Piece of pipe is a term used to describe a section of piping used in plumbing and other applications. The two most common types of pieces of pipe are the TEE (3 letters) and the ELBOW (5 letters). A TEE is a type of pipe fitting that has three openings, allowing for the connection of two pipes at a 90 degree angle. An ELBOW is a type of pipe fitting that has two openings, allowing for the connection of two pipes at an angle other than 90 degrees.