Inline filters are used to keep your compressed air clean and free of particulates and oils that are passed from your compressed air equipment into your system. These filters can technically be placed anywhere in the compressed air piping systems. Some of the most common placements are the following:
- Directly after the commercial air compressor
- Before and after the air dryer (refrigerated air dryers, desiccant air dryers)
- Just prior to point of use (i.e. on each compressed air drop)
- All of the above
- Or any other way that is specific to your system’s needs
Keep in mind, the better the compressed air is filtered before entering the main distribution piping, the more chance that you can eliminate the need for point-of-use filtration in the future. Point-of-use filtration can be costly to install and maintain.
There are four different types of inline filtration offered by PneuTech; particulate, coalescing, activated carbon, and 2 in 1 filtration.
Utility Coalescing: Utility grade coalescing elements offer a particulate removal down to 1 micron and a maximum oil carryover of 0.4 PPM. These elements are typically used as pre-filtration to your compressed air dryer.
High efficiency Coalescing: High efficiency coalescing elements offer a particulate removal down to 0.01 micron and a maximum oil carryover of 0.008 PPM. These elements are typically used as post-filtration to your compressed air dryer.
Activated Carbon: This type of filter removes hydrocarbon mist and vapor. It is used in many different applications, but mostly in industries such as food and pharmaceutical. Activated carbon elements offer a max carryover of 0.002 PPM.
2 in 1 Filter: The 2 in 1 filter element is unique in its design, offering particulate removal down to 1 micron as well as oil absorption through its bed of activated carbon material. This element is ideal for pre-filtration on a desiccant dryer.
There are a few different factors that determine when you need to change your inline filter(s). An industry standard rule is once a year, or every 8000 hours of operation. However, there are multiple variables that can affect this rule and cause the need for replacement sooner than this. Below are a few examples of these variables:
- High oil carryover from the compressor equipment causing the inline filter to become saturated quicker than usual
- Increased amounts of particulate due to corrosion within the piping and/or equipment
- Improperly sized filtration
Note: Keeping an eye on your differential pressure gauge can help to indicate when element replacement is necessary.