🇺🇸 NCCER Certification · subject

NCCER Certification Plumbing Syllabus

The Plumbing syllabus for NCCER Certification in full: 4 chapters, 12 topics and 12 sub-topics, every one listed below, plus 57 Plumbing flashcards with answers.

4Chapters

12Topics

12Sub-topics

57Flashcards

Plumbing syllabus: all 4 chapters

Expand any chapter to see its topics and sub-topics.

Plumbing Safety, Tools, and Math
3 topics
- Plumbing Safety Practices
  - Trenching and excavation safety
  - Confined space and gas hazards
- Plumbing Tools
  - Cutting, threading, and joining tools
  - Test and measuring instruments
- Plumbing Math and Measurement
Pipe, Fittings, and Valves
3 topics
- Plastic Pipe and Fittings
  - PVC, CPVC, PEX, and ABS
  - Solvent welding and crimp/expansion joints
- Metallic Pipe and Fittings
  - Copper soldering and pressing
  - Steel and cast-iron pipe
- Valves and Their Applications
Drain, Waste, and Vent (DWV) Systems
3 topics
- DWV Theory
  - Traps, vents, and trap seals
  - Fixture units and pipe sizing
- Slope, Cleanouts, and Installation
- Testing and Inspection of DWV
Water Supply and Fixtures
3 topics
- Water Distribution Systems
  - Cold and hot water sizing
  - Backflow prevention and cross-connection control
- Fixture Installation and Trim
- Water Heaters and Pressure Controls

NCCER Certification Plumbing flashcards — 57 questions with answers

What is the primary purpose of a Safety Data Sheet (SDS) on a plumbing job site?
To provide information on a chemical's hazards, safe handling, storage, first aid, and emergency/spill procedures.
What does 'lockout/tagout' (LOTO) accomplish before servicing equipment?
It isolates and de-energizes energy sources (electrical, water, gas) and tags them so the equipment cannot be turned on while being worked on.
When working in a trench 5 feet or deeper, what OSHA protection is generally required?
A protective system such as sloping, shoring, or a trench box (shielding) to prevent cave-ins.
What personal protective equipment is required when soldering or brazing copper pipe?
Safety glasses/face protection, gloves, and adequate ventilation to avoid inhaling flux fumes.
What is the main danger of a confined space such as a sewer manhole or tank?
Oxygen-deficient or toxic/explosive atmosphere; it requires atmospheric testing, ventilation, and a permit before entry.
Why must plumbers be cautious about cross-connections in a water system?
A cross-connection can allow contaminated water to backflow into the potable supply, causing health hazards.
What tool is used to cut copper tubing squarely and leave a clean burr-free edge?
A tube cutter (with the burr removed by a reamer).
What is the purpose of a reamer on a pipe?
To remove the inside burr after cutting so the burr does not restrict flow or cause turbulence.
What wrench is specifically designed to turn threaded steel pipe and fittings?
A pipe wrench (Stillson wrench), which grips harder as more force is applied.
Why should two pipe wrenches be used when tightening or loosening a threaded joint in a run?
One acts as a backup wrench to hold the fitting steady and prevent twisting/loosening adjacent joints.
What tool cuts external threads onto steel pipe?
A pipe threader (die and stock).
What is the function of a basin wrench?
To reach and turn faucet supply nuts in tight spaces behind a sink/lavatory.
What hand tool is used to clear clogs by physically breaking up or retrieving an obstruction in a drain?
A drain/sewer auger (snake).
In plumbing math, what is the formula for the area of a circle?
A = pi * r^2 (pi times the radius squared).
How do you convert a fraction of an inch like 3/8 to a decimal?
Divide the numerator by the denominator: 3 / 8 = 0.375 inch.
What is the 'take-off' (make-up) in pipe measurement?
The distance the pipe is engaged into a fitting, which must be subtracted from the end-to-end (face-to-face) measurement to get the cut length.
What is the constant used to find the travel of a 45-degree offset given the offset (rise)?
Travel = offset x 1.414 (the 45-degree constant).
How do you calculate the volume of water in a pipe or tank in cubic feet?
Volume = area of the cross-section x length (for a cylinder, pi * r^2 * length).
How many gallons are in one cubic foot of water?
Approximately 7.48 gallons.
What does Pythagorean theorem give a plumber when laying out offsets?
The travel (hypotenuse): a^2 + b^2 = c^2, where the rise and run are the legs.

Show the other 37 Plumbing flashcards

Name three common types of plastic pipe used in plumbing and one typical use of each.
PVC (cold water/DWV), CPVC (hot and cold water), and PEX (flexible water distribution); ABS is also used for DWV.
How is rigid PVC or ABS plastic pipe joined?
With solvent cement (chemical weld) — primer then cement for PVC; cement only for ABS.
Why is primer used before solvent cementing PVC pipe?
It softens/cleans the surface so the cement can chemically fuse the pipe and fitting properly.
What temperature rating distinguishes CPVC from standard PVC?
CPVC withstands higher temperatures (rated for hot water up to ~200 F), whereas PVC is for cold water/drainage only.
How is PEX tubing typically connected to fittings?
By crimp rings, cinch/clamp rings, or expansion (cold expansion) fittings.
What does the schedule number (e.g., Schedule 40 vs 80) of plastic or steel pipe indicate?
The wall thickness/pressure rating; a higher schedule number means a thicker wall.
Name the three common types (tempers/wall thicknesses) of copper water tube and their color codes.
Type K (green, thickest), Type L (blue, medium), and Type M (red, thinnest).
How are copper tube joints typically made for water service?
By soldering (sweating) with flux and solder, or by brazing for higher strength/pressure.
What solder is required for potable water lines in the U.S.?
Lead-free solder (50/50 tin-lead is prohibited on potable water systems).
What is the purpose of flux when soldering copper?
To clean the metal, prevent oxidation during heating, and help the solder flow into the joint by capillary action.
What type of metallic pipe is commonly used for natural gas and high-pressure applications?
Black steel (galvanized for water/air; black for gas) threaded pipe.
What is a dielectric union used for?
To join two dissimilar metals (e.g., copper to steel) and prevent galvanic corrosion by electrically isolating them.
What is the primary function of a gate valve?
To fully open or fully close (isolate) flow; it is not designed for throttling.
What valve type is best for throttling/regulating flow?
A globe valve.
What valve provides quick quarter-turn shutoff and full flow when open?
A ball valve.
What is the purpose of a check valve?
To allow flow in only one direction and prevent backflow.
What valve automatically opens to relieve excess pressure or temperature on a water heater?
The temperature and pressure (T&P) relief valve.
What does the abbreviation DWV stand for?
Drain, Waste, and Vent.
What is the purpose of a trap (P-trap) on a fixture?
To hold a water seal that prevents sewer gases from entering the building while allowing waste to pass.
What is the purpose of the vent portion of a DWV system?
To admit air to the system, equalize pressure, and protect trap seals from siphoning or back-pressure.
What is trap siphonage and what prevents it?
Loss of the trap's water seal due to negative pressure; proper venting prevents it.
What is the standard recommended slope (grade) for horizontal drainage pipe 3 inches and smaller?
1/4 inch per foot of run.
What is a cleanout and why is it required in a DWV system?
An accessible opening (capped fitting) that allows access for clearing blockages in drain piping.
Where must cleanouts generally be installed in a drainage system?
At the base of stacks, at changes in direction, at the building drain/sewer connection, and at intervals along long horizontal runs.
What test uses water to check DWV piping for leaks before the system is covered?
A water (hydrostatic) test, filling the system to create a 10-foot head of water on the piping.
What alternative test uses pressurized air to find DWV leaks?
An air test, pressurizing the system and watching the gauge for pressure loss.
What is the purpose of a final smoke or peppermint test on a DWV system?
To detect leaks in trap seals or piping by the escape of visible smoke or detectable odor.
What device prevents backflow into the potable water supply at a hose bibb or irrigation connection?
A backflow preventer such as a vacuum breaker or reduced-pressure zone (RPZ) assembly.
What is the main supply line called that brings potable water from the meter into the building?
The water service line (which feeds the building's water distribution/main).
What is a water hammer and how is it controlled?
A pressure shock/banging from suddenly stopped flow; controlled with water hammer arrestors (air chambers).
What is the purpose of a fixture's trim?
The visible, finished working parts (faucet, handles, stopper, supply stops, escutcheons) installed after rough-in.
What seals the joint between a toilet (water closet) and the closet flange?
A wax ring (wax gasket).
What two energy sources are most common for residential water heaters?
Electricity (heating elements) and natural gas/propane (a burner).
On a gas water heater, what safety control shuts off gas if the pilot/flame goes out?
The thermocouple/flame sensor working with the gas control valve (and the FVIR/flammable vapor controls).
What is the function of the dip tube in a tank-type water heater?
It directs incoming cold water to the bottom of the tank so it is heated before being drawn from the top.
What device on a water heater protects the steel tank from corrosion?
The sacrificial anode rod.
What component controls building water pressure where the supply pressure is too high?
A pressure-reducing valve (PRV), typically set to deliver around 50-60 psi.

NCCER Certification Plumbing FAQ

What is in the NCCER Certification Plumbing syllabus?

NCCER Certification Plumbing is split into 4 chapters: Plumbing Safety, Tools, and Math, Pipe, Fittings, and Valves, Drain, Waste, and Vent (DWV) Systems and Water Supply and Fixtures. Together they contain 12 topics and 12 sub-topics.

How many chapters are in NCCER Certification Plumbing?

4 chapters, containing 12 topics and 12 sub-topics. The largest chapter is Plumbing Safety, Tools, and Math, with 3 topics.

Are there flashcards for NCCER Certification Plumbing?

Yes — a 57-card Plumbing deck, printed in full in the flashcards section of this page and available in the Examius app with spaced repetition. The free plan covers one exam of your choice, including its flashcards; Examius Pro, a one-time purchase, unlocks every other exam and deck.