Parker Hannifin, of Irvine, Calif., introduces a new series of KF-Type Centering Ring seal assemblies for improved sealing performance on semiconductor KF and ISO plant vacuum pump systems and vacuum testing equipment. The seal assemblies are available in NW flange sizes ranging from ½-to-12 inches. Seven standard elastometer seal materials offer a range of price and performance choices. Assemblies consist of either an aluminum or stainless steel centering ring with an integral elastometer o-ring seal.