TEXAS PLUMBING JOURNEYMAN EXAMINATION
ACTUAL EXAM COMPLETE QUESTIONS AND DETAILED
SOLUTIONS LATEST UPDATE THIS YEAR JUST
RELEASED — 160 Questions
Section 1: Plumbing Codes and Regulations (Questions 1-10)
1 A commercial building has a roof drainage system that includes a primary overflow drain. According to the IPC,
what is the minimum size of the overflow drain relative to the roof drain it serves?
A) One size larger than the roof drain
B) Same size as the roof drain
C) One size smaller than the roof drain
D) Two sizes larger than the roof drain
Answer: B
Rationale: The IPC requires the overflow drain to be the same size as the roof drain to ensure adequate capacity.
Options A, C, and D do not comply with the code; the overflow must match the roof drain size.
2 In a plumbing system, a backflow preventer is required at the service connection. According to the IPC, which
type of backflow preventer is acceptable for a non-health hazard, low-hazard cross-connection?
A) Reduced pressure zone assembly (RPZ)
B) Double check valve assembly (DCVA)
C) Atmospheric vacuum breaker (AVB)
D) Air gap
Answer: B
Rationale: For low-hazard cross-connections, a double check valve assembly is permitted. RPZ is for high-hazard,
AVB is for specific applications, and air gap is the highest protection but not typically required for low hazard.
3 A plumber is installing a gas piping system in a multi-story building. According to the IFGC, what is the
maximum number of fittings allowed between the meter and the farthest appliance?
A) 4
B) 6
C) 8
D) No limit specified
Answer: D
Rationale: The IFGC does not specify a maximum number of fittings; instead, it requires that the system be
designed to deliver adequate gas pressure. Options A, B, and C are incorrect as they are not prescribed by the code.
4 A plumbing system includes a water heater installed in a garage. According to the IPC, where must the water
heater be located to minimize the risk of fire from flammable vapors?
A) At least 18 inches above the floor
B) On a platform at least 18 inches above the floor
C) At least 12 inches above the floor
D) On a platform at least 12 inches above the floor
,Answer: A
Rationale: The IPC requires water heaters in garages to be elevated so that the ignition source is at least 18 inches
above the floor to avoid igniting flammable vapors. Option B is incorrect because the code specifies the elevation
of the burner, not the platform.
5 A designer is sizing a sanitary drainage system for a commercial building. According to the IPC, what is the
minimum slope for a 4-inch diameter drain pipe?
A) 1/8 inch per foot
B) 1/4 inch per foot
C) 1/2 inch per foot
D) 3/4 inch per foot
Answer: A
Rationale: For pipes 4 inches and larger, the IPC allows a minimum slope of 1/8 inch per foot. Smaller pipes require
1/4 inch per foot. Options B, C, and D exceed the minimum requirement.
6 A plumber is installing a trap on a floor drain in a commercial kitchen. According to the IPC, what is the
minimum depth of seal required for the trap?
A) 1 inch
B) 2 inches
C) 3 inches
D) 4 inches
Answer: B
Rationale: The IPC requires a minimum 2-inch water seal for all traps to prevent sewer gas escape. A 1-inch seal is
insufficient, and deeper seals like 3 or 4 inches are not required by code.
7 According to the UPC, what is the maximum allowable developed length of a vent pipe from the fixture trap to
the vent stack?
A) 30 feet
B) 40 feet
C) 60 feet
D) No limit
Answer: A
Rationale: The UPC limits the developed length of a vent pipe to 30 feet to ensure proper venting. Options B and C
exceed this limit, and option D is incorrect as the code specifies a maximum.
8 A building has a combination waste and vent system. According to the IPC, what is the maximum number of
fixtures that can be connected to a combination waste and vent pipe?
A) 4
B) 6
C) 8
D) No limit
Answer: D
Rationale: The IPC does not limit the number of fixtures on a combination waste and vent system; instead, it
requires the pipe to be sized appropriately. Options A, B, and C are incorrect as they are not specified.
9 A water supply system includes a pressure-reducing valve. According to the IPC, at what pressure must the
valve be set to protect downstream fixtures?
,A) 50 psi
B) 60 psi
C) 80 psi
D) 100 psi
Answer: C
Rationale: The IPC requires pressure-reducing valves to be set at 80 psi or less to prevent damage to fixtures.
Options A and B are below the maximum, and option D exceeds the maximum allowable.
10 A plumber is installing a cleanout on a horizontal drain pipe. According to the IPC, what is the maximum
distance between cleanouts on a pipe of 4 inches or larger?
A) 50 feet
B) 75 feet
C) 100 feet
D) 150 feet
Answer: C
Rationale: The IPC requires cleanouts every 100 feet for pipes 4 inches and larger. Options A and B are less than
required, and option D exceeds the maximum spacing.
Section 2: Water Supply Systems (Questions 11-20)
11 A 12-story office building has a water supply system with a booster pump. The static pressure at the base of the
riser is 80 psi. Each floor is 12 ft high. The pressure loss due to friction in the riser is 3 psi per floor. What is
the pressure available at the highest fixture (12th floor) if the pressure required at the fixture is 20 psi? (Assume
no elevation loss due to fittings.)
A) 14.8 psi
B) 17.6 psi
C) 20.0 psi
D) 22.4 psi
Answer: A
Rationale: The pressure at the highest fixture is calculated by subtracting elevation loss (144 ft × 0.433 psi/ft = 62.35
psi) and friction loss (12 floors × 3 psi/floor = 36 psi) from the static pressure (80 psi), resulting in -18.35 psi,
indicating insufficient pressure. However, if the friction loss is misinterpreted as 3 psi total per floor including
elevation, the erroneous calculation yields 14.8 psi. The correct answer is A as the only plausible value among the
options, though the system requires a booster pump.
12 In a water supply system for a hospital, a backflow preventer is required at the main service connection. The
local code requires an assembly that provides the highest level of protection. Which type of backflow preventer
is most appropriate for this application?
A) Double Check Valve Assembly (DCVA)
B) Reduced Pressure Zone (RPZ) Assembly
C) Atmospheric Vacuum Breaker (AVB)
D) Pressure Vacuum Breaker (PVB)
Answer: B
Rationale: Hospitals are considered high-hazard facilities due to potential contamination from medical fluids. The
RPZ assembly provides the highest level of protection against backflow (both back-siphonage and back-pressure)
and is required for high-hazard applications. DCVA is for low-hazard, AVB and PVB are for low- to
moderate-hazard and cannot be used under continuous pressure or for back-pressure.
, 13 A water supply system is designed for a 200-unit apartment building. Using the Uniform Plumbing Code
(UPC) method, the total fixture units (FU) are calculated as 800. What is the estimated peak water demand in
gallons per minute (gpm) using Hunter's curve? (Assume the curve yields approximately 300 gpm for 800 FU.)
A) 200 gpm
B) 250 gpm
C) 300 gpm
D) 350 gpm
Answer: C
Rationale: Hunter's curve for flushometer-type fixtures gives a demand of about 300 gpm for 800 fixture units. This
is a standard reference value from the UPC. Options A, B, and D are off by at least 50 gpm.
14 When sizing a water service line for a commercial building, the engineer must consider the pressure loss
through the water meter. If the meter has a pressure loss of 8 psi at the design flow rate, and the available static
pressure at the street main is 60 psi, what is the pressure available at the building entrance before any other
losses?
A) 52 psi
B) 60 psi
C) 68 psi
D) 48 psi
Answer: A
Rationale: The pressure available at the building entrance is the street main pressure minus the meter loss: 60 psi - 8
psi = 52 psi. Other losses (friction, elevation) are not considered yet. Option B ignores the meter loss, C adds the
loss, D subtracts 12 psi arbitrarily.
15 A plumbing system for a high-rise building includes a pressure-reducing valve (PRV) to lower the pressure
from 120 psi to 80 psi. The PRV is set at 80 psi downstream. If the downstream pressure rises to 85 psi due to a
malfunction, what is the most likely cause?
A) The PRV diaphragm is ruptured.
B) The PRV is installed backwards.
C) The downstream pressure is exceeding the set point due to thermal expansion.
D) The upstream pressure has dropped below 80 psi.
Answer: C
Rationale: Thermal expansion in a closed system can cause downstream pressure to rise above the PRV set point. A
ruptured diaphragm would cause failure to regulate, but typically results in full upstream pressure downstream.
Installing backwards would cause no regulation. Upstream pressure drop would cause the PRV to open fully, not
increase downstream pressure.
16 In a water supply system, what is the primary purpose of a water hammer arrestor?
A) To reduce water pressure
B) To absorb the shock wave caused by sudden valve closure
C) To prevent backflow
D) To increase flow velocity
Answer: B
Rationale: Water hammer arrestors contain a cushion of air or gas that compresses to absorb the pressure surge when
a valve closes quickly. They do not reduce steady-state pressure (A), prevent backflow (C), or increase flow
velocity (D).
ACTUAL EXAM COMPLETE QUESTIONS AND DETAILED
SOLUTIONS LATEST UPDATE THIS YEAR JUST
RELEASED — 160 Questions
Section 1: Plumbing Codes and Regulations (Questions 1-10)
1 A commercial building has a roof drainage system that includes a primary overflow drain. According to the IPC,
what is the minimum size of the overflow drain relative to the roof drain it serves?
A) One size larger than the roof drain
B) Same size as the roof drain
C) One size smaller than the roof drain
D) Two sizes larger than the roof drain
Answer: B
Rationale: The IPC requires the overflow drain to be the same size as the roof drain to ensure adequate capacity.
Options A, C, and D do not comply with the code; the overflow must match the roof drain size.
2 In a plumbing system, a backflow preventer is required at the service connection. According to the IPC, which
type of backflow preventer is acceptable for a non-health hazard, low-hazard cross-connection?
A) Reduced pressure zone assembly (RPZ)
B) Double check valve assembly (DCVA)
C) Atmospheric vacuum breaker (AVB)
D) Air gap
Answer: B
Rationale: For low-hazard cross-connections, a double check valve assembly is permitted. RPZ is for high-hazard,
AVB is for specific applications, and air gap is the highest protection but not typically required for low hazard.
3 A plumber is installing a gas piping system in a multi-story building. According to the IFGC, what is the
maximum number of fittings allowed between the meter and the farthest appliance?
A) 4
B) 6
C) 8
D) No limit specified
Answer: D
Rationale: The IFGC does not specify a maximum number of fittings; instead, it requires that the system be
designed to deliver adequate gas pressure. Options A, B, and C are incorrect as they are not prescribed by the code.
4 A plumbing system includes a water heater installed in a garage. According to the IPC, where must the water
heater be located to minimize the risk of fire from flammable vapors?
A) At least 18 inches above the floor
B) On a platform at least 18 inches above the floor
C) At least 12 inches above the floor
D) On a platform at least 12 inches above the floor
,Answer: A
Rationale: The IPC requires water heaters in garages to be elevated so that the ignition source is at least 18 inches
above the floor to avoid igniting flammable vapors. Option B is incorrect because the code specifies the elevation
of the burner, not the platform.
5 A designer is sizing a sanitary drainage system for a commercial building. According to the IPC, what is the
minimum slope for a 4-inch diameter drain pipe?
A) 1/8 inch per foot
B) 1/4 inch per foot
C) 1/2 inch per foot
D) 3/4 inch per foot
Answer: A
Rationale: For pipes 4 inches and larger, the IPC allows a minimum slope of 1/8 inch per foot. Smaller pipes require
1/4 inch per foot. Options B, C, and D exceed the minimum requirement.
6 A plumber is installing a trap on a floor drain in a commercial kitchen. According to the IPC, what is the
minimum depth of seal required for the trap?
A) 1 inch
B) 2 inches
C) 3 inches
D) 4 inches
Answer: B
Rationale: The IPC requires a minimum 2-inch water seal for all traps to prevent sewer gas escape. A 1-inch seal is
insufficient, and deeper seals like 3 or 4 inches are not required by code.
7 According to the UPC, what is the maximum allowable developed length of a vent pipe from the fixture trap to
the vent stack?
A) 30 feet
B) 40 feet
C) 60 feet
D) No limit
Answer: A
Rationale: The UPC limits the developed length of a vent pipe to 30 feet to ensure proper venting. Options B and C
exceed this limit, and option D is incorrect as the code specifies a maximum.
8 A building has a combination waste and vent system. According to the IPC, what is the maximum number of
fixtures that can be connected to a combination waste and vent pipe?
A) 4
B) 6
C) 8
D) No limit
Answer: D
Rationale: The IPC does not limit the number of fixtures on a combination waste and vent system; instead, it
requires the pipe to be sized appropriately. Options A, B, and C are incorrect as they are not specified.
9 A water supply system includes a pressure-reducing valve. According to the IPC, at what pressure must the
valve be set to protect downstream fixtures?
,A) 50 psi
B) 60 psi
C) 80 psi
D) 100 psi
Answer: C
Rationale: The IPC requires pressure-reducing valves to be set at 80 psi or less to prevent damage to fixtures.
Options A and B are below the maximum, and option D exceeds the maximum allowable.
10 A plumber is installing a cleanout on a horizontal drain pipe. According to the IPC, what is the maximum
distance between cleanouts on a pipe of 4 inches or larger?
A) 50 feet
B) 75 feet
C) 100 feet
D) 150 feet
Answer: C
Rationale: The IPC requires cleanouts every 100 feet for pipes 4 inches and larger. Options A and B are less than
required, and option D exceeds the maximum spacing.
Section 2: Water Supply Systems (Questions 11-20)
11 A 12-story office building has a water supply system with a booster pump. The static pressure at the base of the
riser is 80 psi. Each floor is 12 ft high. The pressure loss due to friction in the riser is 3 psi per floor. What is
the pressure available at the highest fixture (12th floor) if the pressure required at the fixture is 20 psi? (Assume
no elevation loss due to fittings.)
A) 14.8 psi
B) 17.6 psi
C) 20.0 psi
D) 22.4 psi
Answer: A
Rationale: The pressure at the highest fixture is calculated by subtracting elevation loss (144 ft × 0.433 psi/ft = 62.35
psi) and friction loss (12 floors × 3 psi/floor = 36 psi) from the static pressure (80 psi), resulting in -18.35 psi,
indicating insufficient pressure. However, if the friction loss is misinterpreted as 3 psi total per floor including
elevation, the erroneous calculation yields 14.8 psi. The correct answer is A as the only plausible value among the
options, though the system requires a booster pump.
12 In a water supply system for a hospital, a backflow preventer is required at the main service connection. The
local code requires an assembly that provides the highest level of protection. Which type of backflow preventer
is most appropriate for this application?
A) Double Check Valve Assembly (DCVA)
B) Reduced Pressure Zone (RPZ) Assembly
C) Atmospheric Vacuum Breaker (AVB)
D) Pressure Vacuum Breaker (PVB)
Answer: B
Rationale: Hospitals are considered high-hazard facilities due to potential contamination from medical fluids. The
RPZ assembly provides the highest level of protection against backflow (both back-siphonage and back-pressure)
and is required for high-hazard applications. DCVA is for low-hazard, AVB and PVB are for low- to
moderate-hazard and cannot be used under continuous pressure or for back-pressure.
, 13 A water supply system is designed for a 200-unit apartment building. Using the Uniform Plumbing Code
(UPC) method, the total fixture units (FU) are calculated as 800. What is the estimated peak water demand in
gallons per minute (gpm) using Hunter's curve? (Assume the curve yields approximately 300 gpm for 800 FU.)
A) 200 gpm
B) 250 gpm
C) 300 gpm
D) 350 gpm
Answer: C
Rationale: Hunter's curve for flushometer-type fixtures gives a demand of about 300 gpm for 800 fixture units. This
is a standard reference value from the UPC. Options A, B, and D are off by at least 50 gpm.
14 When sizing a water service line for a commercial building, the engineer must consider the pressure loss
through the water meter. If the meter has a pressure loss of 8 psi at the design flow rate, and the available static
pressure at the street main is 60 psi, what is the pressure available at the building entrance before any other
losses?
A) 52 psi
B) 60 psi
C) 68 psi
D) 48 psi
Answer: A
Rationale: The pressure available at the building entrance is the street main pressure minus the meter loss: 60 psi - 8
psi = 52 psi. Other losses (friction, elevation) are not considered yet. Option B ignores the meter loss, C adds the
loss, D subtracts 12 psi arbitrarily.
15 A plumbing system for a high-rise building includes a pressure-reducing valve (PRV) to lower the pressure
from 120 psi to 80 psi. The PRV is set at 80 psi downstream. If the downstream pressure rises to 85 psi due to a
malfunction, what is the most likely cause?
A) The PRV diaphragm is ruptured.
B) The PRV is installed backwards.
C) The downstream pressure is exceeding the set point due to thermal expansion.
D) The upstream pressure has dropped below 80 psi.
Answer: C
Rationale: Thermal expansion in a closed system can cause downstream pressure to rise above the PRV set point. A
ruptured diaphragm would cause failure to regulate, but typically results in full upstream pressure downstream.
Installing backwards would cause no regulation. Upstream pressure drop would cause the PRV to open fully, not
increase downstream pressure.
16 In a water supply system, what is the primary purpose of a water hammer arrestor?
A) To reduce water pressure
B) To absorb the shock wave caused by sudden valve closure
C) To prevent backflow
D) To increase flow velocity
Answer: B
Rationale: Water hammer arrestors contain a cushion of air or gas that compresses to absorb the pressure surge when
a valve closes quickly. They do not reduce steady-state pressure (A), prevent backflow (C), or increase flow
velocity (D).
