1. HOME
  2. HOME
  3. Technical Information
  4. Bellows glossary
  5. About usage environment

About usage environment

Even identically shaped bellows will vary in performance if they are used with different shapes.
Terminology related to the environment that will affect a bellows performance is shown.

Pressure types

溶接ベローズ
※左右にフリックしてご覧いただけます。
Name Description
Internal vacuum Conditions under which the inside of bellows is vacuum and the outside is
atmospheric pressure
External vacuum Conditions under which the inside of bellows is atmospheric pressure and
the outside is vacuum
Internal pressure State in which a pressure higher than the outside of bellows is applied to the
inside, or its pressure
External pressure State in which a pressure higher than the inside of bellows is applied to the
outside, or its pressure
Equal pressure State in which equal pressure is applied to the inside and outside of bellows
* Normally, both the inside and outside are atmospheric pressure in this
state
* This state is frequently used during maintenance
Fluctuating pressure Pressure changes in operating cycle, which greatly affects life performance
depending on condition
* There are cases when it occurs at the time of stop bellows or due to volume
changes caused by expansion/contraction, etc.
Average pressure Average pressure in the case where fluctuating pressures are applied;
assuming that the external pressure is negative and the internal pressure is
positive:
(maximum pressure + minimum pressure)/2
Pressure fluctuation width fluctuating pressures are applied;
assuming that the external pressure is negative and the internal pressure is
positive:
|maximum pressure - minimum pressure|

Usage environment (other than pressure)

※左右にフリックしてご覧いただけます。
Name Description
Working temperature Temperature at which the bellows is used, the characteristics of which are
dependent on the materials used.
With increasing temperature, the life performance deteriorates.
SUS304(L), SUS316(L) --- 500°C or less
AM350 equivalent --- 450°C or less
Hastelloy®C-22 --- 800°C or less
Baking Treatment by raising temperature, which is commonly performed in the vacuum
industry with a heater in order to remove moisture and impurities in vessels.
The commonly-used temperature is about 100 to 250°C.
Working fluid Gas, liquid, or vapor filled inside or outside the bellows.
Corrosive fluid is taken into consideration when bellows material is selected.

Glossary of bellows terms

Product Information List

Inquiry

For document requests and inquiries,
Please contact us using the email form below or by phone.