Texas Journeyman Plumber
Examination Practice Exam 2026 | 100
Questions & Answers with Detailed
Rationales | Complete Exam Prep &
Study Guide
Q1. What is the minimum required slope for a horizontal drainage pipe 3 inches
or smaller in most plumbing applications?
A. 1/16 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Rationale: A 1/4 inch per foot slope provides adequate flow velocity for smaller
drainage pipes and helps prevent blockages.
Q2. Which plumbing code is primarily adopted and enforced for plumbing work in
Texas?
A. National Electrical Code
B. International Mechanical Code
,C. International Plumbing Code (IPC)
D. International Fire Code
Rationale: Texas plumbing requirements are based on adopted plumbing codes
and Texas regulations, with the IPC being a commonly referenced plumbing
standard.
Q3. What device prevents contaminated water from flowing backward into the
potable water supply?
A. Pressure regulator
B. Expansion tank
C. Backflow prevention device
D. Water meter
Rationale: Backflow prevention devices protect drinking water systems from
contamination caused by reverse flow.
Q4. A plumbing vent primarily serves what purpose?
A. Increase water pressure
B. Heat water lines
C. Allow air into the drainage system and protect trap seals
D. Remove solid waste
Rationale: Vents maintain proper air pressure in drainage systems and prevent
siphoning of traps.
Q5. What is the minimum trap seal depth generally required for plumbing traps?
A. 1 inch
B. 2 inches
,C. 6 inches
D. 12 inches
Rationale: A minimum trap seal prevents sewer gases from entering the building
while allowing proper drainage.
Q6. Which pipe material is commonly used for underground building sewer lines?
A. Copper tubing
B. PVC or ABS pipe
C. Aluminum pipe
D. Galvanized sheet metal
Rationale: PVC and ABS are commonly approved for underground drainage
because they resist corrosion and provide long service life.
Q7. What is the purpose of a cleanout?
A. Increase water temperature
B. Provide access for clearing blockages in drainage piping
C. Reduce water pressure
D. Prevent freezing
Rationale: Cleanouts allow maintenance access for drain cleaning equipment.
Q8. Which fitting changes the direction of a drainage pipe while maintaining
smooth flow?
A. Tee fitting
B. Coupling
C. Wye fitting
D. Cross fitting
, Rationale: Wye fittings create smoother directional changes in drainage systems
compared with standard tees.
Q9. What type of valve is commonly installed on water supply lines to control
flow?
A. Check valve
B. Shutoff valve
C. Relief valve
D. Float valve
Rationale: Shutoff valves allow water service to fixtures or sections of piping to
be stopped for repairs.
Q10. What is the purpose of a water heater temperature and pressure relief
valve?
A. Increase heating speed
B. Reduce pipe size
C. Prevent excessive temperature and pressure buildup
D. Filter sediment
Rationale: The relief valve protects water heaters from dangerous pressure or
temperature conditions.
Q11. Which material is commonly used for residential hot and cold water
distribution piping?
A. Cast iron
B. Copper tubing
C. Concrete
D. Clay pipe
Examination Practice Exam 2026 | 100
Questions & Answers with Detailed
Rationales | Complete Exam Prep &
Study Guide
Q1. What is the minimum required slope for a horizontal drainage pipe 3 inches
or smaller in most plumbing applications?
A. 1/16 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Rationale: A 1/4 inch per foot slope provides adequate flow velocity for smaller
drainage pipes and helps prevent blockages.
Q2. Which plumbing code is primarily adopted and enforced for plumbing work in
Texas?
A. National Electrical Code
B. International Mechanical Code
,C. International Plumbing Code (IPC)
D. International Fire Code
Rationale: Texas plumbing requirements are based on adopted plumbing codes
and Texas regulations, with the IPC being a commonly referenced plumbing
standard.
Q3. What device prevents contaminated water from flowing backward into the
potable water supply?
A. Pressure regulator
B. Expansion tank
C. Backflow prevention device
D. Water meter
Rationale: Backflow prevention devices protect drinking water systems from
contamination caused by reverse flow.
Q4. A plumbing vent primarily serves what purpose?
A. Increase water pressure
B. Heat water lines
C. Allow air into the drainage system and protect trap seals
D. Remove solid waste
Rationale: Vents maintain proper air pressure in drainage systems and prevent
siphoning of traps.
Q5. What is the minimum trap seal depth generally required for plumbing traps?
A. 1 inch
B. 2 inches
,C. 6 inches
D. 12 inches
Rationale: A minimum trap seal prevents sewer gases from entering the building
while allowing proper drainage.
Q6. Which pipe material is commonly used for underground building sewer lines?
A. Copper tubing
B. PVC or ABS pipe
C. Aluminum pipe
D. Galvanized sheet metal
Rationale: PVC and ABS are commonly approved for underground drainage
because they resist corrosion and provide long service life.
Q7. What is the purpose of a cleanout?
A. Increase water temperature
B. Provide access for clearing blockages in drainage piping
C. Reduce water pressure
D. Prevent freezing
Rationale: Cleanouts allow maintenance access for drain cleaning equipment.
Q8. Which fitting changes the direction of a drainage pipe while maintaining
smooth flow?
A. Tee fitting
B. Coupling
C. Wye fitting
D. Cross fitting
, Rationale: Wye fittings create smoother directional changes in drainage systems
compared with standard tees.
Q9. What type of valve is commonly installed on water supply lines to control
flow?
A. Check valve
B. Shutoff valve
C. Relief valve
D. Float valve
Rationale: Shutoff valves allow water service to fixtures or sections of piping to
be stopped for repairs.
Q10. What is the purpose of a water heater temperature and pressure relief
valve?
A. Increase heating speed
B. Reduce pipe size
C. Prevent excessive temperature and pressure buildup
D. Filter sediment
Rationale: The relief valve protects water heaters from dangerous pressure or
temperature conditions.
Q11. Which material is commonly used for residential hot and cold water
distribution piping?
A. Cast iron
B. Copper tubing
C. Concrete
D. Clay pipe
