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Compressed Air Treatment


Breathing Air


A breathing air supply is regarded as a vital part of every hospital infrastructure and is one of the few medicines that are manufactured on-site. Compressed breathing grade air can be used for a wide variety of applications such as anaesthetics, lung ventilation, intensive therapy, pneumatic surgery tools, nebulizers and many more where the quality of the air is vitally important.

The problem

In compressed air fed systems, ambient air is drawn into the compressor, therefore any contaminants present in the ambient air plus those introduced by the compressor itself will be present unless removed by a purification system.

Contaminants present can include:

  • Carbon monoxide

  • Carbon dioxide

  • Water vapor

  • Micro-organisms

  • Atmospheric dirt

  • Oil vapor

  • Water aerosols

  • Condensed liquid water

  • Liquid oil

  • Oil aerosols

  • Rust

  • Pipescale

Parker Domnick Hunter has introduced Breathing Air Purifiers with CO /CO2 reduction, series BA-DME and BAM

BA-DME The Parker domnick hunter BA-DME range consists of Breathing Air Purifiers which are ideal for point of use multiple personnel protection at medium flow rates. At the inlet, a General Purpose Filter removes particles, dirt and aerosols, followed immediately by a second stage High Efficiency Coalescing Filter to reduce oil and water content. A third stage Activated Carbon Filter removes oil vapour and odor. The fourth stage ,adsorption dryer, reduces the water vapour content of the compressed air (to -40°C pdp) and CO2, NO and NO2 levels to below the legal permissible limits. Downstream of the adsorption dryer, a catalyst converts carbon monoxide to carbon dioxide, again, to below the legal limits. A final Dust Filter captures any particulates carried over from the adsorption materials.

BAC-4015 The Parker domnick hunter BAC-4015 is a fully pneumatic, portable Breathing Air Purifier designed to provide complete protection for up to four personnel. Five purification stages will ensure the highest quality air that is free from particulate dusts, vapours, odours, carbon dioxide (CO2) and carbon monoxide (CO). The flow rate is easily adjustable from a pressure regulator and monitored by inlet/outlet pressure gauges on the front facia. The BAC-4015 is housed in an extremely strong and robust lockable case for total security.

BAM range The Parker domnick hunter BAM Breathing Air Purifiers consist of six purification stages mounted on a portable skid for high-capacity multiple personnel breathing air applications. At the inlet, a first stage water separator removes bulk water, followed immediately by a second stage high efficiency coalescing filter to reduce oil and water content and a third stage activated carbon filter to remove oil vapour and odours. The fourth stage adsorption dryer, reduces the water vapour content of the compressed air (to -40°C pdp) and CO2, NO and NO2 levels to below the legal permissible limits. Downstream of the adsorption dryer, a catalyst converts carbon monoxide to carbon dioxide, again, to below the legal limits. A final dust filter captures any particulates carried over from the adsorption materials.
Built to exaction standards, the BAM series is engineered to exceed breathing air certified standards. As standard the BAM series are fitted with a CO monitor meaning that there are no high – priced additional expenses or delays to arrange external monitor fitting






Drain Valves

As part of the compressed air purification process, filtration and separation devices are installed in the compressed air system to remove all contamination. The collected oily water condensate must then be removed from the downstream filters, dryers and air receivers, for legal disposal.


The Parker Zander ED series level sensing drains, detect and discharge only when condensate is present. With no mechanical sensor parts and a sensing system that works with all types of compressed air condensates, including aggressive oil-free.
The intelligent operation of our ED series always ensures no loss of valuable compressed air.

Our ED series drain valve cover installations with compressed air flow up to 66000 m3/hr and pressure up to 40 barg


Compressed Air Filters


Condensate Management

Discharging oil contaminated condensate from compressed air systems is not only harmful to the environment, it is also probably illegal. Oil spillages from industry do not have to be big to be serious.
One liter of oil can cover 3500m2 of water surface.
International standards such as ISO14001 also require the compressed air user to comply with local environmental legislation and show use of protective systems and procedures.


After the oily condensate has been efficiently removed from the compressed air system it cannot be discharged directly to the foul sewer without first having the oil content reduced to within legal disposal limits.
The Parker domnick hunter ES2000 Series Oil / Water Separators are a simple, economical and environmental solution which serve this purpose.

ES2000 Series Oil/water separators are installed as part of the compressed air system and simply reduce the oil concentration in the collected condensate to a level permitted, for discharge. This allows the larger volume of clean water, up to 99.9% of the total condensate, to be discharged safely into the foul sewer and the relatively small amount of concentrated oil to be disposed of legitimately and economically

Breathing Air Purity Test Kit – Air Quality Testing for compressed air systems

The domnick hunter Breathing Air Purity Test Kit (APTK1) allows for a convenient ‘on the spot’ indication of compressed air quality. This comprehensive test kit is compact, easy to operate and can be used to indicate the level of contamination both upstream and downstream of purification equipment.

It is supplied complete with oil mist, water vapour CO and CO2 test tubes to allow immediate multiple testing.

In addition to the detection of compressed air contaminants listed above, the domnick hunter APTK1 also features an Oxygen Analyser allowing for constant real-time display of the oxygen content within the compressed air system

Common Questions-Information

What are the main sources of contamination in a compressed air system?

  • The atmospheric air
    Air compressors draw in vast volumes of air from the surrounding atmosphere which contain large concentrations of airborne contaminants.

  • The type and operation of the air compressor
    The air compressor can also add contamination from wear particles to coolants and degraded lubricants.

  • Air receivers and piping system
    The air receiver and system piping stores and distributes the compressed air but will also retain the large amounts of contamination drawn into the system. Additionally they cool the moist compressed air to cause condensation on a large scale. This will promote corrosion, poor performance and potentially the buildup of sources of microorganisms.

Which are the main types of contamination in a compressed air system?


  • Particulate
    Particulate contamination in a compressed air system is a combination of atmospheric dirt, microorganisms, rust and pipe scale. Atmospheric dirt and microorganisms exist in the large volumes of compressed air drawn in and rust and pipe scale occur due to corrosion of the compressed air system.
    The dirt and rust can cause blockage or damage to the production equipment and of course if a few microorganisms were to enter a clean sterile environment enormous damage could be caused.

  • Water
    In a compressed air system water exists as water vapor, condensed liquid water and water aerosols. Of the main contaminants found in a compressed air system water is either directly or indirectly responsible for the majority of problems experienced by the compressed air user.
    The water vapor enters the system through the compressor intake. The compression procedure causes the condensation of a large amount of the water vapour which has to be removed. Even after that removal there might be occasions where further local cooling of the compressed will have as result more water vapour to be condensed.
    Water in any form must be removed to enable the system to function correctly and perform efficiently.

  • Oil
    Oil is introduced into the compressed air system either through the compressor intake as a vapour or by the compressor as a liquid or as an aerosol (fine mist). The atmospheric air contains oil in the form of unburned hydrocarbons and its concentration can vary betwwen 0,05 and 0,5mg per cubic meter. On the other hand a typical concentration of 2 – 5mg per cubic meter enters the system from the oil used as lubricant from the compressor itself.
    The main problems with oil in the compressed air system are due to the oil mixing with water already present. At this point the oil has lost its lubricating properties often becoming very acidic, which causes severe corrosion problems.

How can I specify the quality of compressed air?
There are three standards currently in use which directly relate to compressed air quality (purity) and testing but the most commonly used standard is the ISO 8573 series and in particular the ISO 8573-1. According this part the compressed air quality is defined by three figures, e.g. 1.1.1. known as classes of compressed air.
The first number identifies the particulate content of the compressed air
The second number identifies the liquid water or vapor water content of the compressed air.
The third number identifies the total oil content of the compressed air.
According to ISO 8573-1 a class 1.1.1 compressed air represents the highest quality of compressed air with specific limits of contamination.
Class 0 for each type of contaminant also exists and it allows the user and an equipment manufacturer or supplier to agree their own levels which typically should be more stringent than class 1.

How can I specify the equipment for compressed air treatment based on ISO 8573-1.
This information should be provided by the equipment manufacturer and it is his responsibility to prove that his equipment complies with the requirements of the ISO 8573-1.

The equipment provided by Parker domnick hunter for compressed air treatment is certified independently by Lloyds register to comply with the requirements of ISO 8573-1 and that the testing procedure is according to ISO 12500

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