Current through Register Vol. 50, No. 9, September 20, 2024
A. General. Pursuant to the requirements of
Chapter 12 of this code, the approval of alternate designed plumbing systems
shall be considered on an individual basis.
1. Scope. The provisions of this appendix
shall assist in governing the materials, design and installation of
non-prescriptive plumbing systems, also known as alternate designed plumbing
systems. In accord with the requirements of Chapter 12 of this code, any one of
the systems mentioned in this appendix shall be designed by a Louisiana
registered professional engineer registered in either civil or mechanical
engineering. Any alternate designed plumbing system shall not be installed
until the plans and specifications have been reviewed and approved by the state
health officer, pursuant to the requirements of Chapter 12 of this
code.
2. General System Provisions.
Discharge pipe systems shall comprise the minimum of pipe work necessary to
carry away the foul water from the building quickly and quietly, with freedom
from nuisance or risk of injury to health.
C. Combination Waste and Vent System. A
combination waste and vent system is an alternate designed plumbing system;
thus, the requirements of Chapter 12 of this code apply to any combination
waste and vent system. Combination waste and vent systems shall conform with
the following.
1. Approval. Plans and
specifications for each combination waste and vent system shall be submitted to
the state health officer for review and approval. Written approval of such
plans and specifications shall be obtained before any installation is
started.
2. Limits. The following
limits shall be applied to any combination waste and vent system.
a. A combination waste and vent system is
limited to dishwashers, floor sinks, indirect waste receptors, floor drains or
similar fixtures which waste at or below floor level and where the fixtures are
not adjacent to walls or partitions thus making it impractical to provide
conventional venting. It consists of the installation of waste piping in which
the trap of the fixture is not individually vented.
b. Caution must be exercised to exclude
appurtenances delivering large quantities of water or sewage such as pumps,
etc., in a combination waste and vent system in order that adequate venting
will be maintained. Water closets, clinical sinks, and urinals shall not waste
into a combination waste and vent system. Sinks, lavatories, etc., that waste
above floor level should not be allowed to waste into a combination waste and
vent system.
3.
Dishwashers. Dishwashers, three-compartment sinks and other scullery sinks in
commercial buildings shall drain through a grease interceptor sized in
accordance with this code and they shall only then be allowed to discharge into
the combination waste and vent system via a floor sink through an air gap
(drainage system) or air break (drainage system). The purpose of this
requirement is to keep grease out of the combination waste and vent system
since such a system is not self-scouring due to the over-sized piping
required.
4. General Design. The
general design elements of a combination waste and vent system shall be as
follows.
a. Every waste pipe and trap in this
system shall be at least two pipe sizes larger than the conventional plumbing
size required in Chapter 7 of this code, and at least two pipe sizes larger
than any fixture tail piece or connection. In addition, the fixture tail piece
or connection itself shall remain normal size in order to limit the rate of
flow and amount of wastewater allowed to enter the horizontal combination waste
and vent waste pipe. In order to maintain a continuous vent space above the
liquid waste within the horizontal waste pipe, all fixtures shall waste into
the horizontal combination waste and vent waste pipe from the horizontal only.
The fixture drain length to the horizontal combination waste and vent waste
pipe shall be limited by Table 913.A of this code. Floor sinks shall be
connected through a running trap two pipe sizes larger than the sink outlet. A
vertical cleanout extension shall be provided on the top of the inlet side of
the running trap and shall be accessible at floor level for rodding out the
trap and fixture drain. Floor sink and waste piping from the floor sink to the
trap shall be sized for the total fixture units draining thereto, based on
Table 723.B of this code, but in no case shall the line be less than 2-inch (51
mm) waste pipe when piping is underground. In addition, the length of such
piping should not exceed the distance permitted for indirect waste to vent (see
§809. A 2, and Figure 2 in
Section
1807 of this code).
b. A vent shall be provided at the upstream
end of each branch, washed over or under by the last fixture on the branch. No
vent shall take off from the horizontal waste branch at an angle of less than
45 degrees (0.785 rad) from the horizontal unless washed by a fixture. A vent
shall be located at all points where branches intersect. A vent shall be
located downstream from all fixtures in the system, in addition to the upstream
vent, separating the combination waste and vent system from all other systems
in the building. All vents in a combination waste and vent system shall be
provided with an accessible above-grade(g) cleanout.
Line cleanouts for horizontal waste piping shall be provided as required in
Chapter 7 of this code. Drainage fixture pattern fittings shall be provided for
all vent piping below the level of 6 inches (152 mm) above the flood-level rim
of the highest fixture connection. No fixtures other than those permitted in
§1811. C.2 of this code shall discharge into any branch or portion of this
system. See Figures 6 and 7 in
Section
1807 of this code.
c. Caution shall be used in the design of the
system to assure that the vertical distance from fixture or drain outlet to
trap weir does not exceed 24 inches (610 mm). Long runs shall be provided with
additional relief vents located at intervals of not more than 100 ft (30.5 m)
to equalize pressure in the system.
5. Size of Vents. The size of vents shall be
in accordance with requirements of §937. B and Table 937.B of this code, but
the internal cross-sectional area of the vent shall be not less than one-half
of the internal cross-sectional area of the waste pipe served (normally,
measured in square inches), except that the vents shall be the same size as the
waste branch to a point at least 6 inches (152 mm) above the flood-level rim of
the highest fixture connected before reduction, in accordance with Table 937.B
of this code.
6. Receptor Drain
Size. Indirect waste receptors shall be sized for the fixture units draining
thereto, regardless of other requirements of this code.
D. Single Stack Discharge and Ventilating
Systems
1. Approval. The purpose of this
Subsection is to make provisions for the design and installation of a single
stack discharge and ventilating plumbing system which is not otherwise allowed
in this code. In accord with Chapter 12 of this code, the plumbing official
shall require that the owner submit necessary plans and specifications to the
state health officer by a Louisiana Registered Professional Engineer registered
in either civil or mechanical engineering.
2. Tests. The single stack discharge and
ventilating system shall be tested in accordance with §1205. C of this
code.
3. General. The following
general provisions are applicable to single stack discharge and ventilating
systems.
a. Trap Function. To prevent exchange
of air between the discharge pipe system and the inside of the building, a trap
having an adequate water seal shall be provided for each fixture (see §1811.
D.4 of this code). The discharge piping system shall be so designed as to
retain adequate water seals in all traps under normal pressure fluctuations
caused by discharge from fixtures (see §1205. C of this code). For design
purposes, the effects of the flow of water in the branch connecting the fixture
to the stack, and the flow of water down the stack, shall be considered
separately. See §1811. D.3.b of this code below.
b. Seal Loss (Branch Effect). Seal losses
produced by flow in a branch depend on the following:
i. the design of the fixture (funnel shaped
fixtures increase the chance of self-siphonage); and,
ii. the length and fall (slope or gradient)
and the diameter of the pipe.
(a). Branch
effects are not affected by the height of the building and they can therefore
be controlled by limiting the length and the fall of the branch.
c. Seal Loss (Stack
Effect). Seal losses produced by flow down the stack depend on the following:
i. the flow load (which depends on the number
of fixtures connected to the stack and the frequency with which they are
used);
ii. the diameter of the
stack; and,
iii. the height of the
stack.
(a). Excessive seal losses can be
prevented by choosing a size of stack appropriate to the height of the building
and to the number of fixtures connected to it.
d. Fixture Layout. Where the layout of
fixtures is suitable, careful design and installation can lead to considerable
economies in pipework by eliminating the need for separate ventilating pipes
(see §1811. D.6 of this code). Where these requirements cannot be followed,
traps shall be ventilated by pipes of adequate size as described in §1811. D.7 of this code.
e. System Design.
Consideration shall be given in design to the following points which, in
addition to being good general practice, will also obviate trouble from the
foaming of detergents.
i. Where practicable,
all fixtures shall be connected to one main stack which is at least 4 inches in
diameter except for one story buildings where a 3-inch stack may be
satisfactory (see §1811. D.6 and Table 1811.D.5.5B of this code).
ii. Where sinks are connected to a separate
stack, the stack shall be larger than normal (a minimum of 4- inch diameter for
buildings over five stories) and connected directly to the building
drain.
iii. For over two sinks,
stacks shall be (when one sink is over another on separate floor levels) a
minimum of 2 1/2-inch diameter.
iv.
The interconnection of stacks is not permitted except when fixtures below such
interconnection are vented as required elsewhere in this code.
v. For buildings more than five stories high,
ground floor fixtures shall be connected separately to the building drain, and
vented back into the main discharge stack above the fixtures on the floor
above, or the vent shall be connected with a main ventilating stack when such
stack is required by Table 1811.D.6C of this code.
vi. Bends and offsets in vertical stacks are
prohibited.
f. Jointing
and Support. The selection of materials, their jointing and support shall be in
consideration of the effects of possible settlement, thermal movement, and
corrosion (see §1811. D.9 of this code). Some materials may require protection
against mechanical damage.
g.
Access. There shall be adequate provision for access to pipework, and the
embedding of joints in the structure shall be avoided (see §1811. D.8 10 of this code).
4. Traps. Traps shall meet the following
requirements.
a. General. The entry of foul
air from the drainage system into the building is prevented by the installation
of suitable traps which are of self-cleansing design. A trap which is not an
integral part of a fixture shall be attached to and immediately beneath the
fixture outlet and the bore of the trap shall be smooth and uniform
throughout.
b. Diameters. The
internal diameters of traps shall be not less than those given in Table
1811.D.4 of this code.
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Table 1811.D.4
Minimum Internal Diameters of Traps
|
|
Type of Domestic Appliance
|
Min. Internal Diameter (in.)
|
|
Lavatory
|
1 1/4
|
|
Sink
|
1 1/2
|
|
Bathtub
|
1 1/2 or 21
|
|
Shower
|
2
|
|
Wash tub
|
1 1/2
|
|
Kitchen waste disposal unit (tubular trap is
essential)
|
1 1/2
|
NOTE:
1. See
Figures 1811.D.5.4A, 1811.D.5.4B, and Table 1811.D.5.5A of this code.
c. Depth of Seals. Traps
of water closets shall have a minimum water seal of 2 inches (51 mm); traps of
other fixtures shall have a minimum water seal of 3 inches (76 mm) for pipes up
to and including 2 inches in diameter and 2-inch minimum water seal for pipes
over 2 inches in diameter.
5. Discharge Pipes. Discharge pipes shall
meet the following requirements.
a.
Diameters. The internal diameter of a horizontal discharge pipe (fixture drain)
shall normally be that of the trap to which it is attached, and in no case
less, except that no fixture drain shall be less than 1 1/2-inch
diameter.
b. Branch Gradients. The
fall or slope of discharge pipes shall be adequate to drain the pipe
efficiently and in no case less than shown in Table 1811.D.5.5C of this code
(see §1811. D.5.e of this code).
c.
Bends, Branches and Offsets. All bends, branches and offsets shall be of easy
radius and there shall be no restriction in the bore of the pipe.
d. Prevention of Cross Flow. To prevent water
closet discharge from backing up a bath waste line, the lattershall be
connected to the stack with its center line either at, above, or at least 8
inches (203 mm) below the center line of the water closet branch (see Figure
1811.D.5.4A of this code). Where this cannot be achieved, a parallel branch may
be used (see Figure 1811.D.5.4B of this code). Alternatively, the level of the
water closet branch connection may be modified as above by dotted lines in
Figure 1811.D.5.4B of this code.
Click Here To View
Image
Figure 1811.D.5.4A
Click Here To View
Image
Figure 1811.D.5.4B
e. Pipe Capacities. Discharge unit values for
plumbing fixtures are given in Table 1811.D.5.5A of this code. For other
fixtures the discharge unit value shall be taken as that given in Table
1811.D.5.5A of this code for a fixture with the same diameter trap with a
comparable use interval. Where other use intervals are expected, the
appropriate discharge unit value may be determined since the values given in
Table 1811.D.5.5A of this code show that the discharge unit value is inversely
proportional to the use interval, i.e., if the use interval is doubled, then
the discharge unit value is halved. The discharge unit values of all fixtures
contributing to flow in a pipe shall be added and the appropriate pipe size
(and fall or slope) chosen from Table 1811.D.5.5B of this code for vertical
stacks or Table 1811.D.5.5C of this code for the building drain or its
horizontal branches.
f. Waste
Disposal Units. Special precautions are necessary where kitchen or food waste
disposal units are connected to the discharge pipe system. The discharge pipe
from such a unit shall connect directly to the main discharge pipe without
intermediate connection with any other discharge pipe. Tubular traps shall
always be used and any instructions as to installation given by the
manufacturer shall be observed. To avoid hot grease being carried into
discharge pipes and drains, where it might build up and cause blockage, waste
disposal units shall always be automatically flushed with cold water in order
to solidify grease before it enters the drainage system.
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Table 1811.D.5.5A
Plumbing Fixture Discharge Unit Values
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|
Type Fixture
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Intervals between use in minutes
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Discharge unit values
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Tank Type W.C.
|
20
|
15
|
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Sink
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25
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8
|
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Wash Basin
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25
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3
|
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Bathtub
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75
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8
|
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Shower Stall
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75
|
4
|
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Garbage Disposal
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25
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4
|
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1 fixture group consisting of 1 W.C., 1 Sink, 1 Tub
and 1 Lavatory
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20
|
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Table 1811.D.5.5B
Maximum Number of Discharge Units Allowed on
Vertical Stacks1,2
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|
Nominal Internal Diameter of Pipe (in.)
|
Discharge Units
|
|
2
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20 (No W.C.)
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|
3
|
200 (No W.C.)
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4
|
850
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5
|
2700
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6
|
6500
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NOTES:
1. The
capacity of a vertical discharge pipe (stack) is limited by the need to
preserve a large air core to prevent excessive pressure fluctuation. The flow
capacity of a stack may therefore be less than that of a pipe of the same
diameter laid at a steep fall.
2.
Discharge pipes sized by this method give the minimum size necessary to carry
the expected flow load. Separate ventilation pipes may be required (see §1811.
D.7 of this code). It may be worthwhile to consider over sizing the discharge
pipes to reduce the ventilating pipework required.
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Table 1811.D.5.5C
Maximum Number of Discharge Units
Connected to Building Drain or Building
Sewer1,2
|
|
Nominal Internal Diameter of Pipe (in.)
|
Slope or Fall Per Foot (in.)
|
|
1/8
|
1/4
|
1/2
|
|
2
|
-
|
10
|
26
|
|
3
|
40
|
100
|
230
|
|
4
|
30
|
430
|
1,050
|
|
5
|
780
|
1,500
|
3,000
|
|
6
|
2,000
|
3,500
|
7,500
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NOTES:
1.
Discharge pipes sized by this method give the minimum size necessary to carry
the expected flow load. Separate ventilation pipes may be required (see §1811.
D.7 of this code). It may be worthwhile to consider over sizing the discharge
pipes to reduce the ventilating pipework required.
2. Building sewer sizes start at 4
inches.
6.
Design of Pipe Systems for Dwellings. The design of a single stack discharge
and ventilating system for dwellings shall conform with the following.
a. General. In dwellings only, the choice and
lay-out of fixtures and their waste pipes may follow the recommendations for
simplified systems as provided in this Subsection. Simplified systems for other
types of buildings may be possible but are not provided for in this
Part.
b. Design of Single Branches
and Fittings. The design of single branches and fittings shall comply with the
following.
i. Branch discharge waste pipes
(fixture drains) serving plumbing fixtures shall have a uniform shallow fall or
slope and the inlet to the stack shall be of a sanitary pattern and have a
sweep of not less than 1-inch (25.4 mm) radius. Any horizontal change of
direction in a fixture drain shall be of long radius and vertical changes of
direction are prohibited.
ii. Water
closet branch inlets to the stack shall be swept in the direction of flow with
a radius at the invert of not less than 2 inches (51 mm). Entries at 45 degrees
(0.785 rad) from the vertical are considered equivalent.
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Table 1811.D.6A
Design of Single Branches and Fittings
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|
Component
|
Design Requirements
|
Possible Problem
|
|
Bend at foot of stack
|
Bend to be of "large radius", i.e., 6-inch minimum
root radius or, if adequate vertical distance is available, two "large radius"
45 bends are to be preferred. Vertical distance between lowest branch
connection and invert of drain to be at least 18 inches for a two story house
and 30 inches for taller dwellings. Where this distance cannot be achieved,
ground floor fixtures shall be connected directly to the building drain and
vented as provided for in other Chapters of this Part (see Figure 1811.D.5.4B
of this code).
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Back pressure at lowest branch, foaming of
detergents
|
|
W.C. branch connection to stack
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Water closet connections shall be swept in the
direction of flow with radius at the invert of not less than 2 inches. Fittings
in other materials shall have the same sweep as cast iron fittings. The length
of unvented water closet is closet branches shall be limited by the diameter of
the branch piping: 6 ft for 3-inch diameter, 10 ft for 4-inch diameter.
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Induced siphonage at lower level in the stack when
water closet is discharged
|
|
Lavatory waste 1 1/4-inch trap and 1 1/2-inch
minimum waste pipe. Lavatories with 1 1/2-inch P.O. plugs may be installed as
provided for sink waste.
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"P" traps shall be used. The maximum fall of the
waste pipe shall not exceed the hydraulic gradient of the pipe. For the maximum
distance between the stack and trap weir see Table 1811.D.6B of this code. Any
bends on plan shall be of not less than 3-inch radius at the center line. Waste
pipes longer than the recommended maximum length shall be vented. As an
alternative, 2-inch diameter waste pipes may be used so long as the hydraulic
gradient is not exceeded, but additional maintenance may be necessary to
maintain the bore.
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Self-siphonage
|
|
Bath waste 1 1/2-inch trap and 1 1/2-inch waste pipe
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"P" traps shall be used (a 2-inch parallel branch,
when required shall not be considered a violation of requirements of other
Sections of this Part, when its vertical length does not exceed 12 1/2 inches,
and the center line of the parallel branch is not more than 12 1/2 inches from
the stack). Owing to the flat bottom of a bath, the trailing discharge normally
refills the trap and the risk of self-siphonage is much reduced. Waste pipes 7
ft 6 in. long at a fall or slope of 1/4 in./ft have been used successfully.
Position of entry of bath waste into stack to be as shown in Figure 1811.D.5.4A
of this Part.
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Self-siphonage
|
|
Sink Waste 1 1/2-inch trap and 1 1/2-inch waste pipe
|
"P" traps shall be used. Owing to the flat bottom of
a sink, the trailing discharge normally refills the trap and the risk of
self-siphonage is much reduced. Fall or slope of 1/4 in./ft shall be
maintained. For maximum length, see Table 1811.D.6B of this code. A sink with 1
1/2-inch tail piece may be drained with a 2-inch horizontal branch not
exceeding 8 feet in length. When a 2-inch branch is used, the trap outlet shall
connect to a 2 x 1 1/2 inches reducing fitting. An opening into the branch
larger than 1 1/2 inches will not be permitted except for a cleanout.
|
Self-siphonage
|
NOTE:
1. Where the
length or fall of the discharge pipe serving a waste fixture is greater than
the recommended maximum in this table, the discharge pipe shall preferably be
vented (see §1811. D.7 of this code) or a larger diameter discharge pipe shall
be used. This may have a maximum length of 10 ft.
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Table 1811.D.6B
Distance From Trap Weir to Stack or Other
Ventilating Pipe
|
|
Minimum Size of Fixture Drain (in.)
|
Distance Trap to Stack or Vent
|
|
1 1/2-inch fixture drains required for lavatories
with 1 1/4-inch traps
|
4 ft 6 in.
|
|
1 1/2
|
5 ft 6 in.
(Other than bath waste)
|
|
2
|
7 ft 6 in.
(For bathtubs see Table 1811.D.6A of this code)
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c. Design of Main Pipework
i. Design details for stacks of various
diameters are given below. The choice of design will depend on the space taken
up by the pipes and the ease with which they can be accommodated in the
building.
ii. An offset in the
stack above the topmost connection to the stack has little effect on the
performance of the system. Offsets below the topmost connection should be
avoided lest extra ventilating pipes be necessary to maintain adequate water
seals.
d. 3- Inch
Stacks. 3-inch stacks in a single stack system are limited to fixtures other
than water closets and to fixtures with maximum drain sizes of 2
inches.
e. 4-Inch Stacks. For
details of ventilating pipes see Table 1811.D.6C of this code.
f. 5-Inch Stacks with No Vents (Single Stack
System). Suitable for buildings up to 12 stories high where the stack serves
one group of fixtures on each floor, or up to 10 stories high where the stack
serves up to two groups of fixtures on each floor.
g. 6-Inch Stacks with No Vents (Single Stack
System). Suitable for buildings up to at least 20 stories high with not more
than two groups of fixtures on each floor.
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Table 1811.D.6C
Ventilating Pipes Required for Various Loading
Conditions
4-inch Discharge Stack
|
|
Number of stories
|
Stack serving one group on each
floor
(Each group consists of a water closet, a
bath, a basin and a sink. Where dwellings contain more fixtures it may be
necessary to provide additional vents)
|
Stack serving two
groups1 on each floor
|
|
Flats (Each complete living unit is on one floor), 1
to 5
|
No separate venting required
|
No separate venting required
|
|
6-11
|
2-inch vent stack connected to the discharge stack
on alternate floors
|
2-inch vent stack connected to the discharge stack
on alternate floors
|
|
12-15
|
2-inch vent stack connected to the discharge stack
on each floor
|
2-inch vent stack connected to the discharge stack
on each floor
|
|
16-20
|
2 1/2-inch vent stack connected to the discharge
stack on each floor
|
3-inch vent stack connected to the discharge stack
on each floor
|
|
Maisonettes (Each complete living unit occupies
space on two floors, with baths on one floor of the unit), 1 to 4
|
Single stack system
|
Single stack system
|
|
5-8
|
Single stack system
|
2-inch vent stack connected to the discharge stack
on alternate (bathroom) floors
|
|
9-15
|
2-inch vent stack connected to the discharge stack
on alternate (bathroom) floors
|
2-inch vent stack connected to the discharge stack
on alternate (bathroom floors)
|
|
16-20
|
2 1/2-inch vent stack connected to the discharge
stack on alternate (bathroom) floors
|
3 -inch vent stack connected to the discharge stack
on alternate (bathroom) floors
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7. Ventilating Pipes. Ventilating pipes shall
comply with the following.
a. General. The
purpose of a ventilating pipe is to maintain equilibrium of pressure within the
system and thus prevent the destruction of trap seals by siphonage or
compression. It will also assist in preventing undue accumulation of foul air
by facilitating air movement in the pipe system.
b. Installation. Ventilating pipes shall be
so installed that there is a continuous fall back into the discharge pipe
system to prevent any possibility of a waterlock or trap preventing the free
movement of air through the ventilating system and to minimize the risk of
internal corrosion. Short turn fittings in the pipework shall be
avoided.
c. Branch Vents. Branch
ventilating pipes may be connected to a main ventilating pipe or be carried
upward either individually or in combination with one another. Such connections
shall be above the flood level of the highest fixture served.
d. Sizes. The diameter of a branch
ventilating pipe or of a ventilating stack shall be as given in Table 1811.D.7
of this code. For extremely long ventilating stacks, a larger diameter pipe
shall be used. See Note 1 in Table 1811.D.7 of this code.
e. Arrangement. A branch ventilating pipe,
when required, shall be connected to the individual fixture discharge pipe
(fixture drain) not less than 3 inches (76 mm) from the crown weir of the trap.
A fixture may be connected to the bottom of a fixture vent, or at the base of a
main ventilating stack to assure its being kept clear.
f. Purpose. The purpose of the ventilating
pipes is to reduce the pressure fluctuations in the discharge stack by allowing
air to enter the stack. Where venting is necessary, therefore, it is often
convenient to do so by cross connecting the ventilating stack and the discharge
stack directly, preferably above the highest fixtures as appropriate. To
prevent cross flow into the ventilating stack, the branch ventilating pipe
shall slope upward from the discharge stack at an angle of not less than 45
degrees (0.785 rad) from the horizontal until it reaches a point 6 inches (152
mm) above the flood level rim of the highest fixture serving the floor, at
which point it may run at a horizontal angle until connecting with the vertical
vent.
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Table 1811.D.7
Branch Ventilation Pipe or Ventilating Stack
|
|
Diameter of branch discharge pipe or discharge
stack, D (in.)
|
Diameter of Ventilating Pipe
(When the vent length exceeds the length of the
discharge stack, the vent shall be at least one pipe size larger than required
by this table except for individual fixture vents)
|
|
Smaller than 3
|
2/3 D
|
|
3 to 4 inclusive
|
2 in.
|
|
Larger than 4
|
1/2 D
|
g.
Discharge Point. The outlet of every ventilating pipe system to the open air
shall be at such a height and position as will effectively prevent the entry of
foul air into the building (see
§907 of this code).
8. Pipe Chases and Enclosures, Etc. Pipework
enclosures, e.g., ducts, casings, etc., shall be of adequate size and shall
have access provisions for maintenance, painting, testing and cleaning. They
shall be constructed appropriately for fire resistance in accordance with
requirements of the applicable codes adopted under the authority of Act 12 of
the 2005 First Extraordinary Session.
9. Choice of Materials. Materials shall
conform to the applicable requirements of other Sections and Chapters of this
code. Fittings used in the construction of single stack plumbing systems shall
in no case be designed with inlet radii less than provided for in this
Subsection.
10. Access to Interior
of Pipework. Sufficient access shall be provided to enable all pipework to be
tested and to provide reasonable access for cleaning and other necessary
maintenance. All access points for clearing purposes shall be carefully sited
to allow the entry of clearing apparatus or the insertion of testing apparatus
and, where these are in ducts, consideration shall be given to the other
services accommodated in the duct.
11. Simultaneous Discharge. The system of
discharge pipes shall be capable of withstanding satisfactorily the effects of
the probable maximum simultaneous discharge of fixtures which will occur in
practice. The number of fixtures to be discharged together to simulate this
effect is given in Table 1811.D.11 of this code.
a. For example, for a block of flats nine
stories high with the stack serving one water closet, one lavatory, one sink
and one bath on each floor, the test discharge is one water closet, one
lavatory and one sink simultaneously discharged on each floor
(i.e., 27 fixtures discharged simultaneously). Where the stack
serves two water closets, two lavatories and two sinks on each floor, the test
discharge is one water closet, one lavatory and two sinks simultaneously
discharged on each floor (i.e., 36 fixtures discharged simultaneously). For the
purpose of this test, baths are ignored as their use is spread over a period
and consequently they do not add materially to the normal peak flow on which
Table 1811.D.11 of this code is based. Where a stack serves baths only, the
number to be discharged simultaneously in a discharge should be taken to be the
same as for sinks.
b. All traps
shall be fully charged and the appropriate combination of fixtures discharged
simultaneously. Trap seals shall be measured at the end of the discharge. The
worst conditions occur when fixtures on the upper floor are discharged. A
reasonable test, therefore, would be to discharge up to one water closet, one
lavatory and one sink from the top of the building, distributing any additional
fixtures along the stack.
|
Table 1811.D.11
Number of Fixtures to be Discharged
Simultaneously for Testing Stability of Trap
Seals
|
|
Number of fixtures of each kind on the stack
|
Water Closet
|
Wash Basin
|
Kitchen Sink
|
Misc.
(ea. Type)
|
|
1-9
|
1
|
1
|
1
|
1
|
|
10-18
|
1
|
1
|
2
|
2
|
|
19-26
|
2
|
2
|
3
|
3
|
|
27-50
|
2
|
3
|
3
|
3
|
|
51-78
|
3
|
4
|
4
|
4
|
|
79-100
|
3
|
5
|
5
|
4
|
i. When the
miscellaneous fixture is a washer drain, omit one sink from test for each
washer drain, except when washers only are connected to the stack.
ii. For washing machine drains (no washers
connected) test shall be conducted with hoses connected to both the hot and
cold water supply out lets and with outlets fully opened. (This is in lieu of
discharge from washers.) Test should be of 5 minutes duration, one-half of one
cup of liquid detergent shall be dispensed into the washer drain pipe at
approximately one-third cup per minute along with the water during the last 3
minutes of each test.
E. Single Stack Plumbing System.
1. Approval. The purpose of this Subsection
is to make provisions for the design and installation of a single stack
plumbing system which is not otherwise allowed in this code. In accord with
Chapter 12 of this code, the plumbing official shall require that the owner
submit necessary plans and specifications to the state health officer by a
Louisiana Registered Professional Engineer registered in either civil or
mechanical engineering. In general, single stack plumbing systems may be
considered for approval by the state health officer for use on the upper floors
of hotel and motel guest rooms but shall not be considered for condominium or
apartment complexes.
2. Tests.
Single stack plumbing systems shall be tested in accordance with §1205. C of
this code.
3. Sovent Single Stack
Plumbing System. Copper sovent systems shall be designed and installed in
accordance with design criteria contained in the Copper Development Association
(CDA) Handbook No. 402/0. Cast iron sovent systems shall be designed and
installed in accordance with design criteria contained in ASSE 1043. Cast iron
fittings shall meet ASME B16.45. Other materials shall meet standards and
specifications listed in Table 703 of this code for drain, waste and vent pipe
and fittings.
F.
Appendix References. Additional provisions for Alternate Designed Plumbing
Systems are contained in Figures 6 and 7 of
Section
1807 of this
code.
AUTHORITY NOTE:
Promulgated in accordance with
R.S.
40:4(A)(7) and
R.S.
40:5(2)(3)(7)(9)(16)(17)(20).
