API Std 613 PDF
This standard covers the minimum requirements for special-purpose, enclosed, precision single- and double-helical one-and two-stage speed increasers and reducers of parallel-shaft design for refinery services. This standard is primarily intended for gear units that are in continuous service without installed spare equipment.
Users of this standard should be aware that further or differing requirements may be needed for individual applications. This standard is not intended to inhibit a gear vendor from offering, or the purchaser from accepting, alternative equipment or engineering solutions for the individual application. This may be particularly appropriate where there is innovative or developing technology. Where an alternative is offered, the gear vendor should identify any variations from this standard and provide details.
This standard includes related lubricating systems, controls, instrumentation, and other auxiliary equipment. This standard is not intended to apply to gear units in general-purpose service, which are covered by API 677; to gears integral with other equipment, such as integrally geared compressors and expanders covered by API 617 or API 672; or to gears other than involute helical.