How to choose a rotary vane vacuum pump
Oil-sealed rotary vane pumps are the workhorse of rough and medium vacuum. A rotor turns eccentrically inside a cylinder; spring- or centrifugally-loaded vanes sweep gas from the inlet to the exhaust while an oil film seals the clearances, lubricates the vanes and carries away heat. Single-stage pumps typically reach the 10⁻¹ mbar decade; two-stage pumps put a second rotor set in series and reach the 10⁻³ mbar decade.
Size the pump on two numbers, not one. Pumping speed (m³/h or L/s) sets how fast you get down; ultimate pressure sets how far. A pump running near its ultimate pressure moves almost no gas, so choose a speed that reaches your working pressure with margin. Then check the details that decide whether it survives your process: gas ballast if you pump water vapour or solvents, corrosion-resistant construction for chemistry, inlet flange size (KF/ISO), motor voltage and phase, noise level, and the oil grade — mineral, PFPE or a hydrocarbon-compatible synthetic.
Typical duties: backing a Roots blower or turbo pump, vacuum packaging and thermoforming, degassing and impregnation, freeze drying, vacuum furnaces, HVAC and refrigeration service, and laboratory filtration. Rotary piston (slide valve) pumps in this range trade a higher noise floor for very high tolerance of dust and continuous heavy duty.
537 models listed, with specifications and quotation within 24 h.
FAQ
What ultimate pressure can a rotary vane pump reach?
A single-stage oil-sealed rotary vane pump typically reaches the 10⁻¹ mbar range; a two-stage pump reaches the 10⁻³ mbar range. The figure on a data sheet is measured dry, at the inlet, with clean oil — a wet or gas-loaded process will not reach it.
How often does the pump oil need changing?
On clean air duty every 3,000 to 6,000 running hours is a common interval. What actually decides it is the process: condensable vapour, solvents or particulates darken and acidify the oil far sooner. Judge by oil colour and level, not only by the calendar.
Can a rotary vane pump handle water vapour?
Only with a gas ballast valve open, and only within the pump's water-vapour tolerance. Running wet without gas ballast emulsifies the oil, which costs you ultimate pressure and eventually the vanes. For continuously wet processes a dry pump or a liquid ring pump is the better fit.
What size pump do I need for my chamber?
Start from chamber volume, target pressure and the pump-down time you can accept, then add the real gas load — leaks, outgassing from surfaces and any process gas. Pumping speed at the working pressure matters more than the peak figure in the catalogue. Send us the volume, target pressure and time and we will size it.
Are your spare parts compatible with Edwards, Leybold or Busch pumps?
Yes — we supply OEM-compatible vanes, seal kits, filters and oils for the common Edwards, Leybold, Busch, Pfeiffer and Agilent rotary vane models. Compatible parts are labelled as such; where a page says a part is genuine, it is the original manufacturer's part. Send the pump model and part number to confirm fit.