If the brazing process includes the usage of flux materials to etch the surfaces, then this acidic material evaporates and enters the vacuum system. Such vapor would attack the oil inside oil-sealed pumps and can cause a pump corrosion. Dry compressing screw pumps are the best choice for this challenging application as they can handle such aggressive vapors. Modern screw pumps out of the DRYVAC or LEYVAC range are perfectly adjusted to cope with the requirements of such application.
Leybold also offers a full range of high vacuum products for all kind of brazing applications. Our most innovative, energy saving diffusion pumps from the DIP and DIJ family are the market standard. For hydrocarbon-free brazing we offer cryo-pumps or turbo-molecular pumps.