Mississippi Residential Plumbing Examination

Under the 2021 International Plumbing Code (IPC), when must a plumbing system be tested and inspected relative to concealment?

• AAfter finish materials are installed so leaks are easier to see
• BBefore any portion of the system is concealed or covered
• COnly after the building sewer is connected to the public main
• DOnly if the system contains more than 20 drainage fixture units

A Mississippi residential plumbing contractor is installing a new water heater. Per IPC 301.7, if the manufacturer's installation instructions conflict with a minimum code provision, which requirement applies?

• AThe manufacturer's instructions always control
• BThe less expensive of the two methods may be used
• CThe more restrictive provisions apply
• DThe contractor may choose either method if both are listed

Which statement best describes how the 2021 International Residential Code (IRC) plumbing chapters relate to a one- and two-family dwelling that is also subject to the 2021 IPC on the Mississippi PSI bulletin?

• AThe IRC plumbing chapters apply only to commercial kitchens
• BThe IRC plumbing provisions are written for dwellings and are used together with the IPC,…
• CThe IRC automatically voids every IPC table for residential work
• DOnly the IFGC applies to residential plumbing; the IRC is structural only

Per IPC 604.8, a pressure-reducing valve is required when static water pressure at the building exceeds which value?

• A60 psi
• B80 psi
• C100 psi
• D125 psi

A 2-inch PVC DWV stack is ready for a rough drainage test. Per IPC 312.2 and 312.3, which test method is acceptable?

• AA 5 psi air test held for 15 minutes
• BA water test with not less than a 10-foot head held for 15 minutes
• CA soap-bubble wipe of each joint with the system at atmospheric pressure
• DA 50 psi air test held for 15 minutes

Upon completion of a copper water-distribution system, IPC 312.5 requires the system to be proven tight under which condition?

• AA water test at not less than the working pressure of the system, or an air test of not l…
• BA 5 psi air test held for 5 minutes
• CA visual inspection of solder joints only
• DA 10-foot head of water applied at the meter only

Per IPC 312.1, who is responsible for furnishing the equipment, material, power, and labor needed to perform the required plumbing tests?

• AThe code official
• BThe water utility
• CThe permit holder
• DThe property insurer

A concealed 1/2-inch PEX water line is bored through a wood stud so that the edge of the hole is 1 inch from the face of the stud. Per IPC 305.6, what protection is required?

• ANo protection is required because PEX is flexible
• BSteel shield plates not less than 0.0575 inch thick (No. 16 gage) covering the bored area…
• CPlastic tape wrapped around the tubing at the stud
• DA wood block nailed over the hole on one side of the stud

Per IPC 301.3, which of the following may discharge through an approved indirect waste system instead of a direct sanitary connection?

• AA water closet
• BA urinal
• CFixtures required by Chapter 8 to be indirectly wasted, such as food-handling equipment
• DA residential sewage ejector discharge

IPC 1002.1 generally requires each plumbing fixture to be separately trapped, except where the code specifically allows a combination fixture. Which installation is prohibited?

• AA two-compartment laundry tray served by one trap
• BA kitchen sink and food-waste disposer sharing one trap
• CA lavatory discharging through a water-closet trap (double trapping)
• DA bathtub with its own 1-1/2-inch trap

Per IPC 303.3, plastic pipe, fittings, and components used in a plumbing system shall be third-party certified as conforming to which standard?

• ANSF 14
• BASTM A53
• CASME B16.3
• DNFPA 13

A copper water pipe will pass through a concrete foundation wall. Per IPC 305.3, the sleeve built into the wall shall be which size relative to the pipe?

• AThe same nominal size as the pipe
• BOne pipe size larger than the pipe
• CTwo pipe sizes greater than the pipe passing through the wall
• DFour pipe sizes greater than the pipe

Where rock is encountered in a sewer trench, IPC 306.2.2 requires the rock to be removed to not less than which depth below the bottom of the pipe before sand bedding is placed?

• A1 inch
• B3 inches
• C6 inches
• D12 inches

Per IPC 307.5, trenching installed parallel to a footing shall not extend into the footing's bearing plane. That upper boundary is a line that extends downward from the outside bottom edge of the footing at which angle from horizontal?

• A30 degrees
• B45 degrees
• C60 degrees
• D90 degrees

IPC 304.2 requires strainer plates on drain inlets to have openings not greater than which least dimension so rodents cannot enter?

• A1/4 inch
• B1/2 inch
• C3/4 inch
• D1 inch

A shower receptor liner is ready for inspection. Per IPC 312.9, the lined floor shall be tested by filling it with potable water to a depth of not less than which amount, measured at the threshold, and holding that water for at least 15 minutes?

• A1/2 inch
• B1 inch
• C2 inches
• D4 inches

IPC 308.10 addresses support of a thermal expansion tank. Which statement is correct?

• AThe expansion tank may be supported solely by the piping that connects to it
• BThe expansion tank shall be supported in accordance with the manufacturer's instructions…
• CNo support is required if the tank is less than 2 gallons
• DThe tank must be hung from a single hanger on the cold-water drop

In IPC Chapter 2 usage, developed length of piping is best defined as which of the following?

• AThe straight-line horizontal distance between two points, ignoring fittings
• BThe length of pipe measured along the centerline of the pipe and fittings
• CThe vertical rise only, from the lowest fixture to the roof
• DThe sum of fixture-unit values on the branch

The Mississippi State Board of Contractors Residential Plumbing classification trade exam is administered by PSI as which type of examination?

• AA closed-book computer exam with no references allowed
• BAn open-book computer-based exam that allows only the bulletin-listed references
• CAn oral interview with a board member
• DA practical shop test with live gas and water

Which valve is the most appropriate isolation valve on a residential fixture supply because it can be fully open with almost no restriction and can be shut with a quarter turn?

• AGlobe valve
• BGate valve used for frequent throttling
• CBall valve
• DCheck valve

A swing check valve is installed on a pumped discharge. In which orientation must the valve be installed to function as intended?

• AWith flow opposite the arrow, so the disc hangs closed
• BWith the flow arrow matching the intended direction of flow so the disc opens with flow a…
• CVertically with flow downward only
• DIn any orientation because check valves are directionless

IPC 604.8 requires a pressure-reducing valve that is installed because static pressure exceeds 80 psi to be equipped with which accessory on the inlet?

• AA vacuum breaker
• BAn inlet strainer
• CA dielectric union only
• DA temperature-and-pressure relief valve

A copper water line is joined to a galvanized-steel water heater nipple. Which fitting is used to limit galvanic corrosion at that joint?

• AA standard copper coupling
• BA dielectric union or other approved dielectric fitting
• CA PVC solvent-weld adapter
• DA cast-iron no-hub coupling

Full-open valves serving a water service or a water-distribution riser are intended to do which of the following?

• AThrottle flow during normal use
• BProvide isolation with the valve fully open or fully closed so the waterway is not used a…
• CRelieve temperature and pressure
• DPrevent backflow from a hose bibb

IPC 604.9 requires a water-hammer arrestor conforming to ASSE 1010 where which condition exists?

• AAny copper tube longer than 10 feet
• BQuick-closing valves, such as on dishwashers, clothes washers, or solenoid irrigation val…
• CEvery lavatory supply, regardless of valve type
• DOnly on the water-heater T&P discharge

A new residential shower valve must limit scald and thermal-shock risk. Which device meets that IPC/IRC control requirement?

• AA two-handle compression faucet with no limit stop
• BA pressure-balancing, thermostatic, or combination balancing/thermostatic mixing valve li…
• CA hose-bibb vacuum breaker
• DA gate valve on the hot supply only

Per IPC 405.3.1, the centerline of a water closet shall be not less than which distance from a side wall or partition?

• A12 inches
• B15 inches
• C18 inches
• D21 inches

Per IPC 421.4, a shower compartment shall have a finished interior of not less than 900 square inches and shall be capable of encompassing a circle with a diameter of not less than which dimension?

• A24 inches
• B30 inches
• C36 inches
• D42 inches

A residential automatic clothes washer discharges through an air break into a standpipe. Per IPC 406.2 and 802.4.3, which standpipe arrangement is required?

• AA 1-1/4-inch trap with the standpipe 12 inches above the trap weir
• BA trap and fixture drain not less than 2 inches in diameter, with the standpipe not less…
• CA 3-inch trap with no height limit on the standpipe
• DDirect connection of the washer hose into a 1-1/2-inch sanitary tee below the floor

Using IPC Table 709.1, what is the drainage fixture unit (DFU) value of one bathroom group that includes a 1.6-gpf water closet?

• A3 DFU
• B4 DFU
• C5 DFU
• D6 DFU

Per IPC Table 709.1, a lavatory is assigned 1 DFU and a minimum trap size of which diameter?

• A1-1/4 inches
• B1-1/2 inches
• C2 inches
• D3 inches

Per IPC 603.1, the minimum diameter of a water-service pipe is which of the following?

• A1/2 inch
• B3/4 inch
• C1 inch
• D1-1/4 inches

A second-story lavatory is 23 feet above the water-service entrance. Ignoring friction, what is the static pressure loss due to elevation if water exerts 0.433 psi per foot of head?

• A5.0 psi
• B8.0 psi
• C10.0 psi
• D13.0 psi

The most reliable backflow protection for a residential potable-water outlet above a flooded receptor is which of the following?

• AA dual check valve buried in the yard
• BAn air gap, with the vertical distance at least twice the effective opening and not less…
• CA hose without a vacuum breaker
• DA gate valve on the supply

A dwelling has a closed water-distribution system because a pressure-reducing valve is installed on the service. What additional device is required to control thermal expansion?

• AA second T&P valve used as the expansion control
• BA listed thermal expansion tank or other approved expansion-control device
• CA hose bibb left cracked open
• DA larger water-heater dip tube

A dwelling water system is sized from these given Water Supply Fixture Unit (WSFU) values: bathroom group with tank water closet 3.6, kitchen sink 1.4, dishwasher 1.4, clothes washer 1.4, hose bibb 2.5. What is the total WSFU if the house has two bathroom groups, one kitchen sink, one dishwasher, one clothes washer, and one hose bibb?

• A10.3 WSFU
• B12.5 WSFU
• C13.9 WSFU
• D15.3 WSFU

Per IPC Table 704.1, the minimum slope of a horizontal drainage pipe 2-1/2 inches or less in diameter is which of the following?

• A1/16 inch per foot
• B1/8 inch per foot
• C1/4 inch per foot
• D1/2 inch per foot

A 4-inch building drain is 48 feet long and is installed at the IPC Table 704.1 minimum slope for 3- to 6-inch pipe. How much total fall is required from the upstream end to the downstream end?

• A3 inches
• B6 inches
• C12 inches
• D24 inches

A 2-inch fixture drain serving a kitchen sink travels 40 feet horizontally. Using the IPC Table 704.1 minimum slope, what is the required fall?

• A5 inches
• B8 inches
• C10 inches
• D20 inches

Per IPC Table 709.1, a private 1.6-gpf water closet is assigned how many drainage fixture units?

• A2 DFU
• B3 DFU
• C4 DFU
• D6 DFU

A one-story dwelling has two bathroom groups with 1.6-gpf water closets (5 DFU each), one domestic kitchen sink (2 DFU), one residential clothes washer (2 DFU), and one floor drain (2 DFU). Using IPC Table 709.1 group and fixture values, what is the total DFU load?

• A11 DFU
• B14 DFU
• C16 DFU
• D21 DFU

Per IPC 1002.4, each fixture trap shall have a liquid seal of not less than 2 inches and not more than which depth, except for special designs relating to accessible fixtures?

• A3 inches
• B4 inches
• C6 inches
• D8 inches

Per IPC Table 909.1, what is the maximum developed length from a 1-1/2-inch trap weir to its protecting vent at 1/4 inch per foot slope?

• A5 feet
• B6 feet
• C8 feet
• D12 feet

A 2-inch floor-drain trap is vented at the Table 909.1 maximum. What is that maximum developed length from trap weir to vent at 1/4 inch per foot?

• A5 feet
• B6 feet
• C8 feet
• D16 feet