Metal expansion joints are flexible components containing one or more metal bellows used in pipelines and duct systems to absorb dimensional changes, such as those caused by thermal expansion, contraction, vibration, and mechanical shifts. These changes are typically caused by thermal expansion or contraction, as well as mechanical vibrations and equipment misalignment. Constructed from high-grade stainless steel or specialized alloys, these joints feature a flexible “bellows” element that can compress, extend, or bend while maintaining a pressure-tight seal for the internal media.