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 are limited to the following pitchline velocities: helical gears shall not exceed 60 meters per second (12,000 feet per minute) and spiral bevel gears shall not exceed 40 meters per second (8,000 feet per minute). This standard includes related lubricating systems, instrumentation, and other auxiliary equipment. Also included in this edition is new material related to gear inspection.