Which plumbing fitting is used to change the direction of a pipe by 90 degrees?

The elbow fitting is specifically designed to change the direction of a pipe by 90 degrees. This type of fitting allows for a sharp turn in the pipe run, which is often necessary in plumbing systems to navigate around obstacles or to direct water flow towards the desired destination. The elbow is commonly used in various plumbing applications, ranging from residential plumbing to industrial installations, and is available in different materials and sizes to suit different pipe systems.

In contrast, the coupling fitting is primarily used to connect two sections of pipe in a straight line without altering the direction. The reducer fitting serves to connect pipes of different diameters, allowing for a gradual change in size rather than direction. The union fitting is utilized for creating a permanent connection between two pipes that can later be easily disconnected for maintenance purposes, but does not facilitate a change in direction.