PLUMBER’S EXAM | INTERIOR DESIGN PROFESSIONAL EXAM
2026/2027 LATEST UPDATE | QUESTIONS AND VERIFIED ANSWERS
| GRADED A+
A journeyman plumber and an apprentice, who are employed by a master plumber, are installing the
DWV-system and water distribution system in a 2-½ story single family dwelling. QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: A trap that serves a single shower stall that is equipped with a hand shower, a rain
head, and a standard shower head shall be no less than ________ in minimum diameter
A) 1-½" B) 2" C) 2-½" D) 3" -
CORRECT|ANSWER
2 inches
A journeyman plumber and apprentice are installing 3-inch floor drains in an open-parking-garage
that is subject to freezing temperatures. QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: The installation of traps at the floor drain locations which are found susceptible to
freezing temperatures may be __________.
A)Increased to 4-inch B) Eliminated C) Wrapped with freeze protection cable D) Insulated -
CORRECT|ANSWER
eliminated
A journeyman plumber and apprentice are installing lab sinks with faucets that are connected to an
acid waste system for-(special hazardous waste) in a medical lab. What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: Vacuum breakers shall be installed with the critical level at least _____-inches
above the flood level rim of the fixture they serve and on the discharge side of the last control valve
to the fixture.
A) 12 B) 6 C) 18 D) 3 -
,CORRECT|ANSWER
6 inches
What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: No plumbing permit shall be issued for cross connection installations that require
______________ until the application for a permit is accompanied by a letter of approval from the
Massachusetts Department of Environmental Protection or its designee.
A) RPBP B) A "critical level" height C) Atmospheric vacuum breakers D) Water recycling systems -
CORRECT|ANSWER
reduced pressure backflow preventer (RPBP)
: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: The waste discharge from safe waste pans serving water heaters or hot water
storage tanks where there is _______ below and shall be piped indirectly to a properly trapped and
vented fixture.
A) People B) Occupancy C) Floors D) Plumbing connections -
CORRECT|ANSWER
occupancy
GIVEN: A journeyman plumber and an apprentice, (who are employed by a master plumber), are
installing the sanitary DWV and water distribution system in a five-story residential condominium
complex. QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: CPVC-(Chlorinated Polyvinyl Chloride) pipe and fittings may be used provided that
none of this material is located within ____-inches of any connection to a hot water tank as defined
in MGL. c. 142, § 17
A) 12 B) 18 C) 20 D) 24 E) 30 -
,CORRECT|ANSWER
24 inches
: A journeyman plumber and apprentice are roughing-in multiple fixtures in a new fitness center. The
facility will include a juice bar, temporary daycare room, men's and women's toilet facilities and
men's and women's locker rooms. QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: A ________-vent is a branch vent that serves two or more floor-outlet fixtures
that are battery wasted. The vent extends from the top of the horizontal soil and/or waste branch in
front of the last fixture waste and connects to a vent stack or stack vent that is adjacent to the down-
stream end of the horizontal branch.
A) Side B) Loop C) Relief D) Circuit -
CORRECT|ANSWER
loop
MATCH:
Elevated pressure
Flow designation
Ten P.S.I.G. or less
Less than 2-P.S.I
A) 3 P.S.I.G. or ten times
B) Inlet pressure
C) E.H.D.
D) Prof. Engineer -
CORRECT|ANSWER
elevated pressure- d
flow designation-c
Ten P.S.I.G. or less-a
Less than 2-P.S.I-b
, N: A journeyman plumber is installing category-I gas appliances and equipment in the basement of a
building. A 120,000 BTU/hr. boiler and 40,000 BTU/hr. water heater are being installed. QUESTION:
What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Gas code knowledge" related
statement: The boiler requires a minimum of _____-cu. ft. of air to support proper combustion
A) 2,400 cu. ft. B) 120 sq. in. C) 3,200 sq. ft. D) 800 cu. ft. -
CORRECT|ANSWER
2,400 cu. ft. 120,000/50
) QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Gas code knowledge" related
statement: The code would require the gas vent penetrating the roof in-[FIGURE-TP-B-Q1-1A: GAS
VENT SIZING] as identified at point-[A] to be not less than ______ above any portion of a building
within 10-feet horizontally.
A) 24" B) 3-feet C) 30-inches D) Forty-two-inches -
CORRECT|ANSWER
24
In Massachusetts copper tubing and fittings may be used for natural gas piping
A) Provided that the tubing is type-k with flared fitting connections. B) When approved by the
authority having jurisdiction.
C) At interior locations only and not concealed.
D) If the gas contains no more than .03 grains of hydrogen sulfide per 100 cu. ft. of gas. -
CORRECT|ANSWER
If the gas contains no more than .03 grains of hydrogen sulfide per 100 cu. ft. of gas
: A journeyman plumber and apprentice, who are employed by a master plumber, are installing a
natural gas fired category-1 boiler and water heater to an interior, clay tile lined, masonry chimney.
When measured in compliance with the code the chimney "height" is 48-feet. QUESTION: What
2026/2027 LATEST UPDATE | QUESTIONS AND VERIFIED ANSWERS
| GRADED A+
A journeyman plumber and an apprentice, who are employed by a master plumber, are installing the
DWV-system and water distribution system in a 2-½ story single family dwelling. QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: A trap that serves a single shower stall that is equipped with a hand shower, a rain
head, and a standard shower head shall be no less than ________ in minimum diameter
A) 1-½" B) 2" C) 2-½" D) 3" -
CORRECT|ANSWER
2 inches
A journeyman plumber and apprentice are installing 3-inch floor drains in an open-parking-garage
that is subject to freezing temperatures. QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: The installation of traps at the floor drain locations which are found susceptible to
freezing temperatures may be __________.
A)Increased to 4-inch B) Eliminated C) Wrapped with freeze protection cable D) Insulated -
CORRECT|ANSWER
eliminated
A journeyman plumber and apprentice are installing lab sinks with faucets that are connected to an
acid waste system for-(special hazardous waste) in a medical lab. What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: Vacuum breakers shall be installed with the critical level at least _____-inches
above the flood level rim of the fixture they serve and on the discharge side of the last control valve
to the fixture.
A) 12 B) 6 C) 18 D) 3 -
,CORRECT|ANSWER
6 inches
What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: No plumbing permit shall be issued for cross connection installations that require
______________ until the application for a permit is accompanied by a letter of approval from the
Massachusetts Department of Environmental Protection or its designee.
A) RPBP B) A "critical level" height C) Atmospheric vacuum breakers D) Water recycling systems -
CORRECT|ANSWER
reduced pressure backflow preventer (RPBP)
: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: The waste discharge from safe waste pans serving water heaters or hot water
storage tanks where there is _______ below and shall be piped indirectly to a properly trapped and
vented fixture.
A) People B) Occupancy C) Floors D) Plumbing connections -
CORRECT|ANSWER
occupancy
GIVEN: A journeyman plumber and an apprentice, (who are employed by a master plumber), are
installing the sanitary DWV and water distribution system in a five-story residential condominium
complex. QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: CPVC-(Chlorinated Polyvinyl Chloride) pipe and fittings may be used provided that
none of this material is located within ____-inches of any connection to a hot water tank as defined
in MGL. c. 142, § 17
A) 12 B) 18 C) 20 D) 24 E) 30 -
,CORRECT|ANSWER
24 inches
: A journeyman plumber and apprentice are roughing-in multiple fixtures in a new fitness center. The
facility will include a juice bar, temporary daycare room, men's and women's toilet facilities and
men's and women's locker rooms. QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Plumbing code knowledge"
related statement: A ________-vent is a branch vent that serves two or more floor-outlet fixtures
that are battery wasted. The vent extends from the top of the horizontal soil and/or waste branch in
front of the last fixture waste and connects to a vent stack or stack vent that is adjacent to the down-
stream end of the horizontal branch.
A) Side B) Loop C) Relief D) Circuit -
CORRECT|ANSWER
loop
MATCH:
Elevated pressure
Flow designation
Ten P.S.I.G. or less
Less than 2-P.S.I
A) 3 P.S.I.G. or ten times
B) Inlet pressure
C) E.H.D.
D) Prof. Engineer -
CORRECT|ANSWER
elevated pressure- d
flow designation-c
Ten P.S.I.G. or less-a
Less than 2-P.S.I-b
, N: A journeyman plumber is installing category-I gas appliances and equipment in the basement of a
building. A 120,000 BTU/hr. boiler and 40,000 BTU/hr. water heater are being installed. QUESTION:
What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Gas code knowledge" related
statement: The boiler requires a minimum of _____-cu. ft. of air to support proper combustion
A) 2,400 cu. ft. B) 120 sq. in. C) 3,200 sq. ft. D) 800 cu. ft. -
CORRECT|ANSWER
2,400 cu. ft. 120,000/50
) QUESTION: What
CORRECT|ANSWER
below shall be considered most correct to complete the following "Gas code knowledge" related
statement: The code would require the gas vent penetrating the roof in-[FIGURE-TP-B-Q1-1A: GAS
VENT SIZING] as identified at point-[A] to be not less than ______ above any portion of a building
within 10-feet horizontally.
A) 24" B) 3-feet C) 30-inches D) Forty-two-inches -
CORRECT|ANSWER
24
In Massachusetts copper tubing and fittings may be used for natural gas piping
A) Provided that the tubing is type-k with flared fitting connections. B) When approved by the
authority having jurisdiction.
C) At interior locations only and not concealed.
D) If the gas contains no more than .03 grains of hydrogen sulfide per 100 cu. ft. of gas. -
CORRECT|ANSWER
If the gas contains no more than .03 grains of hydrogen sulfide per 100 cu. ft. of gas
: A journeyman plumber and apprentice, who are employed by a master plumber, are installing a
natural gas fired category-1 boiler and water heater to an interior, clay tile lined, masonry chimney.
When measured in compliance with the code the chimney "height" is 48-feet. QUESTION: What
