Which type of fitting is used for horizontal branch connections to the stack in a vertical position?

The appropriate fitting for horizontal branch connections to a vertical stack is the sanitary tee. This fitting is specifically designed to facilitate the proper flow of waste and drainage while minimizing the risk of clogs and backups. The sanitary tee allows for the branch line to connect in a way that maintains a smooth transition and encourages gravity flow, which is essential in plumbing systems.

Using a sanitary tee is crucial in vertical applications because it effectively directs waste flow from the branch to the stack at an angle that helps avoid turbulence and ensures that solids can easily pass through without getting trapped. This design helps prevent blockages and supports effective drainage across the system.

In contrast, other fittings such as elbow fittings or long radius tee-wyes may not provide the same level of performance in this specific application, as they are not engineered to accommodate horizontal branches in a vertical arrangement as optimally as a sanitary tee does. A pipe coupler, on the other hand, is intended solely for joining two pieces of pipe and does not serve the functional role needed for branch connections.