Technical data
3
A compressed air line is an energy line
designed to transport compressed at-
mospheric air with as little loss as pos-
sible from the compressor to the point of
use.
Physically, atmospheric air is a gas mix-
ture consisting of nitrogen (≈78 %), oxy-
gen (≈21 %) and argon (≈1 %) as well as
traces of carbon dioxide and other gases.
Air quality
The quality of the air is defined in the
Pneurop 6611 quality guideline first pub-
lished in 1984.
The compressed air quality requirements
will depend on the type of application.
This quality must be supplied by the unit
producing the compressed air and should
not be impaired by the distribution net-
work.
Polybutene (PB), as a material for mould-
ing pipes and fittings (couplings, tees,
elbows), complies with the KTW recom-
mendations for plastics and drinking wa-
ter issued by Germany’s Federal Health
Office. It is also tested in accordance
with the rules of the German Association
for Gas and Water (DVGW), work sheet
W 270.
The pipework must convey the com-
pressed air from the compressor to the
point of use with as little reduction as
possible in:
• the air quality,
• the air quantity, and
• the operating pressure.
Excessive quality demands will increase
the cost of the compressed air. The air
quality requirements are the basis for
determining the type of air treatment and
the pipework material of the distribution
system.
Criteria for a compressed air line
Class Max. particle size Max. particle
density
Pressure dew
point
Dew point
Max. oil
content
e mg/m
3 0
C* mg/m
3
1 0.1 0.1 -40 0.01
2 1 1 -20 0.1
3 5 5 2 1.0
4 40 Not specified 10 5.0
5 Not specified 25.0
* Max. value
Class 1: e.g., photographic industry
Class 2: e.g., aerospace industry
Class 3: e.g., packaging industry
Class 4: e.g., general industrial pur-
The pressure dew point
indicates the high-
est permissible water
content of the air.
-40
0
C = 0.117 g/m
3
-20
0
C = 0.88 g/m
3
2
0
C = 5.57 g/m
3
10
0
C = 9.36 g/m
3
Compressed Air Applications Manual | Planning criteria Compressed Air Applications Manual | Criteria for a compressed air line