Drainage and Venting Systems Flashcards
6 cards from real 306A practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Drainage and Venting Systems flashcards as text
What is the purpose of a 'yoke vent' (bypass vent)?
Answer: To relieve pressure at the base of a tall soil stack by connecting the soil stack to the vent stack at regular intervals
A yoke vent connects the soil stack to the vent stack at intervals (typically every 10 storeys in tall buildings) to relieve the positive pressure that builds at the base of the stack and the negative pressure that develops higher up.
What is the maximum number of fixture units that can be connected to a 4-inch horizontal branch drain?
Answer: 160
A 4-inch horizontal branch drain can serve up to 160 fixture units according to the drainage load tables, providing sufficient capacity for large groups of fixtures.
Why must a drain serving a laundry standpipe discharge into a trapped receptor?
Answer: To provide an air gap between the washing machine discharge and the drainage system for backflow prevention
A laundry standpipe with an air gap between the washer discharge hose and the standpipe opening provides backflow prevention, ensuring contaminated drain water cannot flow back into the washing machine.
What is the recommended height of a laundry standpipe above the floor?
Answer: 600 to 900 mm
A laundry standpipe should extend 600 to 900 mm above the floor to prevent the discharge hose from being pushed too deep into the standpipe (which could create a direct connection) while keeping it low enough to prevent siphoning the washing machine.
What is a 'sump pit' used for in a drainage system?
Answer: Collecting sub-soil drainage or sewage from fixtures below the building sewer level for pumping
A sump pit collects water from sub-soil drainage (weeping tile) or sewage from fixtures installed below the level of the building sewer. A sump pump then lifts this water up to the building drain or storm system.
According to Canadian plumbing code, what is the minimum size of a vent serving a building subdrain sump?
Answer: 2 inch
A sump pit requires a minimum 2-inch vent to handle the air displacement during pump operation and to prevent negative pressure that could slow the pump's discharge rate.