2024 Commercial Plumbing Inspector – Practice Exam

1. In institutional occupancies, employee toilet facilities must be kept separate from facilities serving whom?

2. What is the minimum required air gap for lavatories with effective openings not greater than 1/2 inch in diameter, when installed close to a wall?

3. When does a waste receptor receiving indirect waste not require a trap?

4. For a water heater installed in an attic, what is the minimum required height for the unobstructed passageway?

5. The potable water supply to lawn irrigation systems must be protected against backflow by an atmospheric vacuum breaker, a pressure vacuum breaker assembly, or what other assembly?

6. What temperature defines Hot Water?

7. If multiple buildings are located on the same lot, what are they permitted to connect to before connecting to the public sewer?

8. In nightclubs, bars, taverns, dance halls and buildings for similar purposes (Assembly occupancy), what is the minimum required lavatory ratio?

9. For piping with a diameter of 2 1/2 inches to 6 inches, what is the minimum required size for the lettering on the pipe identification?

10. After construction, how must an individual water supply system be treated before utilization?

11. Where are cross connections permitted?

12. Where drainage piping is roughed-in for future fixtures, what is the minimum required size for the rough-in vent connection?

13. Siphonic roof drains and drainage systems must be designed in accordance with which two standards?

14. Hot water supply systems must be equipped with automatic temperature controls capable of adjustment across what range?

15. For the purposes of calculating the minimum number of lavatories required, how much rim space of a group wash fixture shall be considered as one lavatory?

16. What material is prohibited from being used for the threaded connection at the end of relief valve discharge pipe?

17. The secondary (emergency) roof drain systems must be sized based on the rainfall rate for which system?

18. What is the minimum required water seal for the outlet opening of an oil separator?

19. What is the maximum vertical spacing allowed for Cross-linked polyethylene (PEX) pipe that is 1 1/4 inches and larger?

20. What is the minimum clear and unobstructed finished width required for the shower compartment access and egress opening?

21. What is the minimum required diameter for the indirect waste pipe used to drain the pan?

22. Based on Table 906.5.1, for a pump discharge capacity of 60 gpm, what is the maximum developed length allowed for a 2-inch diameter sump vent?

23. What is the maximum temperature permitted for water supplied by tankless water heaters intended for domestic uses?

24. What is the minimum flow pressure required at the fixture supply outlet for a residential sink?

25. When solvent cementing ABS plastic joints, the solvent cement must conform to which standard?

26. Gravity sewer tests shall consist of plugging the end of the building sewer, filling with water, testing with not less than a 10-foot (3048 mm) head of water, and maintaining pressure for what duration?

27. What is strictly prohibited from covering cleanout plugs?

28. Where a vitrified clay or other brittleware, acid-resisting trap is installed underground, how far beyond the bottom and sides of the trap must the concrete embedment extend?

29. Which type of trap is prohibited because it relies on interior partitions for the seal, unless made of approved material resistant to corrosion?

30. Where vent terminals extend through the side wall, what is the minimum distance required from the lot line?

31. What is the maximum travel distance for public drinking fountains in a covered or open mall relative to a tenant space?

32. Where the public sewer is a combined system for both sanitary and storm water, how must the sanitary sewer connect to the public sewer?

33. Storage water heaters operating above atmospheric pressure must be provided with an approved, self-closing (levered) pressure relief valve, a temperature relief valve, or a combination thereof, conforming to which standard?

34. Dispensing systems that dispense interceptor performance additives are prohibited unless the system dispenses what substance for the enhancement of aerobic bioremediation?

35. For percolation tests in “Other Soils,” what is the minimum and maximum period allowed for the soil to swell after the 4-hour saturation period?

36. Where is a food waste disposer prohibited from discharging its waste?

37. For an alternative engineered design, how many complete sets of signed and sealed construction documents must the registered design professional submit to the code official?

38. Where must the discharge pipe from a potable water-supplied trap seal primer valve connect to the trap?

39. Double sanitary tee patterns are prohibited from receiving the discharge of back-to-back water closets unless the horizontal developed length between the outlet of the water closet and the connection to the double sanitary tee pattern is what minimum length?

40. For caulked joints on hub and spigot cast-iron pipe, the molten lead must be poured to a depth of not less than what minimum dimension?

41. Where are slip joints permitted to be installed on a trap?

42. What characteristic are threaded drainage pipe fittings required to have?

43. When calculating minimum plumbing fixtures, how are fractional numbers of persons resulting from applying fixture ratios handled?

44. Underground water service pipe installed outside the structure must have a working pressure rating of not less than what minimum pressure at 73.4°F (23°C)?

45. The relieving capacity of each pressure or temperature relief valve must equal or exceed what characteristic of the water heater or storage tank?

46. How long must the code official retain one set of approved construction documents, or as required by state or local laws?

47. How must the construction and installation methods for a chemical waste drainage vent system conform?

48. Which standard must dual check-valve backflow preventers installed on the water supply system comply with?

49. Where water pressure from the street main is insufficient to provide the required flow pressures, what system must be installed?

50. How must the water supply to an automatic clothes washer be protected against backflow?

51. If the 97.5-percent outdoor design temperature is 0°F (-18°C) or less, what is the minimum required diameter for vent extensions through a roof or wall?

52. What is the maximum horizontal distance allowed between the outlet of a laundry tray and the side of the standpipe it connects to?

53. Waste products from manufacturing or industrial operations shall not be introduced into the public sewer until what specific determination has been made by the code official or other authority having jurisdiction?

54. Metallic piping, excluding cast iron, ductile iron and galvanized steel, shall not be placed in direct contact with which surrounding components?

55. How are fixtures located in single-user toilet facilities and bathing rooms accounted for in the total required fixture count for a building?

56. Nonmedical oxygen systems must be designed and installed in accordance with which combination of standards?

57. Where must the hot water or tempered water return line be routed when a temperature-actuated mixing valve is used in a recirculating system?

58. Based on Table 906.1, for a 2 1/2-inch soil or waste stack with a total fixture unit load of 42 dfu, what is the maximum developed length allowed if a 2-inch diameter vent is used?

59. In climates where the 97.5-percent value for outside design temperature is less than 0°F (-18°C), what protection is required for vent pipes installed on the exterior of the structure?

60. What is the minimum size requirement for a manhole for a below-grade nonpotable water storage tank located outside of a building?