Compressed air preparation

Compressed air preparation

If you want to ensure a high level of process reliability and machine availability, you must provide for proper compressed air preparation from the very beginning, when planning the system. Because a clean compressed air supply without particles, water or oil helps prevent malfunctions in pneumatic components, increases component service life and reduces machine failures and downtimes. Festo offers you systems that ensure compressed air purity in accordance with ISO 85731:20110.

Compressed air preparation – Festo systems

Our maintenance units are the core of our compressed air preparation solutions. They ensure the right compressed air quality and filter compressor oil, condensate and dirt particles from the air. Depending on the application, a service unit consists of a pressure regulator, various filters, a branch module and pressurization and exhaust valves. Various combinations are available and in stock at Festo. In addition, service units can be configured individually in the MS modular system.

Compressed air service unit

The Festo range also includes the appropriate filter regulators , compressed air filters , lubricators and pressure regulators. Additionally, we offer on/off valves and soft-start valves , compressed air dryers , compressed air distributors and pressure amplifiers. Our compressed air preparation is supplemented by condensate drains , pressure indicators and comprehensive accessories .

Service: Compressed air consumption analysis

Optimal compressed air supply, reliable cost planning, reliable processes: Our qualified service technicians determine your machine's individual compressed air consumption and provide you with facts for more safety, efficiency and transparency.

Our service package includes:

  • Specification of the static compressed air consumption of machines at standstill and when in operation
  • Determination of leakage loss
  • Installation and removal of measuring devices with standard parts (fittings, tubing, etc.)
  • Analysis of the measurement results
  • Documentation of the measurement results


  • Optimal compressed air supply
  • Reliable processes
  • Reliable cost planning

Festo Energy Saving Services

Why compressed air preparation?

Untreated compressed air contains contaminants in the form of particles, water and oil. Water and oil can be in liquid or gaseous form and change from one state to another within the compressed air system. None of these three contaminants are present in a compressed air system in their pure form; they form a mixture. The composition of this mixture can vary greatly at different times in different places in the system. For example, water can collect in branch lines, or particles can become deposited in a dead zone over time, and then be propelled along at one stroke by a pressure surge.

Each cubic meter of compressed air contains millions of dirt particles, significant quantities of water and oil, and even heavy metals such as lead, cadmium and mercury. If these are not filtered out, the proper functioning of the system components cannot be guaranteed over the long term. Furthermore, these hazardous materials significantly impair product quality. Correct compressed air preparation is therefore vital in order to reduce machine breakdowns and downtime and guarantee process and product reliability.

Poorly prepared compressed air causes faults such as:

  • Fast seal wear
  • Oiled-up valves in the control unit
  • Dirty silencers

Possible impact on the user and machine:

  • Reduced machine availability
  • Higher energy costs due to leaks
  • Higher maintenance costs
  • Shorter component and system service life

How clean should compressed air be?

Compressed air must always be so clean that it cannot cause any malfunctions or damage. As each filter also creates a flow resistance, for economic reasons compressed air should be only as clean as necessary. The wide application range of compressed air places many different requirements on compressed air quality. If high quality air is required, several filtration stages are necessary.

ISO 8573 regulates how clean compressed air must be. This is the designation for a group of international standards for the purity requirements for compressed air and specifies the maximum content of solid particles, water and oil that can be present in compressed air. This standard has been mandatory for pneumatic automation since 2010. Therefore it is essential to observe certain parameters to achieve energy-efficient compressed air preparation in compliance with this standard. Festo air preparation units and filters guarantee trouble-free function. You can find out which standard your application must comply with in our brochure "Reliable processes thanks to perfect compressed air preparation."

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Compressed air quality engineering tool

Our engineering tool can help you select the right combination of air preparation units for your compressed air preparation. This program will help you to put together a maintenance unit correctly. Enter the required compressed air quality on this page, either via your application, an ISO code or via the free filter selection.

To the engineering tool

Service: Compressed air quality analysis

Clean compressed air - reliable processes and an increased service life for all pneumatic components: Our qualified service technicians analyze the quality of your compressed air directly at the extraction point.

Our service package includes:

  • Inspection of decentralized compressed air preparation at point of use
  • Measurement of the residual oil content (up to ISO 8573-1:2010 class 2)
  • Measurement of the pressure dew point (up to ISO 8573-1:2010 class 2)
  • Analysis of the measurement results with recommendations for improvements
  • Documentation of the measurement results
  • Additional measurements on request


  • Increasing the life expectancy of pneumatic components
  • Identification of weak points
  • Increasing process reliability

Festo Energy Saving Services