PLUMBING EXAM QUESTIONS AND
ANSWERS
what is a "wet vent" - Answer-pipe that conveys waste - 15 feet
what is the minimum size of a water closet vent? - Answer-2 inches
what is the minimum size required vent through the roof (VTR)? - Answer-3 inches
are all fixtures required to have their own vent? - Answer-no
what is the purpose of a trap? - Answer-so that sewage does not go everywhere
list 5 ways to potentially break a trap seal - Answer-1) postive pressure
2) negative pressure
3) send things down the drain
4) an unused bathroom
5) leak
6) improperly installed
which fixtures require a trap? - Answer-
what or where is the crown weir? - Answer-the highest point on the internal bottom
surface of the crown of a plumbing trap
what is the trap arm? - Answer-the pipe between the trap weir and the vent pipe
can a fixture be double trapped? - Answer-no
which fixture has a built in trap? - Answer-the toilet
what is the max drop for a fixture tail pipe before it reaches the trap? - Answer-2 - 3
inches
cleanouts - Answer-- required where in the building sewer meets the public sewer
- serves as a dual purpose: to test the system as well as a normal cleanout
- acoustical clean outs required for all horizontal drain pipping (distance cannot exceed
100)
what is the term developed length? - Answer-when applied to a pipe and fittings, the
length along the centre line of the pipe and fittings
what type of pipe is typically used for residential plumbing drainage systems - Answer-
PVC
ANSWERS
what is a "wet vent" - Answer-pipe that conveys waste - 15 feet
what is the minimum size of a water closet vent? - Answer-2 inches
what is the minimum size required vent through the roof (VTR)? - Answer-3 inches
are all fixtures required to have their own vent? - Answer-no
what is the purpose of a trap? - Answer-so that sewage does not go everywhere
list 5 ways to potentially break a trap seal - Answer-1) postive pressure
2) negative pressure
3) send things down the drain
4) an unused bathroom
5) leak
6) improperly installed
which fixtures require a trap? - Answer-
what or where is the crown weir? - Answer-the highest point on the internal bottom
surface of the crown of a plumbing trap
what is the trap arm? - Answer-the pipe between the trap weir and the vent pipe
can a fixture be double trapped? - Answer-no
which fixture has a built in trap? - Answer-the toilet
what is the max drop for a fixture tail pipe before it reaches the trap? - Answer-2 - 3
inches
cleanouts - Answer-- required where in the building sewer meets the public sewer
- serves as a dual purpose: to test the system as well as a normal cleanout
- acoustical clean outs required for all horizontal drain pipping (distance cannot exceed
100)
what is the term developed length? - Answer-when applied to a pipe and fittings, the
length along the centre line of the pipe and fittings
what type of pipe is typically used for residential plumbing drainage systems - Answer-
PVC
