Nuclear and aerospace

In the frame of Ariane 5 program, Idrosapiens developed and qualified a wide range of bellows expansion joints for the compensation of the thermal dilatations and cinematic movements of the propellant and pressurisation lines of the first and second cryogenic stages of the launcher.

The joints have been designed to operate in contact with exotic media like liquid oxygen or hydrogen and to sustain extreme environmental conditions (temperature, pressure, vibrations).
More than 30 different types of expansion joints have been designed and qualified, all made from 316 L stainless steel for the parts in contact with the propellants:

  • axial joints with diameters from 90 to 185 [mm]
  • axial/angular joints with diameters from 40 to 185 [mm]
  • gimbal joints with diameters from 30 to 185 [mm]
  • angular (LOX tank penetration) joint with a diameter of 185 [mm]
  • free bellows (universal joints) with diameters from 20 to 60 [mm]

All the joints are thigh welded (zero leakage) and designed to operate with pressures from vacuum to 30 [bar], temperature ranging from 4 [K] (liquid helium temperature) to 350 [K], movements from ± 100 [mm] for the axial joints to ± 20 [deg] for the gimbals.