This International Standard 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 International Standard is applicable to overhung pumps, between-bearings pumps and vertically suspended pumps (see Table 1). Clause 9 provides requirements applicable to specific types of pump. All other clauses of this International Standard are applicable to all pump types. Illustrations are provided of the various specific pump types and the designations assigned to each specific type. Relevant industry operating experience suggests pumps produced to this International Standard are cost effective when pumping liquids at conditions exceeding any one of the following: – discharge pressure (gauge) 1 900 kPa (275 psi; 19,0 bar) – suction pressure (gauge) 500 kPa (75 psi; 5,17 bar) – pumping temperature 150 °C (300 °F) – rotative speed 3 600 r/min – rated total head 120 m (400 ft) – impeller diameter, overhung pumps 330 mm (13 in) NOTE – For sealless pumps, reference can be made to API Std 685. For heavy duty pump applications in industries other than petroleum, petrochemical and gas processing, reference can be made to ISO 9905.