FAQ About Metal Expansion Joints

What is a Metal Expansion Joint?

Metal expansion joints are balancing elements for movements due to thermal expansion. They consist of one or more metal bellows, connectors at both ends and, depending on the application, different accessories such as connecting shafts and joints. Unnecessary vibrations in systems can seriously damage both the system and surrounding equipment.

Metal expansion joints help isolate these vibrations as well as dampen noise and pressure fluctuations. There are different types of metal expansion joints that serve different purposes, such as lens type, cardan joint, articulated, externally pressurized, pressure expansion joint.

How to Choose Material?

After the ambient temperature, ambient pressure, fluid type, geometric values and movement amounts are determined, the material that provides the highest cycle value is selected as a result of the calculation made according to the standard suitable for the expansion joint type.

What are the Standards?

• EN 14917 – European Standard specifies requirements for the design, manufacture and installation of metal Expansion joints for pressure applications

• EN 13445 – European Standard for Fireless Pressure Vessels is a standard that provides rules for the design, manufacture and inspection of pressure vessels.

• EN 13480 – A European Standard specifying requirements for industrial piping systems and supports, including safety systems made of metallic materials. EN 13480 can be applied to above-ground, ducted or underground metallic pipes.

• AD2000 – German code of practice for pressure vessel design and manufacture, drawn up by a working group of numerous associations that together form the “Pressure vessel working group”.

• ASME B31.1 – An American National Standard, a Power Piping Code. Establishes minimum requirements for the design, materials, fabrication, installation, testing, inspection, operation and maintenance of power piping systems.

• ASME B31.3 – Process Piping Code, an American National Standard, provides a minimum set of rules for the design, materials, fabrication, testing and inspection practices used in the construction of process piping systems.

• ASME VIII Div. I – An American National Standard that provides rules for the design, manufacture and inspection of boilers and pressure vessels.

• EJMA – A design code made by the Expansion Joint Manufacturers Association, an organization founded in 1955. The standard provides guidelines for the design, manufacture and safe installation of metallic expansion joints.

What is the Scope of Warranty?

Our metal expansion joints are under our warranty for 2 (two) years after shipment.

Situations outside the scope of warranty are stated below;

• Development of different conditions other than the specified working environment conditions (Pressure, temperature, movement, etc.)
• Improper assembly techniques (See: Important issues in assembly)
• Improper storage conditions before assembly (Moisture, dirt , chemical, etc.)

What are its accessories?

Metal expansion joint on its own can absorb any axial, lateral and angular movement in pipelines, channels and vessels. Adding accessories to the metal expansion joint increases complexity but also improves movement capabilities and extends life cycle. Some accessories for metal Expansions include:

  • Liners
  • External Protection
  • Hinges
  • Gimbals
  • Limit Rods
  • Pantographic Connections

What are the Production Stages?

The expansion joint project is designed based on the data submitted by the end user or the supervision done by our experts. Before manufacturing, the project is finalized by making the necessary revisions.

All raw materials to be used in production are checked during the pre-production quality control processes and are included in production. Laser cutting, welding preparation, assembly, and welding during the manufacturing process all use quality control procedures to reduce the defect rate of the final product.

Before shipping, the finished product is examined one last time in accordance with the project, and every parameter is documented and captured on camera. When a product bears the "BundleTec" quality stamp, it becomes guaranteed.

Where is it used?

Where there are elongations due to high temperatures or vibrations due to high air flow in production industry enterprises such as Oil and Gas, Energy Production, Construction, Chemistry, Iron-Steel, Shipbuilding, LNG-LPG, Defense, Cryogenic, Paper, Food and Beverage, Pharmaceuticals, etc.

The positions of the expansion joints on the line are calculated using 3D digital analysis methods such as BIM and CFD. The basic principle of these calculations is to transfer the total extension to the Expansion Joint equally and accurately.