This standard covers the minimum requirements for rotary positive displacement process pumps and pump units for use in the petroleum@ petrochemical@ and gas industry services. Controlled-volume pumps@ hydraulically driven pumps and positive displacement reciprocating pumps are not included (see API 674 for positive displacement reciprocating pumps and API 675 for controlled-volume pumps). For rotary positive displacement pumps in auxiliary services (e.g. lube oil systems)@ manufacturer's standard with demonstrated experience is acceptable. Annex A contains datasheets which purchasers are encouraged to use (informative). Annex B provides guidance for factors affecting twin screw efficiencies (informative). Annex C contains an inspector's checklist (informative). Annex D contains forms which may be used to indicate vendor drawing and data requirements (VDDRs) (informative). Annex E gives guidance regarding net positive suction head (NPSH) vs net positive inlet pressure (NPIP) (informative). Annex F gives guidance on pulsation and vibration control techniques (informative). Annex G provides a typical piping and instrumentation diagram for multiphase pump (MPP) skids (informative). This standard requires the purchaser to specify certain details and features. A bullet (?) at the beginning of a paragraph indicates that either a decision by@ or further information from@ the purchaser is required. Further information should be shown on the datasheets (see example in Annex A) or stated in the quotation request and purchase order.