Vent pipes shall not be less than 11/4 inches (32 mm) in diameter. Vents exceeding 40 feet (12 192 mm) in developed length shall be increased by one nominal pipe size for the entire developed length of the vent pipe.
Also to know is, can you reduce the size of a vent pipe?
The line can be reduce in size and be kept small if there are enough additional vents to give the required aggregate area out through the roof. 2. The pipe size cannot be reduced but has to be full size from the house sewer all the way to the roof.
One may also ask, how do you measure a vent? To determine the proper vent size for a single-appliance vent, use Table 1 or 2 (pages 12-14). Determine Total Height (H) and Total Lateral Length (L) based on location of appliance and vent and the height to vent termination. Read down the Total Height (H) column at the left to a height equal to the Total Height.
Hereof, what is the minimum size of a vent pipe for kitchen sink?
The minimum diameter of the vent pipe is 1 1/4 inches in both cases.
How many fixtures can a 2 inch vent handle?
Under the Uniform Plumbing Code, a 2” vent can handle 24 fixture units(F.U). In a residence, a lavatory sink= 1.0 F.U., bathtub/shower= 2.0 F.U.