TOPIC 8: Vents and Venting System Flashcards
Portion of the drainage pipe installation intended to
maintain a balanced atmospheric pressure inside the
system
VENTILATION
pipe or opening used for ensuring the
circulation of air in a plumbing system and for relieving the
negative pressure exerted on trap seals
Vent Pipe
- the ‘backbone’ of the entire sanitary
system - Connected to the Main Soil & Waste
Stack - The portion where waste does not
travel through
Main Soil & Waste Vent
- Continues to the roof; the portion
penetrating the roof is called the
Vent Stack Through Roof (VSTR)
- the principal artery of the venting
system to which vent branches are
connected. - serves as support to the Main Soil &
Waste Vent - a.k.a. ‘Collecting Vent Line’
Main Vent
a pipe installed to vent a fixture trap, that connects with the vent system above the fixture served or terminates in the open air.
Individual Vent or Back Vent
an arrangement of venting so
installed that one vent pipe
serve two (2) traps.
Unit, Common, or Dual Vent
a vertical vent line that provides
additional circulation of air between
the drainage and vent systems or to
act as an auxiliary vent on a specially
designed system such as a
“yoke vent” connection between the
soil and vent stacks.
Relief Vent
a pipe connecting upward from a soil
or waste stack below the floor and
below horizontal connection to an
adjacent vent stack at a point above
the floor and higher than the highest
spill level of fixtures for preventing
pressure changes in the stacks.
Yoke or By-pass Vent
- a group vent pipe which starts in front of the extreme (highest) fixture connection on a horizontal branch and connects to the vent stack.
- a.k.a. ‘Loop Vent’
- Serves a battery of fixtures
Circuit Vent
- a vertical vent connection on a
horizontal soil or waste pipe
branch at a point downstream
of the last fixture connection
and turning to a horizontal line
above the highest overflow
level of the highest fixture
connected there - Used in spaces without partitions
Looped Vent
that portion of a vent pipe through which wastewater also
flows through.
Wet Vent
a pipe or shaft to convey foul air
from a plumbing fixture or a room
to the outer air.
Local Vent
a vent that does not carry liquid or
water-borne wastes.
Dry Vent
the extension of a soil or waste stack
above the highest horizontal drain
connected to the stack.
Stack Vent
the vertical vent pipe installed
primarily for providing circulation of
air to and from any part of the soil, waste of the drainage system.
Vent Stack
The uppermost end above the roof has traditionally been referred to as
Vent Stack Through Roof (VSTR).
Vents Required: Each trap shall be protected against ___ and ____through venting.
siphonage and backpressure
Vents not Required: on a _____ which discharges through a horizontal indirect waste pipe into a secondary interceptor. The secondary interceptor shall be properly trapped and vented.
primary settling tank interceptor
Vents not Required: ____. Such sink shall
discharge by means of an approved indirect waste pipe into a floor sink or other approved type receptor.
Traps serving sinks in an island bar counter
SIZE OF VENTS:
The sizes of vent piping shall be determined from its ___ and ____ connected thereto.
length and the total number of fixture units
SIZE OF VENTS: The diameter of an individual vent shall not be less than _____ nor less in size than ____ of the drain to which it is connected.
32 mm (1-1/4”); one-half (1/2) the diameter
GRADES & CONNECTIONS
All horizontal or branch vents shall be free from _____ & shall be graded and connected to drip back by
gravity to the drainage pipe it serves.
drops or sags
GRADES & CONNECTIONS
Each vent shall rise vertically ____ above the highest level rim of the fixtures served before offsetting horizontally.
152 mm
GRADES & CONNECTIONS
All vent pipes shall extend ____ above the roof or shall be reconnected to the soil or waste stack vent at a point below the roof.
undiminished in size
GRADES & CONNECTIONS
____ fixtures having same level inlet openings, may be served by a common vertical vent pipe connected to an
approved double branch fitting.
Two (2)
GRADES & CONNECTIONS
The “vent stack through roof” (VSTR) shall be increased ____ pipe size above the connection between the stack vent and the horizontal vent.
one (1)
VENT TERMINATION
VSTR shall terminate vertically not less than ____ above
the roof nor less than ____ from any vertical surface
nearby.
150 mm; 300 mm
VENT TERMINATION
Each vent opening shall terminate:
Not less than ___ from any openable window;
Not less than ___ above any openable window;
Not less than___ away from any lot line, alley and street boundary lines.
3.00 m; 0.90 m; 0.90 m
VENT TERMINATION
Vertical vent pipes shall extend ___ distant from any part
of the roof that is used for human activities and shall extend
not less than ___ above such roof.
3.00 m; 2.10 m
VENT STACK & RELIEF VENTS
Each soil or waste stack extending ____
above the building drain shall be served by a parallel vent
stack which shall extend undiminished in size from its upper
terminal at the roof and connect to the soil or waste stack at
ground level and at every fifth floor levels with a ____
at a point below the horizontal soil or waste branch
connection to the stack and at the nearby vent stack above
the same floor to provide a relief vent.
ten (10) or more storeys; “yoke vent”
VENT STACK & RELIEF VENTS
The yoke vent connection at the vent stack shall be placed
____ the floor level and, by means of a wye branch at the soil stack, shall be placed below the fixture branch serving that floor.
1.0 m above
VENT STACK & RELIEF VENTS
The size of yoke vent shall be ____ than either the soil stack or the vent stack, whichever is smaller.
not less in diameter
SANITARY SYSTEM PROBLEMS
Trap Seal Loss
Retardation of flow
Deterioration of the materials
Direct effect of the Minus & Plus Pressure inside the system due to inadequate ventilation of traps
Trap Seal Loss
Trap Seal Loss: Attributed to the following conditions
Siphonage
Back Pressure
Capillary Action
Evaporation
Wind Effects
Trap Seal Loss: Attributed to the following conditions: direct and momentum
Siphonage-
Trap Seal Loss: Attributed to the following conditions: caused by extreme temperatures, idleness
Evaporation-
Trap Seal Loss: Attributed to the following conditions: strong winds blow the trap seal
Wind Effects
Due to the effect of atmospheric pressure and/or gravity
Retardation of flow
Due to the formation of acids
Deterioration of the Materials
is a pipe that does not connect directly with the drainage system but conveys liquid wastes by discharging into a plumbing fixture, interceptor or receptacle directly connected to the drainage system.
Indirect Waste Pipe
The process of supplying or removing air by natural or artificial means to or from any
space, such air may or may
have not been conditioned.
VENTILATION
A pipe installed to
provide a flow of
air to and from a
drainage system
or to provide
circulation of air
within such
system to protect
the trap seal from
siphonage and
backpressure.
VENT
A vertical vent pipe installed primarily for the purpose of
providing circulation of air to or from any part of the building drainage system.
VENT STACK, MAIN VENT
The extension to the open air of a soil or waste stack above the highest horizontal branch
drain or fixture branch connected to the stack.
STACK VENT, SOIL AND WASTE
VENT
Type of venting system where the vent connects with a single
fixture trap, usually at the
back and extends vertically and connects with a stack vent, a vent stack or branch vent.
INDIVIDUAL VENT/BACK VENT
A branch vent which
serves two or more traps
and extends from in front
of the last fixture
connection of a horizontal
branch to the vent stack.
Circuit venting can be
used when two or more
fixtures, such as
lavatories, are installed in
a row. The circuit vent is
connected to the waste
drain line between the last
two fixtures in the row.
Then the circuit vent is
connected to the main
vent.
CIRCUIT VENT
A VENT ARRANGEMENT FOR A
GROUP OF PLUMBING FIXTURES, CONSIST OF A VENT PIPE WHICH IS CONNECTED TO THE WASTE OR SOIL BRANCH IMMEDIATELY
BEFORE THE FIRST FIXTURE OF THE GROUP.
LOOP VENT
A type of ventilation
system used on
fixtures in a room
away from a wall or
partition.
LOOPED VENT
