API STD 677
General Purpose Gear Units for Petroleum, Chemical, and Gas Industry Services
|Publication Date:||1 July 1997|
1.1.1 This standard covers the minimum requirements for general-purpose, enclosed single and multistage gear units incorporating parallel shaft helical and right angle spiral bevel gears for the petroleum, chemical, and gas industries. Gears manufactured according to this standard shall be limited to the following pitchline velocities. Helical gears shall not exceed 60 meters per second (12,000 feet per minute), and spiral bevels shall not exceed 40 meters per second (8,000 feet per minute). Spiral bevel gearsets shall be considered matched sets. Other types of gears may be suitable for certain applications, but they are not covered by this standard.
This standard includes related lubricating systems, instrumentation, and other auxiliary equipment. This standard is not intended to apply to gears in special-purpose service, which are covered in API 613; to gears integral with other equipment; to epicyclic gear assemblies; or gears with non-involute tooth forms.
1.1.2 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.