18-29-916.1 Size of stack vents and vent stacks.

   The minimum required diameter of stack vents and vent stacks shall be determined from the developed length and the total of drainage fixture units connected thereto in accordance with Table 18-29-916.1, but in no case shall the diameter be less than one-half the diameter of the drain served or less than 1 1/2 inches (40 mm).

Table 18-29-916.1
Size and Developed Length of Stack Vents and Vent Stacks

Total Fixture Units Being Vented (DFU)	Diameter of Vent (inches)
	1 1/2**	2	2 1/2	3	4	5	6	8	10
	Maximum Developed Length of Vent (feet)
8	100	*
20	50	150	*
42	30	100	300	*
60	N.P.	50	80	400	*
500	N.P.	N.P.	70	180	700	*
1,100	N.P.	N.P.	N.P.	50	200	700	*
1,900	N.P.	N.P.	N.P.	N.P.	70	200	700	*
3,600	N.P.	N.P.	N.P.	N.P.	N.P.	60	250	800	*
5,600	N.P.	N.P.	N.P.	N.P.	N.P.	N.P.	60	250	*
8,400	N.P.	N.P.	N.P.	N.P.	N.P.	N.P.	N.P.	N.P.	0

 

*    = Unlimited.

**   = Not permitted for water closets

N.P.   = Not Permitted

(Amend Coun. J. 3-27-02, p. 82090, § 3)