The Last 111 Test: DWV Systems (Part 4) Flashcards
What is the inlet?
Where water enters from the fixture
What is the top dip?
The inside curve of the pipe under the inlet
What is the bottom dip?
The bottom of the lowest curve of the lowest pipe beneath the inlet
What is the Weir?
The highest point in the seal of the trap
What is the fixture drain?
The point where wastewater leaves the trap and goes into the drainage piping
What are the ways a trap can lose it’s seal?
Siphonage, Aspiration, Momentum, Oscillation, Back Pressure, Evaporation, Capillary Attraction, and Cracks.
What is Siphonage?
Siphonage occurs when there is negative pressure inside the DWV piping.
What is Aspiration?
In piping, Aspiration takes place when a large volume of water flows near the trap, creating negative pressure.
What is Momentum?
The momentum or speed of water rushing through a pipe can force the standing water out of a trap and empty it.
What is Oscillation
Oscillation, or wind effect, is one of the least likely ways a trap can lose its seal.
What is back pressure?
Back pressure can cause a trap seal to break. Back pressure is pressure inside the DWV piping that is greater than atmospheric pressure.
What is Evaporation?
When traps are seldom used the water seal evaporates over time.
What is Capillary Attraction?
Capillary Attraction may cause a trap seal to break if a porous material such a string or paper is caught in a trap.
What is a Crack
A crack in the the trap.
WHAT IS A TRAP?
A trap is a or device that provides a liquid seal of 2 to 4 inches.
