Getting a solid grasp on core expansion joint terminology makes planning your facility’s pipe system layout much simpler. To help make some expansion joint jargon clearer, here’s a brief expansion joint glossary of terms.
Bellows
First, expansion joint bellows are a localized portion of the joint. Bellows consist of flexible ring-like convolutions made from metal. Though thin, these bellows withstand significant angular, lateral, and axial forces while in use. Their beginning and ending points are called tangents, which are straight and unconvoluted.
Expansion Joint
Meanwhile, expansion joints are the entire subsection of piping that breaks up pipe systems to mitigate various threats. These threats include excessive thermal expansion, reverberating vibration, extreme temperatures, and other factors.
Flange Ends
A flange end is on one side of an expansion joint apparatus. The flange end has a specific surface or perforation that allows for the mating end of a nearby pipe to attach. The term “mating end” simply refers to a corresponding pipe feature where the flange end of an expansion joints fits readily. Typically, these flange ends are broader than weld ends.
Flow Liner
Flow liners fit inside of an expansion joint, allowing internal fluids to pass without excessively vibrating the pipe system. These features are especially important when fluids travel at high velocities, threatening to cause damaging resonant vibrations.
Tie Rods
Tie rods run along the length of an expansion joint, secured to both ends to help bellows stand up to significant axial expansion. They can also limit angular forces if two or more affix to a joint.
Torsion
While axial expansion and compression along the length of the joint and lateral movement perpendicular to the joint make sense, torsion is more complicated. Rather than a bending force (angular forces), torsion is a twisting action without significant displacement.
Weld Ends
While a flange end occupies one side of an expansion joint, a weld end occupies the other. A weld end typically consists of a tube-like pipe section fit for welding to a nearby pipe, hence the name.
If you need further assistance thinking through your project beyond this expansion joint glossary of terms, contact our team at Triad Bellows. We have decades of collective experience and expertise as an industrial bellows manufacturer and offer comprehensive services for your pipe system.
