A change in direction of a sewer shall be made only with certain types of fittings. Which of these types is incorrect?

In plumbing, particularly in sewer systems, the direction of pipes must be managed carefully to maintain flow and prevent blockages. Among the options provided, using fittings like elbows, wyes, and tees is acceptable for changing the direction of sewer pipes.

Elbows are commonly used to make sharp turns, and they come in various degrees to accommodate different angles. Wyes are utilized for branching off, allowing for a smooth transition to another sewer line at a different angle. Tees also facilitate the joining of pipes, allowing for flow in multiple directions without significant disruption.

In contrast, a fourteenth bend is not a standard fitting used for plumbing applications. The curvature and angle of such a bend are atypical and not designed for proper sewer flow. Its use could lead to reduced efficiency and increased risk of clogs, making it an unsuitable choice for this purpose. Therefore, identifying it as the incorrect type of fitting for changing the direction of a sewer is accurate and highlights the importance of using appropriate plumbing fittings to ensure reliable system operation.