Massachusetts Plumbers Journeyman Practice Exam

How many fixtures may be installed in a battery waste-and-vented system if a vent is provided for every eight fixtures?

1. 6

2. 8

3. 10

4. 12

The correct answer is: 8

In a battery waste-and-vented system, when a vent is provided for every eight fixtures, the regulation is based on the concept of maintaining proper drainage and venting for the plumbing system's performance. Each vent allows for the equalization of pressure within the system, facilitating the efficient flow of waste and preventing siphonage or backpressure that could disrupt the system's function. Given that the rule states a vent for every eight fixtures, it is clear that a maximum of eight fixtures can be serviced effectively without needing additional vents. Therefore, when constructing or analyzing such a system, you can install up to eight fixtures to comply with this venting requirement. This ensures that all fixtures function correctly and meet plumbing code standards for effective drainage and air flow. In contrast, if the number of fixtures exceeds eight without additional venting, it may compromise the system's performance, leading to potential operational issues, such as slow drainage or backups. The design must adhere to this guideline to maintain a well-functioning plumbing system.