In an American Petroleum Institute 1581 filter separator, coalescers are rated for what minimum gallons per minute per inch of length?

The correct answer is based on the specifications provided by the American Petroleum Institute (API) for coalescers used in filter separators. Coalescers are designed to remove water and other contaminants from fuels by agglomerating them into larger droplets that can then be separated out.

In the context of API 1581, coalescers must maintain a minimum flow rate to ensure effective separation and filtration. The standard specifies that coalescers should be rated for a minimum of 2.27 gallons per minute (GPM) per inch of length. This rating ensures that the coalescing process occurs efficiently and that the system can handle the expected flow without compromising the quality of the separation process.

Understanding this figure is crucial for appropriate sizing and selection of coalescers in fuel systems to ensure that they function effectively under operational conditions. Failure to adhere to the specified minimum rate could result in inadequate performance and potential contamination issues within the fuel system.