Expansion Bellows

Product Description

An Expansion Bellows (or Expansion Joint) is a device used in piping systems to absorb thermal expansion, contraction, and other movements while maintaining a pressure-tight seal.

What Does an Expansion Bellows Contain?

1. Bellows Element

   • The core component: a corrugated, flexible metal structure (often stainless steel) designed to absorb axial, lateral, and angular movements.

   • Made from thin-walled metal sheets formed into convolutions for flexibility.

2. End Connections

   • Flanges, weld ends, or threaded ends for connecting to the pipeline.

   • These provide secure mounting and leak-proof integration into the system.

3. Inner Sleeve (Liner) (optional)

   • Protects the bellows from flow-induced vibration, erosion, and turbulence.

   • Often used in high-velocity fluid or gas applications.

4. Cover (Shroud) (optional)

   • External protective cover to shield the bellows from mechanical damage and environmental exposure.

5. Tie Rods / Control Rods (optional)

   • Absorb pressure thrust and prevent over-extension.

   • Common in restrained bellows to limit movement in specific directions.

6. Hinges / Gimbals (optional)

   • For special designs like hinged or gimbal expansion joints, enabling controlled angular movements while resisting pressure thrust.

7. Insulation (if required)

   • For high-temperature applications, insulation materials may be wrapped around the bellows.

Summary Table