Air Compressor Oil Change: Lifespan, Roles and How to do It

When it comes to compressors, maintenance is vital. This is a factor many people consider during their compressor purchasing process as they calculate the life cycle cost of compressor. However, when considering oil replacement frequency for oil-injected air compressors, many people incorrectly underestimate the importance of regularly changing the oil as its lifetime directly affects the total operating cost and efficiency of the user's equipment.

Oil plays a critical role in oil-cooled rotary screw air compressors. Let’s quickly have a look at what compressor oils do.

The ultimate function of compressor oil is to keep compressors moving and maintaining optimum performance of compressors.

Ambient temperature, air humidity level and air intake quality (dust level) are the 3 main factors which impact the overall oil lifetime. Based on years of experience and in-depth analysis of connected machines, Atlas Copco developed a world heat map where regions are categorized as being mild, demanding or extreme.

Middle East, which is characterized by hot summers with high humidity (as high as 90% in some areas) and frequent sandstorms during periods of seasonal change, is categorized as being an extreme region.

What does this mean for the oil? The sweltering and humid heat can decrease oil life expectancy and change the characteristics of the oil. Overtime this can result in the oil not performing its core tasks as it should.

The lifetime of an oil, and consequentially, the specified oil drain interval depends of the operating conditions in which the oil is used. Oil ageing is happening due to the process of oxidation of the oil. The rate of oxidation is closely linked with the operating conditions (read temperatures, air quality and humidity level).

Due to the process of oxidation, particle formation happens. It starts with small solvable particles but overtime these particles will stick to each other and form larger particles. Within a certain size, these particles will still be filtered out by the oil filters & separators.

At a certain moment the specified oil drain interval is reached, and it is time to change the oil. 

By doing so, it is avoided:

• even larger harmful particles are being formed.
• the oil becomes too acid attacking weaker materials in the oil circuit like seals and gaskets.
• the oil becomes too thick as a result of viscosity increase blocking smaller channels in your oil circuit

As a result of changing the oil at its specified oil drain interval, you are sure the next oil drain interval is also guaranteed!  By doing so, the machine remains in optimal condition, reliability is secured, and performance remains as it should be.

Atlas Copco lubricants are a unique blend of chemical properties, engineered for optimal performance in their dedicated functions. These carefully selected additives interact in the right proportion to obtain optimal overall performance from your compressor. Also, we are having an oil to match the requirement of each condition of compressor.

Herewith you can find an overview of the lubricant portfolio for oil injected screw compressors. For extreme conditions, which is the case for machines running in the Middle East region, the Atlas Copco synthetic portfolio is the way forward.

Apart from the non-foodgrade, premium lubricants, like Rs Ultra & Rs Xtend Duty, a NSF-H1 approved oil is available which is an oil specifically designed for OIS machines running in food and beverage, pharmaceuticals & packaging industries. 

Get in touch with us. Describe your air compressor application, ambient conditions, workflow pattern and maintenance intervals to our experts and they will identify the Compressor Oil from our portfolio that will meet your needs.