A plumber solders a joint with a torch between wall studs. What must be immediately available in the work area?OSHA, 29 CFR 1926.352. Written to NOCTI Plumbing (4061), Safety
A sewer trench is to be dug across a yard. What does the OSHA excavation rule require before the ground is opened?OSHA, 29 CFR 1926.651. Written to NOCTI Plumbing (4061), Safety
Molten solder and drain cleaner can both splash. Which protection does the construction rule require for those hazards?OSHA, 29 CFR 1926.102. Written to NOCTI Plumbing (4061), Safety
With no soil classification made, a trench wall is sloped back for protection. What is the steepest slope the OSHA rule allows?OSHA, 29 CFR 1926.652. Written to NOCTI Plumbing (4061), Safety
Show all 50 questions (46 more)
Plumbing Math 5
A horizontal branch must fall 3 inches on its way to the stack at 1/4 inch per foot. How long is the branch?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 8. Written to NOCTI Plumbing (4061), Plumbing Math; the arithmetic was worked twice
A length of pipe measures 14 5/8 inches. A piece 2 3/4 inches long is cut from it. Ignoring the saw cut, what is left?Written to the NOCTI Job Ready Credential Blueprint for Plumbing (4061), Plumbing Math; the answer is arithmetic on the numbers in the question, worked twice
One drainage fixture unit stands for about 7.5 gallons per minute. About how much discharge do 6 fixture units stand for?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 1. Written to NOCTI Plumbing (4061), Plumbing Math; the arithmetic was worked twice
Two parallel runs are 12 inches apart, center to center. About how long is the travel piece between the 45-degree fittings, center to center?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 6. Written to NOCTI Plumbing (4061), Plumbing Math; the arithmetic was worked twice
Water stands in a riser 30 feet above a gauge. About what pressure does the gauge show?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), Appendix E. Written to NOCTI Plumbing (4061), Plumbing Math; the arithmetic was worked twice
General Plumbing Practices 12
A drain line passes through a fire-rated wall. What is the fire caulk around the pipe there for?Wikipedia, Firestop. Written to NOCTI Plumbing (4061), General Plumbing Practices
A drain, waste and vent riser diagram is drawn in isometric. What is the angle between any two of its three axes?Wikipedia, Isometric projection. Written to NOCTI Plumbing (4061), General Plumbing Practices
A finished waste system is given an air test. About what air pressure does the Army manual apply?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 8, Testing. Written to NOCTI Plumbing (4061), General Plumbing Practices
A toilet specification sheet is checked against the federal standard. How much water per flush does that standard allow?US EPA WaterSense, Residential Toilets. Written to NOCTI Plumbing (4061), General Plumbing Practices
A water line joins galvanized pipe straight to copper pipe. Which kind of corrosion does that invite?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 3. Written to NOCTI Plumbing (4061), General Plumbing Practices
Copper tubing is classed by wall thickness. Which type has the thick wall?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 6. Written to NOCTI Plumbing (4061), General Plumbing Practices
In drainage work, what is the stack?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 8. Written to NOCTI Plumbing (4061), General Plumbing Practices
What does a storm sewer carry?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 1. Written to NOCTI Plumbing (4061), General Plumbing Practices
What is oakum?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 6. Written to NOCTI Plumbing (4061), General Plumbing Practices
What is PEX tubing made of?Wikipedia, Cross-linked polyethylene. Written to NOCTI Plumbing (4061), General Plumbing Practices
Which pipe is a gray or black plastic used for storm or sanitary drainage and joined with solvent cement?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 1. Written to NOCTI Plumbing (4061), General Plumbing Practices
Which tool tightens the locknuts of a faucet from under the bowl?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 7, Faucet Installation. Written to NOCTI Plumbing (4061), General Plumbing Practices
Joining Pipes and Fittings 5
Copper and galvanized steel must be joined at a water tank. What does a dielectric union put between the two metals?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 3. Written to NOCTI Plumbing (4061), Joining Pipes and Fittings
How does solvent cement join plastic pipe to a fitting?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 6. Written to NOCTI Plumbing (4061), Joining Pipes and Fittings
How is hubless cast-iron soil pipe joined?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 1. Written to NOCTI Plumbing (4061), Joining Pipes and Fittings
Solder for drinking water lines must be lead free. How much lead may lead-free solder and flux contain, at most?US EPA, Use of Lead Free Pipes, Fittings, Fixtures, Solder, and Flux for Drinking Water. Written to NOCTI Plumbing (4061), Joining Pipes and Fittings
What is pipe dope for on a threaded steel joint?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 6. Written to NOCTI Plumbing (4061), Joining Pipes and Fittings
Drainage 4
A water closet has no waste pipe of its own. What usually connects it to the stack?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 8. Written to NOCTI Plumbing (4061), Drainage
By the Army plumbing manual, where is a cleanout installed in a waste line?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 8. Written to NOCTI Plumbing (4061), Drainage
The stack is connected to the house drain. Which fitting does the Army manual use at the base, to keep pressure to a minimum?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 8. Written to NOCTI Plumbing (4061), Drainage
What decides the size of a horizontal drainage branch?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 8. Written to NOCTI Plumbing (4061), Drainage
Vent Installation 2
What is a wet vent?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 9. Written to NOCTI Plumbing (4061), Vent Installation
Which vent serves a battery of fixtures, such as a row of lavatories on one horizontal branch?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 9. Written to NOCTI Plumbing (4061), Vent Installation
Water Supply and Distribution 3
What does a vacuum breaker on a hose bibb prevent?Wikipedia, Vacuum breaker. Written to NOCTI Plumbing (4061), Water Supply and Distribution
What is an air gap in a water supply?Wikipedia, Air gap (plumbing). Written to NOCTI Plumbing (4061), Water Supply and Distribution
Which valve lets water flow one way only and closes by itself to stop backflow?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 7. Written to NOCTI Plumbing (4061), Water Supply and Distribution
Hot Water Systems 3
What does the temperature and pressure relief valve on a water heater do?Wikipedia, Water heating, Explosion hazard. Written to NOCTI Plumbing (4061), Hot Water Systems
What is the drain at the bottom of a hot-water storage tank for?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 5. Written to NOCTI Plumbing (4061), Hot Water Systems
Why does an electric water heater need no flue?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 5. Written to NOCTI Plumbing (4061), Hot Water Systems
Traps 4
A floor drain in a warm, dry storeroom has not been used for months, and sewer gas is noticed. What emptied its trap?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 9. Written to NOCTI Plumbing (4061), Traps
A string hangs over the outlet weir of a trap and slowly empties it. Which kind of trap seal loss is this?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 9. Written to NOCTI Plumbing (4061), Traps
An old lavatory drains through a full S-trap. What does the Army manual say to do with it?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 9. Written to NOCTI Plumbing (4061), Traps
How deep is the water seal of the most common fixture trap?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 9. Written to NOCTI Plumbing (4061), Traps
Installing Fixtures 3
A faucet comes with no gasket. What is put on its bottom before it is set on the lavatory?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 7, Faucet Installation. Written to NOCTI Plumbing (4061), Installing Fixtures
What does a flushometer valve do on a urinal or water closet?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 4. Written to NOCTI Plumbing (4061), Installing Fixtures
Which parts seal a floor-mounted water closet bowl to the drain?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 4. Written to NOCTI Plumbing (4061), Installing Fixtures
Plumbing Service and Repair 5
A bathtub P-trap is stopped up. Where does the drain snake go in?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 3. Written to NOCTI Plumbing (4061), Plumbing Service and Repair
A compression faucet drips from the spout when it is shut. What is replaced first?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 7, Compression Faucet Repairs. Written to NOCTI Plumbing (4061), Plumbing Service and Repair
A garbage disposal is being replaced. Where in the kitchen drain does the unit sit?Wikipedia, Garbage disposal unit. Written to NOCTI Plumbing (4061), Plumbing Service and Repair
A lavatory with an overflow opening is plunged to clear its trap. What is done to the overflow first?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 3. Written to NOCTI Plumbing (4061), Plumbing Service and Repair
Water in a toilet tank rises until it runs into the overflow pipe. Where should the water level stop after the ball cock is adjusted?US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001), chapter 4, Ball-Cock Repairs. Written to NOCTI Plumbing (4061), Plumbing Service and Repair
How this list was compiled: Our own questions, written to the competency list of the Job Ready Credential Blueprint for Plumbing (code 4061, version 01, copyright 2010) that NOCTI publishes at https://www.nocti.org/wp-content/uploads/2020/09/JRPlumbing4061.pdf , read 2026-10-13: a written assessment of 173 questions in 3 hours over eleven areas (Safety 8%; Plumbing Math 10%; General Plumbing Practices 24%; Joining Pipes and Fittings 9%; Drainage 8%; Vent Installation 4%; Water Supply and Distribution 7%; Hot Water Systems 6%; Traps 8%; Installing Fixtures 7%; Plumbing Service and Repair 9%), plus a performance assessment of two jobs. This bank holds 50 in those proportions. Every rule and definition was read on 2026-10-13 on the public page named under its question: US Army FM 3-34.471, Plumbing, Pipe Fitting, and Sewerage (2001, the copy at archive.org), OSHA construction standards in 29 CFR 1926 on osha.gov, two US EPA pages (lead-free plumbing under the Safe Drinking Water Act, and WaterSense residential toilets), and Wikipedia. Every length and size in a sum is made up for the drill, and each computed answer is arithmetic that was worked twice. Licence: Questions, choices and explanations are original work of this site. FM 3-34.471 is a work of the United States Army approved for public release, and no question or example is copied from it.
How it works
Practice for the NOCTI Plumbing test with 50 questions of our own, filed under the eleven areas of blueprint 4061. NOCTI has no part in it: this free NOCTI plumbing practice test is unofficial, with no affiliation, endorsement or sponsorship.
Read the full guide
What the eleven areas weigh
General Plumbing Practices is 24% of the written assessment. Plumbing Math is 10%, Joining Pipes and Fittings and Plumbing Service and Repair 9% each, Safety, Drainage and Traps 8% each, Water Supply and Distribution and Installing Fixtures 7% each, Hot Water Systems 6% and Vent Installation 4%.
No code book on this page
Plumbing codes differ from place to place and the model codes are private text, so no code section is asked. A size or slope here is the one printed in US Army FM 3-34.471.
The rough-in jobs stay in the shop
A drain, waste and vent rough-in and a water supply rough-in for two lavatories, each made ready for a leak test, are the performance half.
Pressure from head: psi is 0.433 times the feet of water above the gauge, so 30 feet is about 13 psi.
A 45-degree offset: the travel, center to center, is the offset times 1.414.
A trap loses its seal by siphonage, back pressure, capillary action or evaporation.
Questions and answers
How many questions does the NOCTI Plumbing test have?
The Plumbing blueprint, code 4061, shows 173 written questions and 3 hours to answer them, in as many as three sessions, then two performance jobs in another 3 hours.
What topics are on the NOCTI Plumbing test?
Eleven written areas: safety, plumbing math, general plumbing practices, joining pipes and fittings, drainage, vent installation, water supply and distribution, hot water systems, traps, installing fixtures and service and repair.
Does the NOCTI Teacher test for Plumbing cover the same areas?
Yes. Code 5175, the Teacher assessment, prints the same eleven areas with weights within a point of these, 168 questions in 3 hours and the same two jobs.
Does the NOCTI Plumbing test follow a plumbing code?
The blueprint names no code book for the written part. Its two performance jobs say the work must adhere to the local plumbing code.