Who has any materials to share on the design and calculation of π-type compensators
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When working on medium-pressure steam piping, I used to design it by relying on previous experience from similar projects, but I was not aware of the specific regulatory requirements and calculation methods. I could only imitate what had been done before. I would be extremely grateful if experienced professionals in thermal piping could provide guidance and share relevant materials and standards with me.
It is described in Tang Jin’s book; you can find this information on this page.
Could you provide a rough title, or help find a link to that book? Thank you.
Could you provide a rough title, or help find a link to that book? Thank you.
Take a look at the power pipeline design manual: for π-compensation, the distance between the two fixing points is generally determined based on temperature and pipe diameter, and then it is decided how large a bend to use. There is usually a range specified based on experience, after which stress analysis is conducted and adjustments are made
But I’ve seen pipeline drawings from some large design institutes, where the length and width of the π-type compensators are greater than those specified in the technical manuals; moreover, they don’t follow a ratio of length to width of 1:0.5 or anything similar. Logically, the longer the length arm, the less stress should be placed on the fixing supports. Is the requirement in actual design not strict enough, with only a minimum value as per calculations being necessary?
I’m not quite sure what you mean by “the length and width of the π-type compensator should be greater than those specified in the manual.” This range is flexible and not fixed; moreover, the ratio isn’t necessarily 1:0.5. The calculations given in the book are rather conservative. Sometimes, if you increase the length of the arms slightly and conduct a analysis using software, you’ll find that it’s still possible to make it work. The so-called empirical values are those that make it easier to determine whether a design will work under the same temperature and pipe diameter conditions. Using such values can save a lot of trouble, but they’re not set in stone. Don’t take the concept of the π-bend too literally. If you design a bend with a length of 4 meters based on certain criteria, but the actual distance available on site is only 3 meters, you can adjust things by adding additional fixing points or other methods to make it more suitable. The conditions on site are variable, so we need to be flexible when dealing with problems
Thank you, I understand it the same way; sometimes one still wants to know why things are the way they are. Thank you again.