Hello all,

can someone post a worked example of a trunnion calc according to the Kellogg method (subject 3810)which includes axial/longitudinal&circumferential (thermal)forces.????

i have a copy of this paper but i am confused about the following:

1.does table A apply to cylindrical attachments?
(i believe this is NOT the case and that f is independant of any factors)

2.What is the correct way of combining axial/longitudinal/circumferential stresses as calculated?
3.how do we include the pressure stresses whith all 3 stresses in operation.


Every spreadsheet i have come across has a different take on this.


your comments are appreciate

I do not have at present a worked expamle, but i will try to answer your question in a different way.

The basic theory behind the Kellog derivation is based on circumferential line load on a cylinder.

If a longitudinal section is cut from the shell of width r times dtheta , the sides of this section are supported by the remaining shell.The stiffness of the shell support can be computed by the load on the differential area divided by the displacement which is poissons ratio times the circumferential strain.

This will result in the well known equation of beam on elastic foundation the solution of which gives the sigma ( =6M/T^2)as 1.17 sqrt R/T^1.5 times P where P is the radial load.

Regarding the combination method I agree with you that different spreadsheets use different way of doing it.

In my opinion the best way to combine should be to use the combination and allowable methods of section VIII DIV 2 Appendix 4 which I have not seen in any of the spreadsheets.

For example bending stresses should be pushed into the secondary category as the attachment is a discontinuity/concentration for which primary bending stresses do not apply.Pressure stresses should be considered in the category "general primary membrane".

Having pushed bending stresses in the secondary category the allowable will go up and qualification of the attachment stress will be easier.

Regards

Hi
I've been trying to rationalise applying the Kellog method to trunnions on elbows [duckfoot, base elbow or whatever you call them]. Obviously a trunnion attached to a stright piece of pipe, must behave differently to one on a curved piece of pipe i.e. and elbow.
I have been trying a method based on the local load calculations fron BS EN 13445 [Pressure Vessels] considering the circumferential loads as acting on a shell with diameter equal to the pipe OD and the longitudinal loads acting on a semispherical head of crown radius equal to the centerline radiius of the elbow plus half the OD of the pipe. Axial loads are included in both cases. The method calculates a bending stress limit in each direction and then calculated maximum allowable forces and moments from there which can be compared via a unity check against your applied loads.
So far the results seem more conservative than applying the Kellogg method to the elbow as if it were a straight piece of pipe. [I generally factor calculated stresses by a SIF of 2.1 as an attempt to include what is happening to the elbow itself in the calculation].
Does anybody else have anything to say about calculating trunnion loadings on elbows as opposed to striaght pipe?

This another example of how the codes sometimes don't work for me.

Surely the code should include an example (no matter how conservative) of how to apply these things to an agreed standard

T.J.N.,

Code writers have (at least for the 29 years included in my committee activity) been compelled to NOT make the Code books into engineering text books. This is a mandate of the main Committee on Pressure Technology (all members are minor deities). It is not our charter to teach engineering or to write "cook books". Codes and Standards work together to be regulatory in nature, not educational.

Having said that, I will point out that in (relatively) recent years the trend towards including "examples" has slightly shifted towards your point of view (e.g., Appendix "H" of B31.3 and the non-mandatory Appendices of B31.1). Regarding the Codes not working for you, I would suggest that you trouble yourself to write official inquiries to the B31.3 book committee asking for clarifications (see B31.3, Appendix Z). If there are enough inquiries (i.e., there is enough interest in the "user community) it is likely some Committee will want to add rules to their book section.

I think that design of trunnions, base elbows, et. al. is an interesting and welcome topic for discussion here. Certainly it will be useful to arrive at a consensus regarding the applicability of some of the old empirical methodologies in piping design (not to mention the desirability of sorting out what it is that they really calculate). Most of us lazy people have gone over to using FE/Pipe (or classic shell theory)to analyze local stresses at the interface of pipe walls and welded appurtenances. I hope that there are more discussions of this topic in this forum.

I am now going to have a look at the BS EN 13445 approach.

Regards, John.

So which one of the numerous methods and then interperations would you make mandatory for this???

Think you could get agreement amongst the comitee members on your favorite method??? (Get 40 friends together and try to get them to agree on something simple for instance say the best beer)

The openess of the codes are sometimes more help than people realize.

Have you used the CAESAR II trunion module and tried building the trunions into your beam element module??

Can anybody point me to where I can find a copy of the paper <“Stress Indices for Piping Elbows with Trunnion Attachments for Moment and Axial
Loads,” by Hankinson, Budlong and Albano, in the PVP Vol. 129, 1987.> as quoted in the CAESAR II users guide. A Google search has turned up nothing. I am very interested to see what it says before using the Trunnion module in Caesar II.

Hi Superpiper,

I have the original MW Kellogg papers on trunnion design, they can answer all your questions so sent me your email address and I will scan them to you

Regards
A

Aaron,
I would like to see a copy of the papers if that is possible. I have the MW Kellogg book, but suspect these are additional to that....
Please email me a copy if you can to
kenny_robertson@<no-spam>btinternet.com

Please remove the <no-spam> from the email address before sending

Cheers

Ohh.!! Super!!!

Thanks Aaron,

Capt Kenny,

"Can anybody point me to where I can find a copy of the paper <“Stress Indices for Piping Elbows with Trunnion Attachments for Moment and Axial
Loads,” by Hankinson, Budlong and Albano, in the PVP Vol. 129, 1987.> as quoted in the CAESAR II users guide".

Try a library or IMechE in London where you will be charged a few pence for a copy. You shouldn't need more than a sedative for the sporran.

Aaron,

May I also kindly request you to send me the scanned copy of the original kellog paper on Trunnion design?

My e-mail address is: abhattac@bechtel.com.

Best regards

Aaron,

I would also be interested in seeing the original kellog paper on Trunnion design.

Thanks,

chris

chris.hogben@amec.com

Aaron,

If its not too much trouble, I'd like to get a copy myself.

Many thanks,

Richard Havard
richard.havard@mustangeng.com

Friends,
I remember that in one case I received lot of requests from forum members to send a copy of some PDF documents for failure theories of isotropic materials.I got a good suggestion from Richard Ay to send it to him directly and he in turn posted it in the forum via a link.

Since many of us require this document, can we request Aaron and Richard Ay to help us that way.

Best regards

Aaron,

I am very much interested also in having a copy of MW Kellog..Your help is highly appreciated..My e-mail ad is: jma121774@yahoo.com...

Many thanks and more power,

Superpiper, I would recommend you to try with FEA. FE-Pipe is made in a way that is more "piping user" friendly than trying to create the model in other FEA software.

Regards

PS By the way..., I don't like to ruin parties, but aren't these Kellogg papers protected by copyrights?
If they aren't not can you add me to the list.
pedro.massabie@snclavalin.com

Aaron, may I have a copy please. My address: sofijanic.ranka@thyssenkrupp.com
Thanks

We say its not the position of the Code to provide a cook book on how to tackle trunnions etc.
Indeed, I have seen xx number of different ways in which the same method (Kellogg) is implemented.

So how is ones work in such area's checked?.

This is relevent to myself, as i have a body of work being check oversees as we speak. in this work, the trunnions are critical, and i expect a fire fight as to the right way calculate them.

I am on my one in this company, and am not the most experianced stress engineer on this forum.
My company will not pay for FE pipe or any books etc, and the papers used by engineers (kellogs etc) are part of a fast dissapearing black art.


it seems that alot of other people are intrested in these kellogs papers, i wonder why?


My point is this. Surely the critical design of potentially leathal pipework should not be based on whispers, rumours and the 99th copy of an obscure 60 year old 'pamplet'

Aaron,

May I also request you to send me the scanned copy of the kellog paper on Trunnion design?

My e-mail address is: rbonavin@bechtel.com.

Best regards

Superpiper,

I really suggest you look into the trunnion model info in CAESAR II its method is based on FEA work by Stone & Webster as I recall some time ago.

This method will cause you to increase the SIFS on your elbows, insert actual trunnion pipe elements with associated SIFs into your model.

Tell your reviewers if they question what you have done its based upon comercial software which was based upon an ASME paper .... and so on.

Can the CAESAR trunnion model accept structural attachments? I don't think it is currently capable of this. Will the new version?

Speaking of which, what is the status of v.5.00?

You're right, no structural attachments.

Version 5.00 won't do this either.

I <font color="#0000ff"><em>hope</em></font> to pull the trigger on 5.00 before the end of September.

Aaron,

Like others, can you please send me a scanned copy of MW Kellogg trunnion design. My e-mail address is arivera@ciateq.mx

Thanks and regards

I've had a look at the CAESAR trunnion module, but hit a problem right from the start. It limits the D/t ratio to between 20 and 60 and the first trunnion I looked at was 4" SCH80 [D/t=13.35!!] B*mmer!
Since I have had no joy [yet] in obtaining a copy of Hankinson et al's paper, can anybody [not-withstanding the stated limits of the Hankinson method] offer some advice on calculating suitable SIFs to use for a bend / trunnion intersection, or offer some sage advice on modifying the Kellogg method for use on elbows.

Hi there Aaron,

Pretty sure I won't be the last one to request this same copy. I do appreciate your kindness. Also, if you could direct me where I can possibly copy or scan it, it might ease the burden on you. I hope members here would be as kind as you are. My email adress: ed-lamigo@cox.net.

Thanks and regards,

Ed Lamigo

Aaron,

Will you please send a copy to me as well.

Thanks in advance,

Kevin Monroe
kevin.monroe@mustangeng.com

Will you please send a copy to me as well.

Thanks in advance

LEONARD@THILL.BIZ

Hey Y'all,

Been thinking, the stress issues here is really a lot like a nozzle calculation? The nozzle just points down to the ground where it is "anchored". WRC-107? Any thoughts?

Regards, John.

John,

My opinion is: Although nowhere explicitely shown in WRC 107 ,a perforation in the wall, I think the intent of WRC 107 is to calculate the stresses at nozzle openings only.The WRC 107 document calculates stresses in shell only and the thickness of the nozzle comes to play ( at least to a great extent)stresses in the nozzle only. So although the attachment parameter in WRC 107 does not mention nozzle thickness for cylindrical attachments, it really does not play an important role in the shell stress calculation.

So WRC 107 basically addresses a real life nozzle connection ( and not a rigid plug connection on an unperforated shell) and hence the trunnion attachment cannot be analyzed with WRC 107.

This is as per my view on WRC 107 and based on numerous discussions I had with COADE in this aspect.

Looking forward to your view and view of other forum members.

Best regards

Aaron,

The particular paper to which you are alluding familiarly echoes some information contained in Kellogg's internal "Piping Mechanical Design Manual." I used to work there. Should that be the case, you know, you could be illegally distributing proprietory data of others via this internet forum....

.........and that leads to the question "what were the reference documents for the internal Kellogg Manual? At what point did someone actually develop all this good design theory from basic statics and strength of materials (and when was it first put into print)? If you follow the trail back far enough (if you can find the trail) it takes you to Roark, Timoshinko and Hooke's law) and some of the olde traditional piping design stuff is really hard to assign to ANY owner. When we publish (or teach) we have some responsibility to assign credit for our sources but sometimes it is not possible. Maybe John Luf wrote all this stuff before I was born (?). I have been presenting piping design and analysis seminars for more than (gulp!) 30 years and when I look back to my original development material I can't find all the sources (but I did find some original drawings of Noah's ark). Some piping design information has been with us sooooo long that it can no longer be considered proprietary.

There have been some "rules of thumb" that I have seen in many corporations' "in-house training materials" that have been passed down from generation to generation. I have been told that "..well, we think that came from the old Kellogg book..." but upon investigation this was not the case.

This topic of trunnion design has taken me back into my olde basement archives (for your folks in Tejas, a basement is a dark little room found under most houses in Yankeeland) to try to find the original source of some of my design notes and I have found an old dusty blue 3-ring binder with the "Grinnell" name on it. I remembered in the mid to late '60s, Grinnell presented a training program for hanger and support design that I helped with. In the binder, there are 8 or 10 pages that focus upon "Grinnell Hanger Standards" 62 and 63. These pages present a step by step procedure for determining what specific (size, etc.) Grinnell pipe stanchion should be ordered with consideration of the size (and wall thickness) of the pipe to be supported, the load, the temperature, the pipe material, etc. They include tables of wall thickness correction factors, temperature correction factors, etc. It is all set up in nice neat tables and charts. Only one problem, there is NO disclosure of the underlying theory!! There are no references. So, use it if you want to, but let the designer beware. Now that I have found this stuff again, I will have to ask Anvil if they happened to inherit the Grinnell archives (let me see now, where did I put Dan Walsh's phone number?).

There just has to be some time limit on copyrights - when "ideas" fall into the public domain (...or else someone owes Matthew, Mark Luke and John a bunch of money).


Regards, John.

Gentlemen,
I am afraid I cant send anyone the trunnion papers as they are over 16 Mb. I have spent a considerable amount of time trying to email them with little success.
With regards to Warren Yins comments, this information has been in the public domain for a very very long time and I am pretty sure that its well past its copyright date and besides I know that as long as I have been in this industry all the major petrochemical companies use the Kellogg Trunnion equations and much much more, they even refer to it in their job notes,hell when I worked for kelloggs I used engineering softwares developed by other companies to help Kelloggs get the job out and visa vera, so lets not pretend to be squeeky clean eh, we are only trying to help each other and the industry.
To Mr. Breen I can only say thanks for your intelligent comments.
I hope this matter is closed now.

Regards
A

15 MB... despites Johns remonstrations I am a simple user of what other persons developed.

One other publication comes to mind it is courtesy of Dr. Wais and can be found on the WRC web site.... it allows one to calc trunnions as well as some other attachements and is used by the folks of the NC industry... WRC 448

Mr. Rich Ay,

I agree with Aaron's conclusion; so, please close the subject stream, at your discretion.

That fellow stress analysts can get upset over my remarks will show that I am still a non-contrite, judgmental sinner, a Texas-size one. To Aaron, my sincere apology.

No one should take offense at anything posted in these forums. Sooner or later there will be disagreements or differences in opinion, but that goes with the territory.

This thread is rather long, and since the e-mail isn't possible, I'm closing this one ...