<P> Limit rods may be used in an expansion joint design to limit the axial compression or expansion . They allow the expansion joint to move over a range according to where the nut stops are placed along the rods . Limit rods are used to prevent bellows over-extension while restraining the full pressure thrust of the system . </P> <P> Expansion joint failure can occur for various reasons, but experience shows that failures falls into several distinct categories . This list includes, but is not limited to: shipping and handling damage, improper installation / insufficient protection, during / after installation, improper anchoring, guiding, and supporting of the system, anchor failure in service, corrosion, system over-pressure, excessive bellows deflection, torsion, bellows erosion, and particulate matter in bellows convolutions restricting proper movement . </P> <P> There are various actions that can be taken to prevent and minimize expansion joint failure . During installation, prevent any damage to the bellows by carefully following the instructions furnished by the manufacturer . After installation, carefully inspect the entire piping system to see if any damage occurred during installation, if the expansion joint is in the proper location, and if the expansion joint flow direction and positioning is correct . Also, periodically inspect the expansion joint throughout the operating life of the system in order to check for external corrosion, loosening of threaded fasteners and deterioration of anchors, guides, and other hardware . </P> <P> Other types of expansion joints can include: fabric expansion joint, metal expansion joint, toroidal expansion joint, gimbal expansion joint, universal expansion joint, in - line expansion joint, refractory lined expansion joint, and more . </P>

Expansion bends have the advantage over the expansion joint for one of the following reasons