Bellow Expansion Joint Deign Calculations:
To be able to design and manufacture the optimum Bellow Expansion Joint following specifications necessary/sufficient:
1. Operational demands for the pipeline and the design of it
It is important to have as much information as possible about the pipe layout. This information is needed when calculating and evaluating which kind of Bellow Expansion Joint must be chosen and where in the pipeline it is to be placed. In this way the best positioning of the Bellow Expansion Joint, fixed points and anchors is achieved and optimum absorption is ensured. When evaluating this, the pipeline is often separated into sections and according to the best way of absorbing movements one or more Bellow Expansion Joints are needed in each section. For each section it is important that Aadesh Industrial Corporation is informed about the temperature, pressure, movements etc. We also need to know the size of the pipes (the actual outer diameter of the pipe and the actual thickness) as the size influences the Bellow Expansion Joint's ability to absorb the given movements.
2. Design pressure
The design pressure must be taken into account when the thickness of the bellow and the connection ends are calculated. The higher the pressure is, the thicker the material has to be. This conflict is solved if instead of a few thick layers several thin layers of bellow material will be used. In this way a greater flexibility is also ensured with a higher thickness of the bellow.
The expected design pressure in the pipeline under test and operation needs to be precisely determined. A better solution is achieved by calculating a larger design pressure than the current pressure; an oversized thickness of material can result in exhaustion.
Vibrations are essential information, because they can significantly shorten the service life of the Bellow Expansion Joint, if the Bellow Expansion Joint is not designed for vibrations. Vibrations are defined from their frequency and the extent of the variation.
Movements the pipeline occur during standard operation. The movements determine both the kind of Bellow Expansion Joint and the accessories needed. Furthermore the movements are important for many other parameters such as the built-in length of the Bellow Expansion Joint.
The medium, which is running through the pipeline, influences the choice of material the bellows are made of. The chosen quality must be resistant to the media. If the media will settle in the bellow, it is necessary to include further design arrangements to avoid this. Such settlements inhibit the bellow to work as intended to. An inner sleeve could be the solution.
6. Design temperature
It is important to know the exact maximum- and minimum temperature under operation as well as the temperature at installation. Additionally the operating pressure and the expansion the Bellow Expansion Joint is going to absorb must be known. Likewise knowledge about the temperature is important for the choice of material because the material has to be resistant towards a given temperature.
The choice of materials is depending on the temperatures, the movements and the media that is continuously running through the pipeline. Another important factor for the choice of material is the environment the Bellow Expansion Joint and the pipeline operates in.
8. Spring force
The spring force is necessary for the Bellow Expansion Joint to absorb the intended movements. The spring force contributes resistance into the system and function as a spring that is compressed or deflects. To moderate this spring force and to prevent it from damaging the Bellow Expansion Joint, the force on the anchors is limited. The extent of spring force is determined by the Bellow Expansion Joint's spring force and by the amount of movements the Bellow Expansion Joint is exposed to.
9. Reactive forces
Reactive forces are the kind of forces that are the basis for the dimension of the fixed points, guides etc. in the pipeline. In that way the extent of the pipe's retaining is determined.
If the Bellow Expansion Joint must be insulated it is important to know. There are two ways of insulating a Bellow Expansion Joint. Both are depended of the positioning of the inner sleeve. The Bellow Expansion Joint is either insulated between the bellows and the inner sleeve or between the Bellow Expansion Joint and the outer casing. The best solution is chosen according to the design of the pipeline.