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NYC Health + Hospitals Plumber
Examination Practice Exam 2026 | 100
Questions & Answers with Detailed
Rationales | Complete Exam Prep &
Study Guide
1. What is the primary purpose of a plumbing trap?
A. To increase water pressure
B. To prevent sewer gases from entering a building
C. To reduce pipe size
D. To increase drainage velocity
Answer: B. To prevent sewer gases from entering a building
Rationale: A plumbing trap maintains a water seal that prevents sewer gases,
odors, and potentially harmful vapors from entering occupied spaces through
the drainage system.
2. Which fitting is commonly used to change the direction of a drainage pipe
by 90 degrees?
A. Sanitary tee
B. Coupling
C. Long-sweep elbow
D. Union
,Answer: C. Long-sweep elbow
Rationale: A long-sweep elbow provides a gradual change in direction and is
preferred in drainage systems because it reduces turbulence and the likelihood
of blockage.
3. What is the primary function of a cleanout?
A. To regulate water pressure
B. To provide access for cleaning and removing blockages
C. To prevent freezing
D. To increase water temperature
Answer: B. To provide access for cleaning and removing blockages
Rationale: Cleanouts provide accessible openings in drainage piping so plumbers
can inspect, clean, and clear obstructions.
4. Which type of valve is commonly used to shut off water to a fixture?
A. Check valve
B. Pressure-relief valve
C. Stop valve
D. Mixing valve
Answer: C. Stop valve
Rationale: A stop valve allows the water supply to an individual fixture or
appliance to be shut off for maintenance or repair without shutting down the
entire building.
5. What is the purpose of a backflow prevention device?
A. Increase water temperature
B. Prevent contaminated water from flowing into the potable water supply
C. Increase drainage capacity
D. Reduce pipe corrosion
,Answer: B. Prevent contaminated water from flowing into the potable water
supply
Rationale: Backflow prevention protects potable water from contamination
caused by reverse flow from nonpotable or contaminated sources.
6. What does DWV stand for in plumbing?
A. Drain, Water, Valve
B. Drain-Waste-Vent
C. Domestic Water Valve
D. Drain-Water Vacuum
Answer: B. Drain-Waste-Vent
Rationale: DWV describes the portion of a plumbing system responsible for
carrying wastewater and providing ventilation for the drainage system.
7. Why are plumbing vents installed?
A. To increase hot-water temperature
B. To provide air circulation and protect trap seals
C. To increase water pressure
D. To filter wastewater
Answer: B. To provide air circulation and protect trap seals
Rationale: Proper venting balances pressure in the drainage system and helps
prevent siphoning or compression of fixture trap seals.
8. Which material is commonly used for domestic water piping?
A. Copper
B. Structural steel only
C. Cast iron only
D. Concrete
Answer: A. Copper
, Rationale: Copper is widely used for potable water distribution because it is
durable, corrosion-resistant under appropriate conditions, and suitable for hot
and cold water.
9. What is water hammer?
A. A method of joining copper pipes
B. A pressure surge caused by sudden changes in water flow
C. A type of drain cleaner
D. A method of testing sewer lines
Answer: B. A pressure surge caused by sudden changes in water flow
Rationale: Water hammer occurs when flowing water is suddenly stopped or
redirected, producing a pressure wave that can cause noise, vibration, and pipe
damage.
10.Which device can help control water hammer?
A. Water-hammer arrestor
B. Cleanout plug
C. Floor drain
D. Strainer
Answer: A. Water-hammer arrestor
Rationale: A water-hammer arrestor contains a means of absorbing the
pressure surge created when water flow is suddenly stopped.
11.What is the purpose of a pressure-reducing valve?
A. Increase excessive water pressure
B. Reduce incoming water pressure to a controlled level
C. Remove sewer gases
D. Increase drainage slope
Answer: B. Reduce incoming water pressure to a controlled level
NYC Health + Hospitals Plumber
Examination Practice Exam 2026 | 100
Questions & Answers with Detailed
Rationales | Complete Exam Prep &
Study Guide
1. What is the primary purpose of a plumbing trap?
A. To increase water pressure
B. To prevent sewer gases from entering a building
C. To reduce pipe size
D. To increase drainage velocity
Answer: B. To prevent sewer gases from entering a building
Rationale: A plumbing trap maintains a water seal that prevents sewer gases,
odors, and potentially harmful vapors from entering occupied spaces through
the drainage system.
2. Which fitting is commonly used to change the direction of a drainage pipe
by 90 degrees?
A. Sanitary tee
B. Coupling
C. Long-sweep elbow
D. Union
,Answer: C. Long-sweep elbow
Rationale: A long-sweep elbow provides a gradual change in direction and is
preferred in drainage systems because it reduces turbulence and the likelihood
of blockage.
3. What is the primary function of a cleanout?
A. To regulate water pressure
B. To provide access for cleaning and removing blockages
C. To prevent freezing
D. To increase water temperature
Answer: B. To provide access for cleaning and removing blockages
Rationale: Cleanouts provide accessible openings in drainage piping so plumbers
can inspect, clean, and clear obstructions.
4. Which type of valve is commonly used to shut off water to a fixture?
A. Check valve
B. Pressure-relief valve
C. Stop valve
D. Mixing valve
Answer: C. Stop valve
Rationale: A stop valve allows the water supply to an individual fixture or
appliance to be shut off for maintenance or repair without shutting down the
entire building.
5. What is the purpose of a backflow prevention device?
A. Increase water temperature
B. Prevent contaminated water from flowing into the potable water supply
C. Increase drainage capacity
D. Reduce pipe corrosion
,Answer: B. Prevent contaminated water from flowing into the potable water
supply
Rationale: Backflow prevention protects potable water from contamination
caused by reverse flow from nonpotable or contaminated sources.
6. What does DWV stand for in plumbing?
A. Drain, Water, Valve
B. Drain-Waste-Vent
C. Domestic Water Valve
D. Drain-Water Vacuum
Answer: B. Drain-Waste-Vent
Rationale: DWV describes the portion of a plumbing system responsible for
carrying wastewater and providing ventilation for the drainage system.
7. Why are plumbing vents installed?
A. To increase hot-water temperature
B. To provide air circulation and protect trap seals
C. To increase water pressure
D. To filter wastewater
Answer: B. To provide air circulation and protect trap seals
Rationale: Proper venting balances pressure in the drainage system and helps
prevent siphoning or compression of fixture trap seals.
8. Which material is commonly used for domestic water piping?
A. Copper
B. Structural steel only
C. Cast iron only
D. Concrete
Answer: A. Copper
, Rationale: Copper is widely used for potable water distribution because it is
durable, corrosion-resistant under appropriate conditions, and suitable for hot
and cold water.
9. What is water hammer?
A. A method of joining copper pipes
B. A pressure surge caused by sudden changes in water flow
C. A type of drain cleaner
D. A method of testing sewer lines
Answer: B. A pressure surge caused by sudden changes in water flow
Rationale: Water hammer occurs when flowing water is suddenly stopped or
redirected, producing a pressure wave that can cause noise, vibration, and pipe
damage.
10.Which device can help control water hammer?
A. Water-hammer arrestor
B. Cleanout plug
C. Floor drain
D. Strainer
Answer: A. Water-hammer arrestor
Rationale: A water-hammer arrestor contains a means of absorbing the
pressure surge created when water flow is suddenly stopped.
11.What is the purpose of a pressure-reducing valve?
A. Increase excessive water pressure
B. Reduce incoming water pressure to a controlled level
C. Remove sewer gases
D. Increase drainage slope
Answer: B. Reduce incoming water pressure to a controlled level
