Viscosity selection range and principle of vacuum pump oil

December 09, 2023

Viscosity selection range and principle of vacuum pump oil
To see whether the vacuum pump oil is good or bad is mainly to see the viscosity and vacuum degree, and the vacuum degree is to see the value at different temperatures, the higher the temperature, the more stable the performance of the vacuum degree is a good oil.

First, recommended vacuum pump oil viscosity range

1, piston vacuum pump (W type) can use general oil, with V100, V150 viscosity grade oil.

2, rotary vane vacuum pump (2X type) selected V68, V100 viscosity grade oil.

3, direct connection (high-speed) rotary vane vacuum pump (2XZ type) selected V46, V68 viscosity grade oil

4, slide valve vacuum pump (H type) selected V68, V100 viscosity grade oil.

5, trochoidal vacuum pump (YZ, YZR) selected V100, V150 viscosity grade oil.

6, Roots vacuum pump (mechanical booster pump) gear transmission system lubrication, can choose V32, V46 vacuum pump oil.

Second, viscosity selection principle

The viscosity of selected oil is one of the important factors in the performance of vacuum pumps. The viscosity of a liquid is the resistance of the liquid to flow, or the internal friction of the liquid. The greater the viscosity, the greater the resistance of the speed of various components, the higher the temperature rise, the greater the power loss; The viscosity is too small, and the sealing performance of the pump is poor, causing gas leakage and the vacuum to deteriorate. Therefore, all kinds of vacuum pumps on the choice of oil viscosity is very important, the principle of oil viscosity selection is:

1, the higher the speed of the pump, the lower the viscosity of the selected oil.

2, the greater the linear speed of the pump rotor, the lower the viscosity of the selected oil.

3, the more accurate the processing precision of the pump parts or the smaller the gap between the friction parts, the lower the viscosity of the selected oil.

4, when the vacuum pump is used in high temperature conditions, the viscosity of the oil is selected to be greatly appropriate.

5, vacuum pumps with cooling water circulation, generally choose oil with lower viscosity is appropriate.

7, other types of vacuum pump, according to its speed, processing accuracy, limit vacuum, etc., choose the corresponding oil.

Third, Viscosity index and viscosity

The viscosity index is usually based on experience that the more "sticky" the better the vacuum. In fact, this is not the case, "thin" and "sticky" are DVC, DVE VG22, 32, 46 relative visual and feel only, and there is no quantitative data. If the viscosity value of two oils is the same at 40 ° C, when the oil is cooled to room temperature, the "thin" oil is better than the "sticky" oil. Because the viscosity index of "thin" oil is higher than that of "sticky" oil. The viscosity of the viscous oil changes with the temperature, and the viscosity changes greatly, that is, the viscosity index is low, and the viscosity index is an important indicator of vacuum pump oil. Pump oils with a high viscosity index have less variation between viscosity and temperature. Moreover, the cold pump is easy to start and has a significant energy saving effect, especially in the summer, with the increase of the ambient temperature and the oil temperature in the pump, the oil limit pressure can maintain a good effect.

Author:

Mr. James

E-mail:

sales@cn-lubricantadditive.com

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+86 13783582233