Plumbers use ____ to change the direction of the pipe.

Plumbers use elbows to change the direction of the pipe because they are specifically designed for this purpose. An elbow is a fitting that allows pipes to bend at an angle, commonly 90 or 45 degrees. This feature is essential in plumbing systems for steering pipes around obstacles or directing flow through walls or corners.

In contrast, while reducers, couplings, and adaptors all play important roles in plumbing, they serve different functions. Reducers are used to connect pipes of different diameters, ensuring that the flow is maintained while adapting to varying sizes. Couplings serve as connectors for two sections of pipe, allowing for the extension of a plumbing system without changing direction. Adaptors similarly connect different types of pipes or fittings, but they do not facilitate bending or directing the flow. Thus, elbows are the fitting to choose when the goal is to alter the pipe direction.