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metal expansion joint is made up of bellows which are one or more convolutions
in the joint. The bellows provide stable, long-lasting, solutions to many
problems involving harmonics, vibration, and high temperature expansion.
The joint must be designed strong enough to accommodate the system design
pressure, as well as, flexible enough to accept the design deflections
for a calculated number of occurrences.
Metal expansion joints are
being successfully utilized in refineries, chemical plants, fossil and
nuclear power systems, heating and cooling systems, and cryogenic plants.
Service conditions have ranged from pressures of 25 microns to 1,000 PSIG
and -420°F to +1800°F. These types of expansion joints are a highly
engineered product and can perform their intended function safely and reliably.
Unlike most commonly used
piping components, bellows are constructed of a relatively thin gauge material
in order to provide the flexibility needed to absorb mechanical and thermal
movement expected in service.
For selection of the proper
metal expansion joint, the following steps should be followed:
1. Select applicable pipe
size
2. Select applicable pressure
range. Proof or test pressure with 150% of listed ratings.
3. Select bellows (single
or dual and number of convolutions) to satisfy deflection requirements.
4. Determine end fittings
and hardware required. |
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