Massachusetts Plumbers Journeyman Practice Exam

According to the text, what size of an indirect waste pipe should a fixture with a waste outlet smaller than 1¼ inches in diameter be connected to?

1. Same size as outlet

2. One size smaller

3. One size larger

4. Two sizes larger

The correct answer is: One size larger

The correct response indicates that a fixture with a waste outlet smaller than 1¼ inches in diameter should be connected to an indirect waste pipe that is one size larger. This requirement is rooted in plumbing design principles, which dictate that when connecting a smaller diameter outlet to a waste system, it is often necessary to increase the pipe size to accommodate potential flow and drainage requirements. By selecting a larger pipe size, you ensure that there is adequate capacity for the waste to flow freely, reducing the risk of blockages and improving the overall efficiency of the drainage system. This practice also helps to minimize potential issues related to backflow or slow drainage, contributing to a cleaner and safer plumbing environment. In contrast, connecting to a pipe of the same size could lead to restricted flow, while using a smaller pipe would exacerbate those issues further. Similarly, opting for an excessively larger pipe than necessary might introduce unnecessary cost and complexity to the plumbing system without providing significant benefits. Therefore, choosing one size larger strikes a balance between functionality and efficiency in the plumbing setup.