The issue of using expansion joints and flanges on vertical pipes!
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The new installation at my company features vertical pipes with a total length of about 30 meters, having nominal diameters of DN800, DN700, DN600, DN400, DN300, DN200, and DN100 respectively. I plan to install a single bellows expansion joint for each of these pipes, using flange connections; all the other vertical pipes will be connected by welding. Is this a reasonable approach? There is also a vertical pipe with a DN600 diameter and a length of 3.5 meters; its ends are embedded in cement. Is it necessary to install an expansion joint for this pipe? PS: The working medium is water at room temperature. This post was last edited by zy19810528 on 2009-4-6 11:31]
The working medium is water, at room temperature! ! ! Why did you choose an expansion joint? It’s better to find someone who understands the subject to design it for you; don’t rush into things just to save on design costs, as that will only lead to more waste in the end! :L
Both the top and bottom of the pipe are fixed in concrete; since the expansion coefficients of steel and concrete are likely to differ, it is planned to install an expansion joint.
First, based on the expansion coefficient of the steel pipe material and the potential temperature differences, calculate the maximum amount of expansion that each section of the pipe is likely to experience. Then what is the stress in the steel pipe at this degree of expansion? Expansion joints are needed only when this value is very large. Expansion joints are not required under normal temperature conditions. The pipeline is not very long and does not require expansion joints.
The connection method is correct, but expansion joints are not necessary.
Of course, if the pipeline is subject to vibration or thermal displacement, it is best to install expansion joints.
There is also a vertical pipe with a DN600 diameter and a length of 3.5 meters; its ends are embedded in cement. Is it necessary to install an expansion joint for this pipe? PS: The working medium is water at room temperature. No expansion joints are needed; let’s take a look at the stress analysis data first
Is the pressure high in a medium at room temperature? But there is no vibration source. It is estimated that no expansion joint is required. Furthermore, expansion joints are prone to damage and leakage, which is not good.
It can be installed and used at room temperature – so what’s the need for an expansion joint?
The use of expansion joints on vertical pipes is not necessary; expansion joints can be used in any orientation other than vertical to reduce the displacement caused by vibrations.
If the lower end of the vertical pipe is equipped with machinery, in order to prevent the weight of the pipe from pressing down on that equipment, an universal expansion joint should be installed, and there should be support above the expansion joint. (There is also a vertical pipe with a DN600 diameter and a length of 3.5 meters; its ends are embedded in cement. Is it necessary to install an expansion joint for this pipe?) ) It is unreasonable to embed the ends in cement; instead, the cement should be placed inside pre-installed sleeves, with the pipes passing through these sleeves.