TheoryJourneyman Plumber 2
Practice Test
750+ practice questions with detailed explanations. Pass your Plumber exam on the first try!
Heads up: the app and the web exam use separate accounts — a web unlock and an in-app purchase do not carry over. Buy on the web to practice on the web.
Journeyman Plumber 2 exam — full Q&A walkthrough
Every question read aloud with the answer explained. Play it on your commute, then test yourself.
30 free Journeyman Plumber 2 questions
Sampled across every topic area — not just the first page. Try them as a quiz or flip them as flashcards.
-
Backflow & Cross-Connection
What is the definition of 'backflow' in a plumbing system?
Correct — A. Backflow is the undesirable reversal of flow in a piping system, which can allow contaminants to enter the potable water supply. Understanding this basic definition is foundational to cross-connection control. -
Backflow & Cross-Connection
A cross-connection is best defined as which of the following?
Correct — B. A cross-connection is any actual or potential link between the potable water supply and any source of pollution or contamination. Eliminating or protecting cross-connections is the goal of cross-connection control programs. -
Backflow & Cross-Connection
Which term describes backflow caused by the downstream pressure exceeding the supply pressure?
Correct — C. Backpressure backflow occurs when downstream pressure becomes greater than the supply (system) pressure, forcing contaminants backward into the potable supply. This can happen in boiler systems, pumped systems, or elevated piping. -
Backflow & Cross-Connection
Back-siphonage is caused by which condition in the water supply system?
Correct — D. Back-siphonage is the backflow of potentially contaminated water caused by a negative pressure (partial vacuum) in the supply piping, similar to the siphon effect. It can occur during water main breaks or high-demand events. -
Backflow & Cross-Connection
Which of the following correctly distinguishes a pollutant from a contaminant in cross-connection control?
Correct — A. In cross-connection control, a pollutant creates an aesthetic nuisance or low-degree hazard (e.g., mineral deposits), whereas a contaminant creates an actual health hazard (e.g., pesticides, sewage). This distinction drives the level of backflow protection required. -
Backflow & Cross-Connection
When classifying cross-connections, a 'high-hazard' connection involves which type of substance?
Correct — B. A high-hazard cross-connection involves a substance that is toxic, pathogenic, or otherwise dangerous to health (e.g., chemicals, sewage). High-hazard connections require a higher degree of protection such as an air gap or reduced pressure principle (RP) assembly. -
Backflow & Cross-Connection
A residential lawn irrigation system supplied by potable water and using chemical fertilizer injection would be classified as which hazard level?
Correct — C. The introduction of chemical fertilizers or pesticides through an injector connected to the potable supply creates a high-hazard cross-connection, regardless of the residential setting. This requires at minimum a reduced pressure principle backflow preventer. -
Backflow & Cross-Connection
Which of the following connections would typically be classified as a LOW-hazard cross-connection?
Correct — D. A garden hose submerged in clean (non-chemical) water represents a low-hazard (pollution) cross-connection since the water itself poses minimal health risk, though back-siphonage protection is still required. The other options involve chemicals that elevate the hazard to high. -
Backflow & Cross-Connection
An air gap is considered which type of backflow protection?
Correct — A. An air gap is an unobstructed vertical distance between the water outlet and the flood-level rim of a receiving vessel. It provides the highest degree of protection because it creates a complete physical separation — no mechanical failure can allow backflow. -
Backflow & Cross-Connection
A Reduced Pressure Principle (RP) backflow preventer works by maintaining which condition?
Correct — B. An RP assembly maintains a reduced-pressure zone between its two check valves. This zone is always at a lower pressure than the supply, ensuring that if either check fails, water flows out through the relief valve rather than backward into the supply. -
Backflow & Cross-Connection
A Double Check Valve Assembly (DCVA) is appropriate for which type of cross-connection?
Correct — C. A DCVA consists of two independently acting check valves and is approved for low-hazard (non-health-hazard) cross-connections such as fire suppression systems without additives or irrigation without chemical injection. It is NOT acceptable for high-hazard applications. -
Backflow & Cross-Connection
Which backflow preventer type is specifically designed to protect against back-siphonage only, and is commonly found on hose bibs?
Correct — D. An Atmospheric Vacuum Breaker (AVB) protects only against back-siphonage by opening to atmosphere when supply pressure drops to zero. It cannot be used where the downstream side may be pressurized and is commonly used on hose bibs and simple irrigation lines. -
Backflow & Cross-Connection
What is the key difference between a Pressure Vacuum Breaker (PVB) and an Atmospheric Vacuum Breaker (AVB)?
Correct — A. A PVB has a spring-loaded check valve in addition to its vacuum breaker and can be installed where downstream pressure may briefly exceed supply pressure. An AVB has no check valve and must never be subject to continuous downstream pressure. -
Backflow & Cross-Connection
A Spill-Resistant Pressure Vacuum Breaker (SRPVB) differs from a standard PVB in which key way?
Correct — B. An SRPVB includes an elastomeric-loaded check valve that prevents frequent nuisance spilling seen in standard PVBs during normal pressure fluctuations, making it more suitable for indoor or finished applications. Its hazard-rating and installation height requirements remain the same as a standard PVB. -
Backflow & Cross-Connection
What is the minimum air gap distance required between a potable water outlet and the flood-level rim of a fixture, per most plumbing codes?
Correct — C. Most plumbing codes (IPC, UPC) require an air gap of at least 1 inch or twice the effective opening of the supply pipe, whichever is greater. This ensures that flood-level water cannot siphon contaminated water back into the supply. -
Backflow & Cross-Connection
An Atmospheric Vacuum Breaker (AVB) must be installed at least how far above the highest downstream outlet or flood-level rim it protects?
Correct — D. An AVB must be installed a minimum of 6 inches above the flood-level rim of the highest downstream outlet to ensure the air port remains above any potential flood condition, preserving its ability to admit air and break the siphon. -
Backflow & Cross-Connection
Where should a Pressure Vacuum Breaker (PVB) be installed relative to the highest downstream outlet it serves?
Correct — A. A PVB must be installed at least 12 inches above the highest downstream outlet or flood-level rim to ensure the air inlet remains above any possible backflow condition. Installing it lower defeats its protective function. -
Backflow & Cross-Connection
A Reduced Pressure Principle (RP) assembly installed in a below-grade vault must meet which critical installation requirement?
Correct — B. When an RP assembly is installed in a vault, the vault must have adequate drainage so the relief valve port remains above flood level and can discharge freely. If the vault floods and submerges the relief valve, the assembly loses its protective function and becomes a direct contamination pathway. -
Backflow & Cross-Connection
An Atmospheric Vacuum Breaker (AVB) must NOT be installed in which situation?
Correct — C. An AVB must not be subject to continuous downstream pressure (more than 12 hours in any 24-hour period) because the internal poppet can stick in the closed position, eliminating its protection. It also cannot be installed downstream of any shut-off valve that would hold it under pressure. -
Backflow & Cross-Connection
Per most cross-connection control program standards, what is the minimum clearance required below an RP assembly to allow for testing and maintenance?
Correct — D. Most authorities require at least 12 inches of clearance below an RP assembly (measured to the floor or nearest obstruction) to allow a tester to connect test gauges and operate test cocks. Larger assemblies may require more clearance per the manufacturer's specifications. -
Backflow & Cross-Connection
How often must most backflow prevention assemblies be tested after installation, per standard cross-connection control program requirements?
Correct — A. Most jurisdictions require backflow prevention assemblies to be tested at installation and then at least annually to verify proper mechanical function. The annual test ensures moving parts have not corroded, fouled, or otherwise failed. -
Backflow & Cross-Connection
Who is qualified to test a backflow prevention assembly?
Correct — B. Testing backflow assemblies requires specific knowledge of test procedures and equipment. Most jurisdictions require testers to hold a certification specifically for backflow assembly testing, issued or recognized by the local water authority, separate from a general plumbing license. -
Backflow & Cross-Connection
During a field test of a Double Check Valve Assembly (DCVA), a tester finds that Check Valve 1 holds but Check Valve 2 leaks slowly. What is the correct action?
Correct — C. Both check valves in a DCVA must hold independently with no leakage past the seat. A leaking check valve means the assembly fails the test and must be repaired or replaced before it is returned to service protecting the potable water system. -
Backflow & Cross-Connection
When testing an RP assembly, what does it indicate if the differential pressure across the first check valve reads LESS than 5 psi?
Correct — D. ASSE 1013 requires the first check valve of an RP to maintain at least 5 psi differential. A reading below 5 psi means the check is not holding the required differential — it is fouled, worn, or damaged — and the assembly fails the test and must be repaired. -
Backflow & Cross-Connection
What test kit component is used to measure the differential pressure across check valves in a backflow preventer test?
Correct — A. A differential pressure gauge (often a double-gauge manometer with test hoses) measures the pressure difference between two points simultaneously, which is necessary to evaluate check valve differential in an RP or DCVA. A single Bourdon gauge can only read one pressure at a time. -
Backflow & Cross-Connection
Before testing a backflow prevention assembly, the tester should notify whom?
Correct — B. Testing an assembly requires briefly shutting off the downstream water supply, which can interrupt service to the building. Notifying the owner or occupant beforehand prevents unexpected disruptions and is a professional standard. -
Backflow & Cross-Connection
Which ASSE standard covers performance requirements for Reduced Pressure Principle Backflow Preventers?
Correct — C. ASSE 1013 is the product standard for Reduced Pressure Principle Backflow Preventers. Each backflow device type has its own ASSE standard (e.g., ASSE 1015 for double checks, ASSE 1020 for PVBs). -
Backflow & Cross-Connection
Which ASSE standard governs Double Check Valve Assemblies (DCVA)?
Correct — D. ASSE 1015 sets the performance requirements for Double Check Valve Assemblies. Knowing the specific standard is important for selecting, installing, and testing backflow preventers in accordance with the authority having jurisdiction. -
Backflow & Cross-Connection
The USC Foundation for Cross-Connection Control and Hydraulic Research is significant because it does which of the following?
Correct — A. The USC Foundation's Manual of Cross-Connection Control is the widely referenced technical guide for cross-connection control programs. Many water utilities and states adopt its recommendations for device selection, installation, and testing procedures. -
Backflow & Cross-Connection
Which EPA rule under the Safe Drinking Water Act (SDWA) most directly motivates utilities to enforce cross-connection control by requiring distribution system integrity?
Correct — B. The Total Coliform Rule (TCR) requires utilities to investigate any positive total coliform sample, which may lead to identifying cross-connections as contamination sources. This regulatory pressure directly motivates utilities to maintain and enforce cross-connection control programs.
Journeyman Plumber 2 sample questions
Tap any question below to reveal the answer and a plain-English explanation.
Backflow & Cross-Connection Which organizations' listing programs are most widely recognized by water utilities and authorities having jurisdiction for approving backflow prevention devices in the United States?
A. ASME (American Society of Mechanical Engineers) and UL (Underwriters Laboratories)
B. NFPA (National Fire Protection Association) and IAPMO
C. USC FCCCHR (Foundation for Cross-Connection Control and Hydraulic Research) and ASSE (American Society of Sanitary Engineering) ✓
D. NSF International and the EPA
Correct — C. The USC FCCCHR and ASSE are the two primary organizations whose device approval/listing programs are referenced by water utilities and plumbing codes to determine which backflow prevention assemblies are acceptable. Devices must typically be listed by one or both bodies to be approved for installation.
Code & Safety What does the acronym 'IPC' stand for in the plumbing industry?
A. International Plumbing Code ✓
B. Indoor Pipe Classification
C. Industrial Pipe Connection
D. International Pressure Code
Correct — A. IPC stands for International Plumbing Code, the model plumbing code developed by the International Code Council (ICC) and adopted by many U.S. jurisdictions.
Drainage (DWV) What does the acronym DWV stand for in plumbing?
A. Drain, Waste, and Vent ✓
B. Drain, Water, and Valve
C. Duct, Waste, and Vent
D. Drain, Waste, and Volume
Correct — A. DWV stands for Drain, Waste, and Vent — the three functions of a residential or commercial drainage system that removes wastewater and controls sewer gases.
Fixtures & Traps What is the minimum water seal depth required for a plumbing trap under the Uniform Plumbing Code (UPC)?
A. 1 inch
B. 2 inches ✓
C. 3 inches
D. 4 inches
Correct — B. The UPC requires a minimum trap seal of 2 inches. This depth prevents sewer gases from entering the building while still allowing normal drainage flow.
Fuel Gas Piping Which pipe material is commonly approved for use on natural gas distribution piping inside a building?
A. CSST (Corrugated Stainless Steel Tubing) ✓
B. PVC schedule 40
C. CPVC
D. Cast iron
Correct — A. CSST is a flexible, corrugated stainless steel tubing that is widely approved for interior natural gas distribution. PVC, CPVC, and cast iron are not approved for gas service inside buildings.
Pipe Sizing & Calculations Which unit is most commonly used to express water flow rate in plumbing supply systems?
A. Gallons per minute (GPM) ✓
B. Pounds per square inch (PSI)
C. British thermal units (BTU)
D. Cubic feet (CF)
Correct — A. Flow rate in plumbing is measured in gallons per minute (GPM). PSI measures pressure, BTU measures heat energy, and CF measures static volume — none express a rate of flow.
Venting What is the primary purpose of a plumbing vent system?
A. To supply fresh water to fixtures
B. To protect trap seals and allow sewer gases to escape safely ✓
C. To increase water pressure at fixtures
D. To drain storm water from the roof
Correct — B. Vent pipes maintain atmospheric pressure in the drainage system, which protects the water seal in each trap from being siphoned or blown out. They also allow sewer gases to exit above the roof.
Water Supply & Distribution What is the standard minimum water pressure required at a plumbing fixture in most U.S. residential codes?
A. 15 psi ✓
B. 5 psi
C. 60 psi
D. 100 psi
Correct — A. Most plumbing codes require a minimum static pressure of 15 psi at each plumbing fixture to ensure adequate flow. Pressures below this may result in poor fixture performance.
About the Journeyman Plumber 2 test
Pass your Plumber Exam with confidence. Journeyman Plumber Exam Prep gives you 750+ realistic practice questions with clear, detailed explanations for every answer.
Covers every topic
Water Supply & Distribution, Drainage (DWV), Venting, Fixtures & Traps, Fuel Gas Piping, Backflow & Cross-Connection — and more.
WHY Plumber PREP
- 750+ exam-style questions, written and reviewed for accuracy
- A detailed explanation for every answer — understand WHY
- Realistic mock exams that mirror the real test
- Track your accuracy by subject with smart analytics
- A personalized study plan that keeps you on pace
Whether it's your first attempt or a retake, our questions and explanations help you master the material and pass on your first try.
You will be tested on
- Core formulas and field calculations
- Codes, standards and compliance
- Safe work practices and PPE
- Tools, materials and on-site reference
How TheoryPractice helps you pass
- Real exam-style questions with instant, detailed explanations
- Full timed mock exams that mirror the real test format
- Flashcards & quiz modes from the same question bank
- Progress tracking so you know exactly when you're ready
Topics in this question bank
Core formulas and field calculations
Codes, standards and compliance
Safe work practices and PPE
Tools, materials and on-site reference
Full Journeyman Plumber 2 bank + unlimited mocks
Try 30 questions free. Unlock the complete Journeyman Plumber 2 question bank, every explanation, and unlimited timed mock exams. Practice on any device.
Unlock Journeyman Plumber 2 →