Whether it is a breather on a Hydraulic system, a gearbox application or bulk fuel/oil reservoir, the importance of a quality breather is generally overlooked.
It is a typical sight to see, a chrome style air breather covered in oil and dust and it most likely has been that way since a week after it was installed.
One of the easy ways to understand the importance of quality filtration is by firstly understanding the importance of a quality breather and the function it has in maintaining a clean system.
A breather is the first place contamination will enter a system. If the system is running 2, 5 or 10 micron filters then why would you fit a 10 or 40-micron breather?
If a 40-micron breather is fitted to a system, this then means that the system pressure and return filters have to not only remove any contamination generated by the system, but they also have to remove any airborne contamination that has entered the system through the 40-micron breather.
Effects from this are a decreased in filter element life, an increase in oil replacement costs and generally it is harder to maintain, consistent oil cleanliness.
“The ingression of contamination through the system breather, is far greater, then what the system pressure and return filters were designed to remove”
By fitting a 3-micron breather to the system, this will eliminate all airborne contamination from entering the system.
The system filters will only have to remove system-generated contamination. With the system filters only having to capture contamination that has been generated from within the system, the oil cleanliness can be achieved and easily maintained.
Important thing to remember:
One size does not fit all. Each application should be look at individually. Correct sizing of the breather is so important, an under rated breather can have the following affects:
Tank over pressurisation, cavitation to the pump, short breather life, introduction of moisture and unwanted contamination. Air flow rates, environmental conditions, type of fluid, volume of reservoir and fluid displacement are all important factors and just one of them overlooked can have adverse results.
Different breathers are available for specific application:
- Humid areas, temperature fluctuations, moist areas – use a desiccant breather (changes colour when it needs to be replaced)
- General hydraulic reservoir – use a breather no greater the 10 micron with a replaceable element or with a visual indicator (A chrome breather can be use if changed regularly)
- High dust environment – use a large breather with replaceable element visual indicator is preferred