The Universal Expansion Joints consist of two bellows elements joined together by a common spool piece so it is also called as Double Bellows
Hinged Expansion Joints are used to absorb angular movement when it occurs in only one plane. They are also called Angular Expansion Joints
The Lateral Expansion Joints also called Tied Universal or Tied Lateral Expansion Joints and are used to absorb lateral deflection
Axial Expansion Joints are the simplest type of expansion joints using a single bellows unit.