Exam Cheat Sheet · Quick Reference

West Virginia Plumbing Contractor

West Virginia  ·  Prov

Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
100
Passing score
70%
Exam time
180 min
Administered by
Prov
Format
Reference materials allowed

West Virginia State Portion 100 questions

General Knowledge 10 Q · 10%
IPC definitions and plumbing code terminologyIPC scope, permit requirements, and inspection proceduresTypes, properties, and applications of plastic pipe (ABS, PVC, CPVC, PEX, PE, PB)Plastic pipe sizing, labeling, schedules, and SDR ratingsReading and interpreting construction drawings (floor plans, riser diagrams, isometric sketches, plumbing symbols)Model plumbing codes (the IPC): structure, purpose, and chapter organizationCode development, revision, and adoption process for model and local codesCompressed-air system components, installation, and safety
Fixtures & Fittings 6 Q · 6%
Minimum number of required plumbing fixtures by occupancy classificationFixture installation requirements and clearancesFaucets and fixture fittings including shower valves and temperature limiting devicesBackflow protection for plumbing fixtures and appliancesFixture-specific standards and waste outlet requirementsFixture materials and construction standards (vitreous china, porcelain enamel, cast iron, stainless steel, fiberglass/GRP, acrylic plastic)Water closet types, flushing mechanisms, and water conservation requirementsUrinal types, flushing devices, and substitution limits for water closetsADA and accessibility requirements for fixture installation and clearancesShower compartment construction, lining materials, and waste outlet requirementsAppliance connections (dishwashers, food waste disposers, washing machines, refrigerator ice makers)Whirlpool bathtub installation requirements including pump access and suction fittings +1 more
Storm Drainage 5 Q · 5%
Rainfall rate determination using 100-year hourly data and NOAA mapsSizing vertical conductors and leaders using code tablesSizing horizontal storm drain piping by pipe diameter and slopeRoof drain flow rate and minimum number of drains per roof areaSecondary (emergency) roof drains and scuppers — requirements and sizingSiphonic roof drainage systems — design standards and installation requirementsStorm drainage pipe materials for above-ground conductors, underground drains, and storm sewersTraps, cleanouts, and backwater valves in storm drainage systemsChapter 15 - Sizing DWV and Storm Systems
Fuel Gas Systems 10 Q · 10%
Gas AppliancesGas PipingGas piping materials and fittings (metallic pipe, copper tubing, CSST, polyethylene plastic)Pipe sizing methods (longest length, branch length, hybrid pressure)Pressure testing and leak checks of gas piping systemsCombustion air requirements for gas appliances (indoor, outdoor, and combination methods)Venting systems for gas appliances (vent types, connectors, termination, sizing)Appliance location, clearances, and installation requirementsSpecific gas appliance requirements (furnaces, unit heaters, unvented room heaters, clothes dryers, water heaters)
Safety 7 Q · 7%
Personal protective equipment (PPE) selection, inspection, and proper useHazard Communication (HazCom) standard, safety data sheets (SDS), and chemical labelsWork zone safety: signs, signals, barricades, and walking/working surfacesHand tool safety: bladed and impact toolsPower tool safety: electrically powered and liquid-fuel toolsTrenching and excavation safety: hazards, protective systems, and OSHA requirementsConfined space classification, entry permits, and atmospheric hazardsLockout/tagout procedures and emergency response planningChapter 1 - Plumbing Safety
Isometrics 13 Q · 13%
Center-to-center and end-to-end pipe length calculationsFitting allowances for threaded, copper, PVC, and welded fittings45-degree offset calculations using diagonal and rise/run constantsOffset calculations for other fitting angles (60°, 22½°, 11¼°, 72°) using trigonometric constantsThree-pipe diagonal assembly layout and pipe length determinationRolling offsets and true offset calculationsParallel offset spacing and equal spacing calculationsReading and applying pipe fitting data tables from appendix referencesChapter 4 - Introduction to Plumbing DrawingsChapter 7 Sanitary DrainageChapter 9 Vents
Water Supply and Distribution 14 Q · 14%
Potable water protection and cross-connection controlBackflow prevention devices and assembliesPipe materials, fittings, and joining methods for water service and distributionWater pressure requirements, pressure-reducing valves, and booster systemsHot water supply system requirements and thermal expansion controlWater piping system sizing using fixture units and segmented loss methodWater heater installation, safety devices, and relief valve discharge pipingWater volume, pressure, and capacity calculationsChapter 11 - Types of ValvesChapter 6 Water Supply and DistributionChapter 9 - Introduction to Water Distribution Systems
Water Heaters 7 Q · 7%
Water HeatersSafety devices for water heaters including relief valves and discharge pipingWater heater installation requirements including access, location, and connectionsHot water supply system requirements including temperature limits and recirculationTypes of water heaters including gas, electric, tankless, heat pump, and indirectWater heater selection criteria including capacity, fuel type, recovery rate, and durabilityThermal expansion protection including expansion tanks and closed systemsGas water heater venting requirements and flue installationWater heater safety hazards including electrical, gas, and steam risksAntisiphon devices, vacuum relief valves, and drain valvesParallel and series water heater connections for multi-unit installationsFlammable vapor ignition resistant (FVIR) water heater requirements +2 more
Drain, Waste and Vent Systems 14 Q · 14%
Indirect WasteSpecial WasteDrainage fixture unit (DFU) values and system sizingHorizontal drainage pipe slope and installation requirementsCleanout placement, sizing, and access requirementsTrap requirements, prohibited trap types, and trap seal protectionVent types, sizing, and terminal requirementsGrease interceptors and other interceptors and separatorsSumps, ejectors, and below-grade drainage systemsPipe materials, fittings, and joint methods for drainage and vent systems
Plumbing Math 9 Q · 9%
Arithmetic operations and formula solving for plumbing applicationsUnit conversions and measurement systems (English and metric)Geometric shapes, area, and volume calculationsPythagorean theorem and right triangle solutionsPipe offset, diagonal, rise, and run calculations using angle constantsWater pressure, head, and force calculationsPipe capacity, weight of water, and volume-to-gallon conversions for cylindrical and rectangular containersRatio of pipe capacities and pipe sizing using units of flowTemperature conversion between Fahrenheit and CelsiusDecimal, fraction, and percentage conversions including inches-to-decimal-foot equivalents3-4-5 ratio and square corner layout using the Pythagorean theoremChapter 3 - Introduction to Plumbing Math +1 more
Plumbing Tools 5 Q · 5%
Hand tool safety and proper work habitsMeasuring and layout tools (folding rules, tape measures, squares)Leveling tools (spirit levels, torpedo levels, laser levels, plumb bobs, chalklines)Hand cutting tools (hacksaws, chisels, manual pipe cutters, shovels)Pipe holding and assembly tools (wrenches, pliers, vises, ratchet threaders)Hammers and screwdrivers used in plumbingPower tool safety (GFCI protection, extension cord ratings, grounding)Power cutting and drilling tools (reciprocating saws, band saws, abrasive saws, drills, drill bits)Chapter 2 - Tools of the Plumbing Trade

Key Distinctions

PVC water supply solvent-cement jointsvsCPVC water supply solvent-cement joints

PVC joints require a purple primer conforming to ASTM F656 followed by solvent cement that is NOT purple (ASTM D2564 or CSA B137.3), while CPVC joints where the manufacturer requires a primer use an orange solvent cement conforming to ASTM F493 (yellow where a one-step cement is allowed).

IPC 2018 Section 605.21.3
Water dispenservsDrinking fountain / water cooler

A water dispenser is manually controlled by the user to dispense potable water into a receptacle such as a cup, glass or bottle, while a drinking fountain lets the user drink directly from a stream of flowing water without accessories and a water cooler is a drinking fountain that also reduces the water temperature.

IPC 2018 Chapter 2 — Section 202, definitions of Water Dispenser, Drinking Fountain and Water Cooler
Leaders/storm drains connected to a combined sewervsLeaders/storm drains connected to a building storm sewer

Those connected to a combined sewer shall be trapped (individual conductor traps being the same size as the horizontal drain they connect to), while those connected to a building storm sewer are not required to be trapped; storm water shall not be drained into sewers intended for sewage only.

IPC 2018 Chapter 11, Section 1103.1
Water service pipe/tubing underground and outside the structurevsHot water distribution pipe and tubing

Water service pipe outside and underground must have a working pressure rating of not less than 160 psi at 73.4°F, while hot water distribution pipe must be rated not less than 100 psi at 180°F.

IPC 2018 Section 605.3
Solid-wedge gate valvevsSplit-wedge gate valve

Solid-wedge gate valves are used for steam, hot water and other services where shock is a factor (the wedge is machined to match the body seat taper), while split-wedge gate valves are used where a more positive closure is needed — low-pressure and cold water lines and lines carrying light volatile fluids such as gasoline, benzene, kerosene and solvents.

Plumbing Basics for Contractors, Chapter 11 — Types of Valves, Section 1.2.0 (Page 480) and Section 2.2.0 (Page 492)
Longest length method (gas sizing)vsBranch length method (gas sizing)

Under the longest length method every section — including short branches — is sized from the single table row for the distance to the most remote outlet (next longer row if the exact length is absent), while under the branch length method each branch is sized using its own length measured from the meter.

IFGC Section 402.4.1, Longest Length Method; Table 402.4(2), Schedule 40 Metallic Pipe (natural gas, 0.5 in. w.c. drop)
Cleanout clearance for 6-inch and smaller pipingvsCleanout clearance for 8-inch and larger piping

Piping 6 inches and smaller requires not less than 18 inches of clearance from the face of the cleanout opening, while piping 8 inches and larger requires not less than 36 inches, measured perpendicular to the face of the opening.

IPC 2018 Chapter 7 — Section 708.1.9 Required Clearance
Building sewers 8 inches and largervsBuilding sewers smaller than 8 inches

Sewers 8 inches and larger must have a manhole not more than 200 feet from the junction of the building drain and building sewer and at intervals of not more than 400 feet thereafter, while smaller sewers use cleanouts at intervals not exceeding 100 feet.

IPC 2018 Chapter 7 — Section 708.1.2 Building Sewers
Metal water heater drain panvsPlastic water heater drain pan

Galvanized steel or aluminum pans shall be not less than 0.0236 inch thick, while plastic pans shall be not less than 0.036 inch thick (other approved materials are also permitted).

IPC 2018 Chapter 5 — Section 504.7 Required Pan
Barrier-type trap seal protection device (ASSE 1072)vsTrap seal primer valves/devices (ASSE 1018 and ASSE 1044)

Barrier-type floor drain trap seal protection devices conform to ASSE 1072, while water-supplied trap seal primer valves conform to ASSE 1018 and waste water-supplied trap primer devices conform to ASSE 1044.

IPC 2018 Chapter 10 — Section 1002.4.1.4 Barrier-Type Trap Seal Protection Device
Face-to-face (face of fitting) dimensionvsCenter-to-center dimension

When a dimension is taken to the face of a fitting the thread makeup for each end is ADDED to get pipe length, whereas with a center-to-center dimension the fitting takeoff/allowance is subtracted (and thread engagement added).

Plumbing Basics for Contractors, Chapter 3 — Section 2.5.3 Face-to-Face Method / 2.5.4 General Principles of Measurement
T&P relief valve temperature settingvsT&P relief valve pressure setting

The temperature setting shall be not more than 210°F, while the pressure setting shall not exceed the tank or water heater manufacturer's rated working pressure or 150 psi, whichever is less (e.g., 150 psi governs for a 160-psi-rated tank).

IPC 2018 Chapter 5, Section 504.5

Key Terms

Water dispenser IPC 2018 Chapter 2 — Section 202, definitions of Water Dispenser, Drinking Fountain and Water Cooler
A plumbing fixture manually controlled by the user for the purpose of dispensing potable drinking water into a receptacle such as a cup, glass or bottle.
Drinking fountain IPC 2018 Chapter 2 — Section 202, definitions of Water Dispenser, Drinking Fountain and Water Cooler
A fixture that allows the user to obtain a drink directly from a stream of flowing water without the use of accessories.
Water cooler IPC 2018 Chapter 2 — Section 202, definitions of Water Dispenser, Drinking Fountain and Water Cooler
A drinking fountain that also reduces the temperature of the water.
Full-open valve IPC 2018 Chapter 2 — Section 202, definition of Full-Open Valve
A water control or shutoff component in which, where adjusted for maximum flow, the flow path through the component's closure member is not a restriction in the component's through-flow area.
Fill valve (antisiphon) IPC 2018 Chapter 2 — Section 202, definition of Fill Valve
A flush tank supply valve containing an integral antisiphon device — an approved air gap or vacuum breaker — positioned on the discharge side of the water supply control valve.
Water outlet IPC 2018 Chapter 2 — Section 202, definition of Water Outlet
A discharge opening through which water is supplied to a fixture, into the atmosphere, to a boiler or heating system, or to devices/equipment requiring water that are not part of the plumbing system — excluding an opening discharging into an open tank that is part of the water supply system.
EHD (Equivalent Hydraulic Diameter) IFGC 2018 — Table 402.4(15), Note 2 (CSST sizing tables, Section 402.4)
The flow designation used in the CSST capacity tables that measures relative hydraulic (flow) efficiency between tubing sizes — the greater the EHD, the greater the gas capacity.
Controlled-flow roof drainage system Plumbing Basics for Contractors, Chapter 15 — Sizing Roof Storage and Drainage Systems, Pages 651 and 653
A roof drainage system that retains stormwater on the roof for an average of 12 hours before draining it, used to prevent storm-sewer overloads during heavy storms (the building must be engineered for the retained water weight).
Crown vent (prohibited location) IPC 2018 Chapter 9 — Section 909.3 Crown Vent
A vent installed within two pipe diameters of the trap weir; such a vent connection is prohibited, and the vent connection may not be below the trap weir except for water closets.
Circuit vent IPC 2018 Chapter 9 — Section 914.1 Circuit Vent Permitted
A vent serving a group of not more than eight fixtures connected to a horizontal branch drain; circuit-vented branches may be connected together with each group of not more than eight fixtures treated as a separate circuit vent.
Stack-type air admittance valve IPC 2018 Chapter 9 — Section 918.3.2 Stack
An AAV that may serve as the vent terminal for a vent stack or stack vent only where the drainage stack served has not more than six branch intervals (at least one stack vent or vent stack in each system must still extend outdoors).
Barrier-type trap seal protection device IPC 2018 Chapter 10 — Section 1002.4.1.4 Barrier-Type Trap Seal Protection Device
A floor drain trap seal protection device conforming to ASSE 1072 and installed per the manufacturer's instructions, used instead of a trap primer valve.
Subsoil drain IPC 2018 Chapter 11, Section 1111.1
A storm drainage pipe for subsoil water that shall be not less than 4 inches in diameter.
Sump pit IPC 2018 Chapter 7 — Section 712.3.2 Sump Pit
The pit receiving a subdrain below sewer elevation; unless otherwise approved it shall be not less than 18 inches in diameter and not less than 24 inches deep, fitted with a gastight removable cover installed not more than 2 inches below grade or floor level.
Riser diagram Plumbing Basics for Contractors, Chapter 4 — Introduction to Plumbing Drawings, Page 202 (Section 2.1.2)
A single-line isometric drawing of the building plumbing showing vertical and horizontal piping with sizes and a riser number referring back to the full set of plumbing drawings; used for material takeoffs.
Frost closure IPC 2018 Chapter 9 — Section 903.2 Frost Closure
Where the 97.5-percent outdoor design temperature is 0°F or less, vent extensions through a roof or wall shall be not less than 3 inches in diameter and any increase in vent size shall be made not less than 1 foot inside the building's thermal envelope.

Formulas to Know

Static (gauge) pressure from head, and head required for a given pressurepsi = vertical height of water above the point (ft) × 0.433 psi/ft; height (ft) = psi ÷ 0.433. Examples: 46 ft × 0.433 = 19.9 ≈ 20 psi; 60 ft × 0.433 ≈ 26 psi; 30 ÷ 0.433 = 69.3 ft; 20 ÷ 0.433 = 46.2 ft; 35 ÷ 0.433 = 80.8 ft; a 10-ft rise loses 10 × 0.433 = 4.33 psi.
45-degree offset travel and runTravel = set × 1.414; run = set × 1.000 (run equals set). Examples: 16 × 1.414 = 22.62 ≈ 22-5/8 in; 20 × 1.414 = 28.28 ≈ 28-1/4 in; run = 20 in.
Drain fall, invert elevation and percent slopeTotal fall = horizontal run (ft) × grade (in/ft); downstream invert = upstream invert − fall; percent slope = (rise in inches per foot ÷ 12) × 100. Examples: 32 ft × 1/8 in/ft = 4 in; 44 ft × 1/8 in/ft = 5.5 in; 48 ft × 1/4 in/ft = 12 in = 1.00 ft, so 100.00' − 1.00' = 99.00'; 101.50' − 0.50' = 101.00'; 1/4 in/ft = (0.25 ÷ 12) × 100 = 2.08%.
Tank volume and capacity in gallonsCylinder: V = π × r² × h (r = half the diameter); rectangular: V = L × W × D; gallons = cubic feet × 7.48. Examples: π × 1.5² × 5 = 35.34 cu ft → 264 gal; π × 2² × 6 = 75.4 cu ft → 565 gal (half height: π × 2² × 3 = 37.7 cu ft → 282 gal); 4 × 2.5 × 3 = 30 cu ft → 224.4 gal.
Threaded pipe length (center-to-center vs face-to-face)Center-to-center: cut length = C-C − (both fitting takeoffs) + (both thread engagements), e.g., 42 − (2 × 2-1/4) + (2 × 1/2) = 38-1/2 in. Face-to-face: end-to-end length = F-F + thread makeup at each end, e.g., 6-3/4 + 1/2 + 1/2 = 7-3/4 in.
Water heater recovery rate and heat-up timeUsable output = input BTU/hr × efficiency; BTU per gallon = 8.33 lb/gal × temperature rise (°F); GPH = usable output ÷ BTU per gallon; time = BTU required ÷ usable output. Examples: 40,000 × 0.75 = 30,000 ÷ (8.33 × 70 = 583.1) = 51.4 GPH; 50 gal × 8.33 × 80°F = 33,320 BTU ÷ (38,000 × 0.76 = 28,880) = 1.154 hr × 60 ≈ 69 min.
Pressure available to overcome pipe frictionAvailable = starting pressure (static at meter, or the PRV outlet setting where a PRV is installed) − elevation loss (ft × 0.433) − meter/device/fitting losses − minimum required residual pressure. Examples: 55 − 13.0 − 4 − 15 = 23.0 psi; 65 − 10.8 − 12 − 8 = 34.2 psi; 45 (PRV outlet) − 15.2 − 7 − 8 = 14.8 psi.
Total equivalent length and friction loss / allowable friction rateTotal equivalent length = developed length × (1 + fitting allowance), e.g., 120 ft × 1.40 = 168 ft; friction loss = equivalent length × (rate ÷ 100), e.g., 168 × (4.2/100) = 7.06 psi; allowable friction rate = (available pressure ÷ total equivalent length) × 100, e.g., (22 ÷ 250) × 100 = 8.8 psi per 100 ft.
Natural gas demand in cubic feet per hourcfh = appliance input (Btu/h) ÷ 1,000. Examples: (50,000 + 40,000 + 100,000) ÷ 1,000 = 190 cfh total at the meter; a 40,000 Btu/h fireplace or water heater = 40 cfh; selected pipe capacity minus demand = margin, e.g., 452 − 340 = 112 cfh.
Vent stack connection to the building drain (maximum distance)Connection must be downstream of the drainage stack within 10 × the diameter of the drainage stack; for a 4-inch stack, 10 × 4 in. = 40 inches maximum (the vent stack may instead connect at the base of the stack at or below the lowest horizontal branch).
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