A Bigger Oil Reservoir Does NOT Lead to Longer Oil Change Intervals

Just like with your vehicle, when it comes to compressors, maintenance is key. It should be factored into the purchasing process as part of the lifetime cost of owning compressors. One important aspect of maintaining an oil-injected compressor is changing its oil.

One important thing to note is with oil-injected compressors, the size of the oil reservoir does not determine how often the oil needs to be changed.

The role of oil in screw compressors

As a coolant, oil plays a critical role in oil-cooled rotary screw air compressors. The oil removes the heat generated during the compression process. Oil also lubricates the rotors and seals the compression chamber. Because compressor oil is used for cooling and sealing, it is important to use special, high-quality oil made specifically for this application and it cannot be substituted with alternatives such as motor oil.

This special oil comes at a cost, and many believe the larger the oil reservoir the longer the oil life, but this is extremely misleading.

Determining oil lifespan

Heat, not the size of the oil reserve determines how long oil lasts. If a compressor is experiencing shortened oil life or requires a larger oil reservoir, the compressor may be generating more heat than originally intended during compression. Another issue could be that excess oil is passing through the rotors because of an unusually large gap.

Ideally, you should consider the total cost of changing oil per running hour and be aware of a shorter than the industry average oil life expectancy. The Compressor’s operator’s manual will lay out the average oil life expectancy and oil capacity of an oil-injected screw compressor.

Large oil reservoirs don’t indicate long oil life span

Large oil reservoirs does not indicate long oil life span. Some manufacturers may imply they lead to longer oil life, but there isn’t any correlation between the two. Before purchasing a new compressor, do you research and adhere to an effective maintenance schedule so you can catch and potential problems early and avoid wasting money on replacing compressor oil.

If you have any questions, please contact us today.