Core TradesQuestion 27 of 700
A horizontal branch drain must carry fixtures totaling 14 drainage fixture units. If a 2-inch pipe is rated for up to 6 DFU and a 3-inch pipe for up to 20 DFU, what is the MINIMUM pipe size?
a.1-1/2 inches
b.2 inches
c.3 inches
d.4 inches
Explanation
Because 14 DFU exceeds the 6-DFU capacity of a 2-inch pipe, the next size that handles the load is the 3-inch pipe (up to 20 DFU). A 4-inch pipe would work but is larger than the minimum required.
Law Reference: 2025 CA Plumbing Code (CPC) Chapter 7 (Sanitary Drainage)Practice all 700 questions free — no signup required.
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