Expansion Bellows

About Expansion Bellows

An Expansion Bellows or Expansion Joint is a device used in piping systems to absorb thermal expansion contraction and other movements while maintaining a pressuretight seal

What Does an Expansion Bellows Contain

Bellows Element

The core component a corrugated flexible metal structure often stainless steel designed to absorb axial lateral and angular movements

Made from thinwalled metal sheets formed into convolutions for flexibility

End Connections

Flanges weld ends or threaded ends for connecting to the pipeline

These provide secure mounting and leakproof integration into the system

Inner Sleeve Liner optional

Protects the bellows from flowinduced vibration erosion and turbulence

Often used in highvelocity fluid or gas applications

Cover Shroud optional

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

Tie Rods Control Rods optional

Absorb pressure thrust and prevent overextension

Common in restrained bellows to limit movement in specific directions

Hinges Gimbals optional

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

Insulation if required

For hightemperature applications insulation materials may be wrapped around the bellows

Summary Table

Component Purpose

Bellows Element Flexibility for thermal and mechanical movement

End Connections Secure pipeline connection

Inner Sleeve Protects against erosion turbulence

Outer Cover Mechanical and environmental protection

Tie Rods Hinges Controls movement resists pressure thrust

Insulation optional Temperature management