scope:

This standard covers the minimum requirements for general-purpose, enclosed single and multistage gear units incorporating parallel shaft spur, and helical gears for use in the petroleum, chemical, and gas industry services. General-purpose and extruder gears manufactured according to this standard are limited to pitch line velocities that do not exceed 60 m/s (12,000 ft/min).

The requirements for parallel shaft helical gears applied to extruder services are included in Section 9 of this standard.

The requirements for epicyclic gears driving equipment, such as electrical generators, centrifugal compressors, and pumps, are included in Section 10 of this standard.

This standard does not apply to gears in special-purpose service, which are covered in API 613, to gears integral with other equipment, or gears with noninvolute tooth forms.

NOTE General-purpose gears are applied in equipment trains that are usually spared, or are in noncritical service. Typical applications for which this standard is intended are cooling tower water pump systems, forced and induced draft fan systems, and other general-purpose equipment trains.