Rhode Island Journeyman Plumber Practice Exam

How should the size of a vent be determined?

1. By its type

2. By its length

3. By its usage

4. By its capacity

The correct answer is: By its capacity

The size of a vent should be determined by its capacity, which refers to the maximum volume of air and gases that the vent can effectively handle. This is important because a properly sized vent ensures that plumbing fixtures can drain effectively while providing the necessary air circulation to prevent negative pressure within the drain system. If a vent is too small, it may create a vacuum that can impede drainage and lead to issues such as slow drainage or trap siphoning. Capacity also relates to the size of the plumbing fixtures that the vent serves as well as the overall plumbing design. By evaluating the capacity requirements based on the expected flow and the number of fixtures, one can select an appropriately sized vent that complies with building codes and ensures optimal performance of the plumbing system.