An expansion joint can relieve stress in piping systems and prevent flange gaskets from being crushed. But which expansion joint is best for your specific application? Let us first describe the two types of expansion joints:
Rubber — a flexible connector fabricated of natural and/or synthetic elastomers and fabric and, if necessary, internal metallic reinforcements designed to provide stress relief in piping systems due to thermal movements and mechanical vibration.
Metal — a flexible element (bellows) constructed of relatively thin gauge material (generally stainless steel) designed to absorb mechanical and thermal movements expected in service.
Temperature
Rubber joints with standard construction and materials have an upper range to 230°F. Most manufacturers, however, can offer special constructions up to 400°F. Metal expansion joints do offer a far greater range, from -420°F to +1800°F. However, working pressures are reduced at elevated temperatures.