LT: Install piping for Sewers Flashcards
The plumbers responsibility ends where for a drainage system?
Property line
What is the main purpose of a sanitary sewer?
To carry liquid / solid waste away from homes and businesses –> direct to final tx aka wastewater treatment plants
Who is in charge of the system that starts at the property line and ends where effluent is returned to the earth?
The Municipal or city
What are the 3 different types of sewer systems?
1) sanitary sewers (black water)
2) storm sewers
3) combined sewers
What type of sewer is crucial in the prevention of flooding?
Storm sewer drainage system
How do storm sewer drainage systems help prevent flooding?
Diverts excess rain / groundwater –> run off from parking lots, roofs, paved streets / sidewalks to nearby waterways via drains and underground pipe system.
True or false: sewage and storm water are channeled via same pipe / terminates in a sewage tx plant and poses problems
True
Where are combined sewers mostly seen?
In areas where it is difficult / impossible to direct storm water to safe disposal locations aka river or lake
Who gives the okay to install combined sewer systems?
Authority having jurisdiction
Combined building drain must travel how far outside a building before it becomes a combined building sewer?
1m
What 2 other names does Asbestos cement go by?
White pipe
Transite
Polyolefin is used in what kind of places?
Lab Line –> for corrosive waste drainage systems
What are the most common ABS pipe lengths?
12 ft and 20ft
(10ft) also available - not common
What does thermoplastic mean?
It can be softened / reformed
What does HDPE mean?
high - density polyethylene
What are some fun facts of HDPE pipe?
noncorrosive, highly flexaible, joints are heat-fused or bell/spigot or mechanical and has a low failure rate
What does RCP stand for?
Reinforced concrete pipe
What is RCP used for?
used in municipal gravity systems
What are the downsides of concrete piping?
It is susceptible to H2S and can corrode in extremely acidic soil
At what depth do Trenches and Excavation pits require a protective system aka sloping or shoring?
4 ft (12m) –> in BC
What is the definition of Confined spaces?
Has limited or restricted means for entry or exit (access/egress) that may complicate the provision of first aid, evacuation, rescue or other emergency response service
What is the first thing to do for Confined space?
Getting a permit
What types of spaces require a permit
hazardous atmosphere, potential for engulfment or suffocation or safety or health hazards
What is the next step after requiring a permit for Confined space?
identifying entry and exits
True or False: a septic tank is considered a confined space.
True
What 2 things are air quality hazards in confined spaces?
Insufficient amount of oxygen
toxic gases - make ill / lose cx
What is included in Pinch points?
commonly fingers / hands but can also involve any area of the body
What is a common cause of pinch points?
Walking or working in area w/ mobile equipment / fixed structures
Do we still see technologies used in past centuries?
yes
What are new innovated sewer systems called?
(Alternative) wastewater collection system
What does wastewater collection system include? (P-V-SD)
pressure sewer systems, vacuum sewer systems / small diameter gravity sewer systems
What is the most used sewer system used worldwide?
Gravity sewer systems
Pressure sewer systems aka sumps are commonly used where?
where the building sewer elevation is higher than the drainage pip feeding into it
Where does a plumber’s responsibility for a drainage system on private property end?
At the property line
What system contains both sewage from toilets / rainwater from roofs / parking lots.
Combined drainage systems
What type of pipe was used in the earliest form of municipal waste systems / are still used where corrosive wastes may be expected?
Vitrified clay
What type of pipe is limited to use on private property because of the small diameters available
ABS
What is the most immediate concern when entering a confined space?
Air quality (PERMIT)
What is the purpose of a lift station in a municipal sewer system?
It pumps sewage from a deep sewer to a higher elevation
What is the most common type of sewer system in both private / municipal use?
Gravity
A FU is equal to what?
1 cubic foot of water through 1 1/4” OD pipe in 1 min
What are the units of measure used to size pipes in storm or combined system?
L/15 min
Where would you find the local rainfall intensity for a city or area?
Weather channel
What information would one consult if calculating the discharge rate from flow control roof drains?
the manufactures specs
What are the units of measure used to size pipes in a sanitary system
Fixture units
What is the conversion factor to be used to represent the flow via a combined building drain from not more than 260FU?
2360 L / 15 min
What is the conversion of 300 FU flowing through a combined building drain?
2730 L / 15 min
(9.1 L/min)
If a fixture discharging CWW drains into a sanitary building drain, What is that pipe now called?
combined building drain
What is the most common grade for above / below ground horizontal drainage pipe that helps ensure solid waste will be carried away by the liquid flow?
2%
What is the min flow velocity?
0.6m/s (2.0 feet/sec –fps)
True or false: Pipes smaller than 8 inches require a manhole.
False - they require acceptable pipe configuration
wye + 1/8th bend
What is the best way to install sewer pipe?
one section at a time
When using bell / spigot pipe, is the bell installed upstream or downstream?
Upstream - code + decreases blockages
What is required if a new building has any fixtures located lower than street level?
Backwater valve
Are backwater valves installed normally open or normally closed?
Normally open
True or false: Plumbers are responsible for 300mm (1’) of backfill.
True
What does RCP mean?
Reinforced concrete pipe
Where is RCP used?
storm sewers systems / sanitary systems
What should be lubricated after installment?
pipe bell also spigot or tongue end
What would be the grade on a sanitary sewer that is 60m long if the starting elevations were 72.875m and 71.350m?
2.5%
72.875 - 71.350 =
ans / 60 =
ans x 100
What kind of pipe allows heavy loads on top and has a shallow burial depth (under public roadways)
RCP
What is considered a normal manhole?
A manhole w/ an overall depth greater than 0.9m (3ft) but not more than 2m (6ft)
True or False: manhole openings are the smallest point
True - so the manhole lids fit
What are 2 things that a manhole installed inside require?
needs a vent to exterior
vent that is min 2”
Do the inlet and outlet elevations differ on sanitary manholes?
Yes, only by the amount of grade required to allow flow by gravity bn them
True or False: the flow through a sanitary manhole must be channeled
True
What is a Lamp manhole?
is a small opening on a sewer that is extended vertically to the grounds surface for the purpose of lowering a lamp or light inside it?
Where are lamp hole needed?
In places where inspection of the flow in needed
True or false: Catch basins are storm sewer inlets that have a specific function
true
What is the purpose of a catch basin?
catch surface water and direct it into a storm sewer system
Where are catch basins located?
at low points on public / private property
next to street curbs, in parking lots/ at bottom of sloping driveways
What would a manhole w/ a depth of 1.5m (5’) be classified as?
a normal manhole
According to the NPC a manhole installed w/in a building must have what also installed?
a vent
What feature of a concrete sanitary manhole is not usually found in a storm manhole?
sculpted channels
What type of catch basin has a shape that is usually long / narrow?
a driveway catch basin
When would a rigid ladder or a corrosion resistant material need to be installed?
where depths exceed 1m
What is the min horizontal dimension of a manhole?
1m except at the top 1.5m can be tapered from 1m –> 600mm at the top
What does the ‘B’ stand for in CSA B70.1?
that it is CSA standard
What is the grade for storm water / trenches?
min 1% approx. 1/8”/foot
According to the NPC / BCPC, what is the min horizontal dimension of a manhole?
1m
According to the NPC / BCPC, a ladder is required to be provided w/ a manhole if it is over what min depth?
1m
What is the area surrounding the channels in a sanitary manhole called?
Benching
What do some installed use as a form for the channels in a sanitary manhole, if they are not precast into the base?
Pipe that is the same diameter as the channel
