DWV take 2 Flashcards
The maximum horizontal length of a w.c fixture drain is?
10 ft (3m)
A vent stack shall be installed to protect the base of every soil or waste stack that passes through more than:
4 storeys
What is the hydraulic load of a 3” floor drain in a public washroom?
no load
The size of the portion of vent pipe that terminates through the roof shall not be less than:
3”
Any roof vent terminating into the open air shall be located at a distance of not less than:
3.5m away from any window, door or other opening
The min developed length of a trap arm shall not exceed:
2 x the pipe diameter
Strap hangers shall not be used to support horizontal pipe greater than:
4”
Fixtures that drain into a vertical section of a relief or circuit vent shall not have a hydraulic load of?
1 1/2 FU
All fixtures shall have a trap w/ a water seal of?
not less than 1 1/2 “ (38mm)
A trap used to carry acid waste shall have a water seal of:
not less than 2” (50mm)
How many fixture units are permitted to drain into a soil or waste stack if the stack was to act as a relief vent?
6 FU each
The max number of a water closets allowed on a 3” soil stack is?
6 water closets
The rate of discharge through an 1 1/4” fixture outlet pipe is called a/an
fixture unit
Where a building trap is installed, a fresh air inlet shall be installed on the building drain upstream of the trap:
2.5.5.4
as close as possible to the trap and w/in 1.2m of the trap
The trap weir is?
The highest part of the lower interior surface
A vertical pipe means:
45 degree from the vertical
The max distance bn hangers on a horizontal run of ABS plastic pipe shall be:
1.2m (4’)
A building sewer begins outside a building at a point?
1m from the building wall
The total fall of a fixture drain from the trap weir to the vent fitting shall not exceed:
two times the diameter of the pipe
Any vent pipe shall extend vertically above the flood level rim of a fixture:
to adjust above the flood level rim before connecting to another vent
The min size of a fresh air inlet for a 7 storey building is:
4”
A shower receptor for 2 or 3 heads is equal to a hydraulic load of:
3 fixture units
A kitchen sink with a domestic type garbage disposal unit installed on it has a hydraulic load of?
1 1/2 FU
A 2” trap not listed in table 2.4.9.3 has a hydraulic load of?
3 FU
The max number of FU that may be connected to a horizontal branch off a 2” stack that passes through 5 storeys is?
6 FU
The max number of FU that may be connected to a 3” stack of 60 meters in developed length is:
102 FU
The max number of FU that may be connected to a 4” building drain at uniform grade of 1 in 50 is?
240 FU
The size of a trap / waste opening for a potato peeler is?
2”
The size of a trap / waste opening for a beauty parlor basin is?
1 1/2”
The min size vent for a 2” trap is?
1 1/2”
The max cumulative change in direction of a trap arm serving a lavatory is?
135 degrees
A branch cannot be connected w/in 1.5m of the base of the stack:
- receives a discharge of 30 of more FUs
- receives a discharge from fixtures located on 2 or more storeys
A common cause of trap seal loss in a properly vented system is?
evaporation
An ABS stack 15m in length, when subjected to a temp change of 50 C, would have a linear expansion of about?
70 mm
A-2.3.3.9
The trap seal refers to the vertical distance measured from?
the trap weir to the trap dip
In testing a 5 storey (15m) stack with water, the pressure at the base of the stack on the gauge would read?
147 kPa
If 8 water closets are required in a washroom, how many urinals could be substituted for w.c’s?
5
(2/3)
The max length of an offset on a 4” soil / waste stack serving as a wet vent is?
max 2.5 m
You must connect a sanitary building drain w/ a combined building sewer. If an open air restaurant is located on the roof of the building, and the roof drain has to be located w/in 1 m of the patio, what must you do to ensure that your rough-in passes inspection?
Place a running trap / clean-out on the storm building drain prior to its connection w/ the building sewer
What is the min length of a trap arm serving a lavatory?
2 1/2”
Which arrangement may allow a fixture to self-siphon?
Trap too far below fixture
If you have a 4” building drain connected to a 3” soil stack, what would the size of the c/o at the base of the stack be?
4”
2.4.7.2
What is the min grade on a building drain?
1%
1/8
What is the primary function of a p-trap?
Keep sewer gases from entering the building
Trap arm size are based on?
The size of the fixture outlet pipe
What would be the size of a trap that serves two lavatories that are in the same room?
1 1/2”
What size of vent terminal would be required for a 1 1/2” vent?
1 1/2” x 3”
2.5.6.5
What is the max size of a trap arm that may drain into a wet vent?
2 w/ the exception of an emergency floor drain
What is the min size of c/o for a 4” pipe?
4”
Flat vent is a trade name for a vent that?
requires a c/o fitting to be placed
The main stack / vent located in a single - family dwelling:
Should be chosen to allow as many fixture as possible to connect to the main stack.
The min drainage pipe size for a lavatory is?
1 1/4”
What is the max degree change of direction on a water closet trap arm?
225 degrees
On a ferrous c/o fitting, all nuts, bolts, caps and plugs shall be?
non-ferrous
Which of the following traps is prohibited from use in a plumbing system?
bell-trap
______ is a vent pipe that serves one fixture?
individual vent
A branch vent:
is two or more dry vents connecting together
the positive or negative pressure in a drainage will never exceed ____ of water column at the trap seal serving the fixture:
1”
What is the max length of a continuous waste serving a kitchen sink?
1200mm
On a fixture drain serving a kitchen you cannot exceed ____ degrees bn c/o:
90 degrees
A 3” (80mm) stack vent is required in a residence because of:
the national plumbing code of Canada
What kind of trap is allowed to be used on an interceptor?
drum trap
The min pipe size for a building sewer that is to be connected to public sewer is:
4 “
A pipe positioned at a 45 degree from the horizontal, is considered to be?
vertical
The continuous waste / vent principle connection is considered as the best arrangement for venting because:
waste water does not enter the vent pipe
A vent connection fitting placed on a trap arm:
must have the vent opening arranged above horizontal centreline of the trap
The min slope to which a trap arm must be installed is?
2% grade
What is the min distance that a vent can terminate above a door?
1m
The waste pipe of dual-vented fixtures must connect at?
same level
What is the min trap seal depth for all traps except those that drain acid wastes?
1 1/2” –> 38mm
When applying a water test to a part of the drainage system:
a 10 ft head must be created
Where does a fixture drain start?
at the trap weir
A building sewer which conducts both sewage / storm water is called a?
combined building sewer
A wet vent pipe acts as a/an ___ pipe and also a/an ____ pipe:
waste / vent
What is the largest size pipe that can be hung w/ perforate steel strap?
4”
What is the min size of a wet vent that serves a water closet?
2” (50mm)
An individual vent becomes a stack vent when:
a fixture drain extends through at least one complete storey
What would happen is the fall on a trap arm was more than one pipe diameter?
the trap may self-siphon
What is the min distance that a vent can terminate above a balcony?
2m
6 ft
What is the portion of the fixture drain bn the trap weir and the vent pipe fitting?
Trap arm
A properly piped wet vented group of fixtures that includes a water closet:
Must have the water closet piped as the lowest vented fixture
What is the max allowable change of direction bn a c/o and the pipe that it serves?
135 degrees
On a building drain you cannot exceed ____ degrees bn c/o?
45 degrees
When sizing the vertical portion of the wet vent, do not include the fixture unit load of the connected fixture?
Lowest (most downstream)
What connects the waste opening of a fixture to the trap serving the fixture?
fixture outlet pipe
Which vent pipe that is an extension of the soil or waste stack above the highest horizontal drain connected to the stack?
stack vent
The combined wastes from a lavatory / a single compartment sink are used to wet vent a 3” water closet. The wet vent size should be?
2”
A fixture drain piped to a drain through one complete storey min is called a:
soil or waste stack
Rain water leader sizing is based on rainfall volume in ____ over a period of 15 min:
mm
What is the min size for a circular rainwater leader?
2”
For conversion of a fixture unit loads to litres for pipe sizing purposes, 260 FU or less is equal to ____ L?
2360
When the number of FU exceeds 260 FU, the load is ____ litres from each fixture unit
9.1
A pump rated at 10 gallons per min would add a load to the combined sewer ____ liters
681
45 x 15 min = 681L
How many fixture units are allowed to connect to the vent stack?
8
How high must a building be before a vent stack is required?
2.5.4.2 (1)
5 storeys
“More than 4 storeys”
How is a bathroom group sized when tied in to the vent stack?
wet vent
How far above the floor level of the lowest storey of the section the yoke vent shall be connected to the vent stack?
1m
Yoke vents are required on buildings of what height?
12 storeys
(more than 11 storeys)
What is the min size of a fresh air inlet?
4”
When circuit venting 3 drinking fountains, what would be the size of the fixture drain immediately downstream of the circuit vent connection?
2”
What are the NPC intended for?
- ensures the quality / functionality of plumbing installations
- protects the health of the occupants / general public
- Protects building structure from damage caused by improper piping installation.
What does AHJ mean?
Authority having Jurisdiction
When does testing + inspection need to be done?
Once piping rough-in has been completed (ground work or above grade)
(piping needs to be under a test while being inspected)
What are the 4 main tests that may be performed on a DWV system?
- Water pressure tests
- Air pressure tests
- Final tests
- Ball tests
How much water column must be applied to all joints?
3m (10’)
How long does a test need to be
done for?
15 min
How much pressure does a air pressure test need?
35 kPa (5 psig)
For final tests, what water column must be maintained for 15 min?
25 mm (1”)
When a pipe is 3” or more, what size of ball is used for a ball test?
min 2” (50mm)
When a pipe is 3” or less, what size of ball is used for a ball test?
1” (25mm)
What is this?
A drop head auger
What is a drop head auger used for?
For cleaning the trap arms of fixtures mounted back-to-back
What is this?
A spade cutter
What is a spade cutter used for?
Following up after augers have been used / to open up floor drains
What is this?
A shark-tooth cutter
What is a shark-tooth cutter used for?
For cleaning pipes of general material clinging to pipe walls
What is this?
A grease C cutter
What does a grease C cutter used for?
For grease blockages in lines leading from garbage disposal units or waste pipes
What is the best tool to use when you suspect that a building sewer is frozen b/c it isn’t buried deep enough?
A steam cleaning machine
