Vacuum diffusion pump oil usually refers to the specialized lubricating oil used in oil diffusion vacuum pumps (referred to as oil diffusion pumps). Oil diffusion pump is a vacuum pump that uses low-pressure, high-speed, and directional flow of oil vapor jet to evacuate. It relies on oil vapor to carry and compress gas molecules, ultimately achieving the effect of vacuuming. The following is a detailed introduction to vacuum diffusion pump oil:


1、 Definition and purpose
Vacuum diffusion pump oil is the key working medium in oil diffusion pumps. It not only plays a lubricating role, but also an important component in forming steam jets. This oil is heated to boiling inside the pump chamber, producing a large amount of oil vapor. These vapors are ejected at high speed through the nozzle, forming a steam jet that carries and compresses gas molecules.


2、 Performance requirements
Vacuum diffusion pump oil needs to meet a series of specific performance requirements to ensure stable operation and efficient pumping of the oil diffusion pump. These requirements include:


Low saturation vapor pressure: to ensure that the pressure of oil vapor is sufficiently low at the operating temperature of the pump, without interfering with the pumping process.
Good thermal stability: During the long-term operation of the pump, oil vapor needs to be repeatedly heated and condensed, so it is required that the vacuum diffusion pump oil has good thermal stability.
Good antioxidant performance: to prevent oil from undergoing oxidation reactions during heating, which can lead to a decrease in performance.
3、 Types and brands
There are many types and brands of vacuum diffusion pump oil, and different brands and types of oil may have differences in performance. Some well-known brands such as IOTA, Shinetsu, Ulvac, etc., all provide high-quality vacuum diffusion pump oil products. These products typically have different performance indicators such as viscosity, refractive index, relative density, and flash point to meet the needs of different application scenarios.


4、 Application and maintenance
Vacuum diffusion pump oil is widely used in the pumping process of high vacuum or ultra-high vacuum environments, such as FPD manufacturing equipment, semiconductor manufacturing equipment, vacuum distillation, purification and degassing, and other fields. During use, it is important to pay attention to the following points to maintain the performance and extend the service life of the pump:


Regularly check the performance of the pump, including checking the pumping rate, sealing performance, and heating efficiency of the pump.
Replace the diffusion pump oil that meets the requirements: Select the appropriate vacuum diffusion pump oil for replacement according to the user manual and pump performance requirements.
Keep the cooling water unobstructed: Before and during the pump heating process, it is necessary to ensure that the cooling water is unobstructed to prevent pump overheating and damage.
Avoid entering the atmosphere inside the pump: When stopping work, the pump should be kept in a vacuum state to avoid pump oil oxidation and performance degradation.