Nevada C-1I Chilled-Water Piping Contractor Examination

Per NAC 624.190(2)(i), a Nevada C-1I chilled-water piping contractor is authorized to fabricate, install, repair, and remove which of the following?

• AThe chiller evaporator barrel, compressor, and condenser
• BPipes, pumps, valves, and other equipment used to transfer chilled water for temperature…
• CDirect-expansion refrigerant piping that is an integral part of a packaged rooftop unit
• DCooling-tower fill, fans, and basin heaters

ASTM B88 copper water tube used on a chilled-water loop is identified in the field by which standard color marking?

• AType K green, Type L blue, Type M red
• BType K red, Type L green, Type M yellow
• CType K yellow, Type L orange, Type M black
• DType K blue, Type L red, Type M green

Which copper product is appropriate for a pressurized closed chilled-water main, and which product is not?

• AType DWV copper is preferred; Type L is drainage only
• BType M copper is required underground; Type K is indoor only
• CASTM B88 Type K, L, or M copper water tube is used for hydronic pressure piping; Type DWV…
• DSoft-temper medical-gas tube is the only listed chilled-water material

Black steel chilled-water pipe installed above ground on a commercial Nevada job is most commonly specified as which product?

• AASTM A53 Grade B Schedule 40, welded, grooved, or threaded as listed
• BASTM A106 Schedule 160 only, because chilled water is a high-pressure steam service
• CGalvanized thin-wall EMT conduit
• DUnlisted fence-post tubing with no ASTM mark

Why is black steel generally preferred over galvanized steel on a closed chilled-water loop?

• AZinc on galvanized pipe can flake into the closed loop and does not add useful corrosion…
• BGalvanized coatings are required by UMC Chapter 12 on every closed loop
• CBlack steel is listed only for steam, so galvanized must be used for chilled water
• DGalvanized pipe cannot be insulated

PEX tubing used on a chilled-water loop that also contains steel pumps, tanks, or valves should be which product?

• AOxygen-barrier PEX (or PEX-AL-PEX) listed for hydronic service in UMC Table 1210.1
• BNon-barrier plumbing PEX, because oxygen helps the inhibitors
• CPEX-AL-PEX only if the aluminum layer is perforated
• DAny orange electrical HDPE conduit

A 2-inch Type L hard-drawn copper chilled-water riser is joined with 95/5 tin-antimony solder. Which statement is correct for UMC 2018 hydronic service?

• A95/5 solder is a listed joining method for copper hydronic tube when the joint is made pe…
• BOnly lead-tin 50/50 solder is permitted on chilled-water copper
• CSoldered joints are forbidden; every copper CHW joint must be a welded steel transition
• DSolder is allowed only on Type DWV copper

Where copper chilled-water tube is joined to a steel pump flange or steel main, UPC 2018 Sections 605.15 and 605.16 require which fitting?

• AA sanitary tee laid on its back
• BA no-hub shielded coupling listed only for cast-iron DWV
• CA dielectric union or other listed dielectric fitting
• DA brass cleanout plug

Grooved mechanical couplings on Schedule 40 steel chilled-water pipe are acceptable when which conditions are met?

• AThe couplings are listed for hydronic service, the groove is cut or rolled to the listing…
• BAny irrigation clamp may be used if it is painted blue
• CGrooved joints are allowed only on steam mains above 250°F
• DThe groove may be cut with a torch as long as the coupling snaps on

Which gasket compound is the ordinary choice for grooved couplings on a 45°F chilled-water or inhibited-glycol loop?

• AEPDM (or the coupling manufacturer's equivalent hydronic compound)
• BCompressed asbestos sheet leftover from an old steam job
• CUnlisted paper fiber cut from a carton
• DLead wool

CPVC pipe may be used on a chilled-water system only when which of the following is true?

• AIt is unlisted plumbing scrap leftover from a DWV stack
• BIt is solvent-welded with ABS cement
• CIt is listed for hydronic service in UMC Table 1210.1 and is rated for the system tempera…
• DIt is used only as a temporary test header and then abandoned in the wall

Schedule 40 PVC is a poor first choice for a pressurized indoor chilled-water supply-and-return main because:

• APVC cannot be solvent-welded
• BPVC is required by Table 1210.1 on every CHW riser
• CMany UMC hydronic listings and job specifications limit PVC, and its pressure rating fall…
• DPVC is listed only for steam at 350°F

A closed chilled-water loop will be filled with 30 percent inhibited propylene glycol. What material concern must the C-1I contractor check before selecting gaskets, valve seats, and plastic pipe?

• AGlycol always allows any rubber or plastic because it is food-grade
• BGlycol makes copper illegal under UMC Table 1210.1
• CThe fluid's chemical compatibility and the reduced heat capacity / higher viscosity must…
• DGlycol requires Type DWV copper only

Which steel-pipe schedule is the ordinary above-ground chilled-water wall thickness on commercial work?

• ASchedule 10 only, on every size including 1/2-inch threaded
• BSchedule 160 on every branch
• CSchedule 40 (or the project-specified standard-weight wall), with Schedule 80 reserved fo…
• DNo schedule is used; wall thickness is chosen by paint color

Press-connect (press-fit) copper fittings on a chilled-water branch are acceptable when:

• AThe fittings are listed for hydronic water service, the tube is the listed type and tempe…
• BAny unlisted hardware-store crimp ring is used on Type DWV tube
• CThe fitting is hammered oval and then wrapped with tape
• DPress fittings are forbidden by UMC Chapter 12 on all hydronic systems

Threaded joints on steel chilled-water pipe are generally limited in practice to which size range, and why?

• A12-inch and larger only, because small pipe cannot be threaded
• BThreading is forbidden on all Schedule 40 pipe
• CAbout 2 inches and smaller, because larger threads are harder to seal, weaken the wall mo…
• DThreading is allowed only on copper Type M

Class 150 steel flanges on a chilled-water main are matched to which gasket and bolt practice?

• AA full-face or raised-face gasket rated for the water temperature and pressure, with bolt…
• BNo gasket; the flange faces are glued with PVC cement
• CWood shims between the flange faces
• DA single bolt tightened until the flange rings

Stainless-steel chilled-water pipe or tube is selected instead of carbon steel primarily when:

• AThe designer wants a cheaper substitute for Schedule 40 black steel on a treated closed l…
• BUMC Table 1210.1 forbids all carbon steel
• CCorrosion resistance, cleanliness, or a specified water-treatment limit justifies the lis…
• DStainless is required on every residential 1/2-inch fan-coil branch

A chilled-water system runs 44°F supply and 56°F return and circulates 120 gpm. Using Q (BTU/h) = 500 × gpm × ΔT, what load is the loop carrying?

• A60,000 BTU/h
• B360,000 BTU/h
• C720,000 BTU/h
• D1,440,000 BTU/h

The most important extra duty of insulation on chilled-water pipe, compared with hot-water pipe, is to:

• ARaise the water temperature to 180°F
• BReplace the need for pipe hangers
• CProvide a continuous vapor retarder so room-air moisture cannot condense on the cold pipe
• DAllow the pipe to be tested with oxygen

Which insulation is preferred on indoor chilled-water pipe when condensation control is the governing concern?

• AUnfaced mineral-wool batts stuffed loosely around the pipe
• BOpen-cell furniture foam glued with white glue
• CClosed-cell elastomeric (or fiberglass with a sealed vapor-retarder jacket) installed at…
• DNewspaper wrapped with packing tape

Per UMC 2018 Table E 503.7.3(2) footnote 3, insulation is not required on which chilled-water piping?

• AIndoor 2-inch mains at 44°F in a mechanical room
• BRooftop 6-inch brine at 30°F
• CDirect-buried cooling-system piping
• DExposed 1-inch CHW in an occupied corridor

Outdoor chilled-water insulation must be protected by which covering?

• AA weather jacket suitable for outdoor service, such as aluminum, stainless, or a listed o…
• BBare ASJ left in the sun
• CA single wrap of cloth duct tape
• DNo cover if the insulation is white

If a buried chilled-water line is insulated, which product is preferred because it is essentially impermeable and crush-resistant when properly cased?

• AUnjacketed fiberglass wrap
• BOpen-cell spray foam
• CCellular glass in a waterproof, noncrushable casing or a listed preinsulated underground…
• DMineral-wool batts in a cardboard carton

A chilled-water branch must carry 100 gpm without exceeding 8 feet per second. Using V = 0.4085 × Q ÷ d² with Schedule 40 steel inside diameters (2 in. = 2.067 in.; 2-1/2 in. = 2.469 in.), what is the smallest listed pipe that stays at or under the limit?

• A2 inch, at about 6.7 feet per second
• B2 inch, at about 9.6 feet per second
• C2-1/2 inch, at about 6.7 feet per second
• D2-1/2 inch, at about 9.6 feet per second

Used pipe, fittings, and valves may be installed on a new chilled-water system only when they are:

• AFree of foreign materials and defects and still comply with the listed material standards…
• BPainted the same color as the new pipe, regardless of wall thickness
• CTaken from a sanitary sewer and flushed once
• DAlways forbidden, even if they are listed and undamaged

PE-RT tubing is acceptable on a chilled-water system when:

• AIt is unlisted irrigation tubing
• BIt is used as a substitute for Schedule 40 steam pipe at 300°F
• CIt complies with the PE-RT standard cited in UMC Table 1210.1 and is rated for the system…
• DIt is solvent-welded with PVC cement

A 4-inch Schedule 40 steel chilled-water main (inside diameter about 4.03 inches) carries 200 gpm. Approximate mean velocity is closest to which value, using V = 0.4085 × Q / d²?

• A2.0 feet per second
• B10.0 feet per second
• C5.0 feet per second
• D20.0 feet per second

Why is Type K copper often specified for underground chilled-water tube instead of Type M?

• AType K has the thickest ASTM B88 wall and better resists burial damage and corrosion allo…
• BType K is the thinnest water tube and is cheaper to bury
• CType M is required underground by ASTM B88
• DType K is yellow DWV tube

Polypropylene (PP or PP-R/PP-RCT) hydronic pipe is joined by which listed method?

• AOrdinary PVC solvent cement
• BNPT threads cut with a steel die without a fusion insert
• CHeat-fusion (socket, butt, or electrofusion) or other fittings listed for that PP system
• DLead-oakum caulked joints

A designer sizes a chilled-water main for 4 feet of friction per 100 feet of pipe at 180 gpm. If the equivalent length of the circuit (pipe plus fittings) is 350 feet, the pipe-friction head is closest to:

• A4 feet
• B28 feet
• C14 feet
• D180 feet

Flexible hose connectors at a chilled-water pump or air handler are acceptable when they are:

• AListed for the temperature, pressure, and fluid, installed without twist, and aligned so…
• BOrdinary garden hose clamped with worm-drive clamps
• CRequired to be the only pipe support on the main
• DMade of unlisted automotive heater hose on every 8-inch riser

Hazen-Williams C is used to estimate pipe friction. Which C-factor set is the most realistic for chilled-water sizing?

• ANew steel about 130–140, aged steel about 100, copper and plastic about 140–150
• BAll materials C = 50, because chilled water is cold
• CAll materials C = 200, because CHW never fouls
• DC is only used for natural-gas pipe

UMC 2018 Section 1205.2 requires hydronic (including chilled-water) piping to be tested at:

• AOperating pressure for 5 minutes
• B10 psi air for 15 minutes on every plastic and steel system
• CNot less than 1.5 times the operating pressure, and not less than 100 psi, held at least…
• DAny pressure the job-site compressor can reach

Under UMC 2018 Section 1205.2, plastic chilled-water pipe shall not be tested with air except:

• AWhenever the crew wants a faster test
• BOn every PVC DWV stack used as a hydronic riser
• CWhenever the test pressure exceeds 200 psi
• DFor listed PEX, PP, PE-RT, and similar systems whose manufacturer authorizes air testing…

A chilled-water loop will operate at 80 psi. What is the minimum UMC 1205.2 hydrostatic test pressure, and how long must it hold with no perceptible drop?

• A80 psi for 10 minutes
• B100 psi for 15 minutes
• C120 psi for 30 minutes
• D240 psi for 60 minutes

Per UMC 2018 Table 313.3, horizontal steel water or hydronic pipe 1 inch and larger shall be supported at intervals not exceeding:

• A4 feet
• B6 feet
• C12 feet
• D25 feet

Per UMC 2018 Table 313.3, horizontal copper or copper-alloy pipe 1-1/2 inches and smaller shall be supported at least every:

• A32 inches
• B12 feet
• C15 feet
• D6 feet

Per UMC 2018 Table 313.3, horizontal PEX, PE-RT, or PP tubing 1 inch and smaller shall be supported at intervals not exceeding:

• A32 inches
• B6 feet
• C12 feet
• D20 feet

UMC 2018 Section 1205.3 requires a new hydronic system to be flushed. The purpose of that flush is to:

• ARaise the loop pressure to the 1205.2 test value
• BAdd refrigerant to the chiller
• CReplace the need for a pressure test
• DRemove cutting oil, slag, solder flux, and construction debris before the pumps, valves,…

UMC 2018 Section 1204 requires hydronic piping to be identified at intervals of not more than:

• A5 feet, and only above a suspended ceiling
• B100 feet, with no room minimum
• COnly at the property line
• D20 feet (6096 mm), but not less than once per room, and visible from the floor

A closed chilled-water loop is filled with inhibited heat-transfer fluid that is not potable water. Per UMC 2018 Section 1204, the pipe marking shall be:

• AA yellow field with the word STEAM
• BNo marking, because insulation hides the pipe
• CA red field that says POTABLE WATER
• DAn orange field with black letters such as CAUTION: HEAT TRANSFER FLUID, DO NOT DRINK

Chilled-water piping should be arranged so that the loop can be drained. The correct installation practice is to:

• AOmit all drains because a closed loop never needs emptying
• BDrill random holes in the bottom of the pipe after insulation
• CRely on the relief-valve discharge as the only drain
• DPitch mains to accessible low-point drain valves and provide high-point vents

Manual or automatic air vents on a chilled-water system belong at:

• AEvery low-point drain only
• BThe chiller compressor discharge
• CThe cooling-tower basin only
• DHigh points and other locations where air can collect, such as coil tops and the air sepa…