The load on DWV-system piping shall be computed in terms of drainage fixture unit (d.f.u.) values in accordance with Table P3004.1.
TABLE P3004.1 DRAINAGE FIXTURE UNIT (d.f.u.) VALUES FOR VARIOUS PLUMBING FIXTURES
TABLE P3004.1 DRAINAGE FIXTURE UNIT (d.f.u.) VALUES FOR VARIOUS PLUMBING FIXTURES
| TYPE OF FIXTURE OR GROUP OF FIXTURES | DRAINAGE FIXTURE UNIT VALUE (d.f.u.)a |
| Bar sink | 1 |
| Bathtub (with or without a shower head or whirlpool attachments) | 2 |
| Bidet | 1 |
| Clothes washer standpipe | 2 |
| Dishwasher | 2 |
| Floor drainb | 0 |
| Kitchen sink | 2 |
| Lavatory | 1 |
| Laundry tub | 2 |
| Shower stall | 2 |
| Water closet (1.6 gallons per flush) | 3 |
| Water closet (greater than 1.6 gallons per flush) | 4 |
| Full-bath group with bathtub (with 1.6 gallon per flush water closet, and with or without shower head and/or whirlpool attachment on the bathtub or shower stall) | 5 |
| Full-bath group with bathtub (water closet greater than 1.6 gallon per flush, and with or without shower head and/or whirlpool attachment on the bathtub or shower stall) | 6 |
| Half-bath group (1.6 gallon per flush water closet plus lavatory) | 4 |
| Half-bath group (water closet greater than 1.6 gallon per flush plus lavatory) | 5 |
| Kitchen group (dishwasher and sink with or without food-waste disposer) | 2 |
| Laundry group (clothes washer standpipe and laundry tub) | 3 |
| Multiple-bath groupsc: | |
| 1.5 baths | 7 |
| 2 baths | 8 |
| 2.5 baths | 9 |
| 3 baths | 10 |
| 3.5 baths | 11 |
| For SI: 1 gallon = 3.785 L. |
| a. For a continuous or semicontinuous flow into a drainage system, such as from a pump or similar device, 1.5 fixture units shall be allowed per gpm of flow. For a fixture not listed, use the highest d.f.u. value for a similar listed fixture. |
| b. A floor drain itself does not add hydraulic load. Where used as a receptor, the fixture unit value of the fixture discharging into the receptor shall be applicable. |
| c. Add 2 d.f.u. for each additional full bath. |