In enhancement to elbows, carbon steel pipe fittings additionally consist of tees, which connect 3 areas of pipe, producing joints for fluid circulation. Equal tees are used when the linking branches are of the same size, while reducing tees are used when the branch pipe is of a smaller size. https://lexyness.com/seamless-vs-welded-elbows-understanding-the-best-fit-for-your-needs/