Waste Pipe Sustems 2 Flashcards
(20 cards)
A positive pressure would create a _____ _____ which would result in the ____ of the trap
Back pressure
Oscillation
What is the maximum developed length measured from trap weir to vent connection if the diameter of the trap arm is 4 inches
3 m
The minimum slope on the drain between a fixture P-trap and its vent connection is
1 to 50 or quarter inch
The maximum change of direction between the trap weir and it’s vent connection for P-trap arm is
135 degrees
The minimum length of any trap arm is _____ the diameter of the ____ ____
2x
Waste pipe
The maximum change of direction between the fixture outlet and its vent connection for siphonic fixtures is
225 degrees
The maximum developed length of the fixture outlet pipe is_____ for a fixture or the vertical leg shall not exceed _______ for a siphonic fixture
48
40 inches
The total fall between a fixture P-trap and vent connection is ______ waste pipe diameter or _____
One
Less
List two reasons why oversize drains tend to be less efficient than properly sized drains
The flow of water is too shallow to properly transport solids
The flow of water fails to provide scouring action needed to keep the drain clear
Professor Roy Hunter from his research, derived that one fixture unit was equal to ____ ____ ____ of water to be discharged in a ______ in a ____ _____ period at _______ velocity
One cubic foot
Quarter inch pipe
60 second
2 ft/s
For horizontal pipe, a minimum velocity of 2 ft./s or _____ or ___ grade would flow down the pipe continuously washing the pipe while leaving the top ____% _____ free for air movement
1 1/4 inch of fall per foot
1:50
71%
Volume
Define fixture unit
The unit of measure based on the rate of discharge time of operation and frequency of use
Define hydraulic load
The Load placed on a section of drainage pipe by one or more fixture units expressed in fixture units
Define maximum hydraulic load
The maximum number of fixture units that may discharge into a horizontal or vertical pipe of a specific size
For vertical pipe flows at 29% full, the maximum velocity is ___ to maintain a scouring action, twirling around a pipe while leaving the centre of the pipe ___% free for air movement to prevent separation of the effluent
7 ft./s
50%
List three methods which can be used for grading waste, pipe or drains
Surveyors level
Eye levels
GPS with laser levels
List three factors that must be considered when determining the pipe elevation before installation
Finish floor elevation
Frost line elevation
Diameter of pipe
Benchmark
Cost
Maximum length of fixture outlet pipe for a lav
48 inches
Maximum length of vertical leg of WC
40 inches
What is Roy hunters system called?
Hunters curve
