The choice of the vacuum pump oil demand _ _ vacuum pump oil

1。 Vacuum pump oil seal performance

vacuum pump oil demand has suitable viscosity. Under the low temperature, vacuum pump can quick start. At high temperature, vacuum pump oil can has good sealing performance. Vacuum pump oil pump temperature is low. To rise. Do not contain light volatile components, reduce the vacuum pump running in the process of recovery.

2, saturated vapour pressure of the vacuum pump oil

saturated vapor pressure is one of the key indicators of vacuum pump oil. In a thermostatic airtight container, vapor and liquid phase to achieve dynamic balance pressure referred to as the saturation vapor pressure.

oil saturation vapor pressure should be as low as possible. Under the high temperature of pump, it should still have enough low saturated vapor pressure and below the limit of the vacuum pump pressure. At 60 ℃ temperatures, it must be at least 6. 5×10 - 5 kPa（ Each elevated temperature 20 ℃, the saturation vapor pressure is about one order of magnitude lower 。

3, the final total pressure and the final differential pressure of the vacuum pump oil eventually full pressure

by skin, thermocouple gage measurement instruments or the material of vacuum pump ( Gas) The sum of the pressure. The test indexes of foreign, now looking at full pressure.

final partial pressure: compressed by mercury vacuum gauge, Mcometer） Measurement of the pump, the limit of the air pressure of two stage rotary vane pump pressure should be 6 x 10 - or less 5 kpa。 Limit the pressure and differential pressure limit points request no more than an order of magnitude. The greater the difference between the two, vacuum pump oil contains the more volatile component, the nature of the oil.

( Note: the final total pressure and partial pressure limit are composed of two level advanced vacuum water pump stop)

4, vacuum pump oil, the smoothness of

friction and wear of friction surface, the surface of the fatigue and wear, corrosion and wear, etc. Both are related to the smooth condition. The excellent properties of the vacuum pump oil is good for inhibiting corrosion and wear and tear; It can effectively reduce the appearance of the adhesive wear and fatigue wear. Fluid smoothing agent on the friction surface is clean, and can also reduce the friction and wear. Reduce the friction resistance, in order to save energy, reduce wear and prolong mechanical life.

5, vacuum pump oil cooling performance cooling performance

lower the temperature of the friction surface is an important function of smoothness. As it moves, a friction surface must restrain the friction and work, and for all the work of inhibition of friction is converted to heat, as a result, the friction surface temperature. Friction heat related to the smooth state. Small heat heat high viscosity, low viscosity, boundary friction heat somewhere in between. It can be seen that with proper viscosity vacuum pump oil not only can complete the smoothness of the liquid, reduce friction heat production, and can be timely to friction tropical out of the pump body.

6, the purity of the vacuum pump oil

not prevent friction pair contact with surrounding medium, cause corrosion, rust and damage. Vacuum pump oil friction performance requirements as much as possible of swept area; Anticorrosive, antirust, keep the friction surface is not affected by oil or external corrosion.

7, the oxidation stability of the vacuum pump oil

oxidation stability illuminates the smooth oil anti-aging performance, this is for industrial assembly line operation the special performance requirements of vacuum pump oil. Smooth oil with different degree of autoxidation tendency, it depends on their chemical composition and external conditions. In the air, Or oxygen) And the presence of metal catalyst, vacuum pump oil under certain temperature of oxidation time show that the acid value, viscosity change and sediment formation. Oxidation will happen in the process of applying, thus gradually formed some aldehyde, ketone, acid and colloid and asphaltene, and oxidation stability is to suppress the detrimental to the performance of the oil.

8, the thermal stability of the vacuum pump oil

said oil resistance to high temperature, the smooth oil on the thermal resistance, synthetic thermal synthesis temperature. Some requirements strict application need vacuum oil vacuum thermal stability.

natural mineral oils has its inevitable defects, poor heat resistance than synthetic oil, oil pump components easily with the thermal oxidation synthesis and degradation, poor stability limit pressure, pumping speed and over time. Ordinary pure mineral oil oxidation test method D943 is about hundreds of hours of synthetic oil D943 can be extended to more than 3000 hours. You can see it has extended service life.

9, vacuum pump oil, the emulsion

during the running of the vacuum pump, water and cold air in the system will be released into the water pump oil. If the vacuum pump oil demulsibility is bad, then mix it with water. Emulsion makes it hard for water from the bottom of the cycle can escape, this may result in a vacuum and smoothness.

therefore, smooth oil demulsibility are industrial important physical and chemical properties. Especially in the pharmaceutical, food, ceramics and other industries using vacuum drying process, the water pump oil emulsification resistance is much more important. Have good ability to resist emulsification of oil resistant oil and water can be very strong, open the gas ballast valve steam and condensate gas discharge after partial water vapor. In addition, low viscosity oil than high viscosity pump more resistant to emulsified oil.

10, vacuum pump oil defoaming performance

in the process of vacuum pump to run, but because of the air, often can produce bubbles, especially when the oil contains surface active additives, tend to produce more bubble, bubble is not easy to fade.

in smooth oil applications use bubble will damage the oil film, not only can make the friction surface of sintering or increase the wear and tear, will promote smooth oil oxidation and the enthalpy change. During the running of the vacuum system, gas reservoir will from time to time through the seal of the vacuum pump oil. Exhaust gas in the reservoir surface produces a large number of air bubbles, from the vent overflow of pump, formation of oil pollution damage and equipment. Contains defoamer pump oil has obvious progress in defoaming effect.