Minnesota Administrative Rules

4715.2310 SELECTING SIZE OF GRAVITY DRAINAGE PIPING.

Subpart 1.

Determination of size.

Pipe sizes for gravity drains shall be determined from subparts 2 and 3 on the basis of drainage load computed from part 4715.2300, subparts 2 and 3.

Subp. 2.

Maximum loads for horizontal drains in fixture units.

		Building Sewer*****, Building Drain and Building Drain Branches - from Stacks**** _
Diameter of Drain	Horizontal Fixture Branch*-	Slope _
(inches)	(f.u.)	1/16 in/ft. (f.u.)	1/8 in/ft. (f.u.)	1/4 in/ft. (f.u.)	1/2 in/ft. (f.u.)
1-1/4	1
1-1/2	3
2	6			21	26
2-1/2	12			24	31
3**	32***		36***	42***	50***
4	160		180	216	250
5	360		390	480	575
6	620		700	840	1,000
8	--	1,400	1,600	1,920	2,300
10	--	2,500	2,900	3,500	4,200
12	--	3,900	4,600	5,600	6,700
15	--	7,000	8,300	10,000	12,000

*Includes Horizontal Branches of the Building Drain.

**No water closet shall discharge into a drain less than 3 inches.

***Not over 2 Water Closets.

****Every building drain that receives the discharge of (3) or more water closets, shall not be less than 4 inches in diameter.

*****No building sewer shall be less than 4 inches in diameter.

Subp. 3.

Maximum loads for soil and waste stacks in fixture units.

Diameter of Stack	Stacks of not more than 3 stories or Branch Intervals	Stacks of more than 3 stories or Branch Intervals	Total at One Story or Branch Interval
1-1/4*	2	2	1
1-1/2*	4	4	2
2*	9	18	6
2-1/2*	20	42	9
3	36***	72***	24**
4	240	500	90
5	540	1,100	200
6	960	1,900	350
8	---	3,600	600
10	---	5,600	1,000
12	---	8,400	1,500

*No water closets permitted.

**Not over 2 water closets permitted.

***Not over 6 water closets permitted, and not over 6 branch intervals on a 3 inch soil stack.

Statutory Authority:

MS s 16B.59; 16B.61; 16B.64; 326.37 to 326.45; 326B.101; 326B.106; 326B.13; 326B.43 to 326B.49

History:

28 SR 146; L 2007 c 140 art 4 s 61; art 6 s 15; art 13 s 4; 33 SR 2042

Published Electronically:

May 14, 2012