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NYC Health + Hospitals Senior Plumber
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
Pdf
__________________________________________________________________
1. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Increase drainage velocity
D. Reduce pipe corrosion
Answer: Prevent sewer gases from entering the building
Rationale: A properly installed trap maintains a water seal that prevents sewer
gases and odors from entering occupied spaces while allowing wastewater to
drain.
2. Which pipe material is commonly used for sanitary drainage because of its
corrosion resistance and durability?
A. Copper
B. Cast iron
C. Aluminum
D. Galvanized steel
Answer: Cast iron
,Rationale: Cast-iron drainage pipe is widely used for sanitary and storm
drainage because it is durable, resistant to many common conditions, and
provides good acoustic performance.
3. What is the purpose of a cleanout in a drainage system?
A. Increase water pressure
B. Provide access for cleaning and inspection
C. Prevent backflow
D. Reduce pipe temperature
Answer: Provide access for cleaning and inspection
Rationale: Cleanouts provide access to drainage piping so blockages can be
located and removed without dismantling the piping system.
4. Which fitting is normally used to change the direction of a drainage pipe?
A. Union
B. Elbow
C. Coupling
D. Cap
Answer: Elbow
Rationale: Elbows change the direction of piping. Drainage systems commonly
use fittings designed to maintain smooth flow and minimize obstruction.
5. What is the main function of a water supply pressure-reducing valve?
A. Increase pressure
B. Remove sediment
C. Reduce excessive incoming pressure
D. Prevent freezing
Answer: Reduce excessive incoming pressure
Rationale: A pressure-reducing valve controls excessive supply pressure to
protect fixtures, piping, valves, and equipment.
, 6. Which device prevents contaminated water from flowing backward into a
potable water system?
A. Expansion tank
B. Backflow preventer
C. Water hammer arrestor
D. Cleanout
Answer: Backflow preventer
Rationale: Backflow prevention devices protect potable water supplies from
contamination caused by backsiphonage or backpressure.
7. What is water hammer?
A. Pipe corrosion caused by chemicals
B. Noise and pressure surge caused by sudden changes in water flow
C. A reduction in water temperature
D. A sewer blockage
Answer: Noise and pressure surge caused by sudden changes in water flow
Rationale: Rapidly closing valves can abruptly stop flowing water, producing a
pressure wave that causes banging, vibration, and possible pipe damage.
8. What device is specifically designed to absorb shock caused by sudden
valve closure?
A. Trap primer
B. Water hammer arrestor
C. Pressure gauge
D. Vacuum breaker
Answer: Water hammer arrestor
Rationale: Water hammer arrestors provide a cushion that absorbs pressure
surges when water flow stops abruptly.
9. What is the purpose of a venting system in sanitary drainage?
A. Increase hot-water temperature
, B. Supply air to the drainage system and protect trap seals
C. Increase water pressure
D. Filter drinking water
Answer: Supply air to the drainage system and protect trap seals
Rationale: Proper venting allows air circulation within drainage piping and helps
prevent siphonage or pressure conditions that could destroy trap seals.
10.What condition occurs when negative pressure pulls water out of a trap?
A. Backpressure
B. Backsiphonage
C. Cavitation
D. Condensation
Answer: Backsiphonage
Rationale: Backsiphonage occurs when negative pressure in the supply or
drainage environment causes water to be drawn backward through a
connection.
11.Why should a plumber avoid using excessive force when tightening
threaded fittings?
A. It increases pipe diameter
B. It may crack or damage the fitting
C. It improves corrosion
D. It eliminates the need for sealant
Answer: It may crack or damage the fitting
Rationale: Excessive torque can damage threads, distort fittings, or crack certain
materials, potentially causing leaks or premature failure.
12.Which tool is commonly used to measure pipe diameter?
A. Pipe wrench
B. Tape measure or caliper
NYC Health + Hospitals Senior Plumber
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
__________________________________________________________________
1. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Increase drainage velocity
D. Reduce pipe corrosion
Answer: Prevent sewer gases from entering the building
Rationale: A properly installed trap maintains a water seal that prevents sewer
gases and odors from entering occupied spaces while allowing wastewater to
drain.
2. Which pipe material is commonly used for sanitary drainage because of its
corrosion resistance and durability?
A. Copper
B. Cast iron
C. Aluminum
D. Galvanized steel
Answer: Cast iron
,Rationale: Cast-iron drainage pipe is widely used for sanitary and storm
drainage because it is durable, resistant to many common conditions, and
provides good acoustic performance.
3. What is the purpose of a cleanout in a drainage system?
A. Increase water pressure
B. Provide access for cleaning and inspection
C. Prevent backflow
D. Reduce pipe temperature
Answer: Provide access for cleaning and inspection
Rationale: Cleanouts provide access to drainage piping so blockages can be
located and removed without dismantling the piping system.
4. Which fitting is normally used to change the direction of a drainage pipe?
A. Union
B. Elbow
C. Coupling
D. Cap
Answer: Elbow
Rationale: Elbows change the direction of piping. Drainage systems commonly
use fittings designed to maintain smooth flow and minimize obstruction.
5. What is the main function of a water supply pressure-reducing valve?
A. Increase pressure
B. Remove sediment
C. Reduce excessive incoming pressure
D. Prevent freezing
Answer: Reduce excessive incoming pressure
Rationale: A pressure-reducing valve controls excessive supply pressure to
protect fixtures, piping, valves, and equipment.
, 6. Which device prevents contaminated water from flowing backward into a
potable water system?
A. Expansion tank
B. Backflow preventer
C. Water hammer arrestor
D. Cleanout
Answer: Backflow preventer
Rationale: Backflow prevention devices protect potable water supplies from
contamination caused by backsiphonage or backpressure.
7. What is water hammer?
A. Pipe corrosion caused by chemicals
B. Noise and pressure surge caused by sudden changes in water flow
C. A reduction in water temperature
D. A sewer blockage
Answer: Noise and pressure surge caused by sudden changes in water flow
Rationale: Rapidly closing valves can abruptly stop flowing water, producing a
pressure wave that causes banging, vibration, and possible pipe damage.
8. What device is specifically designed to absorb shock caused by sudden
valve closure?
A. Trap primer
B. Water hammer arrestor
C. Pressure gauge
D. Vacuum breaker
Answer: Water hammer arrestor
Rationale: Water hammer arrestors provide a cushion that absorbs pressure
surges when water flow stops abruptly.
9. What is the purpose of a venting system in sanitary drainage?
A. Increase hot-water temperature
, B. Supply air to the drainage system and protect trap seals
C. Increase water pressure
D. Filter drinking water
Answer: Supply air to the drainage system and protect trap seals
Rationale: Proper venting allows air circulation within drainage piping and helps
prevent siphonage or pressure conditions that could destroy trap seals.
10.What condition occurs when negative pressure pulls water out of a trap?
A. Backpressure
B. Backsiphonage
C. Cavitation
D. Condensation
Answer: Backsiphonage
Rationale: Backsiphonage occurs when negative pressure in the supply or
drainage environment causes water to be drawn backward through a
connection.
11.Why should a plumber avoid using excessive force when tightening
threaded fittings?
A. It increases pipe diameter
B. It may crack or damage the fitting
C. It improves corrosion
D. It eliminates the need for sealant
Answer: It may crack or damage the fitting
Rationale: Excessive torque can damage threads, distort fittings, or crack certain
materials, potentially causing leaks or premature failure.
12.Which tool is commonly used to measure pipe diameter?
A. Pipe wrench
B. Tape measure or caliper
