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100+ Free AZ ROC R-37R Plumbing Practice Questions

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2026 Statistics

Key Facts: AZ ROC R-37R Plumbing Exam

100 Questions

Official Question Count

PSI R-37R content outline

240 Minutes

Time Limit

PSI R-37R content outline

70%

Passing Score

PSI R-37R content outline

$66

Trade Exam Fee

roc.az.gov/licensing-fees

$61

Statutes and Rules Exam Fee

roc.az.gov/licensing-fees

13 Areas

Subject Areas

PSI R-37R content outline

The Arizona ROC R-37R Plumbing (Residential) Examination is 100 scored multiple-choice questions in 240 minutes, open book, with a 70% passing score and a $66 PSI exam fee. This free bank is an English-language multiple-choice study aid weighted to the official PSI subject areas; it is not the official exam and does not reproduce PSI items.

Sample AZ ROC R-37R Plumbing Practice Questions

Try these sample questions to test your AZ ROC R-37R Plumbing exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1What is the standard minimum slope required per foot for horizontal drainage piping with a diameter of 2 inches or less?
A.1/8 inch per foot
B.1/4 inch per foot
C.1/2 inch per foot
D.1 inch per foot
Explanation: Per standard plumbing codes (IPC/UPC), horizontal drainage piping of 2-1/2 inches or less in diameter must be installed with a minimum slope of 1/4 inch per foot (2 percent slope) toward the sewer to maintain proper cleansing velocity.
2In 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?
A.1 DFU
B.2 DFUs
C.3 DFUs
D.6 DFUs
Explanation: Under standard DWV sizing tables (IPC Table 709.1 / UPC Table 702.1), a gravity tank water closet (1.6 gpf or 1.28 gpf) is assigned a value of 3 DFUs for drainage design.
3What is the minimum diameter required for a trap arm serving a standard residential lavatory?
A.1 inch
B.1-1/4 inches
C.1-1/2 inches
D.2 inches
Explanation: Standard plumbing codes require a minimum trap size and trap arm diameter of 1-1/4 inches for a residential bathroom lavatory.
4According 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?
A.3 feet
B.5 feet
C.6 feet
D.8 feet
Explanation: Under the IPC (Table 909.1), the maximum developed distance from the trap weir to the vent fitting for a 1-1/2 inch trap arm at a 1/4 inch per foot slope is 6 feet. (Under the UPC it is 3 ft 6 in, but IPC allows up to 6 ft).
5A 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?
A.8 DFUs, requiring a 2-inch pipe
B.10 DFUs, requiring a 3-inch pipe
C.10 DFUs, requiring a 2-inch pipe
D.12 DFUs, requiring a 4-inch pipe
Explanation: Total DFU = (2 × 3) + (2 × 1) + (1 × 2) = 6 + 2 + 2 = 10 DFUs. Because the branch receives discharge from water closets, the minimum size is 3 inches (a 2-inch drain cannot carry water closets, which require a 3-inch minimum drain).
6To 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?
A.Half the pipe diameter
B.One pipe diameter
C.Two pipe diameters
D.Three pipe diameters
Explanation: The vertical distance or fall between the trap weir and the vent fitting inlet must not exceed one inside diameter of the trap arm pipe. Exceeding one pipe diameter creates an S-trap condition, leading to siphoning.
7What is the maximum allowable distance between cleanouts on a 4-inch horizontal drainage pipe inside or under a building?
A.50 feet
B.75 feet
C.100 feet
D.150 feet
Explanation: Cleanouts must be installed at intervals not exceeding 100 feet in horizontal drainage lines of 4 inches or smaller.
8A 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?
A.6 inches
B.12 inches
C.18 inches
D.24 inches
Explanation: Total vertical drop = Length × Slope = 48 feet × 0.25 inches/foot = 12 inches (or 1 foot).
9Where 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?
A.1 foot above or 5 feet horizontally
B.2 feet above or 10 feet horizontally
C.3 feet above or 6 feet horizontally
D.4 feet above or 12 feet horizontally
Explanation: Plumbing code requires vent terminals to be located at least 2 feet above any openable door, window, or air intake, or at least 10 feet horizontally away from them, to prevent sewer gases from entering the building envelope.
10Under 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?
A.3 inches
B.6 inches
C.12 inches
D.18 inches
Explanation: Vents extending through a roof must terminate at least 6 inches above the roof surface (or higher where snow accumulation dictates local cold-climate adjustments).

About the AZ ROC R-37R Plumbing Exam

The Arizona ROC R-37R Plumbing (Residential) Examination is the open-book, computer-delivered PSI trade exam for the Arizona Registrar of Contractors R-37R residential plumbing classification. Its official content outline runs 100 scored questions in 240 minutes at a 70% passing score across 13 subject areas, and code items are drawn from the 2018 International Plumbing Code, 2018 International Fuel Gas Code, 2018 International Mechanical Code, NFPA 13/13D/13R, and Arizona Administrative Code Title 18 Chapter 9. The R-37R trade exam is taken in addition to the mandatory Arizona Statutes and Rules Training Course and Exam (SRE).

Assessment

One 100-question open-book multiple-choice trade examination, 240 minutes, 70% to pass. Code questions are written to the exact editions named in the PSI R-37R reference list (International Plumbing Code 2018, International Fuel Gas Code 2018, International Mechanical Code 2018, NFPA 13/13D/13R, and Arizona Administrative Code Title 18 Chapter 9).

Time Limit

240 minutes

Passing Score

70%

Exam Fee

$66 (Arizona ROC / PSI Services LLC)

AZ ROC R-37R Plumbing Exam Content Outline

16%

Drainage Waste and Vents

Building drains, branch drains, DFU loading, drain slope, cleanouts, stack sizing, individual/common/wet venting, air admittance valves, and trap-arm limits.

13%

Water Supply Systems

Water service and distribution sizing by WSFU, pressure loss and static head, approved pipe materials and joints, valves, hangers, and disinfection.

10%

General Knowledge and General Regulations

Permits, inspections, approved materials and listings, workmanship, testing of rough and finished work, and Arizona contractor regulations.

10%

Fuel Gas

IFGC/NFPA 54 gas pipe sizing tables, appliance shutoffs, sediment traps, CSST bonding, combustion air, venting categories, and gas pressure tests.

10%

Septic and Sewer

Building sewer materials and sizing, on-site wastewater treatment under Arizona Administrative Code Title 18 Chapter 9, septic tank and disposal field siting, and setbacks.

7%

Plumbing Fixtures (including water heaters and accessibility)

Fixture clearances and rough-in, water closets, showers and tubs, mixing valves and scald limits, water heater installation, T&P relief piping, and accessibility.

5%

Backflow Prevention

Cross-connection hazard classes, air gaps, atmospheric and pressure vacuum breakers, DCVA and RPZ selection, and test/maintenance duties.

5%

Roof Drains and Storm Drainage Systems

Roof drain and overflow sizing, rainfall-rate design, conductors and leaders, and separation of storm from sanitary drainage.

5%

Specialty Plumbing, Interceptors, and Traps

Grease and sand interceptors, special-waste and indirect-waste receptors, trap seals and primers, and prohibited trap types.

5%

Isometric Analysis

Reading and checking DWV and water-supply isometric drawings for correct fittings, fixture connections, vent takeoffs, and code compliance.

5%

Fire Sprinklers

Residential sprinkler provisions referenced by NFPA 13, 13D and 13R, supply connections, and coordination with the domestic water system.

5%

Excavation

Trenching and shoring under OSHA 29 CFR 1926 Subpart P, soil classification, pipe bedding and backfill, and Arizona 811 utility locates.

4%

Indirect Waste

Indirect waste piping, required air gaps and air breaks, waste receptors, and appliance drains such as clothes washers and dishwashers.

How to Pass the AZ ROC R-37R Plumbing Exam

What You Need to Know

  • Passing score: 70%
  • Assessment: One 100-question open-book multiple-choice trade examination, 240 minutes, 70% to pass. Code questions are written to the exact editions named in the PSI R-37R reference list (International Plumbing Code 2018, International Fuel Gas Code 2018, International Mechanical Code 2018, NFPA 13/13D/13R, and Arizona Administrative Code Title 18 Chapter 9).
  • Time limit: 240 minutes
  • Exam fee: $66

Keys to Passing

  • Work through all 100 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

AZ ROC R-37R Plumbing Study Tips from Top Performers

1Minimum slope for horizontal drainage pipe 2-1/2 inches and smaller is 1/4 inch per foot; 3-inch through 6-inch pipe may drop to 1/8 inch per foot where approved.
2Learn IPC Table 909.1 trap-arm distances (1-1/4 in = 5 ft, 1-1/2 in = 6 ft, 2 in = 8 ft, 3 in = 12 ft). The exam is written to the IPC, not the UPC, so do not memorize UPC trap-arm limits.
3A DWV water test fills the system to a minimum 10-foot head for 15 minutes; the alternative air test is 5 psi for 15 minutes.
4Isometric Analysis and Septic and Sewer are each worth 5 and 10 questions - practice reading DWV isometrics and review Arizona Administrative Code Title 18, Chapter 9 on-site wastewater rules.
5Tab the 2018 IPC, 2018 IFGC and NFPA 13D before exam day; open-book time management is the main constraint over 240 minutes.

Frequently Asked Questions

How many questions are on the official Arizona ROC R-37R exam?

The PSI content outline for R-37R lists 100 scored multiple-choice questions with 240 minutes of testing time.

What is the passing score for the AZ ROC R-37R exam?

70%, which is 70 correct answers out of the 100 scored questions. The trade exam and the Arizona Statutes and Rules Exam are scored separately.

Which code editions does the R-37R exam use?

PSI writes R-37R code questions only to the editions in its reference list: the 2018 International Plumbing Code, 2018 International Fuel Gas Code, 2018 International Mechanical Code, and NFPA 13, 13D and 13R.

Is the R-37R exam open book?

Yes. Candidates bring their own bound references, which may be tabbed with permanent tabs and highlighted before the session but not written in during the exam.

What does R-37 include that R-37R does not?

R-37 Plumbing, Including Solar covers everything in R-37R plus solar applications, and R-37 candidates sit an extra 30-question, 75-minute R-37 Solar examination.