Page 1 of 77
TEXAS MASTER PLUMBER EXAMINATION –
EXAM PREP GUIDE | LATEST UPDATE 2026/2027 |
PRACTICE QUESTIONS AND ANSWERS.
Table of Contents
Plumbing Codes
Water Heater Installation
OSHA Code Federal Regulations
Texas Accessibility Standards
Liquefied Petroleum Gas Piping Installation
Plumbing Related Mathematics
Plumbing License Law and Board Rules
, Page 2 of 77
Question 1: A vent pipe connecting upward from a soil or waste stack to a vent
stack to prevent pressure changes in the stacks is a:
A) crown vent
B) common vent
C) loop vent
D) yoke vent
Correct Answer: D
A yoke vent connects a soil or waste stack to a vent stack to prevent pressure
changes. This is a fundamental plumbing code definition tested on the TSBPE
Master Plumber exam.
Question 2: New, altered, or replaced plumbing:
A) may be covered if not inspected after 48 hours
B) may be covered if all ends are exposed
C) shall be left uncovered until inspected and approved
D) may be covered if bad weather damage should occur
Correct Answer: C
Plumbing codes require that new, altered, or replaced plumbing shall be left
uncovered until inspected and approved. Covering work before inspection is a code
violation.
Question 3: Water closets or bidets shall not be set closer than ______ from its
center to any sidewall or partition.
, Page 3 of 77
A) 10 inches
B) 12 inches
C) 15 inches
D) 18 inches
Correct Answer: C
Water closets and bidets require a minimum of 15 inches from the center of the
fixture to any sidewall or partition. This is a standard plumbing fixture clearance
requirement.
Question 4: The maximum number of fixture units on a 2-inch horizontal drainage
pipe is:
A) 12
B) 20
C) 28
D) 32
Correct Answer: B
A 2-inch horizontal drainage pipe is limited to 20 fixture units under the plumbing
code. This is a critical drainage sizing calculation.
Question 5: What is the minimum slope required for horizontal drainage piping 3
inches and smaller?
A) 1/8 inch per foot
B) 1/4 inch per foot
C) 1/2 inch per foot
D) 1 inch per foot
, Page 4 of 77
Correct Answer: B
Horizontal drainage piping 3 inches and smaller requires a minimum slope of 1/4
inch per foot. Pipes 4 inches and larger may use 1/8 inch per foot where approved.
Question 6: Which of the following is the definition of an "air gap"?
A) The unobstructed vertical distance through the free atmosphere between the
lowest opening of a water supply outlet and the flood-level rim of a fixture
B) A pipe that connects two vent stacks
C) A fitting that connects two drainage pipes
D) A device that prevents backflow by mechanical means
Correct Answer: A
An air gap is the unobstructed vertical distance through free atmosphere between a
water supply outlet and the flood-level rim of a fixture. It is the most effective
backflow prevention method.
Question 7: What is the maximum length of a fixture drain from the trap to the
vent?
A) 2 feet
B) 3 feet
C) 4 feet
D) 6 feet
Correct Answer: B
The fixture drain from the trap to the vent must not exceed 3 feet. This distance is
measured from the trap weir to the vent connection.
Question 8: A cleanout is required on horizontal drainage piping at:
TEXAS MASTER PLUMBER EXAMINATION –
EXAM PREP GUIDE | LATEST UPDATE 2026/2027 |
PRACTICE QUESTIONS AND ANSWERS.
Table of Contents
Plumbing Codes
Water Heater Installation
OSHA Code Federal Regulations
Texas Accessibility Standards
Liquefied Petroleum Gas Piping Installation
Plumbing Related Mathematics
Plumbing License Law and Board Rules
, Page 2 of 77
Question 1: A vent pipe connecting upward from a soil or waste stack to a vent
stack to prevent pressure changes in the stacks is a:
A) crown vent
B) common vent
C) loop vent
D) yoke vent
Correct Answer: D
A yoke vent connects a soil or waste stack to a vent stack to prevent pressure
changes. This is a fundamental plumbing code definition tested on the TSBPE
Master Plumber exam.
Question 2: New, altered, or replaced plumbing:
A) may be covered if not inspected after 48 hours
B) may be covered if all ends are exposed
C) shall be left uncovered until inspected and approved
D) may be covered if bad weather damage should occur
Correct Answer: C
Plumbing codes require that new, altered, or replaced plumbing shall be left
uncovered until inspected and approved. Covering work before inspection is a code
violation.
Question 3: Water closets or bidets shall not be set closer than ______ from its
center to any sidewall or partition.
, Page 3 of 77
A) 10 inches
B) 12 inches
C) 15 inches
D) 18 inches
Correct Answer: C
Water closets and bidets require a minimum of 15 inches from the center of the
fixture to any sidewall or partition. This is a standard plumbing fixture clearance
requirement.
Question 4: The maximum number of fixture units on a 2-inch horizontal drainage
pipe is:
A) 12
B) 20
C) 28
D) 32
Correct Answer: B
A 2-inch horizontal drainage pipe is limited to 20 fixture units under the plumbing
code. This is a critical drainage sizing calculation.
Question 5: What is the minimum slope required for horizontal drainage piping 3
inches and smaller?
A) 1/8 inch per foot
B) 1/4 inch per foot
C) 1/2 inch per foot
D) 1 inch per foot
, Page 4 of 77
Correct Answer: B
Horizontal drainage piping 3 inches and smaller requires a minimum slope of 1/4
inch per foot. Pipes 4 inches and larger may use 1/8 inch per foot where approved.
Question 6: Which of the following is the definition of an "air gap"?
A) The unobstructed vertical distance through the free atmosphere between the
lowest opening of a water supply outlet and the flood-level rim of a fixture
B) A pipe that connects two vent stacks
C) A fitting that connects two drainage pipes
D) A device that prevents backflow by mechanical means
Correct Answer: A
An air gap is the unobstructed vertical distance through free atmosphere between a
water supply outlet and the flood-level rim of a fixture. It is the most effective
backflow prevention method.
Question 7: What is the maximum length of a fixture drain from the trap to the
vent?
A) 2 feet
B) 3 feet
C) 4 feet
D) 6 feet
Correct Answer: B
The fixture drain from the trap to the vent must not exceed 3 feet. This distance is
measured from the trap weir to the vent connection.
Question 8: A cleanout is required on horizontal drainage piping at:
