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  • Peg Minichiello

The Effects of Varnish in Your Air Compressor and How To Clean it

Updated: Sep 13, 2019

The effects of varnish formation in your air compressor often go unnoticed. Because the process occurs slowly over a period of time it may not be immediately evident and will not affect your day-to-day operations.

Until it does.

Varnish formation not only effects your air compressor; it can also affect other components of your system including the oil cooler, lines, thermal valve, oil filter assembly and sump.  

The Effects of Varnish Formation

In the industry, varnish is thought of as an invisible enemy to your equipment. There are many effects that varnish formation has on an air compressor such as:

  • Increased operating temperature of equipment

  • Decreased oil life

  • Increased energy consumption

  • Decreased heat transfer

  • Increased bearing wear

  • Reduced filter efficiency and life

  • Plugging of oil flow ports and strainers

  • Deterioration of seal materials

  • Sticking of moving components

  • Catalytic degradation of lubricants

  • Decreased reliability of equipment

How To Clean Varnish

Unfortunately cleaning varnish is not as easy as it might sound. Thankfully in today’s day and age we have technology at our disposal to help us.

The most common method of eliminating varnish from lubricant is through off-line filtration but this can be quite expensive. Balanced charge agglomeration, cellulose media, electrostatic separators and other technologies have proven that this is a viable technique.

Top-treat and run-in cleaners are also a popular choice as these cleaners remove varnish from internal surfaces and allow it to be carried to the separation equipment. These cleaners have a typical service life of around 2000 hours, making them cost-effective solutions.

These cleaners come as either concentrates or fully formulated lubricants that are added to the existing lubricant.

Fully formulated lubricant removes light varnish from internal surfaces and have been designed to replace the lubricant every 2 – 4 hours. Unfortunately, they’re not the ideal solution for a heavy buildup of varnish.

Concentrated cleaners are added to existing lubricant at a 10% concentration and are popular because they are fast-acting. They quickly dissolve light varnish and can even cut through heavier varnish. They can only be used for a short period of time and must be removed in one to two weeks after being added to the sump.

Remember, some cleaners feature harmful chemicals or have volatile components in their formulas. It’s important to opt for a non-toxic, non-hazardous cleaner.

Are you interested in preventing varnish formation?

As you can see, varnish formation can be a huge problem that, when left unchecked, can have serious consequences. Preventative maintenance is one of the best ways to keep your air compressor in top shape and can prevent unexpected failures from occurring.

CDA can provide a service program to meet your company’s needs. Rely on our team and book your site visit today: 925.667.3400/

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