Latest Version: 6.0
Question: 1
Where can a backflow device with an atmospheric vent be installed?
A. Below ground
B. Ground level
C. In pits
D. Above ground
Explanation:
Answer: D
Backflow preventers that have ports and vents must be installed above ground. They cannot be installed level with the ground or in a sealed pit because they utilize atmospheric pressure to help prevent backflow.
Question: 2
Which of the following best describes a permanent seal that is pushed on or mechanically fastened?
A. Soldered
B. Solvent cement
C. Mechanical joint
D. Fusion
Explanation:
Answer: C
Mechanical joints can be present for all types of piping and can either be a push-on fitting or a mechanically fastened joint that usually includes some type of elastomeric gasket. We must always check with manufacturers' specifications when using these items to ensure there are no limitations on where they can be placed.
Question: 3
Which of the following scenarios could supply a 5 psi gas system inside the building?
A. Laundromat
B. Restaurant
C. Single dwelling unit with threaded steel
D. Warehouse with welded joints
Answer: D
Explanation:
The single house dwelling unit, restaurant, and laundromat do not meet the requirements that the code stipulates to allow them to run 5 psi inside the structure. The warehouse and the welded joints are both exceptions that allow there to be a 5 psi line inside the structure.
Question: 4
When can a clothes washer standpipe be installed below the floor level?
A. When permitted
B. If space allows
C. Sometimes
D. Never
Explanation:
Answer: D
Clothes washer standpipes must never be installed below the floor level, but also can not be installed more than 18 inches above the floor. This is one fixture that is held to standards to ensure there are no failures when it comes to excess suds.
Question: 5
When there are two fixtures that are set back to back or side by side, and they are within the distance required between the trap and vent, how many drain lines are needed to serve the fixtures?
A. Four
B. Three
C. One
D. Two
Explanation:
Answer: C
If the fixtures are side by side or back to back, they can be serviced with only one drain line, and the proper double fittings must be used (i.e., sanitary tee). There is no common scenario in which you would need more than one waste line.
Question: 6
What is the main purpose of a p-trap?
A. To collect debris
B. To prevent back-ups
C. To seal sewer gases
D. To prevent cross-connections
Explanation:
Answer: C
The main purpose of the p-trap is to prevent any sewer gasses from escaping into the building. Backflow preventers prevent cross connections, backwater valves prevent back-ups when located upstream of the clog, and wye strainers are devices that can be installed on potable systems to catch large debris that may be present in the water.
Question: 7
When should dielectric unions be used?
A. When PEX attaches to copper
B. When PEX attaches to PVC
C. When copper attaches to copper
D. When two dissimilar metals connect
Explanation:
Answer: D
Dielectric unions should be used when two dissimilar metals connect. A perfect example of this would be galvanized iron pipe and copper needing to be connected. This would be required to prevent galvanic corrosion.
Question: 8
When dealing with multi-dwelling units, why must there be one or more shut-offs throughout the unit?
A. To keep homeowners from turning their water off
B. Routine maintenance
C. To be able to work on one unit without having to shut the other one down
D. For emergencies only
Explanation:
Answer: C
Individual water shut-offs on the inside of separate dwellings allow people to operate and work on separate systems if needed, without affecting the other units next door.
Individual shut-offs do come in handy in emergencies, but that is not the main reason for them. When homeowners know the location of their shut-off, they can turn off the water in an emergency,
Question: 9
When installing black iron gas systems underground, what is the minimum depth it must be buried?
A. 10 inches
B. 12 inches
C. 14 inches
D. 18 inches
Explanation:
Answer: B
The minimum cover is 12 inches, but if there are chances of the piping being damaged by external factors in the soil, it should be increased to 18 inches.
Question: 10
What is the main characteristic needed for each trap?
A. Accessible
B. Slip-joint
C. Concealed
D. Self-cleaning
Answer: D
Explanation: Each trap needs to be self-cleaning. Although it is nice if they are accessible (i.e., in a cabinet), that isn't always the case for tubs, showers, and other concealed traps. It is helpful if traps are concealed, accessible, and slip-joint, but it is not required.
