What Are Different Types of Expansion Joints?

Expansion joints come in several primary types including metallic, fabric, and rubber varieties.

These components prevent system damage by accommodating movement from thermal expansion, vibration, and other forces.

Here’s a look at the expansion joints most commonly used in piping and structural systems.

Expansion Joints At a Glance

Metallic Expansion Joints

Metallic expansion joints use stainless steel, Inconel, or other alloy bellows to absorb movement in piping systems.

These joints handle temperatures exceeding 1000°F while maintaining system integrity. 

The corrugated bellows design allows compression, extension, and lateral movement as needed.

Types include:

Single Expansion Joints

Single expansion joints are the most basic design, featuring one bellows section with end connectors. 

They accommodate axial, lateral, and angular movement but require proper anchoring and guiding.

Without restraint hardware, these joints transfer the full pressure thrust to adjacent piping and equipment. 

Universal Expansion Joints

Universal expansion joints feature two bellows sections connected by a central pipe. 

This design allows for significant lateral movement while also accommodating axial and angular deflection.

The twin-bellows configuration makes these joints ideal for systems with misalignment issues or where multi-plane movement is expected. 

Hinged and Gimbal Expansion Joints

Hinged expansion joints use hinged hardware to control movement in a single plane while restricting movement in other directions. 

Gimbal joints extend this concept using two pairs of hinges with a floating center ring. 

This allows angular rotation in any plane while preventing axial movement, making them ideal for three-dimensional piping systems.

Pressure-Balanced Expansion Joints

Pressure-balanced designs use additional bellows and hardware to neutralize the pressure thrust forces generated in the system. 

These sophisticated joints eliminate the need for heavy anchoring by balancing the pressure forces internally.

Pressure-balanced expansion joints include elbow and in-line configurations for different piping arrangements.

pumps where external forces must be minimized.

Non-Metallic Expansion Joints

Non-metallic options provide alternatives for applications where metal isn’t ideal. 

These joints offer different performance characteristics based on their construction materials.

Types include:

Fabric Expansion Joints

Fabric joints use fiberglass, PTFE,, or composite fabrics for flexibility. 

These cost-effective components provide excellent vibration isolation and noise reduction. 

They excel in duct systems and low-pressure applications where extreme temperatures aren’t a concern.

Rubber Expansion Joints

Rubber joints made from EPDM, neoprene, or natural rubber provide superior vibration isolation. 

They resist corrosion and accommodate movement in multiple directions simultaneously.

These versatile components operate at lower temperatures than metallic joints but offer excellent chemical resistance.

Specialized Expansion Joint Types

Beyond the common categories, several specialized expansion joint designs serve unique applications and requirements.

Toroidal expansion joints feature rounded, torus-shaped bellows for improved flow characteristics. Thick-wall expansion joints use reinforced bellows for extreme pressure conditions.

Rectangular metallic expansion joints accommodate non-circular duct systems. Refractory-lined versions include internal insulation for ultra-high-temperature applications.

Conclusion

Choosing the right expansion joint requires evaluating operating temperature, pressure, and required movement.The media flowing through the system often dictates material selection. For example, aggressive chemicals might require specialized elastomers or alloys to prevent premature failure.

Keep these factors in mind when making your buying decision. For high-quality expansion joints, view our product collection