NOCTI Plumbing Practice Test

These questions are part of the practice quiz. Start practicing

• On a water heater, which device helps prevent overheating and scalding by releasing pressure?
• Who is responsible for housekeeping safety at the jobsite, lab, or work area?
• What hygiene action should a plumber perform immediately after opening a drain?
• VTR on plans means
• In a water supply line, what is typically the first shutoff valve located before the meter?
• What is one of the most important steps in calculating an offset for any angle?
• To protect your lungs when dust is present, you should use a
• Which statement is true about testing brazed joints in medical gas piping?
• Which organization must safety glasses comply with?
• In boiler operation, which device regulates draft?
• When preparing a joint to be soldered, flux is put on which surfaces?
• Water heater manufacturers specify water heater sizes by which unit?
• Bidet water lines must be a minimum size and type of
• Couplings for mechanical hubless cast iron (no-hub) must have a/an?
• What action is recommended before plugging in an electric power tool?
• Which color-coded copper tubing is Type L?
• What tool is used to thaw frozen piping safely?
• High density PE piping underground is joined with/by?
• In order for your safety glasses to be in compliance with industry standards, they must be in complicance with
• How far must excavated soil be kept away from trench edge?
• Which statement about urinals is true?
• Black iron pipe and galvanized fittings are made from which metal?
• A drainage system that only allows floor drains, floor receptors, sinks, lavatories, standpipes, washing machines and laundry tubs, with no toilets, is called a
• Which device should be used with a disposal on a double bowl sink to direct waste?
• You should not use a portable electric tool unless it has a
• Plumbers use this gas to prevent oxidation from forming inside the tubing while brazing.
• What is the code measurement for the flood level rim of a kitchen sink?
• If a mushroom head develops on a chisel, swaging tool, or packing iron, what is the recommended course of action?
• The stamp or term on water closets 'GPF' stands for
• The primary role of a backflow prevention device is to prevent
• When replacing a trap under a sink, plumbers should always have which item?
• Plumbers and Pipefitters need to use __________ when brazing copper with copper-phosphorus brazing rod.
• A wax ring is installed between which plumbing components?
• Grease traps in commercial kitchens are designed to reduce the amount of what entering the drain?
• When opening a drain to repair or remove a blockage, what hazard should a plumber be aware of?
• What are the main parts of a compression style faucet?
• Behind the wall anchoring device used for wall-hung commercial closets is called what?
• What must be removed when connecting a dishwasher drain to a garbage disposal?
• At what water pressure does a boiler pressure relief valve discharge?
• In a trap, the letter C best describes which feature?
• Oily rags should be kept in a ____.
• Which blueprint view is described as an aerial view, representing the floor layout?
• Which fixture does not require an external trap?
• Which valve would cause the highest restriction to flow?
• Before changing a drill bit or a saw blade, you should
• What is the name of the valve used to reduce the pressure from the water supplier?
• A plumber should look at the ______ when a two-piece gravity water closet is continuously running.
• Which device helps control boiler pressure by accommodating water expansion?
• A 30-foot drain has a total fall of 7 1/2 inches. Which is the total drop?
• A vent that serves only one fixture (unless connected to two back-to-back fixtures) is called an ____.
• Copper tubing color coded blue corresponds to which Type?
• A water heater can explode if a ______ is not installed.
• Which joining method is most prevalent for steel pipe and fittings?
• What is the best sanitary practice immediately after finishing work on a drainage system?
• In the offset example, the insertion depth for each 45-degree fitting is what?
• Plumbers and pipefitters determine pipe size based on which dimension?
• The circuit vent connects to which stack?
• For rapid exit in a deep trench, which item should be present?
• Which vent is typically located on the top floor and is the last connection before the stack vent goes through the roof?
• Boilers must have a combination device to maintain pressure and protect the plumbing system. Which components comprise this combination?
• The pressure relief valve on a water heater must open at or not exceed what pressure?
• If two different water supplies are connected and one is not potable, a plumber should install a
• When using PVC cement or primer, you should always make sure to
• All concealed drainage piping should be tested at
• GFCI outlets are used to protect against shock in which environment?
• What temperature should the return water maintain to take full advantage of primary-secondary piping around the boiler?
• Copper tubing color coded green corresponds to which Type?
• A hot water boiler will have gravity circulation within the system unless a _________ is installed
• The main advantage of primary-secondary piping around the boiler is to protect the return water temperature above what value?
• When changing a drill bit or a saw blade in a portable electric tool you should always do this first
• What is the minimum size of the hot and cold water supply lines to a bathtub?
• The tool used to move molten lead from the pot to the joint is?
• The best tool to tighten clamps on no-hub and fernco fittings is?
• Plumbers and pipefitters should ______ when replacing galvanized steel piping with PEX.
• Which valve is used to increase or decrease flow through a pipeline?
• A device installed on the supply of the boiler and removes air from the system
• The most important purpose of venting traps is to
• What is used as an island vent alternative method?
• It is always safer to use knife, chisel or razor knife if the blade is
• In residential applications, threaded steel piping is predominantly used for which system?
• Which material is acceptable for the housing of a hot water recirculation pump?
• The tool used to take the lead from the lead pot to the lead joint is?
• In a deep trench, what is required for rapid exit?
• What is one of the most important safety items a plumber should use when operating loud tools such as jackhammers or grinders?
• PVC solvent cement should be used in ______.
• A plumber would use a ________ to prevent contamination to a potable water supply.
• When brazing copper with a phosphorus brazing rod, which condition is avoided by using no flux?
• The best way to ensure personal safety on the jobsite is to wear
• In plumbing terminology, what does the acronym DWV stand for?
• A two-piece gravity flush water closet has the following parts in the tank.
• To prevent freezing, reduce noise, and cut down on condensation, plumbers install __________ on the outside of piping.
• In surveying, which term is often used interchangeably with a builder's level?
• A builder's level is best described as which type of instrument?
• When assembling a CPVC joint, plumbers should use?
• A vertical vent serving two or more fixture branches on the same level is known as a ____ vent.
• What is the 'center to center' measurement for a 45 degree, 10 inch offset when multiplied by 1.414?
• Bidet water supply lines must be minimum size and type of
• When servicing a flushometer, it can be turned off at the ________.
• In faucet connections, 1/2" MIP refers to a type of connection described as what?
• The most predominant method used to join steel pipe and fittings is?
• In a single-pipe baseboard loop, water flows through baseboard units in series before returning to the boiler. Which option describes this arrangement?
• From the point of a waste connection, the vent pipe grade or slope should be directed
• When a plumber tightens the clamps on no-hub and or fernco fittings, the best tool to use for this is a
• Residential dishwasher installations must have what to prevent backflow of waste into the unit?
• For proper safety on a jobsite, which of the following is recommended footwear and eye protection?
• For a 12' extension ladder leaning against a wall, bottom should be how far from the wall?
• Between the faucet base and the sink, which material is used to seal leaks?
• Which device is used to start a sewage ejector pump when water reaches a certain level?
• What is the best tool to unclog a stopped-up closet?
• A trap used in a commercial kitchen to lower the amount of grease entering the drain line is called a
• A DWV piping system relies on gravity at a fall of how many inches per foot?
• Black iron and galvanized pipe and fittings are made from which material?
• For a lavatory installation, the center line measurement is 19 inches.
• What is the maximum temperature setting for a tub or shower faucet (valve)?
• What does a flow check prevent?
• When a plumber finishes soldering a joint, what should be used to test it for leaks?
• Which piping material is specified for underground building drains in residential construction?
• Which device prevents backflow from a non-potable water source into the potable water system?
• When assembling threaded pipe and fittings, joint compound (pipe dope) is applied to which threads?
• Which function does the automatic air vent serve?
• What type of protection should be used above 90 decibels?
• What is a practical use for employing two wrenches when tightening a fitting?
• Which cement is used for CPVC joints?
• Which primer effect is correct when assembling PVC?
• If your safety glasses become scratched up or worn out, you should
• Which device is commonly used to detect leaks in gas piping before activation?
• Which device prevents backflow in a piping system by allowing flow in one direction only?
• Copper tubing color coded red corresponds to which Type?
• If a blueprint marks VTR, what does it indicate?
• Which material is NOT commonly used to manufacture urinals?
• Plumbers and pipefitters use which tool to flare copper tubing and connect?
• The temperature on a temperature and pressure relief valve for a water heater should open at or below which temperature?
• Which direction should you face when using a step ladder?
• A boiler pressure relief valve is designed to protect against which condition?
• Plumbers use behind the wall what to anchor a wall-hung commercial type closet to the wall?
• The reason for using a foot pedal with a power threading machine is
• When using a step ladder, which direction should the user face?
• Whirlpool or Jacuzzi tubs require a minimum drain line size of
• The largest pipe you can insert into a Ridgid 535 pipe threading machine is?
• Which valve is commonly used to maintain radiant floor water temperature by mixing hot supply with cooler return water?
• A mandatory (code required) control that is installed on all hot water and steam boilers
• In a residential water heater, which component directly regulates the water temperature?
• A gate valve is designed to remain fully open or fully closed. Which statement best describes its use?
• What safety step should plumbers take before using an electric power tool?
• What is the correct distance for a PEX ring from the tubing edge before tightening the cinch clamp?
• Which valve is commonly used to throttle flow in piping systems?
• When should the final rough plumbing testing be completed?
• A plumber would use a PVC saw to cut through which materials?
• The minimum trap size for a bathtub is
• Shoring in trench work is used to do what?
• Which type of trap is prohibited for residential use?
• The main advantage of primary secondary piping at the boiler is/are
• Plumbers use drawings that show both vertical and horizontal piping in a clear single view that are called
• One of the most simplistic piping designs for hot water baseboard heat is
• A potable water distribution system is tested with which method?
• Which temperature should the T&P relief valve be designed to open to protect the water heater?
• Which component in the tank directly releases water to the bowl during a flush?
• PEX fittings are joined with?
• In vent piping, the direction from the waste connection to the branch or main vent is generally
• Which two components must be installed on boilers to manage system pressure and protect the plumbing system?
• What type of piping is typically used for underground building drains?
• Which boiler type uses a glass sight gauge to indicate water level?
• Material Safety Data Sheets (M.S.D.S.) are responsible to be furnished and updated by the
• What does DFU stand for in drainage calculations?
• Which component is responsible for admitting water into the tank until it reaches the full level in a gravity flush toilet?
• Which tool is used to test a drainage, waste, and vent system?
• Which piping arrangement is considered the simplest for hot water baseboard heat?
• On a color-coded blueprint, which color line is used to designate gas lines?
• When setting up a tripod and builder's level, what is the first step?
• In residential installation, the flood level rim distance from the finished floor in the drawing is typically how many inches?
• Boilers require a ______ control to help control the draft going through the boiler.
• All torches that plumbers could use, should be ignited with a
• A 3 or 4 way mixing valve is used in a radiant system to maintain
• The purpose of primer when assembling PVC is to?
• The tool that gauges PEX joints joined by a band is called?
• High water alarms are part of the apparatus of which pump?
• What is the most common material used to manufacture a urinal?
• What is the minimum drain size for residential sinks with garbage disposal?
• Which term describes a non-compression single-handle faucet with hot and cold water openings?
• Discharge from a sump pump should never connect to which type of sewer?
• A correct step for installing PVC or ABS is to?
• Plumbers use this ratchet type "snap cutter" to cut?
• The best way to handle dusty conditions is to wear a ______.
• What is the correct name for the component that loops under the cabinet to prevent backflow from a dishwasher?
• Cast iron boilers are made up of several what?
• Which term describes a fitting used to connect two pipe sections with a threaded joint?
• What is the required slope for the horizontal portion of a vent connector on residential oil-fired water heaters toward the chimney, in inches per foot?
• The __________ provides all items necessary to test any of the plumbing drains or water lines within the building.
• OSHA is the abbreviation for which agency?
• What component regulates the temperature on a water heater?
• To discharge the contents of a fire extinguisher, after pulling the pin, what action is required?
• What is the purpose of the tool used to test a drainage, waste and vent system?
• When installing a food waste disposal onto a double bowl sink, the disposal should be installed with a 'baffle tee' to direct waste in which direction?
• Which of the following joints depends on capillary action?
• In a trap diagram, the letter B most likely labels which component of the trap?
• If a backflow preventer is installed at the water meter, which component must be installed?
• Which term describes drawings that show vertical and horizontal piping in a single view?
• Insulation installed on exterior piping primarily serves to prevent what?
• What is the smallest vent size allowed for a 3-inch drain line?
• What hygiene step is recommended after replacing a wax ring or lavatory trap?
• According to the National Standard Plumbing Code, the minimum trap size for a shower base (not a tub) is
• What is the primary function of a draft control in a boiler?
• For brazed joints in medical gas piping, what is used to test them?
• What are the correct steps for making a solder joint?
• A PEX ring should be ____________ inches from the edge of the tubing before you tighten the cinch clamp?
• The snap cutter is used to cut which pipe material?
• When installing a faucet on a vitreous china sink, which material should be used between the base of the faucet and the sink?
• Which term describes the undesirable connection between a potable water supply and a non-potable source?
• Which valve is used to prevent radiant floor overheating by mixing hot supply water with cooler return water?
• At what depth in feet does a trench require shoring?
• On the North wall, the dimension between fixtures and walls is which of the following?
• When making a 20 inch offset in a 2 inch waste stack using PVC DWV pipe and 45 degree fittings, the length of the pipe between the two 45 degree fittings minus the 3/4 inch insertion depth for each 45 is
• If a drain pipe is 28 feet long, calculate the total drop with a slope of 1/8 inch per foot.
• Plumbers use __________ when pouring a horizontal lead joint.
• On a plumbing blueprint, which symbol indicates a union?
• How many drainage fixture units (DFU) does a residential clothes washer require?
• Prior to turning on the gas supply, plumbers test natural gas or LP gas lines with
• For a field fabricated shower stall (no base), what must be installed and connected to the drain?
• During a sanitary drainage (DWV) pressure test at 5 psi, how long must the pressure be held to pass inspection?
• The part of a blueprint that shows the view of the building from the street is called what?
• All plumbing codes prohibit the use of which type of traps?
• What is the pressure at the base of a 60-foot-high cylinder if pressure increases by 0.434 PSIG per foot?
• What is the recommended hygiene practice after replacing a wax ring or lavatory trap?
• What is the minimum trap size required by plumbing codes for serving an automatic clothes washer?
• Plumbers should place the connection for the branch vent at least how far above the flood level?
• Which of the following is essential PPE when operating loud tools?
• Which document is typically provided by the employer to inform workers about chemical hazards and required handling?
• If a tank leaks water into the bowl, the most probable cause is the
• Electric water heaters are heated by which element?
• How much should a plumbers extension ladder extend above the roof when using one?
• The standard rough-in measurement for a water closet from the back wall to the center of the closet flange is
• What is the primary device that turns on a sewage ejector or effluent pump?
• If a face-to-face measurement is given to the plumber, what is the next step?
• Which statement best describes loop vent?
• Plumbers and pipe fitters use which type of valve to direct fluid in a pipe in one direction?
• Which ladder material is safest to use when working around electrical hazards?
• Steam boilers that are not filled all the way to the top with water and have a glass sight gauge mounted on the side to indicate the water level are typically what type of boiler?
• Fall protection height for scaffolding?
• For hubless cast iron couplings, what feature helps prevent pipe ends from contacting each other?
• What is the purpose of flaring copper tubing in plumbing connections?
• The 2009 IPC code requires hangers to be installed at every ______ feet for PVC piping.
• What is the correct step if safety glasses are scratched or worn out?
• A hot water recirculation pump must have a housing made of which material?
• Which device prevents backflow into the water supply?
• Which component discharges when the boiler pressure reaches its limit?
• What is the best way to ensure a safe job site?
• Which ladder material is preferred near electrical hazards?
• In order for the operator to be safe, electrical tools should
• Which plumbing fixture is wall-mounted and receives only liquid waste?
• The 2009 IPC code requires 1 1/4" and smaller copper tubing to be supported every ______ feet.
• Which of the following is used for air testing of concealed drainage piping?
• After finishing work on a faucet in a customer's home, what should plumbers do?
• A wax ring is used between which components?
• Potable water is required for
• If a plumber, pipefitter or apprentice is cut on a jobsite while wearing gloves and is exposed to bloodborne pathogens, what should be done first?
• A DFU (Drainage Fixture Unit) for a single lavatory is usually equal to
• For PEX joints, which statement lists the correct joining methods?
• Besides 1/2" MIP, which is another popular hot and cold water line connection type?
• What is the minimum cold water supply line size to a urinal?
• Which item is essential to wear on the jobsite for eye safety?
• In a color-coded blueprint, which line color indicates a gas line?
• Which statement is true about the waste and overflow in a bathtub drain assembly?
• Which practice best helps keep a jobsite safe by reducing tripping hazards?
• Before repairing a water closet, the first step is to
• Residential sinks that have a garbage disposal require a minimum drain size of which measurement?
• In blueprint terminology, which plan corresponds to the aerial view of the structure?
• GPF on a water closet is a measure of
• After calculating the center to center measurement of an offset, the very next step is
• The Stop and Waste Valve is primarily used to:
• The drain connection (part that actually attaches to the tub itself) for a residential bathtub is called
• What is the PSIG per foot used in the example for calculating base pressure?
• Which vent serves two or more fixtures on the same level?
• Plumbers use the constant multiplier 1.414 for calculating any
• During rough-in, which task is required before drywall is installed?
• Where must air admittance valves be installed according to code?
• Connecting a potable source of water and a non-potable source of water in the same line is called
• What insertion depth is used for each 45 degree fitting in the offset example?
• Fall protection is required when scaffolding is how many feet above the ground?
• When using two wrenches to tighten a fitting, how should the wrenches be positioned?
• What is the minimum waste outlet size for a lavatory?
• Whirlpool or Jacuzzi tubs require a minimum size drain line?
• When plumbers need to pull a water closet for access to open a drain, what is required to reset the water closet?
• Which device is used to check for leaks in LP or natural gas lines?
• Which device is associated with detecting high wastewater levels in a sewage system?
• Who provides all items necessary to test a building's plumbing drains or water lines?
• What is the minimum trap size specified for serving an automatic clothes washer?
• Which trap type is explicitly prohibited in residential plumbing?
• How many dimension lines do isometric drawings typically have?
• PE pipe used for residential wells is connected by/with?
• Prior to drywall, the rough-in phase requires testing of which systems?
• Minimum cold water supply line size to a urinal?
• What is the minimum size tailpiece or trap for a kitchen sink with a dishwasher?
• In offset calculations, the distance between the centerlines of two fittings is called what?
• Which factor is fixed in rough-in standards for water closets?
• A non-compression single-handle faucet that contains the hot and cold water openings is a ______ faucet.
• To operate correctly, a residential dishwasher should be supplied with which type of water line?
• Sump pumps require what device installed on their discharges to prevent backflow?
• Which valve is the first valve before the water meter according to Allentown Water Authority code?
• Plumbers must remove what component when connecting the dishwasher drain to a garbage disposal?