A water-sizing isometric shows two branches converging at a tee before the main riser: Branch 1 carries 5 WSFU and Branch 2 carries 3 WSFU. What is the combined WSFU load downstream of the tee?
Not quite. The answer is C: 8
Once two branches join at a tee, everything downstream of that point has to be sized for both loads combined — 5 plus 3 gives 8 WSFU, the number to carry forward into the next segment's sizing, not either branch's individual load alone.
Reference: UPC 2021 §610.9; Table 610.3 (Fixture units accumulate on the piping that serves them)
Checked against the official text
Checked against the 2021 UPC text. Washington's exam is written against the 2015 edition, which we have not read for this section, so confirm it against your 2015 book.
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