ASME VIII - Div 2- Saddle Support

[eng_65]

Hi,

At section 4.15.3.6 of ASME VIII Div 2, there's an equation (4.15.42) to calculated "the horizontal force at the minimum section at the low point of the saddle". Can anyone explain me what this force is and the meaning of horizontal in this context? I'm not a vessel designer and I'm having troubles understanding this section. Would you have a diagram, freebody or drawing to explain?

For info, I have a small pressure vessel, horizontal, on 2 saddles.

Thank you very much.

 

[AWDMIKE]

This is commonly called the saddle splitting force. There is a force distribution Zick derived in his paper for a cylinder resting on a support saddle. The total of the horizontal components of this distribution is the saddle splitting force, as it tends split the saddle in half at the point in the saddle which has the least amount of material in tension, presumably at the lowest point of the vessel which is the shortest height of the saddle. Please refer to Adobe pages 8 and 11 for a full description.

For anyone thinking they have found a nicely scanned version of Zick's paper in this post, please note that it is the original version and does not have any corrections made as the document on Codeware's site claims to have. I have not gone through and checked the difference between the two, and am only uploading this one since the equations are very clear and each variable can be read easily, whereas many of the Zick papers on the internet have some poor quality sketches and equations.

Hope this is helpful.