SYNTHETIC COMPRESSOR OIL CONTAMINATION: THE ENEMY OF ROTARY SCREW COMPRESSORS
Rotary Screw air compressors are excellent scrubbers of their environment. Also synthetic compressor oil is formulated to be contaminant resistant. As a result, they continuously ingest high volumes of airborne contaminants and force them into the oil. This makes the compressor’s oil extremely vulnerable to acidic and oxidizing gases ingested from the atmosphere. As these contaminants accumulate and concentrate in the oil, they chemically react to produce harmful acidic byproducts and degrade the oil’s ability to lubricate, cool and protect compressor internals against corrosion. Even the slightest concentration (parts per billion) of the wrong pollutants or chemical vapors can destroy compressor fluids and internals, and negatively impact compressor reliability and maintenance costs.
Many “oil-related” problems are not the oil’s fault at all, but often can be traced back to compressor oil contamination ingested from the air. Ingested Contaminants are equally destructive to both petroleum and synthetic base stocks alike. Knowing how to detect, avoid, and control these contaminants gives compressor users the ability to eliminate, or at least minimize, the harmful impact these contaminants can have on their compressor fluid.
Detecting harmful contaminants and identifying their source can sometimes be tricky. However, with routine oil analysis and simple observations of the compressor’s operating conditions and environment, compressor users can gain important clues to detect the presence of harmful vapor contaminants. Below are some of the symptoms and effects which may indicate you have a problem with ingested contaminants:
COMPRESSOR OIL CONTAMINATION CHART
| High TAN | Short Fluid Life Corrosion | High Oil & Filter Usage High Maintenance Costs |
| Low pH | Corrosion Bearing Wear Short Fluid Life | Air-end Failure Corrosion of Bearings, Coolers and Condensate Drains |
| High Viscosity | High Temperatures High Amp Draw | Oil Degradation, Leaks, Loss of Performance |
| Varnish / Deposits | Wear & Fouling High Temperatures High Amp Draw | Air-end FailurePlugged Coolers and Separators, High Oil Carryover |
COMPRESSOR OIL CONTAMINATION CONCLUSION
Firstly, industrial environments are often rich in harmful pollutants and chemical vapors that can wreak havoc with expensive compressor fluids. Strong oxidizing and acidic gases are extremely destructive to compressor fluids and internals. As a result, they have shown to reduce fluid and air-end service life by more than 90%. In documented cases, as little as 100 ppm of Chlorides present in the air has resulted in air-end failures in less than 18 months. Click here for more.
Residual compressor oil contamination left behind from a previous oil fill can also be destructive to compressor fluids and severely impact fluid life. During a typical compressor oil change, as much as 20% of the old acidic fluid is unavoidably left behind to contaminate and reduce the life of the new oil. Compressor fluids with a history of high TAN, low pH or those that have varnished, if not thoroughly drained can have a dramatic impact on the service life of the new fluid. Even when a flush is performed after draining the old fluid, varnish and other baked-on acidic deposits will slowly dissolve into the new fluid, increase its acid level, and reduce its useful life.
Synthetic Compressor Oil Strategy
The best strategy for dealing with compressor oil contaminants is to eliminate them at the source by supplying the compressor with the cleanest, driest and coolest air available. Specific care should be taken to locate compressors as far away from the equipment and areas listed below, that are known sources of problem contaminants:
- Cooling Towers.
- Water Softeners.
- Boilers.
- Thermal Oxidizers.
- Smelters.
- Loading Docks.
- Busy Highways.
- Chemical Storage Areas.
- Kilns.
- Welding Areas.
- Maintenance Shops.
- Parts Cleaners.
- Paint Booths.
Sometimes it is not practical to eliminate compressor oil contaminants from being ingested. In situations like this, controlling the accumulation and concentration of contaminants in the oil is the only strategy available. It is designed to limit their impact on fluid performance and life. Fluid contamination manifests itself primarily as an acid problem. As a result, controlling fluid acid levels can be an extremely effective course of action to minimize the impact of atmospheric contaminants. Fluid Metrics’ Compressor Oil Purifier (COP) with ion exchange acid removal technology is proven to control fluid acid levels, improve fluid performance, and increase useful service life. There are many documented cases where fluids suffering short fluid life from ingested contaminants have realized more than a 5 fold increase in service life after employing a COP.
More on Traditional & Synthetic Compressor Oil Contamination
Feel free to contact us if you have more questions on synthetic compressor oil contamination and how we can help eliminate it.
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