Three-way connectors, also known as pipe fittings three-way or three-way pipe fittings, and three-way joints, are primarily used to alter the direction of fluid flow and are installed where the main pipeline branches off. They can be categorized by pipe diameter. Generally, they are made from carbon steel, cast steel, alloy steel, stainless steel, copper, aluminum alloy, plastic, polyvinyl chloride (PVC), and other materials.