Arizona ROC R-37 Plumbing Including Solar (Residential) Examination

Per the International Plumbing Code (IPC) as adopted in Arizona, what is the maximum static water pressure allowed at a plumbing fixture before a pressure reducing valve (PRV) must be installed?

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

A contractor is calculating total Water Supply Fixture Units (WSFU) for a home containing 1 bathroom group with a tank-flush water closet (2.5 WSFU), a lavatory (1.0 WSFU), a shower (2.0 WSFU), plus 1 kitchen sink (1.5 WSFU). What is the total WSFU load?

• A5.5 WSFU
• B7.0 WSFU
• C8.5 WSFU
• D10.0 WSFU

Water is being pumped upward to a fixture location 40 feet above the main supply line elevation. Assuming no pipe friction losses, what is the static pressure drop due to elevation alone?

• A10.45 psi
• B17.32 psi
• C20.00 psi
• D24.60 psi

When sizing a water supply service pipe using the standard IPC developed length sizing method, what percentage allowance is standardly added to the measured length of pipe to account for friction loss through fittings and valves if exact fitting losses are not itemized?

• A10 percent
• B25 percent
• C50 percent
• D100 percent

Which backflow prevention assembly is required for high-hazard cross-connections subject to continuous backpressure or backsiphonage, and requires an air gap drain discharge line that must never be submerged?

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

What is the minimum physical air gap required between the outlet of a potable water faucet spout and the flood level rim of a lavatory when the faucet outlet is 1/2 inch in diameter and not affected by nearby side walls?

• A0.5 inch
• B1.0 inch
• C1.5 inches
• D2.0 inches

What is the maximum horizontal hanger support spacing required for PEX tubing sizes 1 inch and smaller per the International Plumbing Code?

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

A Double Check Valve Assembly (DCVA) is suitable for installation under which of the following cross-connection hazard conditions?

• AHigh hazard toxic chemical feed lines under backpressure
• BLow hazard non-health conditions under continuous backpressure or backsiphonage
• CHigh hazard sewage pump discharge connections
• DLawn irrigation systems with chemical fertilizer injectors

When installing a potable water thermal expansion tank on a domestic hot water system equipped with a check valve backflow preventer, at what pressure should the tank's internal air bladder be pre-charged prior to installation?

• A15 psi below incoming static water pressure
• BEqual to the incoming static cold water main pressure
• C150 psi to match the T&P valve setting
• DAlways factory set at 30 psi and never adjusted

A Pressure Vacuum Breaker (PVB) installed on a residential irrigation main must be elevated at least how many inches above the highest downstream sprinkler head or outlet?

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

Seamless copper tube for water distribution is color-coded by wall thickness standard. Which color represents Type L copper pipe?

• AGreen
• BBlue
• CRed
• DYellow

A residential water main delivers 65 psi static pressure at the street meter. Pressure losses are: 4 psi across the meter, 10.8 psi vertical elevation rise (25 ft), and 8.0 psi total pipe friction. What is the available residual pressure at the topmost fixture?

• A42.2 psi
• B48.2 psi
• C53.0 psi
• D61.0 psi

Before placing a newly installed potable water distribution system into service, the system must be disinfected. What is the standard chlorine concentration and contact time requirement per IPC 610?

• A10 ppm chlorine solution held for 1 hour
• B50 ppm chlorine solution held for 24 hours
• C100 ppm chlorine solution held for 12 hours
• D500 ppm chlorine solution held for 30 minutes

Under the Safe Drinking Water Act and IPC standards, what is the maximum allowable lead content in flux and solder used on potable water supply systems?

• A0.2 percent
• B0.5 percent
• C2.0 percent
• D8.0 percent

What primary operational feature distinguishes a Spill-Resistant Vacuum Breaker (SVB) from a standard Pressure Vacuum Breaker (PVB)?

• ASVB can handle high-hazard backpressure.
• BSVB closes its internal check valve before the air inlet opens, minimizing water spillage…
• CSVB does not require annual certified testing.
• DSVB can be installed below downstream flood level rims.

A standard 5/8-inch by 3/4-inch residential displacement water meter is generally rated for a maximum continuous flow capacity of approximately:

• A10 GPM
• B20 GPM
• C35 GPM
• D50 GPM

According to Hunter's Curve for sizing water supply distribution pipes, why do systems predominantly serving flushometer valves require much larger pipe sizes than systems serving tank-flush water closets for the same total fixture count?

• AFlushometer valves run continuously for hours.
• BFlushometer valves create instantaneous high peak flow demands (30-35 GPM per flush) comp…
• CTank-flush water closets consume more total water volume per day.
• DFlushometer valves operate at higher static pressures.

How must a completed water-supply piping system be tested under IPC Section 312.5?

• AWith water at not less than system working pressure, or with air at not less than 50 psi…
• BWith 5 psi of air for 5 minutes for every piping material
• CWith 300 psi of water for 2 hours
• DAt normal pressure for 1 minute without inspecting the joints

Which design standards does IRC Section P2904 recognize for an automatic residential fire-sprinkler system?

• ANFPA 13D or IRC Section P2904, which the IRC treats as equivalent for this purpose
• BNFPA 20 only
• CThe plumbing contractor's preferred layout without a standard
• DNFPA 13E only

What distinguishes a multipurpose residential sprinkler system from a stand-alone system under IRC Section P2904?

• AA multipurpose system supplies both domestic fixtures and fire sprinklers; a stand-alone…
• BA multipurpose system contains no fire sprinklers
• CA stand-alone system must supply kitchen faucets
• DThe terms describe pipe color only

Per the International Plumbing Code, what is the standard minimum slope required for a 3-inch horizontal drainage pipe?

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

Where physical constraints prevent a standard 1/4 inch per foot pitch, what is the minimum allowable slope for a 4-inch horizontal building drain or building sewer under the IPC?

• A1/16 inch per foot
• B1/8 inch per foot
• C3/16 inch per foot
• D1/4 inch per foot mandatory with no exceptions

A residential bathroom group consists of 1 water closet (3.0 DFU), 1 lavatory (1.0 DFU), and 1 bathtub/shower combination (2.0 DFU). What is the total Drainage Fixture Unit (DFU) load assigned to this bathroom group?

• A4.0 DFUs
• B5.0 DFUs
• C6.0 DFUs
• D8.0 DFUs

Per IPC Table 710.1(1), what is the maximum number of Drainage Fixture Units (DFUs) allowed on a 3-inch horizontal building drain sloped at 1/4 inch per foot?

• A20 DFUs
• B35 DFUs
• C42 DFUs
• D160 DFUs

What is the maximum developed length of a trap arm for a 1-1/2 inch lavatory drain from the trap weir to the vent fitting per IPC Table 909.1?

• A3.5 feet
• B5.0 feet
• C6.0 feet
• D8.0 feet

Every fixture trap shall have a liquid seal depth of not less than ____ inches and not more than ____ inches, except where special design approval is obtained.

• A1 inch; 3 inches
• B2 inches; 4 inches
• C2 inches; 6 inches
• D3 inches; 5 inches

What size cleanout is required for a 3-inch DWV line, and what is the minimum clearance required directly in front of the cleanout opening for rod access?

• A2-inch cleanout with 12 inches clearance
• B3-inch cleanout with 18 inches clearance
• C3-inch cleanout with 24 inches clearance
• D4-inch cleanout with 36 inches clearance

What is the maximum horizontal distance allowed between cleanouts on a straight run of horizontal building drain piping under the IPC?

• A35 feet
• B50 feet
• C75 feet
• D100 feet

When installing an Air Admittance Valve (AAV / Studor valve) to vent an island sink fixture branch, the valve must be located at least how many inches above the horizontal fixture drain branch?

• A2 inches
• B4 inches
• C6 inches
• D12 inches

Under IPC 912 horizontal wet venting rules, what is the minimum required pipe size for a wet vent serving a bathroom group consisting of a water closet, lavatory, and tub/shower?

• A1-1/2 inches
• B2 inches
• C3 inches
• D4 inches

Which of the following trap configurations is explicitly prohibited by modern plumbing codes due to high susceptibility to self-siphonage?

• AP-trap
• BS-trap
• CDeep seal P-trap
• DIntegral water closet trapway

Per IPC 903.1, a vent pipe penetrating the roof surface must extend vertically above the roof penetration a minimum distance of:

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

What is the minimum horizontal separation distance required between a building sewer pipe and a potable water service line installed in separate trenches?

• A2 feet
• B5 feet
• C10 feet
• D12 feet

According to IPC 911 circuit venting rules, what is the maximum number of battery fixtures (such as wall-hung water closets or lavatories) permitted to be served by a single circuit vent loop?

• A4 fixtures
• B6 fixtures
• C8 fixtures
• D12 fixtures

What are the minimum and maximum allowable standpipe height limits above the trap weir for a residential clothes washer drain receiver per IPC 802.4?

• AMin 12 inches; Max 24 inches
• BMin 18 inches; Max 42 inches
• CMin 24 inches; Max 48 inches
• DMin 30 inches; Max 60 inches

What is the minimum diameter allowed for a building drain or vertical drainage stack that receives discharge from a standard residential water closet?

• A2 inches
• B2-1/2 inches
• C3 inches
• D4 inches

When performing a water head pressure test on a newly roughed-in DWV piping system per IPC 312.2, the system must be filled with water to a minimum head height of:

• A5 feet above the lowest point
• B10 feet above the section being tested
• C20 feet above the roof line
• D50 feet under pressure pump

A vertical DWV stack in a multi-story home has a horizontal offset greater than 45 degrees. How must the horizontal offset section be sized per IPC 711?

• ASame size as the upper vertical stack section
• BSized as a horizontal building drain based on total DFUs entering above the offset
• COne pipe size smaller to increase scouring velocity
• DAlways 4 inches minimum regardless of DFU count

In an island sink fixture vent installation (loop venting under IPC 916), where must the return bend of the island vent loop be positioned relative to the sink?

• ABelow the floor line
• BAs high as possible beneath the island countertop, above the flood level rim if feasible
• CDirectly below the trap weir elevation
• DInside the vertical drainage stack

Which of the following fittings is explicitly PROHIBITED for connecting two horizontal DWV drain lines changing direction horizontal-to-horizontal?

• AWye fitting
• BCombination wye and 1/8 bend
• CLong sweep 1/4 bend
• DSanitary tee

What is the primary difference between a direct (open-loop) solar water heating system and an indirect (closed-loop) solar system?

• ADirect systems use photovoltaic panels to produce electricity for an electric water heate…
• BDirect systems circulate potable household water directly through the solar collectors; i…
• CIndirect systems operate without a circulation pump.
• DDirect systems can only be used in freezing climates.

When selecting the tilt and orientation of a fixed solar-thermal collector, what should the installer use as the controlling design basis?

• AThe collector manufacturer's instructions, site solar access, roof geometry, and the syst…
• BA mandatory 33.5-degree tilt for every Arizona site
• CA vertical orientation for every domestic-water system
• DThe angle that places the collector in the most shade at noon

In a solar drainback thermal system, how is freeze protection achieved when collector temperatures drop near freezing or when the circulator pump shuts off?

• AElectrical resistance strip heaters warm the collectors.
• BWater in the collectors automatically drains by gravity into an unpressurized indoor drai…
• CGlycol antifreeze solution is automatically injected into the loop.
• DA motorized valve dumps domestic hot water to the sewer.

Per plumbing codes governing solar water heating, under what condition is a double-wall heat exchanger with an intermediate leak detection vent MANDATORY?

• AWhen pure distilled water is used as the heat transfer fluid.
• BWhen non-potable or toxic fluids (such as ethylene glycol or chemical additives) are used…
• CWhenever solar collectors are installed on a steep pitched roof.
• DOnly for solar thermal pool heating systems.

What is the basic operating logic of a differential controller in a pumped solar water-heating loop?

• AStart the pump when the collector sensor is sufficiently warmer than the storage sensor,…
• BRun the pump only when the tank is hotter than the collector
• CRun continuously whenever the outdoor temperature is above freezing
• DUse collector temperature alone and ignore storage temperature

What is the recommended solar azimuth orientation for flat-plate solar collectors installed in Arizona to maximize daily solar energy absorption?

• ATrue North
• BTrue East
• CTrue South (or within 15 degrees of True South)
• DTrue West