Rubber expansion joints on the other hand are manufactured of resilient elastomers plus the joint itself acts as a vibration dampener, not at risk of exhaustion/cycle failure. They're the rubber and metal joints – temperature range, pressure, motion allowance, corrosion/chemical resistance abrasion resistance, installation prerequisites, servicing demands and lifespan; charges. https://metal-bellows-expansion-j13580.imblogs.net/89084005/everything-about-types-of-expansion-joints-in-piping