Particles
The first position describes solid particles through defined size or concentration limits. It does not automatically specify one filter element.
Compressed-air quality
What does ISO 8573-1 mean?
Define quality at the measurement point.
ISO 8573-1 classifies particles, water and oil. It does not automatically select a filter or dryer range; that follows the process requirement, measurement point and operating conditions.
01 Meaning
ISO 8573-1 classifies
particles, water and oil.
It defines classes for particles, water and oil. A class statement only makes sense when order, standard edition and measurement point are clear. It does not replace process approval or treatment selection.
Water
The second position uses pressure dew point or liquid water depending on class. Dew point must fit operating pressure and the coldest relevant point.
Oil
The third position limits total oil from aerosol, liquid and vapour according to the standard definition. Activated carbon may be an additional stage.
02 Application to class
Do not choose the “best” class –
define the required class.
Required quality comes from product, machine, process or manufacturer needs. Without that basis, an unnecessarily strict class may only add pressure loss, regeneration and energy.
01
Define consumer
Which machine, product or process receives the air?
02
Define measurement point
Compressor room, network, machine or critical point of use?
03
Confirm limits
Define particles, water, oil and any other contaminants separately.
04
Plan evidence
Method, operating state, frequency and responsibility.
03 Ask the filter question correctly
Filter grade and air class
are not the same.
Manufacturers use their own filter-grade names. ISO 8573-1 classifies the resulting air at a measurement point. The chain is selected to achieve that result under actual conditions.
| Stage | Typical task | Important limit |
|---|---|---|
| Water separator | remove larger liquid droplets | does not replace drying or fine filtration |
| Particulate filter | reduce solids in a defined range | monitor loading and pressure loss |
| Coalescing filter | collect and separate fine liquid and oil aerosol | does not universally remove oil vapour |
| Adsorption stage | reduce selected gaseous contaminants | life depends on inlet burden and operation |
| Dryer | limit water vapour to required pressure dew point | size for temperature, pressure, load and target |
04 Common errors
A class without context
is not a design.
These errors cause unnecessary cost or quality that never reaches the user.
No measurement point
Dryer outlet quality does not guarantee quality after a long network.
No pressure
Dew point and moisture are misunderstood without pressure context.
Product name only
A “fine filter” is not proof of a specific air class.
Over-quality
Unnecessary targets can add pressure loss and energy.
05 Common questions
ISO 8573-1
in practice.
What does ISO 8573-1 mean?
It classifies compressed-air purity for particles, water and oil. It is not a universal food, product or equipment certification.
Which filter grade do I need?
The better question is which air quality the user needs. Filter names are manufacturer-specific. Treatment follows the contaminants, target and inlet conditions.
Does one class apply to every nitrogen generator?
No. Current nano ranges have different feed-air requirements. The current manual and data sheet for the exact model are authoritative.
Where should quality be measured?
Where the quality is contractually or operationally required. Additional points may be useful after the dryer, in the network or at the consumer.
Next step
Quality issue or new requirement?
Define the handover point first.
MX Solutions can assess the process need, installed treatment and next useful measurement.