2024 Commercial Plumbing Inspector – Practice Exam

1. Following construction, new potable water systems must be filled with a water/chlorine solution containing not less than 50 parts per million (50 mg/L) of chlorine and allowed to stand for what minimum duration?

2. What is strictly prohibited regarding the trapping of a single fixture?

3. Gravity grease interceptors shall be designed and tested in accordance with which standard?

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

5. In a sewage pump or ejector system (non-pneumatic), the drainage piping below sewer level must be vented in what manner?

6. Electrically operated, refrigerated drinking water coolers must be listed and labeled in accordance with which standard?

7. For a 4-inch building drain with a slope of 1/8 inch per foot, what is the maximum number of drainage fixture units permitted?

8. A potable water-supplied trap seal primer valve must conform to which standard?

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

10. Components of a plumbing system installed along alleyways, driveways, parking garages or other locations exposed to damage shall be recessed into the wall or otherwise protected in what manner?

11. In which situation shall the code official not be required to give a written notice prior to stopping the work?

12. What is the minimum required weight for sheet lead used for prefabricated vent pipe flashings?

13. What is the minimum required diameter for a water service pipe?

14. How must the discharge piping from a grease interceptor connect to the sanitary drainage system?

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

16. In making solder joints for copper pipe, the solder must conform to which standard?

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

18. Backflow preventers with intermediate atmospheric vents are permitted to be installed where subject to what condition?

19. Sewage pumps or ejectors that receive the discharge of water closets must be capable of handling spherical solids with a diameter up to what maximum dimension?

20. In a combination potable water heating and space heating system requiring space heating water temperatures greater than 140°F (60°C), what is the maximum temperature the mixing valve must limit the potable hot water distribution system to?

21. A fixture combining one sink and laundry tray or a two- or three-compartment sink or laundry tray in one unit is defined as what?

22. What is the maximum liquid seal required for each fixture trap?

23. What must the design of reclaimed water systems conform to?

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

25. According to Table 604.10.1, what is the maximum demand (gpm) allowed for a 1-inch manifold sized for a velocity of 8 feet per second?

26. After completion of the entire system installation, a vacuum drainage system must be subjected to a vacuum test of what minimum measurement?

27. What is the maximum developed length allowed for individual seepage trenches?

28. 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?

29. What quality is required for porcelain enameled surfaces on plumbing fixtures?

30. What two types of valves must the discharge piping of a storm sump pump system include, in non-dwelling applications?

31. Sanitary floor sinks must conform to which standard?

32. The vent system for a chemical waste drainage system must be tested for chemical resistance in accordance with what standard?

33. Where must a water-hammer arrestor be installed?

34. If a laundry tray waste line connects to a standpipe for an automatic clothes washer drain, what is the minimum required height of the standpipe above the trap weir?

35. Where must the opening of the overflow pipe in a flush tank be located relative to the flood level rim of the water closet or urinal?

36. Where stack vents and vent stacks connect into a common vent header, how must the developed length be determined for sizing?

37. What is the minimum required width for the continuous solid flooring in the attic passageway leading to a water heater?

38. In business occupancies, what is the required ratio for drinking fountains?

39. Reduced pressure principle, double check, and pressure vacuum breaker backflow preventer assemblies must be tested at the time of installation, immediately after repairs or relocation, and at least how often thereafter?

40. What is prohibited from being installed in the discharge piping serving a relief valve?

41. If hot and cold water is supplied to an emergency shower, what standard must the temperature-actuated mixing valve comply with?

42. What is the minimum diameter required for a floor drain outlet?

43. What is the maximum developed length allowed for hot or tempered water piping from the source to the fixture?

44. What material must storm water traps be made of?

45. Where must the maximum allowable working pressure be clearly and indelibly marked on domestic hot water storage tanks and water heaters?

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

47. What document governs all maintenance and operations of nonflammable medical gas systems and nonmedical oxygen systems?

48. Bends are prohibited within what distance of any fitting or valve in polyethylene (PE) pipe installation?

49. Third-party certifiers or inspectors for cast-iron soil pipes and fittings shall comply with the minimum inspection requirements of Annex A or Annex A1 of which specified standards?

50. Where must the valve on the cold water branch line supplying a hot water storage tank or water heater be located?

51. Where must the trap priming fixture drain connect to the receiving floor drain, trench drain, or floor sink?

52. For a protected vent terminal, the roof element covering the vent pipe must provide an open area to the outdoors that is not less than what area?

53. Based on Table 314.2.2, what is the minimum condensate pipe diameter required for equipment capacity up to 20 tons of refrigeration?

54. What type of joint must be used between different piping materials?

55. What must a hub drain be in the form of, extending above a water-impervious floor?

56. Where must the termination point of the relief valve discharge piping be located?

57. The cleanout serving the junction of the building drain and the building sewer must be located at the junction or within what developed length upstream of the junction?

58. What is the water supply fixture unit value for a vacuum-type water closet?

59. What is the minimum required depth for an oil separator below the invert of the discharge drain?

60. What is the minimum required weight for sheet copper used for vent pipe flashings?