advantages include: no oil sludge formation; longest service life among all 3 oil types.
The shortage is that the cost is obvious higher than the other 2 types.