TEXAS PLUMBING JOURNEYMAN EXAM 2026/2027 | 300 EXAM-READY
QUESTIONS & VERIFIED ANSWERS | IPC + TEXAS CODE
Definitions & Codes — 300 Questions and Answers
Q1: What is the definition of a 'plumbing system'?
ANSWER A plumbing system includes all potable water supply and
distribution pipes, plumbing fixtures, fittings, water-treating or water-using
equipment, drainage and vent pipe, and devices within a structure.
Q2: Define 'potable water.'
ANSWER Potable water is water free from impurities in amounts sufficient to
cause disease or harmful physiological effects and conforming to the
requirements of the Texas Commission on Environmental Quality (TCEQ).
Q3: What is an 'approved' material or method in plumbing?
ANSWER Approved means acceptable to the authority having jurisdiction
(AHJ) — the entity responsible for enforcing the plumbing code in that
jurisdiction.
Q4: Define 'fixture unit' (FU).
ANSWER A fixture unit is a measure of the probable discharge into the
drainage system by various types of plumbing fixtures; it is used to size drain
pipes and water supply pipes.
Q5: What is a 'trap' in plumbing?
ANSWER A trap is a fitting or device that provides a liquid seal to prevent
the emission of sewer gases into a building without materially affecting the
flow of sewage or wastewater through it.
Q6: Define 'vent pipe.'
ANSWER A vent pipe is a pipe installed to provide a flow of air to or from a
drainage system or to provide a circulation of air within such system to protect
trap seals from siphonage and backpressure.
Q7: What is a 'backflow preventer'?
, ANSWER A backflow preventer is a device or means to prevent backflow —
the undesirable reversal of flow of a liquid, gas, or suspended matter into the
potable water supply.
Q8: Define 'cross-connection.'
ANSWER A cross-connection is any physical connection or arrangement
between a potable water supply system and any plumbing fixture, tank,
receptacle, or device through which it may be possible for non-potable water
to enter the potable system.
Q9: What is the 'authority having jurisdiction' (AHJ)?
ANSWER The AHJ is the organization, office, or individual responsible for
enforcing the requirements of a code or standard, or their designated
representative.
Q10: Define 'branch vent.'
ANSWER A branch vent is a vent pipe connecting one or more individual
vents with a vent stack or stack vent.
Q11: What is a 'circuit vent'?
ANSWER A circuit vent is a branch vent that serves two or more traps and
extends from in front of the last fixture connection of a horizontal branch to the
vent stack.
Q12: Define 'wet vent.'
ANSWER A wet vent is a pipe that serves as both a vent and a drain for one
or more fixtures simultaneously.
Q13: What is a 'stack vent'?
ANSWER A stack vent is the extension of a soil or waste stack above the
highest horizontal drain connected to the stack.
Q14: Define 'soil pipe.'
ANSWER A soil pipe is a pipe that conveys the discharge of water closets or
fixtures having similar functions, with or without the discharges from other
fixtures.
Q15: What is a 'waste pipe'?
ANSWER A waste pipe is a pipe that conveys only liquid waste, free of fecal
matter.
Q16: Define 'drain.'
ANSWER A drain is any pipe that carries wastewater or water-borne wastes
in a building drainage system.
Q17: What is a 'building drain'?
, ANSWER The building drain is the lowest horizontal piping of a drainage
system that receives the discharge from soil, waste, and other drainage pipes
inside and conveys it to the building sewer.
Q18: Define 'building sewer.'
ANSWER The building sewer is that part of the horizontal piping of a
drainage system that extends from the end of the building drain and conveys
its discharge to a public sewer, private sewer, individual sewage disposal
system, or other approved point of disposal.
Q19: What is a 'sanitary sewer'?
ANSWER A sanitary sewer is a sewer that carries liquid and water-carried
wastes from residences, commercial buildings, industrial plants, and
institutions — not stormwater, surface water, or groundwater.
Q20: Define 'storm sewer.'
ANSWER A storm sewer is a sewer that carries stormwater, surface water,
condensate, cooling water, and similar liquid wastes — not sewage.
Q21: What is a 'sewage ejector'?
ANSWER A sewage ejector is a device for lifting sewage by means of air
pressure, a pump, or similar mechanism when fixtures are located below the
level of the building sewer.
Q22: Define 'grease trap' (interceptor).
ANSWER A grease trap (or grease interceptor) is a device designed to retain
grease and fatty substances found in kitchen waste before they enter the
sanitary sewer.
Q23: What is a 'backwater valve'?
ANSWER A backwater valve is a device installed in a drain or pipe to
prevent backflow (reverse flow) of sewage into lower-level fixtures.
Q24: Define 'check valve.'
ANSWER A check valve is a self-closing valve that allows flow in only one
direction — it prevents reverse flow in a pipeline.
Q25: What is a 'gate valve'?
ANSWER A gate valve is a valve that uses a gate (wedge-shaped disc) to
start or stop flow; when open it provides an unobstructed passageway with
very little pressure drop.
Q26: Define 'ball valve.'
, ANSWER A ball valve is a valve in which a rotating ball with a hole through it
controls the flow; it provides a tight shutoff and is quick to open or close with a
quarter turn.
Q27: What is a 'pressure-reducing valve' (PRV)?
ANSWER A PRV is a valve that automatically reduces the incoming water
pressure to a lower, more manageable level to protect piping, fixtures, and
appliances downstream.
Q28: Define 'water hammer.'
ANSWER Water hammer is a hydraulic shock (knocking noise) caused by
the sudden stopping or change in direction of water flow in a pipe, resulting in
a pressure wave.
Q29: What is a 'water hammer arrestor'?
ANSWER A water hammer arrestor is a device used to absorb the pressure
wave created when water flow is suddenly stopped to prevent damage to
pipes and fixtures.
Q30: Define 'air gap.'
ANSWER An air gap is the unobstructed vertical distance through the free
atmosphere between the lowest opening from any pipe supplying water to a
tank, plumbing fixture, or receptor and the flood level rim of that vessel — it is
the highest level of backflow protection.
Section 2: Pipe Materials & Fittings
Q31: What does 'CPVC' stand for and where is it commonly used?
ANSWER Chlorinated Polyvinyl Chloride — CPVC is used for hot and cold
water distribution inside buildings; it is rated for higher temperatures than
standard PVC.
Q32: What does 'PEX' stand for?
ANSWER Cross-linked polyethylene — a flexible plastic pipe used for hot
and cold water supply systems, radiant floor heating, and potable water
distribution.
Q33: What is 'galvanized steel' pipe?
ANSWER Galvanized steel pipe is steel pipe coated with zinc to resist
corrosion; it was historically used for water supply but is now rarely installed
new due to corrosion and mineral buildup issues.
Q34: Define 'copper Type L.'
QUESTIONS & VERIFIED ANSWERS | IPC + TEXAS CODE
Definitions & Codes — 300 Questions and Answers
Q1: What is the definition of a 'plumbing system'?
ANSWER A plumbing system includes all potable water supply and
distribution pipes, plumbing fixtures, fittings, water-treating or water-using
equipment, drainage and vent pipe, and devices within a structure.
Q2: Define 'potable water.'
ANSWER Potable water is water free from impurities in amounts sufficient to
cause disease or harmful physiological effects and conforming to the
requirements of the Texas Commission on Environmental Quality (TCEQ).
Q3: What is an 'approved' material or method in plumbing?
ANSWER Approved means acceptable to the authority having jurisdiction
(AHJ) — the entity responsible for enforcing the plumbing code in that
jurisdiction.
Q4: Define 'fixture unit' (FU).
ANSWER A fixture unit is a measure of the probable discharge into the
drainage system by various types of plumbing fixtures; it is used to size drain
pipes and water supply pipes.
Q5: What is a 'trap' in plumbing?
ANSWER A trap is a fitting or device that provides a liquid seal to prevent
the emission of sewer gases into a building without materially affecting the
flow of sewage or wastewater through it.
Q6: Define 'vent pipe.'
ANSWER A vent pipe is a pipe installed to provide a flow of air to or from a
drainage system or to provide a circulation of air within such system to protect
trap seals from siphonage and backpressure.
Q7: What is a 'backflow preventer'?
, ANSWER A backflow preventer is a device or means to prevent backflow —
the undesirable reversal of flow of a liquid, gas, or suspended matter into the
potable water supply.
Q8: Define 'cross-connection.'
ANSWER A cross-connection is any physical connection or arrangement
between a potable water supply system and any plumbing fixture, tank,
receptacle, or device through which it may be possible for non-potable water
to enter the potable system.
Q9: What is the 'authority having jurisdiction' (AHJ)?
ANSWER The AHJ is the organization, office, or individual responsible for
enforcing the requirements of a code or standard, or their designated
representative.
Q10: Define 'branch vent.'
ANSWER A branch vent is a vent pipe connecting one or more individual
vents with a vent stack or stack vent.
Q11: What is a 'circuit vent'?
ANSWER A circuit vent is a branch vent that serves two or more traps and
extends from in front of the last fixture connection of a horizontal branch to the
vent stack.
Q12: Define 'wet vent.'
ANSWER A wet vent is a pipe that serves as both a vent and a drain for one
or more fixtures simultaneously.
Q13: What is a 'stack vent'?
ANSWER A stack vent is the extension of a soil or waste stack above the
highest horizontal drain connected to the stack.
Q14: Define 'soil pipe.'
ANSWER A soil pipe is a pipe that conveys the discharge of water closets or
fixtures having similar functions, with or without the discharges from other
fixtures.
Q15: What is a 'waste pipe'?
ANSWER A waste pipe is a pipe that conveys only liquid waste, free of fecal
matter.
Q16: Define 'drain.'
ANSWER A drain is any pipe that carries wastewater or water-borne wastes
in a building drainage system.
Q17: What is a 'building drain'?
, ANSWER The building drain is the lowest horizontal piping of a drainage
system that receives the discharge from soil, waste, and other drainage pipes
inside and conveys it to the building sewer.
Q18: Define 'building sewer.'
ANSWER The building sewer is that part of the horizontal piping of a
drainage system that extends from the end of the building drain and conveys
its discharge to a public sewer, private sewer, individual sewage disposal
system, or other approved point of disposal.
Q19: What is a 'sanitary sewer'?
ANSWER A sanitary sewer is a sewer that carries liquid and water-carried
wastes from residences, commercial buildings, industrial plants, and
institutions — not stormwater, surface water, or groundwater.
Q20: Define 'storm sewer.'
ANSWER A storm sewer is a sewer that carries stormwater, surface water,
condensate, cooling water, and similar liquid wastes — not sewage.
Q21: What is a 'sewage ejector'?
ANSWER A sewage ejector is a device for lifting sewage by means of air
pressure, a pump, or similar mechanism when fixtures are located below the
level of the building sewer.
Q22: Define 'grease trap' (interceptor).
ANSWER A grease trap (or grease interceptor) is a device designed to retain
grease and fatty substances found in kitchen waste before they enter the
sanitary sewer.
Q23: What is a 'backwater valve'?
ANSWER A backwater valve is a device installed in a drain or pipe to
prevent backflow (reverse flow) of sewage into lower-level fixtures.
Q24: Define 'check valve.'
ANSWER A check valve is a self-closing valve that allows flow in only one
direction — it prevents reverse flow in a pipeline.
Q25: What is a 'gate valve'?
ANSWER A gate valve is a valve that uses a gate (wedge-shaped disc) to
start or stop flow; when open it provides an unobstructed passageway with
very little pressure drop.
Q26: Define 'ball valve.'
, ANSWER A ball valve is a valve in which a rotating ball with a hole through it
controls the flow; it provides a tight shutoff and is quick to open or close with a
quarter turn.
Q27: What is a 'pressure-reducing valve' (PRV)?
ANSWER A PRV is a valve that automatically reduces the incoming water
pressure to a lower, more manageable level to protect piping, fixtures, and
appliances downstream.
Q28: Define 'water hammer.'
ANSWER Water hammer is a hydraulic shock (knocking noise) caused by
the sudden stopping or change in direction of water flow in a pipe, resulting in
a pressure wave.
Q29: What is a 'water hammer arrestor'?
ANSWER A water hammer arrestor is a device used to absorb the pressure
wave created when water flow is suddenly stopped to prevent damage to
pipes and fixtures.
Q30: Define 'air gap.'
ANSWER An air gap is the unobstructed vertical distance through the free
atmosphere between the lowest opening from any pipe supplying water to a
tank, plumbing fixture, or receptor and the flood level rim of that vessel — it is
the highest level of backflow protection.
Section 2: Pipe Materials & Fittings
Q31: What does 'CPVC' stand for and where is it commonly used?
ANSWER Chlorinated Polyvinyl Chloride — CPVC is used for hot and cold
water distribution inside buildings; it is rated for higher temperatures than
standard PVC.
Q32: What does 'PEX' stand for?
ANSWER Cross-linked polyethylene — a flexible plastic pipe used for hot
and cold water supply systems, radiant floor heating, and potable water
distribution.
Q33: What is 'galvanized steel' pipe?
ANSWER Galvanized steel pipe is steel pipe coated with zinc to resist
corrosion; it was historically used for water supply but is now rarely installed
new due to corrosion and mineral buildup issues.
Q34: Define 'copper Type L.'
