Which type of fittings may be used in vertical drainage systems in plumbing?

In vertical drainage systems, various types of fittings can be utilized effectively to manage the flow and direction of wastewater. An elbow fitting is used to change the direction of the drainage pipe, which is essential in vertical configurations to route the pipe around obstacles or to connect to horizontal runs. Tee fittings are crucial as they enable the connection of additional branch lines to the main vertical pipe, allowing for the efficient drainage of multiple fixtures. Likewise, a wye fitting serves a similar purpose by connecting two branches at an angle, which can help maintain flow direction and minimize turbulence in the system.

The inclusion of all these fittings—elbows, tees, and wyes—in vertical drainage systems enhances their functionality and adaptability in various plumbing scenarios. This broad array of fittings is necessary to ensure that the system can handle the complex routing demands typically found in buildings. Thus, selecting 'All of the above' acknowledges that each fitting has a specific role in ensuring the effective operation of vertical drainage.