Connecticut Plumbing Contractor (P-1) Exam – Full
Mock Examination Newest (2025 - 2026 Update)
From Real Past Papers Questions – Set 100 Most
Common Exam Frequently Tested Questions And
Answers In Details 100% Verified Exam Highly
Recommendable For Grade A+
1. What is the primary purpose of a plumbing vent system?
A. Increase water pressure
B. Carry wastewater
C. Protect trap seals and allow proper drainage
D. Filter drinking water
Explanation: Protect trap seals and allow proper drainage is correct because
vents equalize pressure, preventing trap siphonage and ensuring smooth
wastewater flow.
2. Which fitting is commonly used to change the direction of a drainage pipe
by 90 degrees?
A. Coupling
B. Union
C. Long-sweep elbow
D. Bushing
Explanation: Long-sweep elbow provides smoother flow and reduces clogging in
drainage systems.
3. Which pipe material is most commonly used for residential DWV systems?
A. Copper
B. Steel
C. PVC
D. Brass
,Explanation: PVC is lightweight, corrosion-resistant, and widely approved for
drain, waste, and vent systems.
4. What is the minimum purpose of a plumbing trap?
A. Increase water flow
B. Prevent sewer gases from entering the building
C. Reduce water temperature
D. Improve pressure
Explanation: Prevent sewer gases from entering the building by maintaining a
water seal.
5. A backflow preventer is installed to:
A. Increase water pressure
B. Remove sediment
C. Protect the potable water supply from contamination
D. Reduce pipe noise
Explanation: Protect the potable water supply from contamination by preventing
reverse flow.
6. Which valve is best suited for full open or full closed service?
A. Globe valve
B. Needle valve
C. Ball valve
D. Check valve
Explanation: Ball valve provides quick shutoff with minimal flow restriction.
7. What is the primary function of a cleanout?
A. Increase pressure
B. Support piping
C. Provide access for cleaning drainage piping
D. Vent sewer gases
Explanation: Provide access for cleaning drainage piping during maintenance.
, 8. Which fixture requires a trap?
A. Roof vent
B. Water main
C. Lavatory
D. Pressure tank
Explanation: Lavatory fixtures require traps to maintain a water seal.
9. Which plumbing system carries wastewater away from fixtures?
A. Potable water system
B. Vent system
C. Drainage system
D. Gas piping system
Explanation: Drainage system transports wastewater safely to the sewer or septic
system.
10.What is the purpose of pipe insulation on hot water lines?
A. Reduce pipe size
B. Increase pressure
C. Reduce heat loss
D. Prevent corrosion only
Explanation: Reduce heat loss improves energy efficiency and maintains water
temperature.
11.Which fitting joins two pipes of the same diameter in a straight line?
A. Tee
B. Elbow
C. Coupling
D. Reducer
Explanation: Coupling connects two straight pipe sections.
12.Which device prevents excessive pressure in a water heater?
A. Check valve
B. Ball valve
Mock Examination Newest (2025 - 2026 Update)
From Real Past Papers Questions – Set 100 Most
Common Exam Frequently Tested Questions And
Answers In Details 100% Verified Exam Highly
Recommendable For Grade A+
1. What is the primary purpose of a plumbing vent system?
A. Increase water pressure
B. Carry wastewater
C. Protect trap seals and allow proper drainage
D. Filter drinking water
Explanation: Protect trap seals and allow proper drainage is correct because
vents equalize pressure, preventing trap siphonage and ensuring smooth
wastewater flow.
2. Which fitting is commonly used to change the direction of a drainage pipe
by 90 degrees?
A. Coupling
B. Union
C. Long-sweep elbow
D. Bushing
Explanation: Long-sweep elbow provides smoother flow and reduces clogging in
drainage systems.
3. Which pipe material is most commonly used for residential DWV systems?
A. Copper
B. Steel
C. PVC
D. Brass
,Explanation: PVC is lightweight, corrosion-resistant, and widely approved for
drain, waste, and vent systems.
4. What is the minimum purpose of a plumbing trap?
A. Increase water flow
B. Prevent sewer gases from entering the building
C. Reduce water temperature
D. Improve pressure
Explanation: Prevent sewer gases from entering the building by maintaining a
water seal.
5. A backflow preventer is installed to:
A. Increase water pressure
B. Remove sediment
C. Protect the potable water supply from contamination
D. Reduce pipe noise
Explanation: Protect the potable water supply from contamination by preventing
reverse flow.
6. Which valve is best suited for full open or full closed service?
A. Globe valve
B. Needle valve
C. Ball valve
D. Check valve
Explanation: Ball valve provides quick shutoff with minimal flow restriction.
7. What is the primary function of a cleanout?
A. Increase pressure
B. Support piping
C. Provide access for cleaning drainage piping
D. Vent sewer gases
Explanation: Provide access for cleaning drainage piping during maintenance.
, 8. Which fixture requires a trap?
A. Roof vent
B. Water main
C. Lavatory
D. Pressure tank
Explanation: Lavatory fixtures require traps to maintain a water seal.
9. Which plumbing system carries wastewater away from fixtures?
A. Potable water system
B. Vent system
C. Drainage system
D. Gas piping system
Explanation: Drainage system transports wastewater safely to the sewer or septic
system.
10.What is the purpose of pipe insulation on hot water lines?
A. Reduce pipe size
B. Increase pressure
C. Reduce heat loss
D. Prevent corrosion only
Explanation: Reduce heat loss improves energy efficiency and maintains water
temperature.
11.Which fitting joins two pipes of the same diameter in a straight line?
A. Tee
B. Elbow
C. Coupling
D. Reducer
Explanation: Coupling connects two straight pipe sections.
12.Which device prevents excessive pressure in a water heater?
A. Check valve
B. Ball valve
