UD25+ Coalescing Filter – G1/2"

The Atlas Copco UD25+ (8102372405) is a compressed air coalescing filter that removes oil aerosols and wet dust from a compressed air line to protect downstream equipment and your finished product. It has G1/2 inlet and outlet connections and a nominal flow rating of 25 litres per second (around 53 cfm), which suits it to smaller compressed air installations. A coalescing filter works by merging the very fine oil droplets carried in the air into larger drops that collect and drain away, while trapping fine solid particles at the same time.

Inside is a single glass fibre element built on our patented Nautilus technology and arranged as a 2-in-1 design. In one housing it does the work that conventionally takes two separate filters, a coalescing stage and a fine particulate stage, so it reaches comparable air purity with a lower pressure drop and takes up less pipework space. A coarse three-dimensional drainage layer carries the separated oil away and stops it being drawn back into the air stream. At its reference conditions the filter brings oil aerosol content down to 0.001 milligrams per cubic metre, reaching an outlet air quality of class 1 for solid particles and class 2 for residual oil, with water content not rated by this filter. Its fractional filtration efficiency reaches 99.999% at both 1 µm and 0.01 µm, and stays at 99.94% even at the most penetrating particle size (MPPS), the hardest particle size to capture.

The UD25+ operates at compressed air pressures from 1 up to 16 bar(g) (about 232 psi) and is rated for ambient temperatures up to 50 °C. Because it is matched to a 25 l/s nominal flow, check the free air delivery of your compressor before ordering so the filter fits your duty, as running well above the rated flow raises the pressure drop and reduces separation efficiency. A saturated element gives an initial pressure drop of roughly 0.2 bar (about 3 psi), which is normal in service.

The push-in element and drain connection are designed for quick replacement, and the ribbed housing makes the filter bowl easy to remove. A built-in service indicator flags when maintenance is due. Plan to replace the element once the pressure drop across the filter reaches 0.35 bar (about 5 psi), or after 8,000 running hours or 12 months in use, whichever comes first.

The UD25+ sits in our range of compressed air filters rated under 300 l/s. Before ordering, check that the line where the filter will sit is threaded for a G1/2 connector and that the bowl can be reached for element changes; if your pipework takes a different size, get in touch with our team and we will help you match the right filter.