Universal Bellows

Product Description

A Universal Bellows (also called a Universal Expansion Joint) is an expansion joint design that consists of two bellows elements connected by a common center pipe (spool piece). It is mainly used to absorb large lateral movements in a single plane or multiple planes, and can also absorb some axial and angular movements.

What Does a Universal Bellows Contain?

1. Two Bellows Elements

   • Two corrugated flexible metallic bellows joined by a center pipe (spool).

   • The dual-bellows arrangement provides high flexibility compared to a single bellows.

2. Center Spool (Intermediate Pipe)

   • A rigid connecting pipe between the two bellows.

   • Maintains spacing and transfers loads between bellows.

3. End Connections

   • Flanges or Weld Ends for pipeline connection.

4. Tie Rods (Optional but Common)

   • Often added to control the pressure thrust and keep the universal joint restrained.

   • Helps guide lateral movement and limits over-extension or compression.

5. Inner Sleeve (Optional)

   • Installed inside to protect bellows from erosion, turbulence, or high-velocity flow.

6. Outer Cover (Optional)

   • Shields the bellows from mechanical damage and environmental exposure.

Key Characteristics

• Movement Absorbed: Primarily lateral displacement, plus some axial and angular movement.

• Ideal For: Piping systems with offsets, large lateral expansion, or where space constraints prevent using a single axial unit.

• Available Types:

  • Unrestrained Universal Bellows  requires external anchors and guides.

  • Tied Universal Bellows  includes tie rods to resist pressure thrust.

Summary Table