18-29-604.5 Size of fixture supply.
   The minimum size of a fixture supply pipe shall be as shown in Table 18-29-604.5. The fixture supply pipe shall not terminate more than 30 inches (762 mm) from the point of connection to the fixture. A reduced-size connector installed between the supply pipe and the fixture shall be of approved type. The supply pipe shall extend to the floor or wall adjacent to the fixture.
Table 18-29-604.5
Minimum Sizes of Fixture Water Supply Pipes
Fixture
Minimum Pipe Size (inch)
Fixture
Minimum Pipe Size (inch)
Bathtubs (60" by 32" and smaller)
1/2
Bathtubs (larger than 60" by 32")
1/2
Bidet
3/8
Combination sink and tray
1/2
Dishwashing machine (domestic)
1/2
Drinking fountain
3/8
Hose bibbs
1/2
Kitchen sink
1/2
Laundry, 1, 2 or 3 compartments
1/2
Lavatory
3/8
Shower, single head
1/2
Sinks, flushing rim
3/4
Sinks, service
1/2
Urinal, flush tank
1/2
Urinal, flushometer valve
3/4
Wall hydrant
1/2
Washing machine (automatic)
1/2
Water closet, flush tank
3/8
Water closet, flushometer valve
1
Water closet, flushometer tank
3/8
Water closet, one piece
1/2
 
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 psi = 6.895 kPa.
(Amend Coun. J. 10-14-21, p. 37722, Art. VI, § 10)