Spring Joint

The transfer of hot air which is sometimes accompanied by flammable particles, must be done by proper equipment that can withstand heat, fire and high gas pressure. Flexible ducts made of refractory materials with unique spring structure are considered as one of the best solutions for this challenge. This product provides very high levels of safety by preventing sudden stops or ignition, and sealing the leads properly which stops gas pressure drops.

Calidit hose ducts guarantee desirable operation up to 1200 °C and under high stress. The nominal compression ratio of 1:10 means that 10 meter-longs of this hose can become about 1 meter-long after compression.

These spring joints can be produced in single, double or triple layers of high temperature resistant textures and alloyed steels fully engineered and designed in form of a spiral structure to withstand high temperatures and pressures and corrosive particles.

The main features of the flexible fire-resistant ducts:

  • Resistant to tearing and piercing
  • Resistant to high temperature and fire
  • Corrosion resistant
  • High flexibility
  • Easy installation
  • No toxic gas emissions


Main applications:

  • Used in steel, petrochemical, oil and gas industries specifically in pipeline junctions to prevent gas leakage and consequent drop in pressure.
  • Hot- and cold-water supply facilities for public buildings
  • Used in power plants
  • Output coils of olefin unit furnaces
  • Networks of industrial food, chemical and electronical pipelines such as pipeline networks for transferring different types of corrosive liquids
  • Utilized in ferrous and non-ferrous industries
  • Used in air conditioning and ventilation installations
  • Compact gas pipeline networks for various industries