ISO 13709:2003 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. ISO 13709:2003 is applicable to overhung pumps, between-bearings pumps and vertically-suspended pumps. Clause 8 provides requirements applicable to specific types of pump. All other clauses of ISO 13709:2003 are applicable to all pump types. Illustrations are provided of the various specific pump types and the designations assigned to each specific type. ISO 13709:2003 is not applicable to sealless pumps.