JOURNEYMAN PLUMBER
LICENSE EXAM PRACTICE
QUESTIONS AND CORRECT
ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES
2026 Q&A | INSTANT
DOWNLOAD PDF
1. What is the minimum slope required for a 2-inch horizontal drain
pipe?
A) 1/8 inch per foot
B) 1/4 inch per foot
C) 1/2 inch per foot
D) 3/4 inch per foot
The minimum slope for a 2-inch drain line is 1/4 inch per foot for proper
drainage, but some codes require 1/2 inch for certain installations to
prevent clogging.
2. What type of valve is typically used to control water flow in a
residential water heater?
A) Gate valve
,B) Check valve
C) Temperature and pressure relief valve
D) Ball valve
The temperature and pressure (T&P) relief valve is required on water
heaters to prevent excessive pressure or temperature.
3. When joining copper tubing with a soldered joint, what is essential?
A) Apply flux and heat evenly
B) Clean tubing, apply flux, and solder properly
C) Use adhesive cement
D) Only tighten fittings
Cleaning removes oxidation, flux prevents oxidation during heating, and
solder ensures a secure leak-free joint.
4. What is the purpose of a trap in plumbing systems?
A) Prevent pipe corrosion
B) Prevent sewer gases from entering the building
C) Increase water pressure
D) Reduce water flow
Traps create a water seal that blocks sewer gases from entering living
spaces.
5. Which pipe material is most resistant to corrosion from acidic
water?
A) Galvanized steel
B) CPVC (Chlorinated Polyvinyl Chloride)
C) Cast iron
D) Copper
CPVC is chemically resistant and suitable for acidic water conditions.
6. What is the maximum distance a water heater can be from a fixture
before a recirculation system is recommended?
A) 25 feet
, B) 50 feet
C) 100 feet
D) 150 feet
Distances over 100 feet can cause delays in hot water delivery, making
recirculation systems practical.
7. Which code governs plumbing installation in the United States?
A) IEC
B) UPC/IPC (Uniform Plumbing Code/International Plumbing Code)
C) NEC
D) NFPA
Plumbing installations must comply with the adopted plumbing code in
the jurisdiction, typically UPC or IPC.
8. What is the correct method to test a newly installed drainage
system?
A) Turn on hot water
B) Conduct a water or air test to check for leaks
C) Use a vacuum pump
D) Heat the pipes
Water or air tests verify the integrity of drain, waste, and vent systems
before covering or use.
9. Which type of water pipe joining method does not require heat?
A) Soldering
B) Brazing
C) Threaded or solvent cement joining
D) Welding
Threaded joints or solvent-welded PVC/CPVC joints do not require heat.
10. What is the minimum air gap for a faucet connected to a potable
water system?
A) 1 inch
LICENSE EXAM PRACTICE
QUESTIONS AND CORRECT
ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES
2026 Q&A | INSTANT
DOWNLOAD PDF
1. What is the minimum slope required for a 2-inch horizontal drain
pipe?
A) 1/8 inch per foot
B) 1/4 inch per foot
C) 1/2 inch per foot
D) 3/4 inch per foot
The minimum slope for a 2-inch drain line is 1/4 inch per foot for proper
drainage, but some codes require 1/2 inch for certain installations to
prevent clogging.
2. What type of valve is typically used to control water flow in a
residential water heater?
A) Gate valve
,B) Check valve
C) Temperature and pressure relief valve
D) Ball valve
The temperature and pressure (T&P) relief valve is required on water
heaters to prevent excessive pressure or temperature.
3. When joining copper tubing with a soldered joint, what is essential?
A) Apply flux and heat evenly
B) Clean tubing, apply flux, and solder properly
C) Use adhesive cement
D) Only tighten fittings
Cleaning removes oxidation, flux prevents oxidation during heating, and
solder ensures a secure leak-free joint.
4. What is the purpose of a trap in plumbing systems?
A) Prevent pipe corrosion
B) Prevent sewer gases from entering the building
C) Increase water pressure
D) Reduce water flow
Traps create a water seal that blocks sewer gases from entering living
spaces.
5. Which pipe material is most resistant to corrosion from acidic
water?
A) Galvanized steel
B) CPVC (Chlorinated Polyvinyl Chloride)
C) Cast iron
D) Copper
CPVC is chemically resistant and suitable for acidic water conditions.
6. What is the maximum distance a water heater can be from a fixture
before a recirculation system is recommended?
A) 25 feet
, B) 50 feet
C) 100 feet
D) 150 feet
Distances over 100 feet can cause delays in hot water delivery, making
recirculation systems practical.
7. Which code governs plumbing installation in the United States?
A) IEC
B) UPC/IPC (Uniform Plumbing Code/International Plumbing Code)
C) NEC
D) NFPA
Plumbing installations must comply with the adopted plumbing code in
the jurisdiction, typically UPC or IPC.
8. What is the correct method to test a newly installed drainage
system?
A) Turn on hot water
B) Conduct a water or air test to check for leaks
C) Use a vacuum pump
D) Heat the pipes
Water or air tests verify the integrity of drain, waste, and vent systems
before covering or use.
9. Which type of water pipe joining method does not require heat?
A) Soldering
B) Brazing
C) Threaded or solvent cement joining
D) Welding
Threaded joints or solvent-welded PVC/CPVC joints do not require heat.
10. What is the minimum air gap for a faucet connected to a potable
water system?
A) 1 inch
