Axial expansion joints

Axial expansion joints are expansion joints that absorb mainly longitudinal movements axially along a straight section of pipe.

HKS axial expansion joint with rotatable flared flanges at both ends and inner guide sleeve
Axial expansion joint flared flanges and guide sleeveby HKS

Advantages of axial expansion joints

  • Simple means of compensation
  • Smaller space requirements
  • No alteration of flow movement
  • Movement possible in any direction
  • No redirection of pipe work required
  • Low unit costs

Disadvantages of axial expansion joints

  • High axial forces at higher pressures
  • Strong fixed points and good axial pipe guides required
  • Small and medium movement absorption
  • For large expansion movements several axial expansion joints are required
  • On long stretches many fixed points and pipe guides are required
Axial expansion joint variants
Connection parts
  • Axial expansion joints can be manufactured with weld ends, fixed flanges or swivel flanges or combinations thereof, depending on customer requirements
Guide tubes
  • To avoid abrasion and turbulence (e.g. at high flow rates in pipe work systems), axial expansion joints can be equipped with inner guide tubes
Outer protection tube
  • To protect the metal bellows against mechanical effects from the outside, axial expansion joints can be equipped with outer protection tubes
One or two bellows
  • Axial expansion joints can be manufactures with one bellows or two bellows that are connected by a central tube (see also » Universal expansion joints)
Vereinfachte grafische Darstellung eines Kompensators in axialer Bewegung