Vacuum technology
Oil-Sealed Screw
Screw rotors with oil sealing. Rough vacuum at scale.
Schematic section, not to scale
How it works
Oil-sealed (oil-injected) screw vacuum pumps use two helical rotors with injected oil that seals the clearances, cools and lubricates. They cover larger rough-vacuum duties than vane pumps, often with variable speed drives.
Gas is trapped between intermeshing rotors and carried from inlet to outlet as the rotors turn; oil injected into the screw element seals the gaps and removes heat, then is separated from the exhaust and recirculated.
Performance range
Roughly 100-2,000+ m³/h; ultimate pressure around 0.35 mbar(a)
Typical industry range. Exact capability is model specific, see each model’s curve.
In the catalogue · 37 models from 5 manufacturers
- Pumping speed
- 282 – 5,000 m³/h · 37 models
- Weight
- 495 – 4,000 kg · 37 models
- Motor power
- 5.6 – 90 kW · 24 models
- Ultimate pressure
- 0.35 – 20 mbar · 24 models
- Noise level
- 65 – 83 dB(A) · 13 models
- Max. vacuum
- 29.9 inHg · 3 models
Spread of each model’s own rated figure, as published by its manufacturer.
Advantages & tradeoffs
- High capacity in a compact package
- Efficient with variable speed
- Stable vacuum over a wide range
- Oil service and separator care
- Not for oil-free processes
- Higher first cost than vane
Best applications
Maintenance
Oil and oil-filter changes, separator element, inlet filter and cooler cleaning.
Energy characteristics
Specific-energy comparisons (kW per unit of flow at your operating point) appear here as sourced performance curves are added. Until then, compare models directly on the Performance Map.
Open the Performance Map