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BEST-IN-CLASS

EXTERNALLY PRESSURISED
EXPANSION JOINTS

Externally Pressurised Expansion Joints are the perfect solutions when the Expansion Joints must absorb very large axial movements under high pressure. In principle, there are no limits to the size of axial movement that can be absorbed by this type of Expansion Joint. In Externally Pressurised Expansion Joints, the bellows element(s) is arranged so that the media flow is on the external side of the bellows, while the inside part of the bellows is only subjected to atmospheric pressure with this side being in direct connection with the atmosphere. External pressurising of the bellows eliminates pressure instability as a design limitation and permits the absorption of large axial compression. Where an internally pressurised bellows will become unstable and buckle due to internal pressure, the pressure around an externally pressurised bellows will have a stabilising effect on the bellows. This makes it possible to achieve a construction of Externally Pressurised Expansion Joints with great flexibility for large axial compensation. With only the outside of the bellows subjected to pressure and the convolutions packed under a cover, the perfect conditions for external insulation or underground installation can be achieved. As the convolutions of Externally Pressurised Expansion Joints are well protected under a cover, transport damage to the convolutions is unlikely to occur but most importantly, the cover offers maximum protection against leaking bellows or bellows failure.

 

Design range within Externally Pressurised Expansion Joints

Belman Externally Pressurised Expansion Joints can be designed within the range:

Dimensions

DIMENSIONS:
DN 15-12.000

Pressure

PRESSURE:
Up to 150 barg or more if required

Temperature

TEMPERATURE:
-256°C to +1000°C

Materials_bellow_Symbol

MATERIALS:
Austenitic stainless steels,
High alloys, Duplex,
Titanium, Hastelloy,
Incoloy, Inconel, Alloy 59

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DESIGN CODES:
EN 13445, EN 13480, EN 14917
ASME VIII, div.I, ASME B31.3
ASME B31.1, EJMA, AD 2000
and others on request

Test and Quality Control

TESTS:
Radiographic examination
(X-ray), Helium leak testing,
Pressure test, Air test, Dye
penetrant test, Magnetic
particle examination and
many more.