The Dry-Pro line of dry vacuum pumps (photo) feature contact-free operation that requires no lubrication in the pumping chamber, minimizing process contamination and pollution caused by the pump operation. The Dry-Pro line offers dry-screw vacuum-pump designs with fixed- or variable-pitch screw rotors. The pumps achieve an ultimate vacuum of.0015 in. Hg, and can operate at any pressure between end vacuum and atmospheric pressure. The pumps’ design offers high vapor and liquid tolerances and can handle corrosives, organics, inorganics and solvents because of its oil-free, non-contacting screw design. In this design, the shafts and screws are one solid piece, which eliminates corrosion between the screw rotor and shaft that can occur in other pump designs, says the company. A low rotational speed avoids noise and vibration. — Gardner Denver Nash, Bentleyville, Pa.