MAX. UNIT LOADING & MAX. LENGTH OF DRAINAGE & VENT PIPING
Pipe Size, inches 1.25 1.5 2 2.5 3 4 5 6 8
Max. F.U.
Drainage Piping (1) 		               
Vertical 1 2 (2) 16(3) 32(3) 48(4)
(Min. for W.C.) 		256 600 1380 3600
Horizontal 1 1 8(3) 14(3) 35(4)
(Min. for W.C.) 		216(5) 428(5) 720(5) 2640
Max. Length
 Drainage Piping


Vertical, ft. 		1.25" 1.5" 2" 2.5" 3" 4" 5" 6" 8"
45 65 85 148 212 300 390 510 750

Horizontal 		Unlimited
Vent Piping Horiz. & Vert. (6), (7) 1.25" 1.5" 2" 2.5" 3" 4" 5" 6" 8"

Max. F.U.

1

8(3)

24

48

84

256

600

1380

3600

Max. Length, ft.

45

60

120

180

212

300

390

510

750

-Ref: UPC, Table 7-5. Refer to Table for exceptions & limitations.
-Discharge Capacity of 1 F.U.= 7.5 gpm

*(1) Excluding trap arms.
*(2) Except urinals, sinks and dishwashers.
*(3) Except 6-unit traps or water closets.
*(4) Only 4 w.c. or 6-unit traps on any vert. pipe or stack. Not more than 3 w.c.'s or 6-unit traps on any horiz. branch or drain.
*(5) Based on 1/4"/ft slope. For 1/8"/ft. slope, multiply horiz. F.U. by a factor = 0.80.
*(6) Diam. of any vent not less than 1.25" nor 1/2 the diam. of the drain to which it is connected.
*(7) Fixture unit load values for drainage and vent piping shall be computed from Tables 7-3 and 7-4. Not to exceed one-third (1/3) of the total permitted length of any vent may be installed in a horizontal position. When vents are increased one (1) pipe size for their entire length, the maximum length limitations specified in this table do not apply.