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SFZ offers a wide range of expansion joints:

Universal expansion joint

Expansion joint with tie-rod

Gimbal expansion joint

Pressure expansion joint

However, SFZ's main approach consists of developing customised expansion joints, using client specifications.

A few symbolic applications of this approach are as follows :

In 2015, as part of the process for developing fourth generation nuclear reactors, SFZ participed in the SILER project (Seismic-Initiated Events Risk Mitigation in Lead-Cooled Reactors), which conducted a study on the risks related to possible earthquakes and on the elaboration of suitable protective measures . 


The objective was to design and implement strategies for limiting damages to the LFR (Lead-Cooled Fast Reactor), such as seismic isolators.

All the partners in the project came together to design flexible joints suited for pressurised steam conduits, leading from the turbine room. As highlighted by the SILER site, this conduct is the most critical because it travels across the seismic interval between the suspended parts and the undamped parts of the plant.

SFZ designed and manufactured a ND 400 gimbal expansion joint with a design pressure of 200 bar and a test pressure of 260 bar. The expansion joint was placed on the test bench to simulate earthquake conditions.

Expansion joint under external pressure to bear significant expansion while still guaranteeing the stability of the bellows.

« Hot Shell » expansion joint with floating hardware and thermocouples for controlling the temperature of the bellows in operation.

Expansion joint for the Fluid Catalytic Cracking Unit (FCCU) with pantographs and refractory concrete.

ND 1500 expansion joint

T° = 780°C

Length = 9300 mm

Height = 3100 mm

Weight = 22 T

Installed on a high temperature gas pipe from a refinery in Germany, this product required a direct order to be given to the steel mill for supplying a special stainless steel (1.4910) that was creep resistant .

The bellows made of Inconel 625 LCF (2 plies of 1.6 mm) are equipped with a second safety layer with a leak detection system. If there is a leak in the internal layer, the client has the option of installing "clam-shell" bellows, which will work as the second safety barrier.


The insulation cassette system was validated by CFD (Computational Fluid Dynamics) in order to guarantee that the bellows remain within the temperature range desired by the client (between 200°C and 450°C).

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