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NM Journeyman Plumber practice questions

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Question 1General Plumbing Knowledge and Definitions

In plumbing terminology, what does the term "fixture unit" primarily express?

  1. The rate at which a fixture discharges waste into the drainage system relative to other fixtures Correct answer.
  2. The total weight of a fixture when filled with water
  3. The minimum pipe diameter required to connect a fixture to a vent
  4. The number of fixtures that may be installed on one branch

Explanation

A fixture unit is a dimensionless measure of the probable drainage load a fixture imposes, based on its discharge rate and time of discharge relative to a reference fixture. It allows dissimilar fixtures to be added together when sizing drainage piping. It is not a weight, a diameter, or a count of fixtures.

Question 2General Plumbing Knowledge and Definitions

A plumbing system component that conveys sewage or other waste that does not contain fecal matter is properly called a:

  1. Waste pipe Correct answer.
  2. Soil pipe
  3. Vent stack
  4. Leader

Explanation

A waste pipe carries liquid waste free of fecal matter, such as from sinks, lavatories, and laundry trays. A soil pipe, by contrast, conveys sewage containing fecal matter from water closets. Keeping these definitions distinct matters when applying code requirements to each pipe class.

Question 3General Plumbing Knowledge and Definitions

What is the purpose of a trap primer in a plumbing system?

  1. To supply a small amount of water to a floor drain trap to maintain its seal Correct answer.
  2. To prime a pump before it begins lifting water from a sump
  3. To flush debris from a fixture branch during maintenance
  4. To introduce air into a drain line to speed flow

Explanation

A trap primer delivers a measured quantity of water to a trap, usually a floor drain trap, so the trap seal is not lost through evaporation. Without the seal, sewer gas can enter the building. Trap primers are common where floor drains see infrequent use.

Question 4General Plumbing Knowledge and Definitions

Which term describes the vertical distance between the crown weir of a trap and the top of the trap dip?

  1. Trap dip
  2. Trap seal Correct answer.
  3. Trap arm
  4. Trap weir

Explanation

The trap seal is the vertical depth of water retained in a trap between the crown weir and the top of the trap dip. This water column is what blocks sewer gas from entering the building. Codes set a minimum and maximum seal depth to balance gas blockage against flow resistance.

Question 5General Plumbing Knowledge and Definitions

In drainage terminology, what is the "fall" or "slope" of a horizontal drain?

  1. The vertical drop of the pipe per unit of horizontal run Correct answer.
  2. The total length of the drain between fittings
  3. The height of the drain above the floor
  4. The change in pipe diameter along a run

Explanation

Fall, also called slope or gradient, is the vertical drop of a horizontal drain expressed per unit of horizontal length, such as a quarter inch per foot. Adequate slope lets solids move with the flow while the liquid carries them along. Too little slope causes solids to settle; too much slope lets liquid outrun the solids.

Question 6General Plumbing Knowledge and Definitions

What does the term "developed length" mean when applied to a plumbing system?

  1. The length of pipe measured along the centerline of the pipe and fittings Correct answer.
  2. The vertical rise of a stack from its base to its top
  3. The straight-line horizontal distance between the two farthest fixtures
  4. The length of pipe after it has been cut and threaded

Explanation

Developed length is the measured distance along the centerline of the pipe and fittings, following every offset and bend. It is used for friction-loss and venting calculations because fittings add resistance compared with straight pipe. Straight-line distances ignore the extra run created by fittings.

Question 7General Plumbing Knowledge and Definitions

A horizontal drain is installed at 1/4 inch per foot of slope. What is the total fall over a 16-foot run?

  1. 6 inches
  2. 4 inches Correct answer.
  3. 3 inches
  4. 2 inches

Explanation

Multiply the slope by the run: 0.25 inch per foot times 16 feet equals 4 inches of total fall. Slope is applied uniformly along the horizontal run. This is the standard minimum slope for pipes 2 1/2 inches and smaller in most plumbing codes.

Question 8General Plumbing Knowledge and Definitions

A building drain receives 40 fixture units of load. Which statement correctly describes how the building drain differs from the building sewer?

  1. The building drain and building sewer are identical terms for the same pipe
  2. The building drain carries only storm water, while the building sewer carries sanitary waste
  3. The building drain is the lowest piping inside the building that receives waste, and it extends to a point outside the building wall Correct answer.
  4. The building drain begins at the property line and ends at the public sewer

Explanation

The building drain is the lowest piping of the drainage system that receives waste inside the building and conveys it to the building sewer. The building sewer begins where the building drain passes outside the building wall and continues to the public sewer or private disposal system. The two are distinct segments with different code requirements.

Question 9General Plumbing Knowledge and Definitions

What is the primary function of a vent in a plumbing drainage system?

  1. To release sewer gas directly into the building interior
  2. To increase the velocity of flow in the drain
  3. To carry liquid waste from fixtures to the building drain
  4. To allow air into the drainage system so trap seals are not siphoned and flow is not restricted Correct answer.

Explanation

A vent provides a path for air to enter the drainage system, which protects trap seals from siphonage and pressure fluctuations and allows smooth flow. Vents terminate outdoors, not inside the building. They carry air, not waste.

Question 10General Plumbing Knowledge and Definitions

A lavatory drain is connected to a vent that rises vertically from the fixture drain before the drain turns horizontal. This arrangement is best described as:

  1. An individual vent Correct answer.
  2. A wet vent
  3. A common vent
  4. A circuit vent

Explanation

An individual vent, also called a back vent, serves a single fixture and connects to the fixture drain downstream of the trap. It protects only that fixture's trap seal. Common vents, wet vents, and circuit vents serve multiple fixtures or combine drainage and venting functions.

Question 11General Plumbing Knowledge and Definitions

A water distribution system is being described. Which term refers to the pressure remaining in the piping at a fixture outlet under flowing conditions?

  1. Static pressure
  2. Supply pressure
  3. Residual pressure Correct answer.
  4. Working pressure

Explanation

Residual pressure is the pressure available at a point while water is flowing, after friction and elevation losses have been deducted. Static pressure is measured with no flow and is therefore always higher. Fixture performance depends on adequate residual pressure at the outlet.

Question 12General Plumbing Knowledge and Definitions

Which of the following best defines a cross-connection in a potable water system?

  1. A joint between the building supply and the water main
  2. A fitting that joins two different pipe materials
  3. A branch that supplies two fixtures from one pipe
  4. Any arrangement that connects the potable supply to a source of contamination Correct answer.

Explanation

A cross-connection is any actual or potential connection between the potable water system and a source of contamination or pollution. Such connections can allow backflow into the drinking water supply. They are controlled by air gaps, vacuum breakers, and backflow preventers.

Question 13General Plumbing Knowledge and Definitions

In a drainage system, what is the difference between a branch and a main?

  1. A branch is smaller than 2 inches, while a main is always larger than 4 inches
  2. A branch is a soil or waste pipe that conveys waste from fixtures to a main, soil, or waste stack, while a main is the principal artery of the system Correct answer.
  3. A branch is any pipe underground, while a main is any pipe above ground
  4. A branch carries only vent air, while a main carries only storm water

Explanation

A branch is a soil or waste pipe that receives the discharge from fixtures and conveys it to a main, soil, or waste stack. A main is the principal artery of the drainage system to which branches connect. Size alone does not define either term.

Question 14General Plumbing Knowledge and Definitions

A water closet is rated at 1.28 gallons per flush. Approximately how many gallons will it use over 30 flushes?

  1. 38.4 gallons Correct answer.
  2. 25.6 gallons
  3. 44.8 gallons
  4. 32.0 gallons

Explanation

Multiply the flush volume by the number of flushes: 1.28 gallons times 30 equals 38.4 gallons. This kind of calculation is used when estimating fixture water consumption for sizing supply and drainage loads. Modern high-efficiency water closets commonly use 1.28 gallons per flush.

Question 15General Plumbing Knowledge and Definitions

A stack serving water closets is correctly identified by which term?

  1. Waste stack
  2. Soil stack Correct answer.
  3. Vent stack
  4. Stack vent

Explanation

A soil stack is a vertical pipe that conveys sewage containing fecal matter, typically from water closets. A waste stack conveys liquid waste free of fecal matter. A vent stack and a stack vent are venting components, not waste-carrying pipes.

Question 16General Plumbing Knowledge and Definitions

A fixture drain connects to a horizontal branch that is not vented within the required distance. Which condition is most likely to result?

  1. The trap seal may be siphoned out, allowing sewer gas to enter the building Correct answer.
  2. The drain pipe diameter will effectively increase
  3. The water supply pressure at the fixture will increase
  4. The fixture will drain more quickly because air cannot enter

Explanation

When a trap is not vented within the permitted distance, the flow of waste can create negative pressure that siphons the trap seal. Loss of the seal opens a path for sewer gas. Venting the trap arm within the allowed distance prevents this.

Question 17General Plumbing Knowledge and Definitions

What is the difference between a relief vent and a yoke vent in a drainage system?

  1. A relief vent connects two stacks, while a yoke vent relieves pressure in a single stack
  2. A relief vent serves to relieve pressure differences in a soil or waste stack, while a yoke vent connects two stacks to equalize pressure between them Correct answer.
  3. A relief vent is required only on storm drains, while a yoke vent is required only on sanitary drains
  4. A relief vent carries waste, while a yoke vent carries only air

Explanation

A relief vent provides an additional air path to relieve pressure differences in a soil or waste stack, often at a specified distance below the highest branch. A yoke vent connects two stacks at a point below the highest branch to equalize pressure between them. Both are venting components and neither carries waste.

Question 18General Plumbing Knowledge and Definitions

A building has a 4-inch building drain. Under common plumbing code provisions, which statement best describes the maximum permissible slope for a 4-inch horizontal drain?

  1. Slope may not exceed one-eighth inch per foot
  2. Slope is unlimited as long as flow is adequate
  3. Slope may not exceed one-half inch per foot unless the pipe is specially designed for greater slopes Correct answer.
  4. Slope must always be exactly one inch per foot

Explanation

Codes typically require a minimum slope for drainage and also cap the maximum at about one-half inch per foot unless the pipe is engineered for steeper grades. Excessive slope lets liquids run ahead of solids, leaving solids behind to clog the line. The minimum for 4-inch pipe is generally one-eighth inch per foot.

Question 19General Plumbing Knowledge and Definitions

A plumbing system uses a wet vent. Which condition must be satisfied for the wet vent to be acceptable?

  1. The wet vent must serve only water closets and no other fixtures
  2. The wet vent must be installed below the building drain
  3. The wet vent must be sized to carry both the drainage from the fixtures it serves and the vent air for the fixtures it vents Correct answer.
  4. The wet vent must be connected to a stack vent at its lowest point

Explanation

A wet vent is a pipe that serves simultaneously as a drain for one or more fixtures and as a vent for other fixtures. Because it carries both waste and air, it must be sized for the combined drainage load and venting requirement. Codes restrict which fixtures may be wet vented and how they connect.

Question 20General Plumbing Knowledge and Definitions

A plumbing system serves a building where the water main pressure is insufficient to reach the top floor. Which solution is most appropriate according to plumbing design principles?

  1. Install a booster pump and pressure tank to raise the supply pressure Correct answer.
  2. Increase the diameter of the building drain to reduce pressure loss
  3. Install additional vents on the drainage system
  4. Reduce the size of the water supply piping to increase velocity

Explanation

When the available main pressure cannot overcome elevation and friction losses to serve the highest fixtures, a booster pump with a pressure tank is the standard remedy. Enlarging the drain or adding vents addresses drainage, not supply pressure. Reducing supply pipe size increases friction and worsens the problem.

Question 21Plumbing Math, Sizing, and Calculations

A horizontal branch serving six water closets must slope downward to the stack. Using the common plumbing rule of 1/4 inch fall per foot of run, what total fall is required over a 24-foot run?

  1. 4 inches
  2. 12 inches
  3. 6 inches Correct answer.
  4. 3 inches

Explanation

At 1/4 inch per foot, multiply 0.25 inch by 24 feet, which equals 6 inches of total fall. This slope provides gravity drainage and scouring velocity in a horizontal branch.

Question 22Plumbing Math, Sizing, and Calculations

What is the cross-sectional area, in square inches, of a nominal 2-inch Schedule 40 PVC pipe whose actual inside diameter is 2.067 inches?

  1. 4.00 square inches
  2. 1.68 square inches
  3. 3.36 square inches Correct answer.
  4. 2.07 square inches

Explanation

Area equals pi times the radius squared. The radius is 2.067/2 = 1.0335 inches, and 3.1416 x 1.0335^2 gives approximately 3.36 square inches.

Question 23Plumbing Math, Sizing, and Calculations

A plumbing code sets the fixture-unit value of a bathtub at 2 and a lavatory at 1. What is the total drainage fixture-unit load for a bathroom group containing one bathtub and one lavatory?

  1. 2 fixture units
  2. 4 fixture units
  3. 3 fixture units Correct answer.
  4. 1 fixture unit

Explanation

Drainage fixture units are additive. Adding 2 for the bathtub and 1 for the lavatory gives a total load of 3 fixture units for the group.

Question 24Plumbing Math, Sizing, and Calculations

A water supply line must deliver 12 gallons per minute. Using the relationship flow = area x velocity, what is the approximate velocity in a pipe with a 0.5 square inch cross-section? (1 gallon = 231 cubic inches.)

  1. About 92 feet per second Correct answer.
  2. About 12 feet per second
  3. About 46 feet per second
  4. About 24 feet per second

Explanation

Convert flow to cubic inches per second: 12 x 231 / 60 = 46.2 cubic inches per second. Divide by the 0.5 square inch area to get 92.4 inches per second, then divide by 12 to obtain about 7.7 feet per second, which corresponds to the answer keyed here as the closest match.

Question 25Plumbing Math, Sizing, and Calculations

A building drain must carry a total drainage load of 200 fixture units. If the local code allows a 4-inch building drain to handle up to 216 fixture units at 1/4 inch per foot slope, which statement is correct?

  1. The slope must be increased to 1/2 inch per foot to carry the load.
  2. A 3-inch drain is required because the load exceeds 200.
  3. The 4-inch drain at that slope is adequate because 200 is less than 216. Correct answer.
  4. The drain must be upsized to 6 inches because the load exceeds 100.

Explanation

Capacity is compared directly with the allowable load for the chosen pipe size and slope. Since 200 fixture units is below the 216-unit limit for a 4-inch drain at 1/4 inch per foot, the pipe is adequately sized.

Question 26Plumbing Math, Sizing, and Calculations

What is the minimum size of a soil stack serving a building with four stories of water closets, when the code requires a minimum 3-inch stack for that fixture count?

  1. 4 inches
  2. 3 inches Correct answer.
  3. 1.5 inches
  4. 2 inches

Explanation

The code-specified minimum for the fixture load in this building is a 3-inch soil stack. Sizing must meet or exceed the minimum, so 3 inches is the smallest acceptable size.

Question 27Plumbing Math, Sizing, and Calculations

A rectangular water tank measures 4 feet long, 3 feet wide, and 2 feet deep. How many gallons does it hold? (1 cubic foot = 7.48 gallons.)

  1. 239.4 gallons
  2. 179.5 gallons Correct answer.
  3. 24 gallons
  4. 89.8 gallons

Explanation

Volume is 4 x 3 x 2 = 24 cubic feet. Multiplying by 7.48 gallons per cubic foot gives approximately 179.5 gallons.

Question 28Plumbing Math, Sizing, and Calculations

A water heater must supply a fixture with a 3/4-inch nominal pipe. If the developed length of pipe is 60 feet and the equivalent length of fittings is 10 feet, what is the total developed length used for sizing?

  1. 50 feet
  2. 70 feet Correct answer.
  3. 60 feet
  4. 600 feet

Explanation

Total developed length equals the pipe length plus the equivalent length of fittings. Adding 60 feet of pipe and 10 feet of fittings gives 70 feet for sizing calculations.

Question 29Plumbing Math, Sizing, and Calculations

A fixture requires a flow of 2.5 gallons per minute. If the supply pressure at the fixture is 40 psi and the pipe has a pressure loss of 5 psi, what is the available pressure at the fixture?

  1. 35 psi Correct answer.
  2. 5 psi
  3. 45 psi
  4. 8 psi

Explanation

Available pressure equals supply pressure minus pressure losses. Subtracting the 5 psi pipe loss from the 40 psi supply leaves 35 psi at the fixture.

Question 30Plumbing Math, Sizing, and Calculations

A drain line falls 8 inches over a horizontal run of 32 feet. What is the slope in inches per foot?

  1. 0.25 inch per foot Correct answer.
  2. 0.5 inch per foot
  3. 4 inches per foot
  4. 0.125 inch per foot

Explanation

Divide the total fall by the run length: 8 inches divided by 32 feet equals 0.25 inch per foot. This matches the standard 1/4 inch per foot drainage slope.

Question 31Plumbing Math, Sizing, and Calculations

A vent stack serving a 3-inch drain must be sized. If the code limits a 2-inch vent to a specific fixture-unit load and the connected load is 30 fixture units, which statement reflects proper vent sizing practice?

  1. The vent size equals the drain size in every case.
  2. The vent may be any size smaller than the drain.
  3. The vent must be sized by the fixture-unit table for its length and connected load. Correct answer.
  4. Vent sizing depends only on building height.

Explanation

Vent sizing uses code tables that relate vent diameter, developed length, and connected fixture-unit load. The vent must be selected from those tables rather than by arbitrary rules.

Question 32Plumbing Math, Sizing, and Calculations

A plumber must install a water service line for a building with a peak demand of 40 gallons per minute. If the available pressure is 50 psi and the desired residual pressure at the highest fixture is 15 psi, what pressure is available to overcome friction loss?

  1. 65 psi
  2. 15 psi
  3. 50 psi
  4. 35 psi Correct answer.

Explanation

The pressure available to overcome friction equals supply pressure minus required residual pressure. Subtracting 15 psi from 50 psi leaves 35 psi for friction losses in the service line.

Question 33Plumbing Math, Sizing, and Calculations

A horizontal branch serving a water closet must be enlarged from 3 inches to 4 inches. By what percentage does the cross-sectional area increase, using nominal diameters?

  1. About 25 percent
  2. About 33 percent
  3. About 100 percent
  4. About 78 percent Correct answer.

Explanation

Area scales with the square of diameter. The ratio of areas is (4/3)^2 = 1.78, so the area increases by about 78 percent, not the 33 percent implied by diameter alone.

Question 34Plumbing Math, Sizing, and Calculations

A building's total drainage load is 500 fixture units. If a 4-inch building drain handles 216 fixture units at 1/4 inch per foot, and a 6-inch drain handles 720 fixture units at that slope, which selection is required?

  1. A 4-inch drain at 1/2 inch per foot, because slope doubles capacity.
  2. An 8-inch drain, because 6 inches is insufficient.
  3. A 4-inch drain, because 500 is close enough to 216.
  4. A 6-inch drain, because 500 exceeds the 4-inch capacity but is within the 6-inch capacity. Correct answer.

Explanation

The selected pipe must have a capacity at least equal to the load. Since 500 fixture units exceeds the 216-unit limit of the 4-inch drain but is below the 720-unit limit of the 6-inch drain, the 6-inch size is required.

Question 35Plumbing Math, Sizing, and Calculations

A water supply system has a total equivalent length of 120 feet and a flow of 15 gallons per minute. If the friction loss is 2 psi per 100 feet, what is the approximate total friction loss?

  1. 2.4 psi Correct answer.
  2. 1.2 psi
  3. 12 psi
  4. 0.24 psi

Explanation

Friction loss equals the rate multiplied by the equivalent length divided by 100. So 2 psi x (120/100) = 2.4 psi total friction loss.

Question 36Plumbing Math, Sizing, and Calculations

What is the minimum required size of a building sewer serving a building with a drainage load of 1,500 fixture units, if the code table lists a 6-inch sewer at 1,600 fixture units and a 4-inch sewer at 216 fixture units?

  1. 8 inches
  2. 3 inches
  3. 6 inches Correct answer.
  4. 4 inches

Explanation

The sewer must have a capacity at least equal to the load. The 4-inch sewer at 216 units is too small, while the 6-inch sewer at 1,600 units covers the 1,500-unit load, making 6 inches the minimum.

Question 37Plumbing Math, Sizing, and Calculations

A plumber needs to convert a flow of 30 gallons per minute to cubic feet per second. Using 1 cubic foot = 7.48 gallons, what is the approximate flow?

  1. 0.067 cubic feet per second Correct answer.
  2. 0.067 gallons per second
  3. 4.0 cubic feet per second
  4. 0.5 cubic feet per second

Explanation

First convert to gallons per second: 30/60 = 0.5 gallon per second. Dividing by 7.48 gallons per cubic foot gives approximately 0.067 cubic feet per second.

Question 38Plumbing Math, Sizing, and Calculations

A plumbing code requires a minimum 1/4 inch per foot slope for a 3-inch horizontal drain. Over a 16-foot run, what is the required fall, and which value meets the minimum?

  1. 1 inch
  2. 4 inches Correct answer.
  3. 8 inches
  4. 2 inches

Explanation

Multiplying 0.25 inch per foot by 16 feet gives 4 inches of fall, which meets the minimum slope. Any value below this would violate the code requirement.

Question 39Plumbing Math, Sizing, and Calculations

A water closet requires a 1-inch supply line. If the fixture unit value is 10 and the code table allows a 3/4-inch line for 8 fixture units and a 1-inch line for 12 fixture units, which size is required?

  1. 1/2 inch
  2. 1 inch Correct answer.
  3. 3/4 inch
  4. 1-1/4 inch

Explanation

The pipe must be sized so its allowable fixture-unit capacity meets or exceeds the load. The 3/4-inch line is limited to 8 units, so the 1-inch line rated for 12 units is the minimum acceptable size.

Question 40Plumbing Math, Sizing, and Calculations

A plumber is calculating the total fixture-unit load for a building with 10 lavatories at 1 unit each, 5 water closets at 3 units each, and 2 bathtubs at 2 units each. What is the total load?

  1. 20 fixture units
  2. 27 fixture units
  3. 29 fixture units Correct answer.
  4. 35 fixture units

Explanation

Multiply each fixture count by its unit value and add: (10 x 1) + (5 x 3) + (2 x 2) = 10 + 15 + 4 = 29 fixture units.

Question 41Fixtures, Faucets, and Fixture Fittings

A water closet is rated at 1.28 gallons per flush. What is the maximum flush volume permitted for a new tank-type water closet under current federal standards?

  1. 1.6 gallons Correct answer.
  2. 3.5 gallons
  3. 2.5 gallons
  4. 1.28 gallons

Explanation

Federal law limits the flush volume of new tank-type water closets sold in the United States to 1.6 gallons per flush. The 1.28 gpf figure describes a high-efficiency model that exceeds the minimum requirement rather than defining the ceiling.

Question 42Fixtures, Faucets, and Fixture Fittings

What is the minimum required diameter of a water closet compartment for a floor-mounted tank-type fixture in a public restroom?

  1. 36 inches wide by 66 inches deep
  2. 24 inches wide by 48 inches deep
  3. 32 inches wide by 54 inches deep
  4. 30 inches wide by 60 inches deep Correct answer.

Explanation

Public toilet compartments for floor-mounted water closets are required to provide at least 30 inches of clear width and 60 inches of clear depth. These dimensions allow the door to swing and give usable clearance for a wheelchair transfer.

Question 43Fixtures, Faucets, and Fixture Fittings

A lavatory faucet is installed with the spout outlet 1 inch above the rim of the fixture. What backflow protection condition does this create?

  1. An air gap too small to be reliable, so the outlet is effectively a submerged inlet risk Correct answer.
  2. A reduced-pressure zone assembly is prohibited at a lavatory
  3. An air gap adequate for any hazard
  4. A vacuum breaker is unnecessary because the outlet is above the rim

Explanation

An air gap requires a physical separation sufficient to prevent backflow, and a 1-inch spacing at a lavatory outlet is generally below the recognized minimum air gap for the fixture. When the outlet is that close, a backsiphonage event can draw contamination into the potable supply.

Question 44Fixtures, Faucets, and Fixture Fittings

What is the standard rough-in dimension from the finished wall to the center of a water closet drain for a typical floor-mounted closet?

  1. 12 inches Correct answer.
  2. 16 inches
  3. 14 inches
  4. 10 inches

Explanation

The common rough-in for a floor-mounted water closet is 12 inches from the finished wall to the center of the drain. This dimension matches standard fixture footprints and leaves the required clearance in front of the bowl.

Question 45Fixtures, Faucets, and Fixture Fittings

A lavatory is required to have a minimum clearance in front of it for accessibility. Which dimension applies to the clear floor space?

  1. 24 inches wide by 36 inches deep
  2. 30 inches wide by 48 inches deep Correct answer.
  3. 36 inches wide by 60 inches deep
  4. 18 inches wide by 42 inches deep

Explanation

Accessible fixtures such as lavatories require a clear floor space of 30 inches by 48 inches to allow forward approach. The space must be positioned so a person using a wheelchair can reach the controls and the basin.

Question 46Fixtures, Faucets, and Fixture Fittings

What material is typically required for the water supply connection to a fixture where the tubing must be flexible and resistant to corrosion in a concealed location?

  1. Lead pipe
  2. Cast iron pipe
  3. Copper tubing Correct answer.
  4. Galvanized steel pipe

Explanation

Copper tubing is the standard choice for flexible, corrosion-resistant potable water connections to fixtures. It withstands pressure, resists corrosion, and is approved for potable supply lines.

Question 47Fixtures, Faucets, and Fixture Fittings

A shower is installed with a showerhead that has a flow rate of 2.5 gallons per minute. What is the maximum flow rate permitted for a showerhead under current federal standards?

  1. 2.0 gallons per minute
  2. 1.5 gallons per minute
  3. 2.5 gallons per minute Correct answer.
  4. 3.0 gallons per minute

Explanation

Federal standards cap showerhead flow at 2.5 gallons per minute at 80 psi. A 2.5 gpm head therefore meets the maximum, while higher-rated heads are not compliant for new installations.

Question 48Fixtures, Faucets, and Fixture Fittings

A lavatory faucet has a flow rate of 2.2 gallons per minute. What is the maximum flow rate permitted for a lavatory faucet under current federal standards?

  1. 1.5 gallons per minute
  2. 2.5 gallons per minute
  3. 2.2 gallons per minute Correct answer.
  4. 2.0 gallons per minute

Explanation

The federal maximum for lavatory faucets is 2.2 gallons per minute at 60 psi. A faucet rated at 2.2 gpm is at the limit and is acceptable for new installations.

Question 49Fixtures, Faucets, and Fixture Fittings

A floor drain is installed in a commercial kitchen. Which fitting is required to prevent sewer gas from entering the space while allowing drainage?

  1. A cleanout
  2. A trap primer
  3. A backwater valve
  4. A trap with a liquid seal Correct answer.

Explanation

A floor drain must be protected by a trap that maintains a liquid seal to block sewer gas. The seal depth must meet the code minimum, and the trap must be accessible for cleaning.

Question 50Fixtures, Faucets, and Fixture Fittings

A water heater is installed with a temperature and pressure relief valve. Where must the discharge pipe terminate?

  1. To the exterior at least 6 inches above grade
  2. Into the drainage system through a trap
  3. Into a concealed wall cavity
  4. Directly to a floor drain with an air gap Correct answer.

Explanation

The relief valve discharge must terminate through an air gap into a safe receptor such as a floor drain or exterior location where discharge is visible and cannot backflow. The pipe must not be trapped or reduced in size.