Improved filters for the compressed air line save energy

The three improved filter systems of the series AFF, AM, and AMD for the main compressed air line reduce costs through less pressure loss, higher filter performance, and particularly maintenance-friendly features. (Photo: SMC Deutschland GmbH)

20% higher flow capacity, up to 60% less pressure loss, and up to 50% less weight — these are the key figures achieved by SMC in the redesign of their main line filters. Combined, the three filter systems of the AFF, AM, and AMD series prepare compressed air according to the cleanliness class ISO 8573. The following filter performances result:

- Main line filter of the AFF series:    1.0 µm
                        Removal of coarse dust particles and water droplets                       
                        Filtration efficiency: 99%
- Microfilter of the AM series:           0.1 µm
                        Removal of dust particles and oil mist
                        Filtration efficiency: 99%
- Sub-microfilter of the AMD series:       0.01 µm
                        Removal of fine dust particles and oil mist
                        Filtration efficiency: 99.9%

For the filters of the AFF and AM series, SMC improved the separation performance regarding the captured particle sizes by a factor of 3. While the detection limit of the predecessor models was still at 3 µm (series AFF) or 0.3 µm (series AM), the new models filter particles down to 1 µm or 0.1 µm. Overall, each of the three filter series includes three sizes with flow capacities of 7.0, 11.0, and 14.5 m³/min.

Save space, maintenance, and costs

"Because the new main line filters of the AFF series remove both water droplets and solid particles, a separate water separator filter is no longer needed," explains Tobias Hartherz, Product Management at SMC Germany. This simplifies installation and saves time and costs in maintenance. Previously, a water separator, e.g., from the AMG series, was required; now, the AFF filters alone require significantly less space. With the same filtration performance, the required installation length has decreased from 490 mm to just 170 mm! And the installation depth has also been reduced: from 220 mm to 160 mm, making installation much easier, especially in tight spaces.

More flow capacity with less pressure drop

Through constructive measures, SMC has succeeded in reducing the pressure drop despite improved filter performance. A maximum of 5 kPa now accounts for the pressure loss across the three filter systems. This has the most significant effect on the AMD sub-microfilters, which generate up to 60% less pressure drop. This optimization results in approximately 20% higher flow capacity. The substantial weight savings are mainly due to the use of thinner stainless steel for the housing body. In the largest model variant of the AFF filter, this means a weight reduction of over 50%, from 10.5 kg to 5 kg.

Smart features make maintenance easier

A stopper function simplifies maintenance of the three filter systems: technicians can safely loosen all four mounting screws without the filter elements falling out. Only when the container is slightly rotated does the stopper unlock, allowing the container to be pulled downward. A clearance of just 40 mm below the filter unit is sufficient for this.

A red indicator on the filter cover shows when maintenance is needed. The various filter elements are color-coded to prevent confusion during replacement. For example, the end caps of the AFF filters are gray, those of the AM series are light blue, and those of the AMD filters are blue. Slots in the end caps allow condensate to drain, preventing it from remaining in the filter housing. Even with media that have high volume flow rates, this prevents carry-over.

The improved filter systems of the AFF, AM, and AMD series enhance the purity of the main line compressed air. At the same time, the higher filtration degree can extend the function and lifespan of downstream products. The reduced pressure loss saves energy and increases flow capacity. Additionally, numerous design improvements have significantly reduced weight and space requirements. Maintenance and replacement of filter elements are now very simple and quick. A maintenance indicator helps plan timely filter element replacements.