All fixtures shall be adequately vented to prevent syphonic
action and to protect trap seals.
A.
Aboveground venting. Vent pipes shall be of cast iron, hub or hubless, galvanized wrought iron, galvanized steel, galvanized yoloy, galvanized malleable iron split couplings (victaulic). Type DWV copper tubing or heavier, brass, lead, stainless steel (409 Type G copper-coated), ABS plastic pipe or PVC plastic pipe. The pipe and fittings for each type of pipe, including malleable fittings, shall comply with the applicable specifications listed in § 131-13.
(1)
Vent pipes exposed to fumes from waste piping carrying corrosive
industrial wastes shall be lead, acid-resisting cast iron, chemical
porcelain, heat-resistant prestressed borosilicate glass, polyethylene
and polypropylene.
(2)
Fittings on ferrous pipe may be of cast iron or malleable iron. Drainage-type
fittings shall be required only where vent lines connect to drainage
lines.
B.
Underground venting. Underground vent pipes shall be of cast iron,
copper tube of a weight not less than Type K hard temper. All underground
vent piping installed parallel to a foundation wall shall be at least
three feet from the building foundation wall when the depth does not
exceed four feet and one-foot additional distance from the foundation
wall shall be required for each additional one-foot depth below four
feet.
A.
The seal of every fixture trap in a plumbing system shall be protected
by being individually connected to a properly vented drain. No vent
shall be required for a leader trap, area drain trap or yard drain
trap.
B.
Stack vents. Every soil or waste stack shall be extended vertically
full size as a stack vent to the open air.
C.
Vent stacks. A vent stack or main vent shall be installed with a
soil or waste stack whenever relief vents or other branch vents are
required in more than one branch interval. The vent stack shall terminate
independently in the open air above the roof or shall be connected
with the stack vent at least six inches above the flood level rim
of the highest fixture and shall connect with the soil or waste stack
through, at or below the lowest horizontal soil or waste branch, or
with the house drain, in such manner as to prevent the accumulation
of rust scale.
(1)
When water closets are installed on this lowest horizontal branch,
they shall be connected to the side of the horizontal branch.
(2)
Every building in which plumbing is installed shall have at least one stack vent or vent stack which shall run undiminished in size and as directly as possible from the building drainage system through to the open air above the roof and as prescribed in accordance with Subsection D(1). The minimum size of the stack vent or vent stack shall be three inches.
D.
Location of vent terminals.
(1)
No vent terminal from a sanitary drainage system shall be directly
beneath any door, window or other ventilating opening of the same
or an adjacent building, nor shall any such vent terminal be within
12 feet horizontally of such an opening unless it is at least three
feet above the top of such opening or above the adjacent roof or party
wall.
(2)
Extensions of vent pipes through a roof shall be terminated at least
two feet above the roof surface and shall be properly flashed. Where
the roof is used for any purpose other than weather protection, the
extension shall extend at least six feet above the roof surface.
A.
Every branch or horizontal soil or waste pipe to which a group of two or more fixtures is to be connected shall have a vent of the same size as the branch by extending the branch full size as required in § 131-96D, connecting to the stack vent six inches above the highest fixture or connecting to the vent stack six inches above the highest fixture connected to the branch. The horizontal branch from the base of a stack connected to the house drain as prescribed in § 131-84D(4), Table P-1, is not subject to these requirements.
 |
(1)
Where the center of a water closet outlet is not more than 48 inches in developed length from the center of four-inch vented soil pipe on a vertical line or through a wye or a wye-and-one-eighth bend on a vented horizontal line, small fixture wastes, not exceeding two that are 1 1/2 inches or less in diameter, may be connected to the side of an ideal bend (closet bend) above the center line without an additional vent. Where the center of a water closet outlet is not more than 18 inches from the center of a three-inch vented soil pipe and the four-inch ideal bend (closet bend) is connected directly to a sanitary tee on a vertical line, small fixture wastes, not exceeding two that are 1 1/2 inches or less in diameter, may be connected to the sides of the bend above the center line without an additional vent, and in accordance with § 131-84E. In lieu of increasing the size of a stack from three inches to four inches, a merion fitting may be used to receive the discharge of a water closet and small fixture wastes. The water closet soil line connected to a merion fitting may be eight feet developed length. The ideal bend (closet bend) shall be not less in size than four inches nominal diameter when receiving the discharge of small fixture wastes. When using three-inch ideal bends (closet bends) to receive the discharge of water closets, this fitting shall be a blind bend containing no drainage connections for other fixtures.
 |
(2)
On existing stacks in old buildings where the center of a water closet outlet is more than four feet and not over eight feet from the center of a vented soil pipe, but otherwise the conditions are the same as in Subsection A(1), an additional one-and-one-half-inch vent will be permitted if the vent is not longer than 30 feet.
 |
B.
Any single water closet or pedestal urinal branch more than eight feet in length or any single waste branch for fixtures other than water closets or pedestal urinals more than 12 feet in length shall have a vent sized at least 1 1/2 the diameter of the branch pipe and, depending on its length and the number of fixture units connected, shall be in accordance with § 131-102D. Table V-1.
 |
A.
All ejectors, except pneumatic ejectors or receiving tanks used for
receiving sewage or other sanitary wastes, shall be provided with
a fresh air inlet. The size of the fresh air inlet shall be four inches
in size for four-inch, five-inch and six-inch drainpipe and six inches
for eight-inch drains discharging into the ejector.
B.
Pneumatic ejectors shall have a fresh air inlet on the inlet piping
on the house side of the inlet valves.
C.
All sumps receiving the discharge from fixtures other than water closets shall be provided with a fresh air inlet pipe. The size of the fresh air inlet shall be not less than two inches and the locations of the fresh air inlet piping shall be in accordance with § 131-26. The drainage piping discharging into the sump shall be vented as provided in this article.
A.
Offsets in soil or waste stacks at an angle greater than 45°
from the vertical serving fixtures below and one or more floors above
the offset shall be vented in either of the methods hereinafter provided.
(1)
Yoke venting offsets. Such offsets may be provided with a yoke vent
equal in diameter to the vent stack or soil stack. The lower end of
the yoke vent shall connect to the soil or waste stack through a wye
below the offset and above the next lower horizontal branch, and the
upper end shall connect to the stack vent or the vent stack not less
than six inches above the highest fixture.
 |
(2)
Separate venting. Such offsets may be vented as two separate soil
or waste stacks with the stack section below the offset and the stack
section above the offset.
 |
B.
All buildings of not more than three stories may have a soil or waste
stack with one offset, at an angle greater than 45° from the vertical,
not exceeding 10 feet in length, without additional venting. No fixtures
shall be permitted above offset, except that one small fixture may
be installed for a heel wash.
 |
A.
Stack vents and vent stacks may be connected into a common vent header at the top of the stacks and extended to the open air above the roof at one point. Such header shall be sized in accordance with the requirements of § 131-102D. Table V-1.
 |
B.
The number of fixture units considered in sizing the vent header
shall be the sum of all fixture units on all stacks connected thereto,
and the developed length shall be the longest vent length from the
intersection at the base of the most distant stack to the vent header
terminal in the open air above the roof, the latter extended to the
open air above the roof as a direct extension of one stack.
A.
Grades. All vent and branch vent pipes shall be free from drops or
sags and shall be graded and connected so as to drip back to the soil
or waste pipe or vent stack by gravity.
B.
Connection to vent stack. A connection between a vent pipe and a
vent stack shall be at least six inches above the flood level rim
of the highest fixture served by the vent pipe. Horizontal vent pipes
forming branch vents, relief vents, circuit vents or loop vents shall
be at least six inches above the flood level rim of the highest fixture
served.
A.
Length of vents. The length of a vent shall be its developed length
from the lowest connection of the vent with the soil stack, waste
stack or house drain to the vent terminal above the roof.
B.
Size of stack vent. The diameter of a stack vent shall be not less
than the diameter of the soil or waste stack of which it is an extension.
 |
C.
Size of vent stack. A vent stack or main vent connecting relief vents, branch vents, circuit vents or loop vents shall have a diameter of at least 1/2 the diameter of the soil or waste stack to which the vent stack or main vent is connected, but in no case less than 1 1/2 inches, and depending on its length and the number of fixture units connected to the vent stack system, shall be in accordance with Subsection D, Table V-1, but not less in size than the branch, circuit or loop vent it is servicing. Where fixtures are installed on the house drain behind the line of vent, a minimum vent stack of 1 1/2 inches shall be required for small fixtures having a fixture unit value not greater than 10 fixture units and a minimum of two inches for one or more water closets and other fixtures, except if a larger size is required according to Subsection D, Table V-1.
 |
D.
Size of relief vent. The diameter of a relief vent shall be not less
than 1/2 the diameter of the horizontal branch to which it is connected,
with a minimum size of 1 1/2 inches, and depending on its length
and the number of fixture units connected to the relief vent system,
shall be in accordance with Table V-1, as follows:
|
Table V-1
| ||||||||
|---|---|---|---|---|---|---|---|---|
|
Size and Length of Vents
| ||||||||
|
Diameter of Vent (inches)
| ||||||||
|
Maximum Length of Vent (feet)
| ||||||||
|
Fixture Units Connected
|
1 1/2
|
2
|
2 1/2
|
3
|
4
|
5
|
6
|
8
|
|
10
|
75
|
310
|
—
|
—
|
—
|
—
|
—
|
—
|
|
20
|
70
|
300
|
—
|
—
|
—
|
—
|
—
|
—
|
|
36
|
35
|
140
|
450
|
—
|
—
|
—
|
—
|
—
|
|
55
|
23
|
85
|
260
|
650
|
—
|
—
|
—
|
—
|
|
75
|
18
|
75
|
240
|
600
|
—
|
—
|
—
|
—
|
|
150
|
—
|
30
|
95
|
240
|
1,000
|
—
|
—
|
—
|
|
225
|
—
|
22
|
70
|
180
|
750
|
—
|
—
|
—
|
|
300
|
—
|
—
|
28
|
70
|
320
|
1,000
|
—
|
—
|
|
480
|
—
|
—
|
20
|
50
|
240
|
750
|
—
|
—
|
|
745
|
—
|
—
|
—
|
20
|
95
|
240
|
1,000
|
—
|
|
1,015
|
—
|
—
|
—
|
18
|
70
|
180
|
750
|
—
|
|
1,665
|
—
|
—
|
—
|
—
|
30
|
80
|
350
|
1,000
|
|
2,320
|
—
|
—
|
—
|
—
|
25
|
60
|
250
|
900
|
|
3,045
|
—
|
—
|
—
|
—
|
—
|
40
|
120
|
450
|
|
3,770
|
—
|
—
|
—
|
—
|
—
|
30
|
80
|
350
|
|
4,500
|
—
|
—
|
—
|
—
|
—
|
25
|
60
|
250
|
 |
