Choosing a vacuum pump: rotary vane, diaphragm or blower?

In short: if you need deep vacuum, choose rocking piston, diaphragm, piston or rotary vane — rotary vane moves the most air of these. If you need to move a lot of air at low vacuum, choose a regenerative blower.

Deep vacuum, moderate flow

• Rotary vane — up to 28 inHg (65 mbar absolute). Lubricated or oil-free, up to 55 cfm
• Rocking piston — up to 29.5 inHg, oil-free
• Piston — up to 28.5 inHg (48 mbar), oil-free
• Diaphragm — up to 29 inHg (31 mbar), oil-free, but only 3.4–110 l/min

Lots of air, low vacuum

The regenerative blowers in the Regenair series only pull a few hundred millibar, but in return they move from 651 to 38 228 l/min. This is what is used for workholding on CNC tables, material conveying and extraction, where what is needed is not deep vacuum but volume.

The blowers by size

• R1 — 0.09 kW, 23/27 cfm, vacuum 20/26.5 inH2O
• R2 — 0.25–0.37 kW, 33/42 cfm
• R4 — 0.75 kW, 75/92 cfm
• R5 — 1.86 kW, 133/160 cfm
• R7 — 7.46 kW, 350/420 cfm, pressure 286/311 mbar
• R9P — 22.4 kW, 1140/1350 cfm
• SDR6 belt-driven — 11.2 kW, 300 cfm (510 m³/h), vacuum 336 mbar

Oil-free is standard here

The diaphragm pumps, rocking piston pumps, piston pumps and regenerative blowers are all oil-free. Only the rotary vane pumps come in both versions. So if oil-free air is a requirement, almost the entire range is open to you.

Voltage and frequency

Gast uses dual-frequency, multi-voltage AC motors on much of the range, and some models are available in 12 and 24 V DC. Tell us what you have available, so that you do not end up with a pump that needs its own power supply.

Tell us what needs to be held or extracted

It is easy to choose the wrong vacuum equipment if you go by the figures alone. Describe the task — what is to be held, lifted or drawn, and how airtight the system is — and we will do the calculations together.