HG/T21574-2018 seems to have an error
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The lifting lugs are drawn according to the TPB standard, but the length of the shims is always much too short. Also, the workshop keeps complaining that the lifting lugs are too large and take up a lot of space; if a large pipe is placed at the top, the lifting lugs designed according to standards cannot be fitted there. There is no reference for custom designs either, which hinders the progress of work. :funk:
There have always been problems with the top plate lugs; in such cases, you can use one of the following three methods: 1. Use longer shims, which allows for exemption from calculations within the standard allowable limits. 2. To adjust the earplate β angle, manual calculations must be performed according to Appendix A. 3. Select any non-standard value and perform manual calculations according to Appendix A. Note: For the top plate lugs (TP), when exemption from calculation is applicable, they must also meet the requirements of Appendix B
If calculation is to be done, what should the minimum value be? Does the lifting lug equipment only need to bear the net weight of the equipment?
The key aspect of lugs is actually the local stress calculation of the head. You should say that it’s quite easy to meet the requirements for the lifting lugs themselves. Then you can also make holes in the lugs in the direction of the normal, so that the shims will be shorter.
Ugh! Senior, what you’re saying is a bit too complex; I don’t understand:dizzy:
This post was last edited by bluishice on 2021-12-24 09:28. There is no minimum value for calculation; you can calculate as much as you want. However, after making the calculations, you can draw it out at a 1:1 scale to take a look; if it seems well-proportioned (i.e., pleasing to the eye), then it’s fine. In the calculations, various operating conditions are basically taken into account. It should be noted that: 1. The slings should be arranged in the plane where the eye plates are located. 2. Check whether the sling interferes with other components (such as nozzles, etc.), taking into account both vertical and horizontal positions. 3. If the above two conditions cannot be met, it will be necessary to adjust the position and angle of the lifting lugs, or to use other types of lifting lugs.
:) I’m asking you because I’m not good at handling non-standard tasks
As for what can be done, the length and width of the shims as well as the height of the holes can be adjusted according to requirements; however, a proper approach would likely involve preparing a calculation sheet
The standard provides verification formulas; you should prepare a calculation sheet according to the standard.