The Dangers of Oil Carryover in Your Compressed Air System
All oil flooded rotary machines will have a small amount of oil carryover. The expected amount of oil carryover will vary based on the model. On average, this is will normally be 3 ppm or less. However, if your oil-carryover exceeds this amount, your equipment faces several costly consequences:
 Contaminating end product, resulting in waste |
 Overheating of air compressor, resulting in catastrophic failure |
 Damage to downstream equipment – such as dryers and filtration |
 Wasted lubricant, and increased operating expense |
What Causes Oil Carryover?
Overfilling the Oil – The higher the oil level in the oil reservoir the less room there is for impingement of the air/oil mixture in the reservoir, therefore resulting in your separator being unable to do its job.
Clogged/Faulty Scavenge Line – The scavenge line, sometimes called the oil return line, has the purpose of returning oil from the dry side of the separator back to the air-end. The components in the oil scavenge line should be cleaned/checked every time the oil filter is replaced on a machine. If any of the component of the scavenger line fails, major oil carryover will occur.
Damaged Air-Oil Separator – The air/oil separator, commonly referred to as simply the separator, should be replaced every 4000 hours or every year. Whichever comes first. A faulty separator will result in oil flowing directly downstream without any filtration.
Lightly Loaded Machine – A machine that is lightly loaded will not run long enough for the heat of compression to warm the oil to stay above the pressurized dew point. Dropping below the pressurized dew point will result in the moisture in the air system being released in the form of condensation, and thus having water contaminating the oil. Having water in the oil can lead to oil carryover, or even to a complete failure of the air-end due to the lack of lubrication and rust from being exposed to the water.
Want to better understanding the effects of Oil Carryover and how to prevent it? Contact Us.