Today we will learn about pipe nipples in very easy words. A pipe nipple is just a short piece of pipe with threads on one or both ends. It helps connect two pipes or fittings together quickly. What Are the Main Types of Pipe Nipples? Close Nipple  – Threads on both ends, almost no space in the middle. Short Nipple  – A little longer than close nipple. Barrel Nipple  – Long and straight, good for joining far pipes. Hex Nipple  – Has six flat sides so you can use a wrench easi