From the design, process, working conditions, installation of these four aspects of the corrugated e

When it comes to the life of the corrugated expansion joint, people will think of the length of time, in fact, the life of the corrugated compensator is expressed in terms of "weeks", which is the rated life of the corrugated expansion joint (weeks) divided by the number of work weeks in the unit of time and calculated service time. Since the life of the expansion joint is expressed in terms of cycles, the following concepts need to be clarified before discussing the life issue:
    Cycle: a complete cycle of the full compensation amount of the metal bellows. That is, compression (or stretching) to the compensation amount and restore the initial position.
    Average fatigue life: that is, the fatigue life calculated by approximating the design formula, substituting the waveform parameters of the bellows.
    Design fatigue life coefficient: It is the coefficient specified for the design fatigue life, taking into account some factors affecting the life of bellows, such as hardening, dimensional error, material properties, environmental factors, etc.
    Design fatigue life: is the ratio of average fatigue life and design fatigue life coefficient.
Discussion of the service life of corrugated metal expansion joints, in fact, as long as it is clear that the core components of a bellows life is sufficient, because the bellows is a flexural component of the waveform expansion joint, relying on its elastic deformation to achieve the compensation capacity of the expansion joint, and other accessories are basically composed of carbon steel, the same material as the pipeline application, and are considered in accordance with the actual life of the pipeline design. It is fully guaranteed to have the same design life as the pipeline. However, there are many factors affecting the service life of bellows, such as: application environment, material selection, performance parameters, manufacturing process, installation rationality, etc. At present, the general material of the corrugated pipe for heating network with austenitic stainless steel, corrugated for no strengthening U-shaped, the formula, parameters, etc. listed in this chapter is only applicable to the range, and from the design, process, working conditions, installation of these four aspects of the discussion.