QUESTIONS AND CORRRECT ANSWERS (VERIFIED
ANSWERS) Q&A 2026|INSTANT DOWNLOAD PDF
1. What is the primary purpose of a plumbing vent system?
A. Increase water pressure
B. Prevent sewer gas entry into building
C. Heat water faster
D. Reduce pipe size
Rationale: Vent systems equalize pressure and allow sewer
gases to escape safely.
Correct Answer: B
2. Which gas is commonly used in residential gas plumbing
systems?
A. Oxygen
B. Carbon dioxide
C. Natural gas
D. Nitrogen
Rationale: Natural gas is the standard fuel in most residential
systems.
Correct Answer: C
,3. What is the minimum slope for horizontal drainage pipes?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. No slope required
Rationale: Proper slope ensures gravity flow of wastewater.
Correct Answer: B
4. What device prevents backflow in plumbing systems?
A. Trap
B. Check valve
C. Faucet
D. Vent stack
Rationale: Check valves stop reverse flow of fluids.
Correct Answer: B
5. What is the purpose of a P-trap?
A. Increase water pressure
B. Store hot water
C. Prevent sewer gases from entering building
D. Drain stormwater
Rationale: Water in the trap blocks sewer gases.
Correct Answer: C
,6. Which material is commonly used for gas piping?
A. PVC
B. Copper Type M
C. Black steel pipe
D. ABS
Rationale: Black steel is standard for gas systems.
Correct Answer: C
7. What is the main function of a pressure regulator in gas
systems?
A. Increase flow rate
B. Reduce gas pressure to safe level
C. Heat gas
D. Filter gas
Rationale: Regulators ensure safe appliance pressure.
Correct Answer: B
8. What is the standard test pressure for gas piping?
A. 1 psi
B. 3 psi
C. 10 psi
D. 100 psi
, Rationale: Typical testing is around 3 psi depending on code.
Correct Answer: B
9. What tool is used to cut threaded pipe?
A. Pipe wrench
B. Pipe cutter
C. Hacksaw
D. Torch
Rationale: Pipe cutters provide clean, straight cuts.
Correct Answer: B
10. What is the purpose of pipe dope or thread sealant?
A. Lubricate pipe exterior
B. Seal threaded joints against leaks
C. Increase pipe diameter
D. Clean pipes
Rationale: Sealants prevent gas or water leakage.
Correct Answer: B
11. Which code governs plumbing standards in Kansas most
commonly?
A. NEC
B. IPC