Roughing Pumps and Backing Pumps

The term roughing pump describes a type of a vacuum pump that is used to initially evacuate a vacuum system, as a first stage of the process towards achieving high vacuum or ultra-high vacuum level.

The backing pump is used with conjunction with another deeper vacuum pump to obtain the deep vacuum level.

Features of Welch Roughing Vacuum Pumps

Oil-Sealed Wet pumps

We offer a range of oil-lubricated rotary vane pumps - from our direct-drive, two stage CRVPro pump family or our belt drive pumps from the DuoSeal family. Rotary vane pumps are robust, offer higher flow and great economy.

Performance ranges for our direct-drive CRVpro pumps go from 1.8cfm to 52.5cfm at 60hz in free flow 1.8 cfm to 52.5 cfm (CRVpro 65); vacuum level 1.5x10-3 to 2x10-3 torr.

Our DuoSeal belt-driven pumps offer free flow ranging from 0.9 cfm 23 cfm (@60Hz) and vacuum level to 1x10-3 torr.

Dry Vacuum Pumps

Welch offers oil-free diaphragm pumps with pumping speed between 0.9 cfm 2.5 cfm (@60Hz) and a backing pressure to 1.5 torr.

For customers looking for an oil-free chemical duty pump we offer our proprietary Chemstar Dry vacuum systems with maximum flow speed ranging from 6.9 to 12.4 cfm and backing pressure to 0.5 torr.

Applications that require roughing pumps, backing pumps or pump packages

There are plenty of applications that need a roughing pump, backing pump and sometimes even pump packages, combining these two. In general terms, you should be choosing a roughing vacuum pump whenever your application requires a deeper vacuum level or quicker evacuation process.

Examples of backing applications that require backing pumps are backing up turbo pumps, backing cryo pumps, or vacuum blowers. An example of application that requires turbo or “pump packages” is as a mass spectrometer. Another examples are surface coating applications, commonly using a backing pump added on a blower, or blower backed diffusion pumps. Sometimes your work routine might require roughing out an annular space for certain media, such as liquid oxygen, liquid nitrogen.

Whatever your lab or industrial applications needs are, and however complex they are, we are here to help to select the right product for your application. Welch is well-known for a highly-trained and experienced staff of vacuum experts. Contact our experts to discuss your application needs.