Metal Expansion Joint Installation Instructions
General installation guidelines for Aflex metal expansion joints. Work through each step in order, and contact Aflex before proceeding if anything is unclear.
Before starting the installation process
Verify that the Aflex serial number plate is securely attached and legible. The serial number plate must remain attached and accessible to maintain positive identification of the expansion joint assembly.
The serial number provides full traceability to the assembly, including materials, welding procedures, qualified welders, inspection records and other quality documentation contained within the Manufacturer's Data Report (MDR).
Inspect the Assembly
Before installation, carefully inspect the expansion joint for any signs of damage. Check the following:
- Bellows element
- Flanges, pipe ends or weld ends
- Hardware (where fitted)
- Shipping bars (where fitted)
- Protective coatings or finishes (where applicable)
Shipping bars may be carrying a factory preset load. Damage during transport may alter the assembly length or preset position.
Shipping Bars
Where fitted, shipping bars must remain installed until the expansion joint has been fully installed.
If shipping bars interfere with installation, contact Aflex before removal.
Check the Installation Gap
Verify that the installation gap matches the overall assembly length specified on the Aflex assembly drawing or datasheet.
The piping system should be adjusted to suit the expansion joint, not the expansion joint forced to suit the pipework, unless specifically stated otherwise on the project documentation.
Lifting and Handling
Where lifting lugs are provided, they should always be used. If lifting lugs are not fitted, support the expansion joint using the structural hardware or end connections.
Never lift or support the assembly by:
- The bellows element
- Shipping bars
- Flow liner
- Any component not specifically designed as a lifting point
Flow Liner Orientation
Where a flow liner is fitted, ensure the expansion joint is installed in the correct flow direction. Flow direction is indicated on the assembly or shipping labels.
Pipe Alignment
Ensure all mating pipework and flanges are correctly aligned before installation.
Expansion joints are designed to accommodate specified thermal and operational movements. They should not be used to correct installation errors or excessive pipe misalignment unless specifically designed for that purpose.
Remove Shipping Bars
Do not remove shipping bars until all flange bolts have been fully tightened or all welding has been completed and the expansion joint is fully supported by the piping system.
Anchors, Guides and Supports
Ensure the piping system incorporates the correct anchors, guides and supports in accordance with the latest EJMA recommendations and the overall piping system design.
Expansion joints are designed to accommodate movement; they are not intended to support pipework or compensate for inadequate piping restraint.
The type, location and load requirements of anchors, guides and supports will vary depending on the expansion joint design and piping configuration.
Unrestrained assemblies transmit pressure thrust to the piping system, while restrained assemblies transmit significantly lower loads. In all cases, anchors, guides and supports must be correctly designed to ensure the expansion joint performs as intended and achieves its expected service life.
Pipe Supports
Expansion joints are not pipe supports.
Ensure adjacent pipework is adequately supported so that dead weight, external loads and equipment loads are not transferred into the expansion joint unless specifically allowed for in the design.
Restraint Hardware
Where restraint hardware such as tie rods, hinges, gimbals or other engineered restraint systems are fitted, they form an integral part of the expansion joint design and must remain installed during service.
Do not remove, adjust or modify any restraint hardware unless specifically instructed by Aflex.
TEB and TUEB assemblies – click this link for additional TEB and TUEB installation information →
Hydrostatic Testing and Operating Pressure
Do not hydrostatically test or operate the expansion joint above the Design Pressure specified on the Aflex assembly datasheet.
If the required site hydrostatic test pressure exceeds the expansion joint design pressure, consult Aflex before commencing the hydrostatic test.
Flange Bolting
Aflex does not specify flange bolt tightening torques.
Protect the Expansion Joint During Installation
Until installation is complete, protect the expansion joint from damage. Avoid exposure to:
- Welding spatter
- Grinding sparks
- Impact damage
- Construction debris
- Contamination by foreign materials
Do not use the expansion joint as a step, work platform, lifting point or support for other equipment.
Need assistance?
If you have any questions or experience any difficulties during installation, contact Aflex before proceeding.
Early consultation can prevent unnecessary damage, minimise downtime and help ensure the expansion joint performs safely and as intended throughout its service life.
Technical notes
- These guidelines apply to Aflex metal expansion joints unless otherwise specified.
- Product-specific installation requirements may apply to certain assemblies and will be provided where necessary.
- Expansion joints should always be installed and operated within the limits specified on the Aflex assembly drawing and datasheet.
- Piping systems incorporating expansion joints should be designed in accordance with the latest EJMA (Expansion Joint Manufacturers Association) recommendations and recognised engineering practice.
Partner with Aflex
30 years of bellows application experience
Aflex helps engineers, consultants and plant operators avoid costly failures through correct expansion joint selection and practical pipeline solutions.
