Which fittings are used to change pipe direction by 90 or 45 degrees?

The fittings used to change the direction of pipes by 90 or 45 degrees are called elbows. These fittings are specifically designed to allow for bends in piping, enabling a change in direction without losing continuity.

When managing plumbing or piping systems, elbows facilitate the flow of liquids or gases around obstacles or in different directions, this minimizes the need for additional fittings and connections which could increase the chances of leaks.

Tees, on the other hand, are used to join three pipes together and create a branch, which does not pertain to changing direction. Reducers are used to connect pipes of different diameters, and adapters are fittings that allow two different sized pipes or connection types to be joined together. Each of these serves distinct functions that do not specifically involve changing the direction by 90 or 45 degrees.