Pipelines, ducts, and vessels that carry hot or cold fluids can encounter thermal expansion. As the metal temperature increases or decreases, the length of the piping system varies due to its thermal expansion or contraction. Unless something is added to compensate for these dimensional changes, high stresses will be created throughout the piping system, potentially causing a great deal of damage.

 

An expansion joint is any device containing one or more convolutions used to absorb dimensional changes, such as those caused by thermal expansion or contraction in a pipe-line, duct, or vessel.