Master Plumbing WSSC questions and
answers 2026\2027 A+ Grade
Waste water discharged into the building drainage system shall not be over _______ *F
- correct answer 140
A water tank holds 50 gallons of water. How much does the 50 gallons of water weigh?
- correct answer 417 lbs
Exterior walls may be notched to a depth exceeding _______________ percent of its width.
- correct answer 25
According to the WSSC PFGC, a full flow building water service valve shall be installed within _____ feet
of where the water service enters the building.
- correct answer 3'
According to the WSSC PFGC, water meters installed inside of buildings shall be located in an area
capable of maintaining _____ *F.
- correct answer 50
In Prince George and Montgomery County, water service piping shall be not less than _____ inches
below grade.
- correct answer 30
A cylindrical tank is 22 inches in diameter and 5 feet tall. How many gallons of water will it hold?
- correct answer 98
The best method of backflow protection is an?
- correct answer Air-gap
, Horizontal drainage piping 4 inches in diameter shall have a minimum slope of _____ per foot.
- correct answer 1/8
Water hammer arrestors shall conform to ASSE _______
- correct answer 1010
A connection between a vent pipe and a vent stack or stack vent shall be at least _____ inches above the
flood level rim of the highest fixture served by the vent.
- correct answer 6 inches
Air admittance valves shall be installed a minimum of ______ inches above insulation materials.
- correct answer 6
A water supply system test done with air shall be at not less than ____ PSI.
- correct answer 50
If you install 80 feet of sewer at 1/4" per foot how many inches of fall in the run?
- correct answer 20
The minimum size water supply pipe to a bidet shall be _____ inch.
- correct answer 3/8
Horizontal drains shall have cleanouts not more than ______ feet apart.
- correct answer 100
Standpipes shall extend a maximum of ____ inches above the trap weir.
- correct answer 42
Shower compartments shall not be less than _____ inches in minimum dimension.
- correct answer 30
Shower liners shall be sloped at _____ towards the drain.
- correct answer 2.0%
answers 2026\2027 A+ Grade
Waste water discharged into the building drainage system shall not be over _______ *F
- correct answer 140
A water tank holds 50 gallons of water. How much does the 50 gallons of water weigh?
- correct answer 417 lbs
Exterior walls may be notched to a depth exceeding _______________ percent of its width.
- correct answer 25
According to the WSSC PFGC, a full flow building water service valve shall be installed within _____ feet
of where the water service enters the building.
- correct answer 3'
According to the WSSC PFGC, water meters installed inside of buildings shall be located in an area
capable of maintaining _____ *F.
- correct answer 50
In Prince George and Montgomery County, water service piping shall be not less than _____ inches
below grade.
- correct answer 30
A cylindrical tank is 22 inches in diameter and 5 feet tall. How many gallons of water will it hold?
- correct answer 98
The best method of backflow protection is an?
- correct answer Air-gap
, Horizontal drainage piping 4 inches in diameter shall have a minimum slope of _____ per foot.
- correct answer 1/8
Water hammer arrestors shall conform to ASSE _______
- correct answer 1010
A connection between a vent pipe and a vent stack or stack vent shall be at least _____ inches above the
flood level rim of the highest fixture served by the vent.
- correct answer 6 inches
Air admittance valves shall be installed a minimum of ______ inches above insulation materials.
- correct answer 6
A water supply system test done with air shall be at not less than ____ PSI.
- correct answer 50
If you install 80 feet of sewer at 1/4" per foot how many inches of fall in the run?
- correct answer 20
The minimum size water supply pipe to a bidet shall be _____ inch.
- correct answer 3/8
Horizontal drains shall have cleanouts not more than ______ feet apart.
- correct answer 100
Standpipes shall extend a maximum of ____ inches above the trap weir.
- correct answer 42
Shower compartments shall not be less than _____ inches in minimum dimension.
- correct answer 30
Shower liners shall be sloped at _____ towards the drain.
- correct answer 2.0%
