Oil-Sealed Vacuum Pumps

The oil does three jobs here: it seals the clearance between vanes and housing, removes the heat of compression and lubricates the sliding surfaces. In the two-stage design the gas passes through two stages in sequence, so the ultimate pressure drops markedly. When wet gas is pumped the gas ballast is opened: it prevents water from mixing into the oil, at the cost of a somewhat reduced attainable vacuum.

Models in our catalog offer capacities from 6 m³/h to 300 m³/h with motor ratings of 0.75–3 kW. On the two-stage series the ultimate vacuum is 10⁻⁴ mbar with the gas ballast closed and 4 × 10⁻³ mbar with it open. Inlet ports are KF 25 and KF 40, oil capacity is 600 ml to 4.5 l, noise level 56–62 dB and ambient temperature 5–40 °C.

The air-cooled, direct-drive design requires no cooling water. In selection, the target ultimate pressure and the moisture content of the pumped gas matter as much as capacity; for a comparison with liquid-ring and lobe booster alternatives see our vacuum pump selection guide.