The Roots 827 DVJ Whispair dry vacuum exhausters from Howden Roots eliminate problems associated with high temperatures at vacuum levels beyond 16 inches Hg. They can be arranged to operate in two- and three-stage systems. Their heavy-duty design is suited for V-belt or direct-drive applications with integral-shaft ductile iron impellers. The casing, headplates, gear cover and drive-end cover are gray iron. Carburized and ground alloy steel spur timing gears are taper-mounted on the shafts and secured with a locknut. Cylindrical roller bearings are splash-lubricated at both the gear and opposite gear ends of the unit. Piston rings reduce air leakage through the headplate bores and lip-type oil seals prevent lubricants from entering the air chamber. Steel mounting feet permit field adaptability to either vertical or horizontal installation requirements. 800/557-6687; www.howdenroots.com.