Help on Bend Trunnion

Dear Pip-Ers,
As far as I know kellogs trunnion evaluation method is not applicable for bend trunnion.
1.Help me to find a method to check stresses on bend trunnion other than FE analysis.
2.Why kellogs method cant be used for for bend trunnions?
Thanks in advance

You are correct, Kellogg 3810 speaks of straight cylinders, not curved pipe.
CAESAR II handles these elbow trunnions by an adjustment to the SIF.
I presented a webinar on this in December 2016. You can stream that presentation from our web site: Trunnion Supported Bends in CAESAR II

Dear Dave Diehl,

Taking advantage of what you mention about the webinar I would like to ask you. How could you get the webinar recorded Dynamic Analysis Part 3 and Part 4 ?, since in the official page they send a display error,

Thank you very much and always succeed

Can you try again? WE just fixes a broken link. Sorry for the trouble...

Dear Dave,
I have the same trouble, Could you post the link where I can download directly?
Sorry for the insist,

I really appreciate all you and your team effort to this help for the stresses engineers around the world,

Best Regard

Without access to FEA software, the best I can offer you is to calculate SIFs through the SIFs @ Bends module on the Analysis tab.

I'll warn you, however, in that it is limited in scope - i.e. specific size and thickness ratios - and the SIFs it calculates are typically very conservative compared to FEA solutions... 1.5x-8x+, I find.

AGA_76
I believe those broken links are repaired.
The set of 4 dynamics webinars is available here: rebundled

Thank you very much Dave, for your quickly answer,

sucess always,

I have been in the same situation many times re: trunnions/trunnions on elbows, both not trusting Kellogg and lacking access to full FEA. I finally constructed a trunnion qualification spreadsheet for myself (Excel 2007 Workbook .xlsx format) based on the nuclear code (ASME Code Case N-392-3 Procedure for Evaluation of the Design of Hollow Circular Cross Section Welded Attachments on Classes 2 and 3 Piping / Section III, Div 1 Nonmandatory Appendix Y-5000) for tee-pattern run attachments. The spreadsheet includes adjustments to stress indices for elbow-mounted trunnions based on the findings of EPRI TR-107453 "Stress Indices for Elbows with Trunnion Attachments." (TR-107453 free for download here: http://www.epri.com/abstracts/Pages/ProductAbstract.aspx?ProductId=TR-107453 )

You first construct a proper CAESAR model (see Dave's webinar). Then, using the CAESAR II output from the trunnion attachment node at the pipe wall, TRUNNION QUALIFICATION SHEET calculates whether the attachment is acceptable under Code Case N-392-3 for tee-pattern trunnions or as modified by EPRI for elbow mounting. Using weld geometry calculated per AWS, it tests whether the ovalized trunnion weld at the pipe wall will overstress and violate the pressure boundary. As Michael Fletcher said above, specific size and thickness ratios apply. I went to pains to make sure the spreadsheet is not a "black box." All the formulae are visible.

Of course, I make no warranties. My sheet is freely available here: http://files.engineering.com/getfile.asp..._N392-3_R0.xlsx

http://65.57.255.42/ubbthreads/ubbthreads.php?ubb=showflat&Number=52480#Post52480

Dear RUs

I found en error in final stress calculation on your spread sheet.

there are primary stress indices B1, B2.
It is right 0.5 and 1.0 each of factor only for straight pipe.
But in case of Elbow Mounted trunnion you can not use that value. you shoud calculate B1, B2 specially according to the FIG.NC-3763.2(b)

Confirm it again.