CO Journeyman Plumber Exam
Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant
Download Pdf.
1. Which plumbing code principle most directly governs the sizing of a
water distribution system in a typical Colorado residential building?
A. Pipe size must be selected solely according to the fixture count
B. Pipe size must be based on available pressure, developed length,
demand, and permitted pressure loss
C. Every branch line must be the same diameter as the building supply
D. The largest fixture in the building determines the size of every pipe
B. Pipe size must be based on available pressure, developed length,
demand, and permitted pressure loss
Rationale: Proper water-distribution sizing accounts for system demand
and hydraulic conditions so that adequate pressure and flow remain
available at the fixtures.
2. What is the primary purpose of a plumbing trap installed beneath a
fixture?
,A. To increase water pressure at the fixture
B. To prevent sediment from entering the drainage system
C. To maintain a water seal that prevents sewer gases from entering the
building
D. To provide additional drainage capacity
C. To maintain a water seal that prevents sewer gases from entering the
building
Rationale: A properly installed trap retains a water seal that separates
the occupied space from gases and odors within the drainage system.
3. A plumbing vent becomes completely blocked downstream of a
fixture trap. What condition is most likely to develop?
A. Increased water pressure
B. Loss or disruption of the trap seal
C. Increased hot-water temperature
D. Reduced pipe corrosion
B. Loss or disruption of the trap seal
Rationale: A blocked vent can cause pressure fluctuations during
drainage, potentially siphoning or blowing the trap seal out and
allowing sewer gases to enter the building.
4. What is the primary function of a building sewer?
A. To distribute potable water throughout the building
B. To convey stormwater from the roof
C. To carry sanitary drainage from the building drain to the public sewer
,or approved disposal system
D. To provide combustion air for fuel-burning appliances
C. To carry sanitary drainage from the building drain to the public sewer
or approved disposal system
Rationale: The building sewer is the portion of the drainage system
outside the building that conveys sanitary sewage toward an approved
point of disposal or public sewer.
5. Which fitting is generally preferred when changing the direction of
horizontal sanitary drainage flow?
A. Sanitary tee installed on its back
B. Long-sweep or drainage-pattern fitting
C. Straight coupling
D. Reducing bushing
B. Long-sweep or drainage-pattern fitting
Rationale: Drainage fittings are designed to provide smoother
directional changes and reduce turbulence, obstruction, and resistance
to the movement of waste.
6. Why must a sanitary drainage system be properly vented?
A. To increase the temperature of wastewater
B. To maintain atmospheric pressure and protect trap seals
C. To eliminate the need for cleanouts
D. To increase potable-water pressure
B. To maintain atmospheric pressure and protect trap seals
, Rationale: Venting permits air movement within the drainage system,
helping prevent excessive positive or negative pressures that could
disturb fixture trap seals.
7. Which condition is most likely to cause a fixture trap to be
siphoned?
A. Excessive positive pressure in the water-supply system
B. Rapid discharge through a properly vented nearby drainage pipe
C. Negative pressure created in the drainage system without adequate
venting
D. An oversized potable-water pipe
C. Negative pressure created in the drainage system without adequate
venting
Rationale: Negative pressure can draw water out of a fixture trap,
breaking the protective water seal and exposing the building to sewer
gases.
8. What is the principal purpose of a cleanout in a drainage system?
A. To increase water temperature
B. To provide access for inspection and removal of obstructions
C. To regulate potable-water pressure
D. To prevent thermal expansion
B. To provide access for inspection and removal of obstructions
Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant
Download Pdf.
1. Which plumbing code principle most directly governs the sizing of a
water distribution system in a typical Colorado residential building?
A. Pipe size must be selected solely according to the fixture count
B. Pipe size must be based on available pressure, developed length,
demand, and permitted pressure loss
C. Every branch line must be the same diameter as the building supply
D. The largest fixture in the building determines the size of every pipe
B. Pipe size must be based on available pressure, developed length,
demand, and permitted pressure loss
Rationale: Proper water-distribution sizing accounts for system demand
and hydraulic conditions so that adequate pressure and flow remain
available at the fixtures.
2. What is the primary purpose of a plumbing trap installed beneath a
fixture?
,A. To increase water pressure at the fixture
B. To prevent sediment from entering the drainage system
C. To maintain a water seal that prevents sewer gases from entering the
building
D. To provide additional drainage capacity
C. To maintain a water seal that prevents sewer gases from entering the
building
Rationale: A properly installed trap retains a water seal that separates
the occupied space from gases and odors within the drainage system.
3. A plumbing vent becomes completely blocked downstream of a
fixture trap. What condition is most likely to develop?
A. Increased water pressure
B. Loss or disruption of the trap seal
C. Increased hot-water temperature
D. Reduced pipe corrosion
B. Loss or disruption of the trap seal
Rationale: A blocked vent can cause pressure fluctuations during
drainage, potentially siphoning or blowing the trap seal out and
allowing sewer gases to enter the building.
4. What is the primary function of a building sewer?
A. To distribute potable water throughout the building
B. To convey stormwater from the roof
C. To carry sanitary drainage from the building drain to the public sewer
,or approved disposal system
D. To provide combustion air for fuel-burning appliances
C. To carry sanitary drainage from the building drain to the public sewer
or approved disposal system
Rationale: The building sewer is the portion of the drainage system
outside the building that conveys sanitary sewage toward an approved
point of disposal or public sewer.
5. Which fitting is generally preferred when changing the direction of
horizontal sanitary drainage flow?
A. Sanitary tee installed on its back
B. Long-sweep or drainage-pattern fitting
C. Straight coupling
D. Reducing bushing
B. Long-sweep or drainage-pattern fitting
Rationale: Drainage fittings are designed to provide smoother
directional changes and reduce turbulence, obstruction, and resistance
to the movement of waste.
6. Why must a sanitary drainage system be properly vented?
A. To increase the temperature of wastewater
B. To maintain atmospheric pressure and protect trap seals
C. To eliminate the need for cleanouts
D. To increase potable-water pressure
B. To maintain atmospheric pressure and protect trap seals
, Rationale: Venting permits air movement within the drainage system,
helping prevent excessive positive or negative pressures that could
disturb fixture trap seals.
7. Which condition is most likely to cause a fixture trap to be
siphoned?
A. Excessive positive pressure in the water-supply system
B. Rapid discharge through a properly vented nearby drainage pipe
C. Negative pressure created in the drainage system without adequate
venting
D. An oversized potable-water pipe
C. Negative pressure created in the drainage system without adequate
venting
Rationale: Negative pressure can draw water out of a fixture trap,
breaking the protective water seal and exposing the building to sewer
gases.
8. What is the principal purpose of a cleanout in a drainage system?
A. To increase water temperature
B. To provide access for inspection and removal of obstructions
C. To regulate potable-water pressure
D. To prevent thermal expansion
B. To provide access for inspection and removal of obstructions
