API 677

General-Purpose Gear Units for Petroleum, Chemical and Gas Industry Services
API Std 677 | 3rd Edition | April 2006 | Reaffirmed: November 2016 |

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). 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. Refer to API Std 613 for Special-Purpose Gear Units.