Use of belt slings for heavy pressure vessel lift
Use of belt slings for heavy pressure vessel lift
(OP)
As part of an ongoing cost reduction exercise, we are currently considering the use of polyester belt slings, for the horizontal lift of a large pressure vessel assembly. The belt slings would be used in place of lifting trunnions, which are time consuming and costly to fit.
2-off lifting slings would be used in place of the trunnions. These would be used in a straight basket lift configuration, around the belly of the column, and attached up to spreader beams via a bow shackle.
As the column has a large diameter to thickness ratio, and weighs around 225 tonnes, we are concerned about the possibility of localised buckling occuring during the lift.
I would appreciate any suggestions for a suitable classical method of analysing this type of flexible sling lift, which preferably does not involve finite element analysis.
Previously this type of lift was assessed by using a "Zick" type of saddle analysis. However, we appreciate that this method is not strictly correct for this type of belly lift.
2-off lifting slings would be used in place of the trunnions. These would be used in a straight basket lift configuration, around the belly of the column, and attached up to spreader beams via a bow shackle.
As the column has a large diameter to thickness ratio, and weighs around 225 tonnes, we are concerned about the possibility of localised buckling occuring during the lift.
I would appreciate any suggestions for a suitable classical method of analysing this type of flexible sling lift, which preferably does not involve finite element analysis.
Previously this type of lift was assessed by using a "Zick" type of saddle analysis. However, we appreciate that this method is not strictly correct for this type of belly lift.





RE: Use of belt slings for heavy pressure vessel lift
RE: Use of belt slings for heavy pressure vessel lift
On a related note, I think it would be extremely interesting to see a nonlinear (due to contact, perhaps deformation) FEA of a steel shell on a concrete saddle and compare it with Zick's strain gage result based formulas. Then run the same shell with modern welded on steel saddles and compare. Note that while a shell element analysis might get you going you'd be best off modeling this with solids - which is too tedious for me... Sounds like a good paper topic. Actually considered it for my Master's thesis topic but chose another which could be handled with axisymmetric geometry instead.
jt
RE: Use of belt slings for heavy pressure vessel lift
I really can't believe that there would be such a massive difference in reality. It just does not ring true.
Due to the criticality of this lift, it looks like we will be employing a consultant to carry out nonlinear FE contact analysis of the problem. I will let you know what the conclusions are.
RE: Use of belt slings for heavy pressure vessel lift
How is going to be put in its operational position @ site?
May be your customer will not be happy of not finding any poitn to lift the vesel from!.
RE: Use of belt slings for heavy pressure vessel lift
The column is therefore only ever subject to a horizontal lift. This is the main reason why the use of belt slings is so attractive in this case.