Filters are a key component of compressed air preparation. The air that comes out of the compression chamber is full of contaminants, such as water vapour from condensation and dirt of various kinds. Particulates creep into the air from the atmosphere, from the pipework and the air hoses, and can include oils and chemicals as well as rust and dust. This contaminated air cannot be permitted to enter into the works of sensitive power tools and equipment, so it must first be cleaned and the particulates filtered out.
Air line filters are used to remove these contaminants from the air in pneumatic systems, which might otherwise cause equipment damage and downtime, with consequent production losses. Filters come in three basic types, including vapour removal filters, oil removal filters (also called coalescing filters) and general purpose filters. Typical pneumatic filters for commercial use can remove microscopic particles from the air, and can be installed in a series of primary and secondary filters, or in a membrane type that allows only air particles to pass through it.
Primary filters remove condensation and water vapour, as well as the larger particulates such as physical contaminants (dust, rust, pollens). Secondary or coalescing filters can remove even more minute particles from the air stream, such as odours, fumes, mist, vapour, oil, moisture and other nanometric sized particles.
End user applications for filtered compressed air include biomedical and clean room environments, food and beverage processing and packaging, marine and aviation applications, analytical instrumentation and many more.