Vacuum technology
Rotary Piston
Oil-sealed piston pumps. Rugged, deep rough vacuum.
Schematic section, not to scale
How it works
Rotary piston vacuum pumps use an eccentric piston turning inside a cylinder, sealed by oil. They are built for heavy, continuous industrial duty such as vacuum furnaces, coating, degassing and drying.
An eccentrically mounted piston rolls around the cylinder wall; a slide valve through the piston admits gas, which is compressed and pushed out through an oil-sealed discharge valve. Two-stage versions reach deeper vacuum.
Performance range
Roughly 30-850 cfm; ultimate around 0.01-0.05 Torr (two-stage lower)
Typical industry range. Exact capability is model specific, see each model’s curve.
In the catalogue · 17 models from 3 manufacturers
- Ultimate pressure
- 0.01 – 0.06 mbar · 17 models
- Motor power
- 2.2 – 29.8 kW · 16 models
- Pumping speed
- 54.4 – 1,440 m³/h · 14 models
- Weight
- 172 – 1,700 kg · 12 models
- Noise level
- 77 – 85 dB(A) · 3 models
Spread of each model’s own rated figure, as published by its manufacturer.
Advantages & tradeoffs
- Very robust in dirty, demanding duty
- Large clearances tolerate particulate
- Deep rough vacuum
- Heavy, with vibration to manage
- Oil service
- Often water-cooled in larger sizes
Best applications
Maintenance
Oil changes, gas ballast and valve inspection, cooling water and filter checks.
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