Rhode Island Journeyman Plumber Exam – Latest Questions & Top-Score Verified Answers

Rhode Island Journeyman Plumber Exam –
Latest Questions & Top-Score Verified Answers

RHODE ISLAND JOURNEYMAN PLUMBER EXAM
300 Questions – Latest Questions & Top-Score Verified Answers



QUESTION 1

What is the minimum slope required for horizontal drainage pipes 3 inches or less in
diameter?

A. 1/8 inch per foot

B. 3/16 inch per foot

C. 1/4 inch per foot

D. 1/2 inch per foot
E. 3/4 inch per foot

RATIONALE: The standard minimum slope for horizontal drainage pipes 3 inches or
less in diameter is 1/4 inch per foot (2%) to ensure adequate flow and prevent solids
from settling in the pipe.


QUESTION 2

What is the maximum distance a P-trap can be from its vent?

A. 2 feet

B. 3 feet

C. 6 feet

D. 8 feet
E. 10 feet

RATIONALE: According to the plumbing code, a P-trap must be within 6 feet of its vent
to ensure proper trap seal protection and prevent siphoning.


QUESTION 3

,Which type of pipe is NOT permitted for use in potable water supply systems?

A. Copper Type L

B. CPVC

C. PEX
D. Galvanized Steel

E. ABS

RATIONALE: ABS (Acrylonitrile Butadiene Styrene) pipe is a drain-waste-vent (DWV)
material only and is not approved for potable water supply systems.



QUESTION 4

What is the minimum water pressure required at the point of service for most residential
buildings?

A. 10 psi

B. 20 psi

C. 40 psi

D. 60 psi

E. 80 psi

RATIONALE: The minimum acceptable water pressure at a residential service point is
40 psi to ensure adequate flow to all fixtures throughout the building.


QUESTION 5

How many fixture units can a 3-inch horizontal branch drain carry?

A. 10

B. 14

C. 20

D. 30

E. 42

,RATIONALE: A 3-inch horizontal branch drain can carry a maximum of 20 drainage
fixture units (DFU) according to standard plumbing code drainage tables.



QUESTION 6

What is the minimum size of a building sewer for a single-family residence?

A. 2 inches

B. 3 inches

C. 4 inches

D. 5 inches
E. 6 inches

RATIONALE: The minimum size for a building sewer serving a single-family residence is
4 inches in diameter to handle the total drainage fixture unit load.



QUESTION 7

What type of valve is required at the main water service entry into a building?
A. Gate valve

B. Globe valve

C. Full-port ball valve

D. Butterfly valve

E. Check valve
RATIONALE: A full-port ball valve is required at the main water service entry because it
provides a complete shutoff with minimal pressure loss and is reliable for emergency
shutoff situations.



QUESTION 8

What is the maximum water temperature setting for a water heater in a residential
occupancy?
A. 100°F

, B. 110°F

C. 120°F

D. 120°F

E. 140°F

RATIONALE: The maximum recommended water heater temperature for residential use
is 120°F to prevent scalding injuries, especially for children and elderly occupants.


QUESTION 9

Which fitting is used to change direction 90 degrees in a drainage system?
A. Tee

B. Coupling

C. Wye

D. Long-sweep 1/4 bend

E. Bushing

RATIONALE: A long-sweep 1/4 bend (long-turn 90°) is used for direction changes in
drainage systems because its gradual curve prevents clogging and maintains proper
flow.


QUESTION 10
What is the purpose of a vacuum breaker on a hose bibb?

A. To increase water pressure

B. To filter sediment

C. To prevent backflow contamination

D. To regulate flow rate

E. To reduce noise

RATIONALE: A vacuum breaker prevents backflow by allowing air into the line when
negative pressure occurs, protecting the potable water supply from contamination
through the hose connection.