Axial expansion joints

Axial expansion joints designed to compensate for thermal expansion in the axial direction only. The axial compensation capability (compression and tension) of expansion joints provided applicable in their bellows and is determined by calculation of linear thermal expansion of the pipeline section.

Axial expansion joints are used:

  • The district heating networks and water supply, to be installed between two fixed supports on long-haul sections of the pipeline to compensate for thermal expansion of large pipes in insulation;
  • The compressor and pumping stations, heat exchangers, as connecting inserts for vibration attenuation and noise reduction, allowing a small deformation of the bellows with frequent recurrence;
  • In systems of flue gas ducts and cooling installations of boilers, pressure vessels, motors, converters and other industrial equipment and machinery.; in aspiration and cogeneration (CHP) systems to compensate for vibrations and deformations of structures of thermal expansion;
  • The gas and water supply, as the flexible connecting elements for valves, ensuring ease of installation and periodic audit work;
  • In aggressive environments in pipelines for cryogenic products, industrial gases and liquids in the chemical industry, to compensate for thermal strains.

Axial expansion joints used in the straight sections of the pipeline. As a rule, on a site between two fixed supports, use only one expansion joint. Installing the expansion joint at the site without support is not allowed. Typically, the axial expansion bellows are not pressure balanced and transmit force to the spacer pipe supports. Supports, in areas with unbalanced pressure axial expansion joints must provide load from spacer effort pipeline weight and friction. There where there is a need to minimize the loads on the support, it is recommended the use of axial pressure balanced expansion joints.

SPA «MARILAND» Ltd. produces axial expansion joints with a nominal diameter of DN 20 to 3200 mm to operate at a nominal pressure of PN 0.1 to 2.5 MPa.

Typical installation schemes axial expansion joints:

Типичные схемы установки осевых сильфонных компенсаторов