Master Plumber (DWV Systems) 2026-2027
Comprehensive Frequently Tested Exam Questions
With Verified Multiple Choice and Conceptual
Actual 100% Correct Detailed Answers
Guaranteed Pass!!Current Update!!
1. The minimum depth of gas piping underground is ____
A. 12"
B. 18"
C. 24"
D. 30" - ANSWER A. 12"
2. Where nonferrous pipe is brazed for gas piping, the brazing materials shall
have a melting point in excess of _____ degrees Fahrenheit
A. 600
B. 800
C. 1000
D. 1400 - ANSWER C. 1000
3. The temperature of water for tankless water heaters shall not be greater
than ___ degrees Fahrenheit
A. 120
B. 130
C. 140
D. 160 - ANSWER C. 140
4. The minimum combustible clearance of Type B vent piping is ____
, A. Listed in the code
B. Listed by the manufacturer and stamped on the pipe
C. 2"
D. 6" - ANSWER B. Listed by the manufacturer and stamped on the
pipe
5. Fixture connections which may be serviced through an access panel are
considered
A. Accessible
B. Readily accessible
C. Not accessible
D. Exposed - ANSWER A. Accessible
6. The part of the lowest piping of a drainage system, which recieves the
discharge from soil, waste and other drainage pipes inside the walls of the
building and conveys it to a point 2' outside the building wall is a
A. House drain
B. House sewer
C. Waste pipe
D. Soil stack - ANSWER A. House drain
7. A vertical vent that is a continuation of the drain to which it connects is a
A. Circuit vent
B. Relief vent
C. Continuous vent
D. Branch Vent - ANSWER C. Continuous vent
8. A vent which also serves as a drain is a
A. Island Vent
, B. Vent Stack
C. Loop Vent
D. Wet Vent - ANSWER D. Wet Vent
9. A stack is always
A. Straight
B. Horizontal
C. Vertical
D. Lengthy - ANSWER C. Vertical
10.A pipe which makes an angle of no more than 45 degrees with the vertical is
considered
A. Vertical
B. Horizontal
C. Diagonal
D. Bent pipe - ANSWER A. Vertical
11.The vertical depth of a trap seal is measured from
A. The crown weir to the top of the dip of the trap
B. The inlet of the trap to the bottom of the trap
C. The crown weir to the bottom dip of the trap
D. The inlet of the trap to the outlet of the trap - ANSWER A. The
crown weir to the top of the dip of the trap
12.The principal artery of the venting system to which branches may be
connected is called
A. Branch vent
B. Vertical vent
C. Vent
, D. Main vent - ANSWER D. Main vent
13.A pressure surge absorbing device operating through the compressibility of
air is called
A. Backflow preventer
B. Air Chamber
C. Flushometer Valve
D. Hammer Arrestor - ANSWER D. Hammer arrestor
14.A device installed in a drainage system to prevent reverse flow is a
A. Sewage valve
B. Check valve
C. Backwater Valve
D. Backflow Valve - ANSWER C. Backwater Valve
15.Any pressure less than that exterted by atmosphere is
A. Vacuum
B. Negative Pressure
C. Positive Pressure
D. Atmospheric Pressure - ANSWER A. Vacuum
16.A plugged fitting located at the base of all soil stacks is called
A. Stack cleanout
B. Stack vent
C. Vent stack
D. Main cleanout - ANSWER A. Stack cleanout
Comprehensive Frequently Tested Exam Questions
With Verified Multiple Choice and Conceptual
Actual 100% Correct Detailed Answers
Guaranteed Pass!!Current Update!!
1. The minimum depth of gas piping underground is ____
A. 12"
B. 18"
C. 24"
D. 30" - ANSWER A. 12"
2. Where nonferrous pipe is brazed for gas piping, the brazing materials shall
have a melting point in excess of _____ degrees Fahrenheit
A. 600
B. 800
C. 1000
D. 1400 - ANSWER C. 1000
3. The temperature of water for tankless water heaters shall not be greater
than ___ degrees Fahrenheit
A. 120
B. 130
C. 140
D. 160 - ANSWER C. 140
4. The minimum combustible clearance of Type B vent piping is ____
, A. Listed in the code
B. Listed by the manufacturer and stamped on the pipe
C. 2"
D. 6" - ANSWER B. Listed by the manufacturer and stamped on the
pipe
5. Fixture connections which may be serviced through an access panel are
considered
A. Accessible
B. Readily accessible
C. Not accessible
D. Exposed - ANSWER A. Accessible
6. The part of the lowest piping of a drainage system, which recieves the
discharge from soil, waste and other drainage pipes inside the walls of the
building and conveys it to a point 2' outside the building wall is a
A. House drain
B. House sewer
C. Waste pipe
D. Soil stack - ANSWER A. House drain
7. A vertical vent that is a continuation of the drain to which it connects is a
A. Circuit vent
B. Relief vent
C. Continuous vent
D. Branch Vent - ANSWER C. Continuous vent
8. A vent which also serves as a drain is a
A. Island Vent
, B. Vent Stack
C. Loop Vent
D. Wet Vent - ANSWER D. Wet Vent
9. A stack is always
A. Straight
B. Horizontal
C. Vertical
D. Lengthy - ANSWER C. Vertical
10.A pipe which makes an angle of no more than 45 degrees with the vertical is
considered
A. Vertical
B. Horizontal
C. Diagonal
D. Bent pipe - ANSWER A. Vertical
11.The vertical depth of a trap seal is measured from
A. The crown weir to the top of the dip of the trap
B. The inlet of the trap to the bottom of the trap
C. The crown weir to the bottom dip of the trap
D. The inlet of the trap to the outlet of the trap - ANSWER A. The
crown weir to the top of the dip of the trap
12.The principal artery of the venting system to which branches may be
connected is called
A. Branch vent
B. Vertical vent
C. Vent
, D. Main vent - ANSWER D. Main vent
13.A pressure surge absorbing device operating through the compressibility of
air is called
A. Backflow preventer
B. Air Chamber
C. Flushometer Valve
D. Hammer Arrestor - ANSWER D. Hammer arrestor
14.A device installed in a drainage system to prevent reverse flow is a
A. Sewage valve
B. Check valve
C. Backwater Valve
D. Backflow Valve - ANSWER C. Backwater Valve
15.Any pressure less than that exterted by atmosphere is
A. Vacuum
B. Negative Pressure
C. Positive Pressure
D. Atmospheric Pressure - ANSWER A. Vacuum
16.A plugged fitting located at the base of all soil stacks is called
A. Stack cleanout
B. Stack vent
C. Vent stack
D. Main cleanout - ANSWER A. Stack cleanout
