Drawing of Metal Bellows

This drawing shows what the metal bellows look like. The figure just before this showed the bellows in cross section. As I explained in the description of the cross section, these are not bellows in the sense that you use fireplace bellows to blow air onto a fire. They're only called bellows because their corrugated shape resembles the corrugated sides of fireplace bellows.

The bellows are essentially a tube. But not quite a tube, because when we say "tube", we normally think of something that has straight sides, that is, something that has the same diameter from one end to the other. The bellows are a tube that has a large diameter at some places and a small diameter in between. In other words, the bellows look like a tube made of corrugated metal (with the corrugations running around the tube, not end to end.) Return to XRS Intro