Questions regarding the placement of pipe fixing points
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“How should the statement \"The load acting on a fixed point in a pipeline should take into account the frictional reaction forces from the sliding supports on either side\" be interpreted and applied in practice?
Under normal conditions, the two ends of the pipeline are fixed while compensation is provided in the middle. Pipeline expansion exerts a pushing force on the fixing brackets at both ends; if the support points in the middle are smooth, this force is transmitted entirely to the fixing brackets. In reality, however, there is friction at each of the intermediate pipe supports, and the force that ultimately reaches the fixing brackets equals the force generated by thermal expansion minus the force absorbed by the compensation mechanism minus the forces resulting from friction at the various pipe supports
Using a tetrafluoride plate, this problem can be ignored
The answer is wrong; don’t be misled. The force acting on the fixed bracket is the force generated by the compensator plus the friction force. There is no force generated by thermal expansion to compensate for the absorbing force. The friction force of all brackets ultimately acts on the fixed bracket. There are generally several types of forces generated by compensators: 1. The elastic force resulting from the deformation of the pipeline itself during natural compensation. 2. The elastic force generated by the bellows compensator and the force exerted by the blind flange. 3. The sleeve compensator generates a blind plate force, as well as a bilinear frictional force; this force is present during operation but absent once the operation is complete. 4. The rotary compensator generates a bilinear frictional force; this force is present during operation but absent once the operation is complete.
For example: the bracket adjacent to a fixed bracket is a sliding bracket. Since forces act in opposite directions, thermal expansion of the pipe causes axial thermal displacement, which results in relative movement between the pipe and the sliding bracket. As the pipe is rigidly connected to the fixed bracket, the friction at that joint is also transmitted to the fixed bracket; this can also be simulated using C2
An objection could be raised that the source of all forces is thermal stress!