Exam Cheat Sheet · Quick Reference

Idaho Plumbing Specialty Water Pump Journeyman Exam

Idaho  ·  PSI Services Contractor

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
50
Passing score
75%
Exam time
150 min
Administered by
PSI Services Contractor
Format
Reference materials allowed

Idaho State Portion 50 questions

2017 Idaho State Plumbing Code Chapter 1 11 Q · 22%
Scope, purpose, and applicability of the codeAuthority Having Jurisdiction — duties, powers, and liabilityPermit requirements and exempt workPermit application and construction document submissionPermit issuance, validity, expiration, and revocationInspections — types, scheduling, and reinspection proceduresSystem testing and approval requirementsViolations, penalties, stop orders, and Board of Appeals
2017 Idaho State Plumbing Code Chapter 2 6 Q · 12%
Potable water supply and distribution terminology (building supply, water distribution pipe, water main, riser, fixture branch, fixture supply)Backflow and cross-connection terminology (backflow, backsiphonage, backpressure backflow, cross-connection, backflow preventer, critical level, air gap)Drainage system terminology (building drain, building sewer, soil pipe, waste pipe, horizontal branch, stack, building subdrain, invert, grade)Venting system terminology (plumbing vent, dry vent, wet vent, vent stack, stack vent, branch vent, individual vent, relief vent, yoke vent, trap primer)Trap and fixture terminology (trap, trap seal, trap arm, tailpiece, fixture unit, fixture drain, plumbing fixture, bathroom group)Pipe joining and materials terminology (joint types—brazed, soldered, welded, flanged, flared, compression; pipe material abbreviations—ABS, CPVC, PVC, PEX, PE, PP; SDR)Nonpotable and alternate water source terminology (gray water, reclaimed water, rainwater catchment system, on-site treated nonpotable water, gray water diverter valve, mulch basin)Authority, approval, and code applicability terminology (Authority Having Jurisdiction, approved, listed, labeled, listing agency, accepted engineering practice, shall/should/may)
2017 Idaho State Plumbing Code Chapter 3 21 Q · 42%
Minimum standards for pipe, fittings, and materials (listing, labeling, and marking requirements)Alternate materials and methods of construction equivalency (AHJ approval and testing)Protection of piping from corrosion, freezing, mechanical damage, and UV exposurePipe hangers, supports, and hanger rod sizing (Table 313.3 and Table 313.6 intervals by material)Prohibited fittings and installation practices (drainage, vent, and waste connections)Trenching, excavation, backfill, and thermoplastic pipe bedding requirementsTest gauge requirements and pressure graduation specificationsAlternative engineered design requirements (permit application, design documents, and AHJ approval)
2017 Idaho State Plumbing Code Chapter 6 12 Q · 24%
Backflow prevention devices and assemblies (air gap, AVB, PVB, SVB, DC, RP) — types, components, and applicable hazard levelsCross-connection control requirements and prohibited connectionsWater supply piping materials, lead content limits, and applicable standards (copper types, PEX, CPVC, PE, PP, PVC, stainless steel)Pipe joining methods by material type (soldered, brazed, flared, mechanical, solvent cement, heat-fusion, push-fit)Water system sizing using fixture units, Table 610.3, and Table 610.4 (pressure ranges, developed length, meter and branch sizing)Water pressure requirements, pressure regulators, expansion tanks, and relief valve discharge pipingValve requirements (fullway shutoff, control valves, multidwelling unit shutoffs) and potable water supply tank requirementsResidential fire sprinkler system installation, piping materials, sizing calculations, and inspection requirements

Key Distinctions

AccessiblevsReadily Accessible

"Accessible" means access may first require removing an access panel, door, or similar obstruction, while "Readily Accessible" means direct access without removing any panel, door, or obstruction.

ISPC 2017 Section 203.0
Brazed jointvsSoldered joint

A brazed joint uses alloys melting above 840°F (449°C) but below the melting point of the parts joined; a soldered joint uses metallic mixtures or alloys melting at temperatures up to and including 840°F (449°C).

ISPC 2017 Section 212.0 - Joint, Brazed
Contamination (High Hazard)vsPollution (Low Hazard)

Contamination is an impairment of potable water quality creating an actual health hazard through poisoning or spread of disease (High Hazard), while pollution does not create a health hazard but adversely and unreasonably affects aesthetic qualities (Low Hazard).

ISPC 2017 Section 218.0 (Pollution)
Soil pipevsWaste pipe

A soil pipe conveys the discharge of water closets, urinals, clinical sinks or similar fixtures (with or without other fixture discharge), whereas a waste pipe conveys only liquid waste free of fecal matter.

ISPC 2017 Section 220.0 - Soil Pipe
Wet ventvsDry vent

A wet vent also serves as a drain, while a dry vent does not receive the discharge of any sewage or waste.

ISPC 2017 Section 222.0 - Wet Vent
"Shall"vs"Should" / "May"

"Shall" indicates a mandatory requirement; "Should" indicates a recommendation or advice that is not required, and "May" is a permissive term.

ISPC 2017 Section 220.0 - Shall
TailpiecevsTrap arm

The tailpiece connects the outlet of a plumbing fixture to the trap, while the trap arm is the portion of the fixture drain between the trap and the vent.

ISPC 2017 Section 221.0 - Tailpiece
Building supplyvsWater distribution pipe / Fixture supply

The building supply carries potable water from the water meter or other source to the building or point of use on the lot; a water distribution pipe conveys water within the building from the building supply to fixtures and outlets, and a fixture supply connects the fixture to the fixture branch.

ISPC 2017 Section 204.0 - Building Supply
RiservsFixture supply

A riser is a water supply pipe extending vertically one full story or more to convey water to branches or fixtures; a fixture supply is the water supply pipe connecting an individual fixture to the fixture branch.

ISPC 2017 Section 219.0 - Riser
Permit application expiration (Sec. 104.3.3)vsPermit expiration for work not commenced (Sec. 104.4.3)

An application for which no permit is issued expires by limitation 180 days after the application date, while an issued permit becomes null and void if the authorized work is not commenced within 180 days from the date of the permit (requiring a new permit).

ISPC 2017 Section 104.3.3
Test gauge for pressure tests of 10 psi or lessvsTest gauge for tests over 10 psi up to 100 psi

Tests of 10 psi or less require gauges of 0.10 psi incrementation or less, while tests exceeding 10 psi but not more than 100 psi require gauges of 1 psi incrementation or less; in both cases the gauge range must not exceed twice the test pressure applied.

ISPC 2017 Sections 318.3 and 318.5
InvertvsGrade

The invert is the lowest portion of the inside of a horizontal pipe, whereas grade is the slope or fall of a line of pipe in reference to a horizontal plane.

ISPC 2017 Section 211.0 - Invert
Battery of fixtures (common horizontal branch)vsFixtures on a common vertical stack

A battery of fixtures is two or more similar, adjacent fixtures discharging into a common horizontal waste or soil branch — not into a common vertical waste or soil stack.

ISPC 2017 Section 204.0

Key Terms

Building Drain ISPC 2017 Section 204.0 - Building Drain
That part of the lowest piping of a drainage system that receives discharge from soil, waste, and other drainage pipes inside the building walls and conveys it to the building sewer, beginning 2 feet (610 mm) outside the building wall.
Hot Water ISPC 2017 Section 210.0 - Hot Water
Water at a temperature exceeding or equal to 120°F (49°C).
Horizontal Pipe ISPC 2017 Section 210.0 - Horizontal Pipe
A pipe or fitting installed in a horizontal position or which makes an angle of less than 45 degrees (0.79 rad) with the horizontal.
Gravity Grease Interceptor ISPC 2017 Section 209.0 - Gravity Grease Interceptor
An interceptor identified by volume, 30-minute retention time, baffle(s), not less than two compartments, a total volume of not less than 300 gallons (1135 L), and gravity separation.
Confined Space ISPC 2017 Section 205.0 (Confined Space definition)
A room or space having a volume less than 50 cubic feet per 1000 Btu/h (4.83 m³/kW) of the aggregate input rating of all fuel-burning appliances installed in that space.
Appliance, Low-Heat ISPC 2017 Section 203.0 (Appliance, Low-Heat definition)
A fuel-burning appliance producing a continuous flue gas temperature, at the point of entrance to the flue, of not more than 1000°F (538°C).
Chimney, Low-Heat Appliance-Type ISPC 2017 Section 205.0
A chimney suitable for removing products of combustion from low-heat appliances producing combustion gases not in excess of 1000°F (538°C) under normal operating conditions, but capable of 1400°F (760°C) during intermittent forced firing for periods up to one hour.
Bathroom Group ISPC 2017 Section 204.0 (Bathroom Group definition)
Any combination of fixtures not to exceed one water closet, two lavatories, either one bathtub or one combination bath/shower, and one shower, and may include a bidet and an emergency floor drain.
Insanitary ISPC 2017 Section 211.0 (Insanitary definition)
A condition such as a trap that does not maintain a proper trap seal, or a trap directly connected to a drainage system whose seal is not protected against siphonage and backpressure by a vent pipe.
Cross-Connection ISPC 2017 Section 205.0
A connection or arrangement, physical or otherwise, between a potable water supply system and a fixture, tank, receptor, equipment, or device through which nonpotable, used, unclean, polluted, or contaminated water or other substances may enter the potable water system under any condition.
Pollution ISPC 2017 Section 218.0 (Pollution)
An impairment of potable water quality that does not create a public health hazard but adversely and unreasonably affects the aesthetic qualities of the water for domestic use; also defined as "Low Hazard."
Trap Seal ISPC 2017 Section 221.0 - Trap Seal
The vertical distance between the crown weir and the top dip of the trap.
Yoke Vent ISPC 2017 Section 222.0 - Yoke Vent
A pipe connecting upward from a soil or waste stack to a vent stack for the purpose of preventing pressure changes in the stacks.
Mulch Basin ISPC 2017 Section 215.0 - Mulch Basin
A subsurface catchment area for gray water filled with mulch and of sufficient depth and volume to prevent ponding, surfacing, or runoff.
Gray Water Diverter Valve ISPC 2017 Section 209.0 - Gray Water Diverter Valve
A valve that directs gray water either to the sanitary drainage system or to a subsurface irrigation system.
Joint, Flanged ISPC 2017 Section 212.0 - Joint, Flanged
A joint made by bolting together a pair of flanged ends (distinct from compression, flared, and general mechanical joints).

Formulas to Know

Static pressure from height of water (head)Static pressure (psi) = height of water above the point (ft) × 0.433 psi/ft; for a gravity system between two elevations use the elevation difference (e.g., 150 ft − 74 ft = 76 ft × 0.433 = 32.91 psi, then subtract friction losses).
Height of water column needed for a given pressureHeight (ft) = pressure (psi) ÷ 0.433 psi/ft, or equivalently pressure (psi) × 2.31 ft/psi (2.31 is the reciprocal of 0.433).
Pressure available to overcome pipe frictionAvailable psi = static pressure at main/meter − (height above meter × 0.433) − meter loss − other device losses (e.g., backflow preventer) − minimum required residual/flow pressure at the fixture.
Allowable friction loss rate per 100 feetRate (psi/100 ft) = (available friction pressure ÷ total equivalent length including fittings) × 100.
Equivalent length with fittings allowanceEquivalent length = developed length (service + main + riser + branch) × 1.5 (adding the printed 50% allowance for fittings).
Identifying the controlling (governing) outletFor each outlet compute: main static pressure − meter loss − (elevation ft × 0.433) − required flow pressure at that outlet; the outlet with the LEAST remaining pressure governs the design (may not be the highest outlet).
Minimum pump discharge pressurePump discharge psi = (lift height ft × 0.433) + piping friction loss + required residual pressure at the fixture (street main pressure and meter loss affect inlet conditions, not the discharge requirement).
Volume and gallon capacity of cylindrical/half-cylindrical vessels and pipeCylinder: V = π × r² × h (use radius, not diameter); half-cylinder trough: V = (π × r² × L) ÷ 2; convert to gallons by multiplying cubic feet × 7.48 gal/ft³ (convert inch dimensions to feet first).
Time to fill a vesselMinutes = (L × W × D in cubic feet × 7.48 gal/ft³) ÷ flow rate in gpm.
Minimum trench width for thermoplastic sewer pipeTrench width = 1.25 × outside diameter + 12 in, OR outside diameter + 16 in (for a 4-in OD pipe: 17 in or 20 in; use 20 in to satisfy both).
Start free practice Full study guide