Without an air line filter - water, oil, and dirt can cause major damage to pneumatic tools, destroy factory equipment, ruin a paint job, and even contaminate food in a production facility.
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Proper air treatment is critical to the health of your air system, and compressor filters are an inexpensive investment compared to a costly repair/replacement job.
Shop Air Line FiltersTo better understand how these filters work, we will break them down into 8 main components.
As air enters, the internal cap forces it into a downward spiral. Just be sure to size the inlet appropriately for your compressor. You should never use a smaller filter on a larger line.
The filter cap directs the flow of air through the filter. An arrow on the outside of the filter indicates the direction of air flow, and should not be installed backwards.
In order for the air to be discharged from the filter, it must follow the air path. The air path consists of entering a cyclonic phase and passing through the filter element.
The filter discharge is the orifice through which the air leaves the filter. The sizing of the discharge should match the inlet size. An under-sized filter will restrict air flow.
The filter element is the part that actually filters the air. The filter element catches particulates you wish to remove from the air. As the filter does its job, it becomes clogged with those particulates.
Once the filter is clogged, it will need to be cleaned or replaced. If CFM (cubic feet per minute) decreases, it may be due to a clog in the filter element. Using too fine of a filter element can cause more frequent clogging.
The filter bowl makes up the largest visible part of the air compressor filter. It connects to the cap housing by either threading into it or twisting and locking into place.
The filter quiet zone is a zone at the bottom of the filter bowl where contaminants, oil, and water are collected. There is usually a horizontal barrier that hangs down from the bottom of the filter element that prevents debris from becoming re-entrained in the air.
Eventually, the water, oil, and debris in the bottom of the filter bowl must be drained. Some filters come with manual drains, requiring you to periodically remove the plug and drain the contents.
Other filters come with float-operated drains or electric auto drains. Failure to regularly open and drain the collected water and debris will cause the water to rise above the barrier and become re-entrained.
Air line filters are measured by the size of the particles they can catch. These particulates are so small they have to be measured in microns (1 micron = one-millionth of a meter). For comparison, a human hair is about 100 microns across and a red blood cell is 8 microns in diameter.
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If you are using fine particulate filters, let's say a 5-micron filter, the element inside will trap seemingly invisible particulates smaller than a red blood cell! To avoid immediate clogging of the unimaginably tiny holes in the filter element, it's best to have a general-purpose filter installed upstream to catch larger particulates. Doing so will save you from frequently replacing the small-sized filters, or tossing them altogether!
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Filtration is key in any compressed air system; properly maintained compressed air filters can improve the lifespan of your air tools and avoid contamination of the system. Compressed air filters are fitted into your pipework system usually before and after the dryer, with the aim of both protecting your dryer and downstream equipment and plant. The filters are designed to remove contaminants (usually oil) that unavoidably enter the compressed air from the compressor and also to remove contaminants that are sucked into the air compressor from the environment (usually dust / grit / microbes etc). The compressed air filter is made up of two parts, a tough housing capable of withstanding the pressure and temperature of the compressed air directly from the compressor and a replaceable filter element. Typically the filter element needs replacing annually.
When buying inline filters for your compressed air system specify the filter based on capacity of the air compressor (always size the filter higher than the air compressor capacity) and then select the type of filter required (see below). We recommend fitting a dust filter (S range) before the dryer and then a high efficiency filter (D range) after the dryer.
You can buy either the complete filters (including housings) or just the replaceable elements from our online shop
Multi-stage filtration is essential for breathing-air or food-grade applications where air quality is of utmost importance. Compressed air filtration is usually carried out in stages, as such our range of filters are available in 5 different grades:
All of these are available to order online from our dedicated online shop
Pre Filter (P Range) This is the first stage that should be considered. It is suitable for intercepting a large quantity of solid and liquid particles up to 3 micron in diameter, with minimal drop in pressure. The filter element is made of layers of glass microfibre and layers of non-woven polyester. This is a low cost way to instantly improve air quality and protect your compressor. The water and dirt is drained from the bottom of the filter.
Dust Filter (S Range) This compressed air filter has the same features as the pre filter, however the element on a dust filter removes solid and liquid particles down to 1 micron. This filter can be used as additional filtration to the pre filter or alternatively it can be used after a pre filter itself to avoid premature clogging of a coalescence filter further down the line. The filter element is made of layers of glass microfiber and layers of non-woven polyester.
Coalesence Filter (C Range) This interception compressed air filter will remove hard and oil particles up to 0.1 micron in diameter. This filter, by means of impact, interception and coalescing principles, causes the submicronic liquid particles, which strain through the element from the inside, to collide with each other, forming microdroplets which will drip at the bottom of the filter housing. The element itself is made of a layer of borosilicate fibre-layer supported by two inner and outer stainless steel structures.
High Efficiency Coalesence Filter (D Range) This is a higher-efficiency version of the coalescing filter which will remove hard and oil particles up to 0.01 micron in diameter. Air passing through this filter is practically 99.99% oil free; therefore it is suitable for use in installations where purity of air is a must. It can be utilised after a dryer as a de-soiling filter and is the perfect pre filter for the activated carbon series.
Activated Carbon Filter (V Range) There are many applications which require air to be free of micro impurities as well as odours and vapours. This activated carbon filter, through the absorption process, is able to attract the odours and vapours left after de-soiling, and attach them to the active carbon particles. The activated carbon filter must always be preceded by a dryer to remove moisture and coalescence filter, ideally a high-efficiency model, to remove contaminates. The filtering element is made of a bed of activated carbon covered by a fibre coating, kept in place by an inside and outside stainless steel wall.
If you have any queries about our range of filters or would like some advice about choosing the right filtration for your application please don’t hesitate to contact us.
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