What is the GPM discharge value used in the fixture unit calculation?

What is the GPM discharge value used in the fixture unit calculation?

• A. 6.5 GPM
• B. 8.3 GPM
• C. 4.8 GPM
• D. 10.2 GPM

Answer: (B)

The GPM discharge value used in fixture unit calculations is 8.3 GPM. This value is the standard amount of flow assigned to one fixture unit, so all fixtures can be expressed in the same units and summed to size the water supply. In practice, you convert fixture demands to fixture units by dividing each fixture’s discharge (in GPM) by 8.3, or multiply the total fixture units by 8.3 to estimate the total GPM on the system. The 8.3 GPM figure is a fixed reference used to normalize different fixtures’ demands, ensuring consistent sizing across the installation.

The GPM discharge value used in fixture unit calculations is 8.3 GPM. This value is the standard amount of flow assigned to one fixture unit, so all fixtures can be expressed in the same units and summed to size the water supply. In practice, you convert fixture demands to fixture units by dividing each fixture’s discharge (in GPM) by 8.3, or multiply the total fixture units by 8.3 to estimate the total GPM on the system. The 8.3 GPM figure is a fixed reference used to normalize different fixtures’ demands, ensuring consistent sizing across the installation.