Metallic expansion joints, or metal bellows, are flexible piping components featuring thin-walled, convoluted, ductile metal tubes (e.g., stainless steel, nickel alloys) designed to absorb thermal expansion, contraction, vibration, and piping misalignment. They protect critical equipment by absorbing axial, lateral, or angular movements while maintaining a sealed, leak-proof system under high-pressure and high-temperature conditions.
Common Types of Metallic Expansion Joints
Single Axial Bellows: The basic element designed for straight pipe thermal growth.
Universal Expansion Joint: Uses two bellows separated by a pipe to absorb large axial, lateral, and angular movements.
Hinged Expansion Joint: Features hinges to restrict movement to angular rotation in one plane, often used in sets.
Gimbal Expansion Joint: Uses a gimbal ring to allow angular rotation in multiple directions.
Pressure Balanced Joint: Designed to absorb movement while cancelling out pressure thrust, ideal for turbine piping.
Clamshell Joints: Split into segments for repair without removing pipes.
