Vacuum technology
Turbomolecular
High and ultra-high vacuum, behind a backing pump.
Schematic section, not to scale
How it works
Turbomolecular pumps reach high and ultra-high vacuum by striking gas molecules with fast-turning bladed rotors. They cannot exhaust to atmosphere: a backing pump (rotary vane, scroll or dry pump) holds their outlet at a low pressure. They are standard on semiconductor tools, coating systems, electron microscopes, mass spectrometers and research vacuum chambers.
A rotor carrying rows of angled blades spins at tens of thousands of revolutions per minute between rows of fixed stator blades. Molecules hit by the blades are pushed toward the outlet, stage by stage; the pump works in molecular flow, where gas molecules collide with the blades more often than with each other.
Performance range
Roughly 10⁻³ down to 10⁻⁸ Pa (10⁻⁵ to 10⁻¹⁰ mbar); pumping speeds from tens to several thousand L/s
Typical industry range. Exact capability is model specific, see each model’s curve.
In the catalogue · 181 models from 4 manufacturers
- Pumping speed
- 43.2 – 19,800 m³/h · 169 models
- Weight
- 1.3 – 250 kg · 164 models
- Ultimate pressure
- 1e-11 – 0.000001 mbar · 127 models
- Noise level
- 45 – 50 dB(A) · 28 models
Spread of each model’s own rated figure, as published by its manufacturer.
Advantages & tradeoffs
- Clean, hydrocarbon-free high vacuum
- Fast start and pump-down
- High speed for light gases with the right rotor
- Needs a backing pump
- Sensitive to sudden air inrush and particles
- Lower compression for hydrogen and helium
Best applications
Maintenance
Bearing service or replacement at the OEM interval (magnetic-bearing pumps far less often), controller and cooling checks, venting and inlet screen care.
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