A pipe is the same as a tube, a long cylinder. It can be made of all kinds of materials, from plastic to wood to metal. The word pipe is often used for something larger than a tube, but there is no hard and fast rule about this.

Pipes for carrying liquids and gases

A pipe would normally be more or less straight, the bends being called connectors. Most of us rely on pipes without even noticing it. Underground water, electricity, gas, and telephone cables all run in pipes. The strength of a pipe gives them protection.

Pipes are very strong because they have no sharp angles. That means that if a pressure occurs in one place, it is shared evenly round the pipe. Round pipes also allow liquids and gases to move more easily than they would if the pipe were square.

Musical pipes

The pipes you know about might be very different from these big pipes. You may be thinking, for example, of wind instruments like a recorder, which is a pipe with holes in. If you blow through a pipe it may set up vibrations, especially if you use a mouthpiece designed to do that. The vibrations may be in the range that we can hear, and if that is the case, the pipe makes a sound. What sound it makes depends on the length of the pipe as well as how big it is across (its diameter). By opening and closing the holes on a recorder, you vary the length of the pipe, and so the note it plays.

Musical pipes could be very long. They are very big in an organ, for example. So to make them easier to use, some musical pipes are folded over on themselves. You will see this in a trumpet, a trombone, a tuba and so on.