Hydrocarbon V/s Silicone-based Diffusion pump oil

Nowadays, the question is raising of which type of pump oil to use, hydrocarbon-based or silicone-based oils is frequently asked by our customers. The simple answer is that diffusion is the movement and you should use silicone-based diffusion pump oil. Hydrocarbon based Dp oil is rarely used in diffusion pumps and based oil is odorless, colorless, and relatively low in cost as it is manufactured from crude oil or mineral oil.


There are several reasons why hydrocarbon diffusion pump oil was replaced by silicone-based oils: Efficiency, Maintenance, Speed, Cost, and Life cycle.

The silicone-based oil is the clear choice but the Silicone-based Dp Oil does cost more, however, when you factor in the time required for maintenance, the life cycle, speed, and efficiency, it will be an appropriate option.

We are the leading Distributor of high-quality Diffusion Oil in India and all over the world. We readily stock large quantities of D.C.204 and X L - 17 and get this at best price in India to ensure our customers are always taken care of in a timely manner when they need to top-off or replace their diffusion pumps with premium grade oils. It is also used in the metalizing process for vacuum purposes as vacuum oil for creating good metallic coating to the product along with aluminum wire and tungsten filament.

For vacuum applications in most severe operating environments including strong acids, oxygen, combustible or corrosive compounds, and even ionizing radiation, our diffusion pump oils are your ideal solution.

Working principle of Oil Diffusion Pump

It works on the principle of gas diffusion to create a vacuum. In the pump, dp oil is heated to its boiling temperature and Vapor of this oil is compressed in a vertically conical hollow cone as it moves up.

Simultaneously this oil Vapor escapes from sprays along the height of the deep cone. Oil Vapor escaping at great speed catches air and then collides with the water-cooled wall of Diffusion Pump and moves down. Trapped air is released at the bottom of Diffusion Pump.

This creates differential strength in the diffusion pump. Substances move when Pressure at the top is minimum (high Vacuum) and at the bottom is maximum (low Vacuum) from the bottom of the booster pump and the air is sucked by the rotary pump.

When to Change the Diffusion Pump Oil ?

One of the major differences between a hydrocarbon and silicone-based diffusion pump oil is its oxidation rate. As hydrocarbon-based oil oxidizes relatively quickly, it turns very dark and thickens with use.

After 3-6 months of repeated heating within the pump chamber, charred deposits will slowly clog the pressure jets decreasing the vacuum rate and pressure. When you notice this decreased vacuum effectiveness, you’ll know that an oil change is required.

Additionally, you can routinely check the color of the oil. New hydrocarbon-based diffusion pump oil is transparent and usually has a slightly yellow hue. When the oil turns dark and gloomy, it is time for an oil change.

A silicone-based diffusion pump that is synthetic oil can be used for a much longer period of time if no outside contamination occurs and when there is minimum air leakage inside the diffusion pump. Silicone oil used in high vacuum environments offer optimal performance due to its low vapor point and high resistance to chemicals, oxidation, and even radiation.

Based on experience, the average oil replacement times range from 6-8 months. New silicone based diffusion pump oil is clear and transparent. With use, it attains a slight yellow tint. For the most part, the discoloration of silicone-based oils do not necessarily affect performance.

Specification :

•Type: Silicone Fluid.

•Physical Form: Transparent, Water-White in Color.

•Special Properties: Chemically Inert, High Thermal Stability, High Resistance to Oxidation and Hydrolysis, Low vapor pressure, Non-Flammable, Non-Toxic.

•Primary Uses: Fast Pumping of large volumes of gas/vapor in the production process; Produces ultimate vacuum of the order of 10-7 Torque; Produces Ultra high and Ultra clean vacuum of the order of 10-9 Torque.

Features & Benefits :

•Industrial and Research applications

•Low Vacuum Time

•Less Frequent Oil Replacement and Reduced Downtime

•Chemically Inert

•Non-Flammable and non-toxic, therefore totally safe to use

•very competitively priced

•Prolonged Service Life

•Minimal Back Streaming

•Compatible with all Diffusion Pumps

Brand :

D. C. 204, Vicco