The Chicago Plumbing Code
Pipe Sizes (inches)
Inside Diameter (inches)
Length (inches)
Minimum Weight Each
2
2 1/4
4 1/2
1 pound
3
3 1/4
1 pound 12 ounces
4
4 1/4
2 pounds 6 ounces
For SI: 1 inch = 25.4 mm, 1 ounce = 28.35g, 1 pound = 0.454 kg