The term PLUMBING TUBE can be broken down into two crossword solutions, PIPE and 4 letters. PIPE is a type of plumbing tube that is used to transport liquids and gases from one place to another. It is made of materials such as metal, plastic, or ceramic and is usually cylindrical in shape. The 4 letters refer to the length of the PIPE, which can range from a few inches to several feet. Plumbing tubes are an essential part of any plumbing system and are used to connect fixtures, appliances, and other components.