Oil-sealed sliding vanes in an offset rotor generate vacuum. Most common industrial vacuum pump.
Typical range
1–25 HP, down to 0.5 mbar (0.015 inHg abs)
Best for
Packaging, pick-and-place, lab, degassing, general industrial vacuum.
Components
- Rotor with sliding vanes
- Stator / cylinder
- Oil reservoir & sight glass
- Oil mist eliminator (exhaust filter)
- Anti-suckback / check valve
- Gas ballast valve
- Intake filter
Common issues
- Poor ultimate vacuum → contaminated oil, worn vanes, leaking shaft seal
- Oil smoke from exhaust → failed/saturated mist eliminator
- Oil in intake line on shutdown → failed anti-suckback valve
- Overheating → low oil, blocked cooling fins, recirculating exhaust
Maintenance
- Daily: check oil level & color (should be clear amber)
- 500–2,000 hrs: change vacuum oil & oil filter
- Annual: replace exhaust mist eliminator, inspect vanes
- Open gas ballast when pumping condensables (water vapor)