Fatigue life testing verifies the bellows’ ability to withstand a specified number of flexing cycles. The Expansion Joint is placed on a test machine and allowed to cycle continually until the bellows fail. The lateral expansion below the manufacturer will help in this test. Fatigue life testing will be conducted on the Expansion Joint. Before testing, the following were unsuitable for installation in an operating system. Therefore, this test must be performed on a prototype Expansion Joint.
What are Prototype Expansion Joints?
A prototype Expansion Joint is defined as one having the same pressure and temperature rating. The testing checks production models for identical diameter, height, and pitch. The general shape of the convolution, as well as the thickness and the type of materials below, are also checked.
The Fatigue Life Expectancy
The fatigue life of a metal joint is affected by many factors. The factors may include temperature, pressure, movement, and vibration. Typically, metal joints have a defined cycle or fatigue life that can be calculated. You can contact lateral expansion joints in India for fatigue testing.
Excessive cycle life requirements do not necessarily guarantee the desired results. An overly conservative estimate of cycles is not recommended. This is because it tends to increase the number of corrugations. It leads to a bellows that is more prone to squirm.
Fatigue life depends on the maximum stress range to which the bellows is submitted during each complete operational cycle. The stress range is due to deflection. It generally affects fatigue more than the stress range. It has happened due to static or variable pressure.
Accordingly, the cycles to fatigue will be reduced if the deflection is increased and vice versa.
The Conclusion
In addition to the shape of the corrugations, the fatigue life is affected by the type of material and the manufacturing process. The cold work hardening of austenitic steel, for instance, induced during the forming process of the corrugations, and generally improves the fatigue life. Contact Flexpert Bellows for tested expansion joints and grow your business significantly.
