“Bellows” can be translated as fuigo or jabara in Japanese. “Fuigo” is a tool that was used to blow air into kilns by blacksmiths long long ago. “Jabara” has various meanings, including the body of an accordion. In vacuum-related fields, cylindrical objects made of metal are pleated to demonstrate expansion/contraction properties, airtightness and spring properties. These are called “bellows.” In other words, “bellows” = “metal expansive pipes.”
Metal bellows are divided mainly into welded bellows (alternately welding the inner diameter and outer diameter of a thin metal washer to form a pleated tube) and formed bellows (pressure is applied to a thin metal pipe to form a pleated bellows tube), and both have distinctive characteristics.
Item | Welded bellows | Formed bellows |
---|---|---|
Expansion/contraction properties | Large | Small |
Cost | High | Low |