Saddle Design

[hockchong]

Hi everyone,
I have design a saddle with external ring. The vessel wall is around 22mm and the ID 4267. I am using finglow to design the saddle and the program show that it required external ring.

My problem is, the ring clash with one of the component and the component can't be move. The only option is the cut portion of the external ring. Can anyone here suggest me the best option to do it. I have no idea. Thank you.

P/S : Please give me option other than FEA.

 

[LSThill]

Hi hockchong (Mechanical)

You have two ENGINEERING TOOL'S:

1) The home of "COMPRESS" is

http://www.CODEWARE.com

2) FE/Pipe

http://www.paulin.com/newprg/fe_pipe.htm

FEPipe is a template driven finite element program designed exclusively for the piping and petrochemical markets. FEPipe handles saddles for axial or lateral loads, a result that Zick could never do, and find stresses in lugs and attachments in the automodeller. FE/Pipe will also produce allowable loads on nozzles which can then be handed to the piping engineer for evaluation. The new version FEPipe 4.100 does a spectacular job with multiple, close proximity nozzles in heads or cylinders using unstructured meshing

Saddle Analysis take less then 10 minits

FOR THE ABOVE ENGINEERING TOOL'S

Leonard Stephen Thill
Leonard@Thill.biz

http://www.thill.biz

 

[Tankman650]

I have done this by branching the stiffener. Use the same size stiffner plate everywhere and use full pen groove welds.
1
11
1 1
1----1
1 1
1 1
1----1
1 1
11
1
1

The above is a graphic. Use 30 deg. slope (45 degrees may be too much) on the branch with connection plate across branch. Assume that stiffener bar is fully loaded before entering the branch to verify weld stresses. The connection plate across the branch is in compression so check buckling allowables.

 

[theArcher]

Refer to MEGEYSY Pressure vessel handbook. in this handbook there is relationships for analyzing saddles and there are some factors for non 360 degree rings.

 

[hockchong]

theArcher,
Can I know what edition of Megeysy you refering to. I can't finf it in my Pressure Vessel Handbook(8th Edition).

Btw, thanks to everyone for the quick answer.

 

[aybee]

maybe is because that volume is up to 11th (12th)? edition

 

[hockchong]

Guys,
I read through UG-29 ASME Sec VIII Div. 1 and it stated that code allow gaps between stiffener as long it meet the requirement of UG-29.2. Am I right about this?

Thanks again for the reply.

 

[PVGuy]

Rings must go completely around the circumference of the vessel unless they are internal to the shell. (See UG-29(b)). UG-29.2 applies to rings on the inside of the shell.