Q. What is coalescing Filtration?
A. Coalescing Filtration:
A steady state process whereby aerosols are caused to agglomerate (come together) into even larger droplets as they pass through the filter element’s fiber matrix, eventually becoming large enough to be gravitationally drained away
Filter Housing Cutaway

Why filter compressed air?
A. Submicronic contaminants in compressed air systems can:
  • plug orifices of sensitive pneumatic instrumentation
  • wear out seals
  • erode system components
  • reduce the absorptive capacity of desiccant air/gas dehydrators
  • foul heat transfer surfaces
  • reduce air tool efficiency
The results include:
  • product rejects
  • lost production time
  • increased maintenance costs

For example, trace amounts of submicronic oil can cause serious fish eye blemishing in automotive finishing operations. Water left in air lines can freeze during exposure to cold, blocking flow or rupturing pipes. Compressor lubricant not captured in a coalescing filter will eventually collect in pneumatic components, causing premature component repair or replacement. Environmental concerns will be raised if oily, compressed air is continually discharged into the atmosphere through a pneumatic muffler.

Compressed Air Contaminants

The contaminants of greatest concern in precision compressed air systems are water, oil and solids. Water vapor is present in all compressed air; it becomes greatly concentrated by the compression process. While air dryer systems can be used effectively to remove water from compressed air, they will not remove the second major liquid contaminant – oil. Most oil comes from compressor lubrication carry-over, but even the air produced by oil-free compressors has hydrocarbon contamination brought into the system through the intake. The third contaminant found in compressed air is solid matter including dirt, rust and scale. Solid particulates, combined with aerosols of water and oil, can clog and shorten the life of air system components and can foul processes.

Facts and Conversions
1 bar = 14.5 pounds per square inch (PSI)
1 PSI = 27.686 inches of water (H2O)
1 PSI = 2.036 inches of Mercury (Hg)

Volumetric Flow Rate:
1 cubic meter per second (m3/s) = 2118.9 feet cubed per minute (ft3/min)
1 ft3/min = 28.3 liters/min
1 cubic meter per hour (m3/hr) = 1.7 standard cubic feet per minute

32°Farenheit = 0° Celcius
°C = (°F-32)5/9

1000 millimeters = 100 centimeters = 1 meter
1 meter = 39.27 inches = 3.281 feet
1 foot = 30.48 centimeters
1 inch = 2.54 centimeters
1 micron (µm) = 10-6 meters = one millionth of a meter
25.4 µm = .001 inch

1 pound = 453.59 grams = 0.45359 kilograms
1 pound = 16 ounces
1 ounce = 28.349 grams

Our knowledgeable sales staff is here to help you find the right product to fit the job and at the right price to fit your budget.
Contact us today at 727-847-4900 or Toll Free 800-761-4298.

Also Available from mdi: Parker Transair Aluminum Pipe and Fittings for Compressed Air

Transair aluminum pipe is the ideal system for compressed air, vacuum, and inert gas applications. It offers significant savings on installation, maintenance and operating costs when compared to traditional compressed air piping systems. Its removable and interchangeable components allow users to easily modify production layouts or execute process changes within minutes. It's the only product with true push-to-connect fittings, eliminating the need to thread, solder or glue pipe. Its unique sealing technology guarantees Transair to be leak-free.

Also Available from mdi: Parker Air Dryers for Compressed Air

Parker Domnick Hunter was the original innovator of compressed air treatment, developing the modern technology which is still the benchmark today. Parker Air Dryer products and systems deliver a unique combination of innovation and excellence in the most demanding applications, helping engineers to maximise the productivity and profitability of their manufacturing and process operations and with a focus on delivering real and lasting value to every customer. is your complete source for Parker Domnick Hunter Compressed Air Dryers, Gas Generators, Process Water Chillers, and Condensate Drains.