ProBoost Air-Cooled Diffusion Pump




Use Welch ProBoost in conjunction with a backing pump like the CRVpro to get deeper vacuum and higher flow.

  • High Vacuum to 10⁻⁵ torr
  • Use with high vacuum and Schlenk lines
  • Employs air cooled diffusion pump
  • Easy Attachment to backing pump

Welch ProBoost is an air cooled gas jet pump (commonly called a diffusion pump). The gas jet is formed by directing boiling silicone vapors through a hollow cone. There are no internal moving parts. The pumping action commences when the vacuum pressure in the still (i.e. wiped film) goes below 0.2 torr (200 millitorr). On an empty, leak free still, ProBoost backed by a rotary vane pump lowers the vacuum pressure to 0.00002 torr (20x lower in pressure than a 2-stage rotary vane vacuum pump can do alone).

ProBoost backed by a rotary vane vacuum pump will lower vacuum pressure to below 0.0001 torr in high vacuum and Schlenk lines. This high vacuum is invaluable to improve the results from reactions using air-sensitive compounds such as organometallics, metal amides, and hydrides.

ProBoost has a built-in control board for fan and heater. When you turn on ProBoost, the fan and heater both turn on. When you turn off ProBoost, the heater turns off immediately and the fan runs for another 20 minutes to cool the pump.


 Maximum Pumping Speed, Air
80 l/sec
Ultimate Vacuum Pressure
0.00002 torr
Minimum Back Pump FAD at 60 Hz
2.8 CFM
Maximum Discharge Pressure
0.2 torr
Ambient Environmental Temp
Heat-up time
7 minutes
Inlet Connection
Discharge Connection
Silicone Oil Capacity
Approximately 30 ml
Cool Down Time
20 minutes
Pump Dimensions, L x W x H
5.5 x 5.4 x 7.5 in
5.6 lbs (2.5 kg)
Shipping Dimensions, L x W x H
13 x 10 x 10 in
Shipping Weight
10 lbs (4.54 kg)