Compressed Air Filters
compressed air filter
| Filter duties | Dry particles; coalescing oil and water aerosols; separate activated-carbon stage for oil vapour |
|---|---|
| Threaded connections | 1/4, 1/2, 3/4, 1 and 2 in nominal pipe sizes; BSP or NPT specified separately |
| Compact housing sizes | 89 × 191; 114 × 343; 152 × 445 mm, external width × height for selected threaded configurations |
| Body options | Coated aluminium for compact lines; steel or stainless steel for specified duties |
| Pressure selection | Standard industrial line duty up to 16 bar(g), subject to the selected housing, drain and temperature rating |
| Element options | Particulate or coalescing grade selected against the contaminant and outlet requirement |
| Condensate handling | Manual, float-operated or electronic level-controlled drain |
| Condition indication | Differential pressure indicator or gauge; optional downstream air-quality measurement |
Configuration options depend on the selected assembly. Drain type changes the overall height; the supplied drawing defines the final connections and service clearance.
The filter assembly, connection arrangement and drain can be customized for your operating conditions and application.
A compressed air filter removes selected contaminants from a pressurised air line before they reach valves, instruments or production equipment. Choosing the element is only part of the job: the housing, drain and installation must let captured contamination leave the air stream without starving the downstream process.
Start with what is reaching the machine
Rust in a valve, oily deposits on a nozzle and water emerging from a hose can come from different parts of the compressed-air network. Intake air introduces contamination; the compressor and pipework can add more; cooling causes water to condense. A filter chosen solely because it matches the pipe thread may leave the main problem untreated.
Solid particles
Particulate media retain rust, scale and other solid matter. The required retention depends on the component being protected and the contamination generated downstream of any central treatment.
Liquid aerosols
Coalescing media collect fine droplets, combine them into larger drops and move the liquid toward the drain. A bowl that cannot discharge its condensate undermines that process.
Oil vapour
Oil in the vapour phase needs a suitable adsorption stage. A finer coalescing element alone does not provide the same function as an activated carbon compressed air filter.
Keep useful pressure at the outlet
A filter becomes a restriction when its flow area is too small, its element is loaded or its connections are unnecessarily narrow. Size it for peak demand at the lowest expected operating pressure, using the supplier's capacity correction data. State whether the flow figure is free-air delivery, standard volume or actual compressed volume; these quantities cannot be exchanged without the reference conditions.
A differential pressure reading is most useful while air is flowing. A low reading at an idle machine does not establish that the filter is correctly sized.
Give collected liquid somewhere to go
Coalescing filters normally need the bowl and drain in the intended vertical orientation. Drain tubing must suit the discharge pressure and route condensate to an appropriate collection or treatment arrangement. A blocked outlet, failed float or incorrectly selected electronic drain can leave water in an otherwise suitable housing.
Heavy water carry-over should be addressed upstream with cooling, separation and drainage. Filters do not reduce the water-vapour dew point; a dryer performs that duty.
Install for the next element change
Leave the manufacturer's specified withdrawal space beneath the bowl and access around its closure. Support the pipework so its weight does not load the filter head. Arrange isolation and controlled depressurisation so service staff can verify that the housing is free of pressure before opening it. Keep replacement element and seal identification with the equipment record.
Use an inline arrangement near a machine where local contamination needs attention. Where several treatment stages must work together, define the complete filter system, including the upstream dryer and downstream pipework.
The filter assembly, connection arrangement and drain can be customized for your operating conditions and application.