“Bellows” is translated as fuigo or jabara in Japanese.
“Fuigo” can be a tool that was used to blow air into kilns by blacksmiths long long ago.
While “Jabara” has various meanings, the body of an accordion may come into your head.
In vacuum field, cylindrical objects made of metals and pleated to have expansion/contraction properties, airtightness, and spring properties are generally called “bellows.”
In other words, “bellows” = “expansive pipes.”
Bellows are not only used for semiconductor, liquid crystal, and vacuum equipment but they are also used as airtight sealing members for gases and fluids across wide range of field, such as accelerators, nuclear fusion, nuclear power, petrochemicals, railways, medicine, and construction.
In particular, a large number of bellows have been adopted as sealing materials for transfer sections where a vacuum is shielded from the atmosphere as well as sealing materials for “complete leak prevention” of vacuum valves and general industrial valves.
Year after year, requirements for special materials and advanced specifications, such as the cleanliness of a bellows surface, upsizing, and long lifetime, are increasing.
There are several types of bellows depending on differences in manufacturing methods, and IRIE KOKEN handles the following three types.
Formed bellows | Welded bellows | Flexible tubes |
*The method of manufacturing flexible tubes is nearly the same as formed bellows.
Since these bellows can be flexibly bent, they are mainly used for connecting the piping of equipment, and flexible tubes are best for long lengths.
Since their applications are limited, these bellows are omitted from the following explanation.
Formed bellows | Welded bellows | ||
Manufacturing method | Bellows forms under pressure on the inside of metal pipes. | Bellows welds the inner and outer edges of precise thin wave-shaped washer. | |
Features |
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Material *1 |
SUS316L Hastelloy®C-22 A5052 A3004 |
SUS316L Hastelloy®C-22 AM350 equivalent |
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Adaptability Comparison *2 |
Expansion/ contraction properties |
○ | ◎ |
Pressure resistance |
○ | ◎ | |
Bendability | ○ | ◎ | |
Price | ◎ | ○ |
Corrosion resistance | Heat resistance | Lifetime characteristics | Magnetism | Price | |
SUS316L | ○ | ○ (500°C or less) |
○ | Non-magnetic | Low |
AM350 equivalent (welded bellows only) |
× | ○ (450°C or less) |
◎ | Magnetic | Higher than SUS |
Hastelloy®C-22 | ◎ | ◎ | ○ | Non-magnetic | High |
*1: The materials listed above are materials we commonly handle. For materials other than the above, feel free to ask us.
*2: Based on our comparisons when the same materials are used.
*Hastelloy®C-22 is a registered trademark of Haynes International, Inc.