What is the maximum number of DFU's allowed for a 6-inch horizontal branch?

The maximum number of Drainage Fixture Units (DFUs) allowed for a 6-inch horizontal branch is indeed 620. This value is determined according to plumbing codes that allocate specific values to various fixture types based on their anticipated load and drainage needs.

The 6-inch horizontal branch is capable of handling a substantial volume of drainage due to its size, allowing for a higher count of fixtures before the system would potentially become overloaded. The allocation of 620 DFUs is based on both empirical data and standards established in plumbing design guidelines, which ensure that the plumbing system can efficiently manage and convey wastewater without issues like blockages or backups.

Understanding this value is crucial for plumbing system design, as it allows plumbers to ensure that the number of fixtures connected to a single horizontal branch does not exceed the capacity, maintaining proper flow and function in the drainage system.