Pipe fittings provide a leak-proof connection to ensure the flow control of a piping system. They can be joined together using several commonly used methods: threading, press, adhesive bonding, solder, brazing, welding, grooved, and more. Pipe fittings come in a vast array of products in several shapes, sizes and materials. The most commonly used fittings include pipe nipples, elbows, tees, unions, couplings, reducing couplings, bushings, caps, plugs, wyes, crosses and adapters.