Duty: where the gas carries dust, moisture or solvent vapour, the chamber is not simply handling air. Dust wears vanes and cylinder walls; moisture and condensate affect sealing (an oil-free pump uses no oil, but condensate still interferes with the vane-to-wall action); corrosive components shorten component life directly.
Dust: fit filtration on the inlet, mounted as close to the pump inlet as practical. A cleanable coarse element plus a finer replaceable one works well, with the fine element changed on differential pressure rather than a fixed number of days — a gauge across the filter tells you. Shorten inspection intervals at powder conveying and weighing stations.
Moisture and solvent vapour: put a condensate separator ahead of the pump, remove condensable fractions before they reach it, and drain regularly. Where there is a lot of moisture, split the pumping into two stages: clear the atmospheric gas at high volume first, then deal with the remaining vapour.
Operation and maintenance: log capacity and pressure trends in the daily walk-round. When pump-down slows or the pressure will not come down, check the filter element and condensate first, then look for vane wear. In dusty duty, lowering the working pressure also extends vane life.
This page describes a selection method, not a specific project record.