Arizona ROC R-37R Plumbing (Residential) Examination

What is the standard minimum slope required per foot for horizontal drainage piping with a diameter of 2 inches or less?

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

In standard plumbing fixture unit tables, what Drainage Fixture Unit (DFU) load value is assigned to a standard residential water closet with a 1.6 gallons per flush gravity tank?

• A1 DFU
• B2 DFUs
• C3 DFUs
• D6 DFUs

What is the minimum diameter required for a trap arm serving a standard residential lavatory?

• A1 inch
• B1-1/4 inches
• C1-1/2 inches
• D2 inches

According to the IPC, what is the maximum allowable horizontal distance from a fixture trap weir to its vent fitting for a 1-1/2 inch trap arm installed at a 1/4 inch per foot slope?

• A3 feet
• B5 feet
• C6 feet
• D8 feet

A branch drain serves 2 water closets (3 DFUs each), 2 lavatories (1 DFU each), and 1 kitchen sink (2 DFUs). What total DFU load does this branch carry, and what minimum pipe size is required?

• A8 DFUs, requiring a 2-inch pipe
• B10 DFUs, requiring a 3-inch pipe
• C10 DFUs, requiring a 2-inch pipe
• D12 DFUs, requiring a 4-inch pipe

To prevent siphoning of the trap seal, plumbing code dictates that the total vertical drop of a trap arm between the trap weir and the vent fitting connection must not exceed what value?

• AHalf the pipe diameter
• BOne pipe diameter
• CTwo pipe diameters
• DThree pipe diameters

What is the maximum allowable distance between cleanouts on a 4-inch horizontal drainage pipe inside or under a building?

• A50 feet
• B75 feet
• C100 feet
• D150 feet

A 3-inch horizontal drain line runs a continuous length of 48 feet at a slope of 1/4 inch per foot. What is the total vertical drop of the pipe over this distance?

• A6 inches
• B12 inches
• C18 inches
• D24 inches

Where a plumbing vent stack terminates through a roof, it must be located at least how far above or horizontally away from any operable door, window, or air intake?

• A1 foot above or 5 feet horizontally
• B2 feet above or 10 feet horizontally
• C3 feet above or 6 feet horizontally
• D4 feet above or 12 feet horizontally

Under standard plumbing code requirements, a plumbing vent terminal extending through a flat roof must extend vertically above the roof surface by at least how many inches?

• A3 inches
• B6 inches
• C12 inches
• D18 inches

In residential DWV design, horizontal wet venting is permitted to serve a maximum of how many bathroom groups located on the same floor level?

• A1 bathroom group
• B2 bathroom groups
• C3 bathroom groups
• D4 bathroom groups

What is the minimum pipe diameter permitted for a building sewer receiving flow from one or more water closets?

• A2 inches
• B3 inches
• C4 inches
• D6 inches

According to standard IPC building drain sizing tables, what is the maximum DFU capacity of a 3-inch horizontal building drain installed at a 1/4 inch per foot slope?

• A20 DFUs
• B27 DFUs
• C35 DFUs
• D42 DFUs

What is the minimum required opening diameter for a cleanout installed on a 4-inch horizontal drainage pipe?

• A2 inches
• B3 inches
• C3-1/2 inches
• D4 inches

What is the primary function of a P-trap installed beneath a plumbing fixture?

• ATo regulate the discharge flow rate into the branch drain
• BTo prevent solid waste from entering the vertical stack
• CTo maintain a liquid seal that prevents sewer gases from entering the living space
• DTo increase water pressure in the fixture drain arm

Standard plumbing code requires fixture traps to have a liquid seal depth within what range?

• A1 inch minimum to 2 inches maximum
• B2 inches minimum to 4 inches maximum
• C3 inches minimum to 6 inches maximum
• D4 inches minimum to 8 inches maximum

How must potable clear-water waste, such as discharge from a relief valve, enter the building drainage system under IPC Section 802.1.3?

• AThrough an indirect waste pipe with an air gap
• BBy a direct sealed connection to a sanitary branch
• CThrough an untrapped pipe into a wall cavity
• DBy connecting it to a fuel-gas vent

Where must an individual or branch-type air-admittance valve be located under IPC Sections 918.4 and 918.5?

• AAt least 4 inches above the horizontal branch drain or fixture drain being vented, access…
• BBelow the trap weir inside a sealed wall cavity
• CAt the same elevation as the branch drain with no access
• DOutdoors as the system's only vent terminal

Which of the following trap configurations is explicitly prohibited by modern plumbing codes due to high siphoning risk?

• AP-trap
• BS-trap
• CDeep seal trap
• DSwivel P-trap

What protection is required when a roof parapet or similar perimeter construction could trap water after the primary roof drains become blocked?

• ASecondary emergency roof drains or scuppers
• BA reduction in primary drain size
• CA connection from the roof to the sanitary vent system
• DNo additional drainage because parapets prevent overflow

Where must a secondary emergency roof-drain system terminate under IPC Section 1108.2?

• ASeparately from the primary system, above grade at a location normally observed by occupa…
• BInside the primary roof-drain pipe below the roof
• CInto a concealed attic space
• DInto a sanitary vent stack

What rainfall rate is used to size a secondary roof-drain system under IPC Section 1108.3?

• AThe same rate used to size the primary roof-drain system
• BHalf the primary design rate
• CA universal 1 inch per hour in every location
• DNo design rate because secondary drains are decorative

When checking roof ponding depth for structural design under IPC Section 1101.7, what condition is assumed for the primary roof drains?

• AThey are blocked
• BThey discharge at twice their rated flow
• CThey are enlarged after the calculation
• DThey are connected to sanitary piping

An indirect waste pipe discharging into a floor sink or waste receptor must maintain an air gap with a minimum vertical distance of:

• A1/2 inch
• B1 inch, or twice the effective opening diameter of the indirect waste pipe, whichever is…
• C2 inches regardless of pipe diameter
• D4 inches above the floor level

What does IPC Section 1101.5 require when storm-drain piping changes size in the direction of flow?

• AThe pipe size must not be reduced in the direction of flow
• BThe pipe must be reduced one nominal size after each branch
• CThe pipe must alternate between larger and smaller sizes
• DThe downstream size is unrelated to the upstream size

What is the maximum static water pressure permitted inside a residential building before an approved Pressure Reducing Valve (PRV) must be installed?

• A60 psi
• B70 psi
• C80 psi
• D100 psi

Which color code is standard for Type L seamless copper water tube used in interior domestic water supply piping?

• AGreen
• BBlue
• CRed
• DYellow

A single-family residence has the following private fixtures: 2 flush tank water closets (2.5 WSFU each), 2 lavatories (1.0 WSFU each), 2 shower heads (1.5 WSFU each), 1 kitchen sink (1.5 WSFU), 1 dishwasher (1.5 WSFU), and 1 clothes washer (2.0 WSFU). What is the total Water Supply Fixture Unit (WSFU) load?

• A12.0 WSFU
• B15.0 WSFU
• C18.5 WSFU
• D22.0 WSFU

A water pipe rises vertically 30 feet to feed a second-floor bathroom fixture. If the static pressure at the base of the riser is 50 psi, what is the static pressure available at the fixture elevation (ignoring friction loss)?

• A37.0 psi
• B40.0 psi
• C43.5 psi
• D63.0 psi

Which backflow prevention assembly provides the highest level of protection against both backpressure and backsiphonage in high-hazard (toxic) cross-connections?

• ADouble Check Valve Assembly (DCVA)
• BPressure Vacuum Breaker Assembly (PVB)
• CReduced Pressure Principle Backflow Preventer (RPZ)
• DAtmospheric Vacuum Breaker (AVB)

What is the maximum horizontal support spacing required for 3/4-inch PEX water distribution tubing?

• A24 inches
• B32 inches
• C48 inches
• D60 inches

To prevent erosion-corrosion and noisy flow in copper cold water piping systems, plumbing design standards recommend limiting maximum fluid velocity to:

• A4 feet per second
• B8 feet per second
• C12 feet per second
• D15 feet per second

A standard 3/4-inch residential water meter under typical street pressure (40 to 60 psi) can supply a maximum load of approximately how many WSFUs under standard sizing tables?

• A15 WSFUs
• B30 WSFUs
• C60 WSFUs
• D90 WSFUs

Which onsite wastewater system falls under Arizona's conventional R18-9-E302 Type 4.02 general permit?

• AA septic tank discharging by gravity to an approved disposal field at less than 3,000 gal…
• BAn industrial wastewater injection well
• CA municipal sewage plant of unlimited capacity
• DA roof-drain dry well receiving no sewage

Where is a Double Check Valve Assembly (DCVA) backflow preventer permitted to be installed?

• AOn chemical injection lines serving lawn fertilizer systems
• BOn low-hazard (non-toxic) cross-connections subject to backpressure or backsiphonage
• COn sewage ejector pump water supply flush lines
• DOn commercial boiler feed lines containing toxic chemicals

Copper piping expands at a rate of approximately 0.0000094 inches per inch per °F. How much will a 100-foot copper hot water pipe expand when heated from 60°F to 160°F (a 100°F rise)?

• A0.56 inches
• B1.13 inches
• C2.25 inches
• D3.50 inches

What is the minimum vertical air gap requirement for a potable water supply outlet with an effective opening of 3/4 inch located not adjacent to a wall?

• A1 inch
• B1.5 inches
• C2.0 inches
• D3.0 inches

When pressure testing a rough potable water piping system using water, what is the minimum test pressure and duration required?

• A25 psi for 10 minutes
• BWorking pressure or 50 psi (whichever is greater) for at least 15 minutes
• C100 psi for 1 hour
• D150 psi for 2 hours

Where should water hammer arrestors conforming to ASSE 1010 be installed in a residential plumbing system?

• AAt the water meter outlet only
• BOn supply lines adjacent to quick-closing automatic valves (e.g., washing machines, dishw…
• CAt the highest point of the hot water riser stack
• DDirectly before the pressure reducing valve

A pressure gauge at the base of a vertical water column reads exactly 17.32 psi. What is the height of the water column above the gauge?

• A20 feet
• B30 feet
• C40 feet
• D50 feet

An Atmospheric Vacuum Breaker (AVB) must be installed at least how far above all downstream piping and the highest downstream flood level rim?

• A2 inches
• B6 inches
• C12 inches
• D18 inches

What universal color is required for marking and identifying non-potable and reclaimed water piping systems?

• AGreen
• BYellow
• CPurple
• DOrange

Which phenomenon causes backsiphonage in a potable water supply distribution network?

• AThermal expansion of hot water in a closed heater
• BNegative or sub-atmospheric pressure in the supply piping
• CExcessive street main pressure above 100 psi
• DWater hammer caused by fast-closing solenoid valves

What flow method from the septic tank to the disposal field does Arizona's conventional Type 4.02 permit authorize?

• AGravity flow only
• BVacuum transport only
• CHigh-pressure injection only
• DAny method chosen after the inspection

Before aggregate or drain lines are placed in a conventional septic-field trench, how must smeared or compacted soil surfaces be prepared under R18-9-E302?

• ARake them to a depth of 1 inch and remove the loosened material
• BPolish them smooth with the excavator bucket
• CSeal them with asphalt emulsion
• DCover them immediately without preparation

How should multiple laterals from an Arizona conventional septic distribution box be constructed where practical?

• AWith watertight connections and laterals of uniform length where practical
• BWith leaking upstream joints to reduce flow
• CWith intentionally unequal lengths regardless of site conditions
• DWithout a distribution box