Metal Expansion Joints

Assembly Instructions & Safety

Assembly and Safety

When in doubt about an installation procedure please contact MACOGA Technical Department before attempting to install the expansion joint.

MACOGA’s warranty may be void if improper installation procedures have been used.

In order to ensure that the Expansion Joint work properly and in order to prolong its working life, it is necessary to respect a series of precautions that make the Expansion Joints almost maintenance free elements.

The most important precautions that must be observed are as follows:


  1. Care should be taken to avoid any damage to the bellows such as dents, scores, arc strikes and weld splatters.
  2. Expansion Joints must be fitted in the appropriate longitude as laid out in the instructions supplied by MACOGA. The Expansion Joints should not be stretched or compressed in order to absorb any defects along the length of the pipe or to rectify any misalignments unless this was taken into account during the initial design and the manufacturing process.
  1. Any field pre-positioning or pre-setting carried out when installing the Expansion Joints must be performed in accordance with the specific instructions supplied by MACOGA, including both the direction and magnitude of the movement.
  2. Once the Expansion Joint has finally been installed and secured, all of the shipping devices, if any, must then be removed and not before.
  3. The Expansion Joint must be fitted according to the direction of flow in relation to the internal sleeve.

Post installation inspection prior to system pressure test

  1. Check that the Expansion Joint has been fitted in the correct place.
  2. Check that the Expansion Joint has been correctly installed with regards to the direction of flow.
  3. Check that all shipping devices have been removed.
  1. Check that all of the supporting structures and anchorage have been correctly installed as planned.
  2. Check that there are no misalignments in the Expansion Joint.

Inspection during and immediately after system pressure test

  1. Check that there are no leaks and no loss of pressure.
  2. Check that the bellows are stable.
  1. Check that all of the anchorage, guides, Expansion Joints and other components of the system are secure and resistant.

Periodic in-service inspection

  1. Check to see if the Expansion Joints in the manner for which they were designed are absorbing the movements.
  2. Check for any unexpected vibrations.
  3. Check that dust and other particles haven’t built up between the convolutions of the Expansion Joint as this could limit or restrict its movement.
  1. Check for the existence of any signs of external corrosion, slack mechanical components (screws, tie rods, etc.) and also check that the anchorage points, guides, etc. are in perfect working order.


  1. Inspect for possible damage during shipment, i.e., dents, broken hardware, water marks on carton, etc.
  2. Avoid damaging the bellows with knocks that can cause dents on the convolutions, strikes, weld spatters, etc.
  3. Do not fix any chains or ropes to the bellows section.
  4. Avoid any movement of the Expansion Joint with its ends misaligned or beyond the limits established at the time of supply, as regards magnitude of movement, maximum angle, etc.
  5. Install the Expansion Joint in the proper length as recommended by MACOGA.
  1. Pre-settings to be carried out in accordance with the established limits, which include direction and magnitude of movement.
  2. Use only designated lifting lugs.
  3. Install the Expansion Joint pointing in the direction of flow in relation to the internal sleeve.
  4. Remove all shipping devices (yellow colour painted) after the installation is complete and before any pressure test of the fully installed system.
  5. Never exceed the permissible test pressure.

The above recommendations are included to avoid the most common errors that occur during installation.

Quality Approvals

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