This document specifies requirements for centrifugal pumps, including pumps running in reverse as hydraulic power recovery turbines, for use in petroleum, petrochemical, and gas industry process services. This document is applicable to overhung pumps, between bearings pumps, and vertically suspended pumps. This document also provides requirements applicable to specific types of pumps. Illustrations are provided of the various specific pump types and the designations assigned to each specific pump type.