ABB EasyLine Series Instructions For Installation Start-Up And Operation page 72

72 EasyLine EL3000 Series Commissioning Instructions
Exhaust Air Connection
Conduct exhaust air directly into the atmosphere at zero pressure
through a line with a large internal diameter which is as short as possible,
or into a gas discharge line.
Use an exhaust air line of PTFE or stainless steel! The temperature of the
medium can be up to 200 °C! Lay the exhaust air line with a downward
gradient.
The inside diameter of the exhaust line should be increased to  10 mm
within no more than 30 cm from the exhaust outlet. If a very long exhaust
air line is used, it's inside diameter must be much larger than 10 mm;
otherwise the pressure regulation in the gas analyzer may not work
properly.
Do not conduct waste air via restrictions or shut-off valves!
NOTE
Dispose of corrosive, toxic or combustible exhaust gases according to the
regulations!