Failures can occur for many reasons, but experience has shown that certain causes of failure fall into fairly distinct categories.
and handling damage. Examples: Denting or gouging of bellows from being
struck by hard objects (tools, chain falls, forklifts, adjacent
structures, etc.); improper stacking for shipping or storage;
insufficient protection from weather or other adverse environmental
Improper installation and insufficient protection.
During and after installation .
Joints with internal liners installed in the reverse direction with
respect to flow; installing an expansion joint in a location other than
as prescribed by the installation drawings; premature removal of
shipping devices; springing of bellows to make up for piping
misalignment; insufficient protection from mechanical damage due to work
in the surrounding area; insufficient protection of bellows during
nearby welding operations and failure to remove shipping devices before
placing system in operation.
Improper anchoring, guiding and supporting of the system.
Anchor failure in service.
Bellows corrosion, both internal and external.
System over-pressure (in-service or hydrotest). Bellows vibration (mechanical or flow induced resulting in high cycle fatigue).