Sewers C2 Flashcards
What role do roof drains have and what are the 2 types
Roof Drain: Collect rain water and snow melt (Usually of a flow control type). And can come in 2 types:
Deep sump (No restriction of flow)
Flow control roof drain (Regulates the flow rater)
What is the benefit to having flow control roof drains?
Flow control roof drains: Enables roofs to have less roof drains as water may sit on the roof longer.
What are parapets used for and how high must they be to do there job?
Parapet wall: is a safely measure so that workers don’t have to where safety equipment, the wall must be at least 1 meter tall for it to act as a railing
What is a scupper
Scupper: Acts as an overflow system for roofs, it is typically a rectangular hole in a parapet wall
What is a rain water leader?
Rain water Leader: A pipe that conducts storm drainage or snow melt from a rooftop to the underground storm building drain.
What is a storm building drain
Storm Building drain: is an underground pipe that is downstream of the rain water leader, sump or catch basin and sends the storm drainage or snow melt to a storm building sewer.
What is a storm building sewer and when does it start
Storm Building sewer: A pipe 1 meter from a building that conducts content form a storm building drain to a municipal storm drainage system.
What is a combined building sewer? are there still aloud to be installed?
Combined building sewer: A sewer that conducts both storm and sewage waist. These are not permitted to be installed
What is a Combined City Sewer?
Combined City Sewer: Caries Rain water run off, storm drainage, sewage and industrial wastewater all in the same pipe
What are the 2 ways of controlling expansion on a rain water leader? what are the regulations associated with them?
Controlling expansion
2 methods:
Expansion joint placed with in 5 feet of the roof (Must be a Vertical expansion joint and not a Slip joint type)
Use a vertical length of pipe that is a Maximum of 5 feet long to the first 90, then have a horizontal that is a minimum of 5 feet. This will compensate for any expansion
Where can corrugated steel pipe be used?
Only be used outside a building in a storm drainage system 2.2.6.8
What must a fixture that is connected to a storm drain have?
Back water valve
What fixtures are permitted to be drained into a storm drain
Floor drain (only clear water waste or strom water)
Drinking fountain
condensates
HWT drain pans
2.4.2.1
How many big Ls per l/s?
900 Big Ls per l/s (2.4.10.3)
How many FU per l/s?
31.7 FU per l/s (2.4.10.3)
How do you find Big Ls for a roof with a adjoining vertical surface?
Find the area of the roof and half the area of the vertical surface put together. then multiply by the max rain fall in 15 mins for the location of the building
(2.4.10.4)
What is the max drain down time when flow control roof drains are installed?
maximum 24 hours (2.4.10.4)
How many scuppers and what minimum distence must they be appart when flow control roof drains are installed?
1 or more and not more then 30 m apart (2.4.10.4)
what is the maximum depth aloud to sit ontop of a roof when flow control roof drains are installed?
150mm (2.4.10.4)
What is the maximum distenc a flow control roof drain can be from the edge of the roof and from eachother?
15m from the edge of roof
30m from each other
(2.4.10.4)
the maximum squared meets that can operate with only 1 roof drain
900 meters squared (2.4.10.4)
What 2 things are required when a parapet is taller then 150mm
scuppers must be installed
there is a minimum requirement of 2 roof drains
Why should traps be placed in possessions that limit air movement in a storm drainage system?
there prevent the air from creating a environment where water could freeze
Is it exeptable to connect a rain water liter to a septic tanks?
No
