Product Description | 2
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2.3 Design Options
The design options described in the following chapters might be combined.
Please refer to the nameplate (NP) to identify the corresponding design option of your
machine.
Design option
Codification
Example
Standard (no design option)
0
MM 1252 AV
0
Gas tight version
G
MM 1252 AV
G
Aqua version
A
MM 1252 AV
A
2.3.1 Gas Tight Version
WARNING
Media potentially dangerous.
Risk of poisoning!
Risk of infection!
• Wear appropriate personal protective equipment in case of high concentration of
the medium in the ambient atmosphere of the machine.
The gas tight version is a design option for applications where the process gas re-
mains in the machine and does not escape to the environment.
It is a very important feature for applications where gases potentially dangerous to hu-
man health are not allowed and the concentration of the process gas must not exceed
the admissible values of the ambient atmosphere of the machine.
This machine is specifically equipped with:
– pressure relief lines
– collecting lines
– shaft seal rings.
Requirements for a proper functioning:
Ambient pressure
The gas tight machine requires an ambient pressure at the
gas discharge during the whole operation range of +/- 200
hPa (mbar), unless otherwise specified on the nameplate.
Leakage rate
The machine is not absolutely gas tight.
The leakage rate of the machine described in this manual is
of 0.1 hPa l/s (mbar l/s) at a suction pressure of 250 mbar. It
can considerably increase up to prohibited pressure values
at the gas inlet/outlet due to used shaft seal rings or clogged
pressure relief lines.
Ambient environment
Closed air cooling systems are not suitable and therefore
prohibited.
• Make sure that the machine is sufficiently vented (see
2.3.2 Aqua Version
The Aqua version is a design option for conveying condensable vapours (water).
This machine is specifically equipped with:
– corrosion protection coating
– optional condensate drain (CD) in the internal silencer.
