Minimum Sizes of Fixture Water Supply Pipes
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
|
1/2
|
Hose bibbs
|
3/4
|
Kitchen sink
|
1/2
|
Domestic
|
3/4
|
Commercial
|
3/4
|
Laundry, 1, 2 or 3 compartments
|
1/2
|
Lavatory
|
3/8
|
Shower, single head
|
1/2
|
Sinks, flushing rim
|
3/4
|
Sinks, service
|
3/4
|
Urinal, flush tank
|
1/2
|
Urinal, flush valve
|
1
|
Wall hydrant
|
3/4
|
Washing machine (automatic)
|
1/2
|
Water closet, flush tank
|
1/2
|
Water closet, flush 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.