Chemical duty usually brings corrosive gas, organic solvent vapour and condensable components. The mechanical pump normally works as a backing or rough-vacuum stage, and conditioning ahead of it — condenser and separator — is essential so that condensable fractions are removed before they reach the pump.
Establish the medium and its concentration, whether acids or alkalis are present, the temperature, whether particles are carried, and the continuous running time. Where the medium is corrosive, check chamber and seal materials with us, or change the staging of the vacuum system.
Size the pump for filtration, degassing and vacuum distillation from the process gas load, not from vessel volume. For processes that release gas intermittently, add a vacuum buffer receiver.