A Guide to Choosing the Right Oil for Your Industrial Air Compressor

Using the correct type of oil in your air compressor is essential for ensuring the reliability, performance and longevity of your industrial compressed air system. Your air compressor is a critical asset and protecting it starts with proper maintenance, including choosing the right oil. To help you determine what type of oil your air compressor takes and understand why using the right oil matters, this blog will discuss the different types of oil, how to choose the right one and answer common questions.

What is Air Compressor Oil

Compressor oil is necessary for the operation of oil flooded air compressors because it provides lubrication to reduce friction between moving parts. In addition, it dissipates the heat generated during the compression process and creates a seal in the compression chamber for maximum efficiency. As oil circulates through the compressor, it picks up contaminants, helping to prevent corrosion and protecting components from damage.

Compressor oils contain specific additives that are designed to prevent rust, oxidation and wear in the high-pressure air environment within the compressor, ensuring efficiency, peak performance and a long service life for your compressor.

Understanding Your Options: Standard vs. Synthetic Compressor Oil

Each air compressor comes with recommendations about the type and grade of oil that should be used. The compressor manufacturer may offer a choice between standard or synthetic oil, but usually provides a viscosity rating that should be followed.

To determine which type of oil is best for your air compressor and application, it is important to know the specifications of the oil and the application.

The following are common options:

• Standard Oil: Standard, mineral-oil-based compressor oil can be used for light-to medium-duty applications with consistent operating conditions. Standard compressor oil costs less than other options upon purchase.
• Synthetic Oil: Best for heavy-duty and continuous applications, synthetic compressor oils are engineered for longer service life, provide better cooling and are better at removing deposits from pump components. Although synthetic compressor oil is more expensive than standard oil, it can last much longer because it does not break down as quickly, which allows for longer intervals between oil changes, ultimately reducing maintenance requirements and costs.
• Food-Grade Oil: Food-grade oils are synthetic, non-toxic oils that are specially engineered to be safely used in food and beverage manufacturing and packaging and other sensitive applications.

How to Select the Right Oil for Your Application

There is no one-size-fits all compressor oil, so selecting the right oil for your compressor and application depends on several factors. To ensure the best choice:

• Always check the air compressor manufacturer’s manual: Using a non-specified oil can damage your air compressor and void the warranty, so consulting the manual, which will provide recommendations about the type and grade of oil to use, is the best way to determine which oil will enhance the performance of your compressor.
• Consider the compressor type: Different compressor types, such as rotary screw and reciprocating compressors, have different lubrication needs. For example, rotary screw compressors require an oil that can handle continuous operation and high thermal loads, while reciprocating compressors may need a specific viscosity for reliable operation. And, oil-free compressors do not require oil in the compression chamber since they are already coated and sealed by design. Again, the manual will include information about which oil type, grade and viscosity will provide the best performance for your compressor.
• Evaluate your operating environment: Temperature extremes, humidity levels and dirty, dusty conditions, as well as continuous or intermittent operations, can have an impact on the performance and longevity of the oil. The operating conditions should be considered when determining which type of oil will provide the best solution.
• Consult an expert: When unsure which oil is right for your air compressor, consult an expert at JHFOSTER Our technicians can ensure you purchase the oil that is engineered to provide the best performance from your equipment.

Common Questions about Air Compressor Oil

Do all compressors need oil?

While all oil-lubricated compressors will need oil, oil-free models, which are used in applications that must comply with strict air-quality standards, do not require oil as they are already lubricated and sealed by design.  Oil free compressors may still require oil in gearboxes located outside of the compression chamber however.

How often should I change the oil in my air compressor?

Again, the manual will provide the best guidance for your specific compressor type and model. However, as a general rule, oil in rotary screw compressors should be changed every 8000 service hours, but this can vary depending on the compressor type, service hours and operating environment.

What happens if I put too much oil in an air compressor?

Adding too much oil can result in damage to components, foaming and excess oil carryover into air lines, which can contaminate downstream equipment and finished products. If this happens, don’t panic! Contamination won’t occur until the pump is turned on, so if you’ve overfilled the reservoir, open the drain plug and let some oil out before starting your compressor.

Can I use engine oil or transmission fluid in my air compressor?

No! Engine oils and transmission fluids do not provide the proper viscosity and contain harmful detergents and additives that are not designed for use in air compressors. Using these in lieu of oils engineered specifically for air compressors will result in damage to components, reduced reliability and will likely void the warranty. Check the manual if there is any doubt or contact an air compression expert at JHFOSTER.

Partner with JHFOSTER for Reliable System Performance

Oil changes are an important part of your air compressor’s maintenance routine, but using the wrong oil leads to inefficient operation, premature wear and unplanned downtime. As your partner in automation and compressed air solutions, JHFOSTER can provide everything you need – from supplying the correct OEM oils and parts to providing complete, customized maintenance programs – to keep your air compression system running at peak performance.

Stop guessing and start optimizing. Contact a JHFOSTER certified technician today to ensure the right oil is being used in your air compressor or to learn more about our comprehensive air compressor service and support plans.