- "Gallons per minute (GPM or gpm), is a unit of volumetric flow rate of liquids. The unit "gallon" is ambiguous, and may refer to either the U.S. liquid gallon (USgpm) or Imperial (UK) gallon (Igpm). Unless the gallon is explicitly declared, it generally is assumed to be the U.S. liquid gallon in the United States, and the Imperial gallon in Britain. Other countries use one or both unit definitions for a gallon, which may lead to confusion as there is a significant difference between the two units." 
- " A unit of measurement that indicates the flow capabilities of a hydraulic component. Gallons per minute is abbreviated gpm." 
Conversion to SI and other common units
Communication Protocol Support
This engineering unit is supported by the following communication protocols:
- 2008 specification.