"Matchless" Dual Unit Expansion Joints

Dual Expansion Joints | Elbow Pressure Balanced Expansion Joint

UNAFLEX® can custom design and manufacture various types of expansion joints based on your needs and requirements of the system. Some commonly used non-standard expansion joint types are:

Dual Expansion Joints

Drilling Information

Dual BellowsDual expansion joints are used where axial movement is larger than can be absorbed by a single expansion joint. The dual assembly consists of two single bellows connected by an interconnecting weld end. In some cases, this interconnecting weld end has an integral anchor base. The anchor base is designed to withstand the forces required to move either bellows but not for pressure forces. When no anchor base is used, interconnecting weld end must be anchored with standard pipe anchors.

Dual expansion joints can also be used where large amount of movement in any combination (i.e. axial, lateral and angular rotation) is required which cannot be absorbed by a single expansion joint. In this type of application, the interconnecting weld end is not anchored but the remaining system must be properly anchored and guided.

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Elbow Pressure Balanced Unit

Drilling Information Pressure Balanced Unit

"MATCHLESS" elbow pressure balanced expansion joints are designed to absorb axial and/or lateral deflection while continuously restraining pressure force. Balance (out of line) bellows creates an equal and opposite force to the working (in line) bellows.

The typical arrangement (as shown) is to have a balance side and a working side separated by an elbowed mid-section. Tie-rods are used to balance and restrain pressure forces.

Additional Types of Expansion Joints Available

  • Gimbal Expansion Joint

  • Hinge Expansion Joint

  • In-line Pressure Balanced Expansion Joint

  • Expansion Joints with Pantograph Linkage

  • Expansion Joints with Two-Ply Testable Bellows

  • Jacketed Expansion Joints

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