As I am doing further work & study on jacketed piping, certain doubt came in my mind.
We are doing stress analysis of jacket piping using Caesar II as describe in manual . In addition to that we make manual calculation for buckling failure & core-jacket interface weld joint failure based on temperature differential between core pipe & jacket pipe.
Question is do we really required to do that additional calculation ?
Jacket pipe will experience jacket fluid temperature no doubt. Now core pipe if I consider will experience core fluid temperature I feel we are in highly conservative approach. Because core pipe internal face have core temperature & external face have jacket temperature . Expansion of core pipe will be as per highest temperature i.e. jacket fluid temperature if I ignore minor error. So there should not be any temperature differential between core & jacket pipe at least no significant difference.
So I feel even if I don’t do any addition calculation for jacket piping there should not be any technical issue.
Generally there are no much difference in temperature between core & jacket line temperature also so conservative calculation has not seriously effect on stress analysis.
I seek expert opinion on this issue please.

Any comments please.

The worst long term case arises if the core and jacket are materials with different expansion rates. The simplest assumption, if the materials are the same would be that temperatures will normally be similar, and thus no great expansion differential or stress problem. That may be dangerously simple though. Consider a steam jacketed sulphur system ... common in refineries and gas treatment plant. When started up the from cold the jacket will steam heat quickly due to insulation, but heat transferred to the core will be conducted into the solid sulphur for quite some time before any wall equilibrium is reached. A large thermal differential and consequential high stress will then exist. Be sure to consider all such possibilities.

SHR,

I like to use PipingOffice calculators along with CAESAR II when I do jacketed piping. Go here:

http://www.pipingoffice.us/

..........and look at "Miscellaneous" calculations.

Regards, John.

One of the many routines in 'Pipemill' software also deals with jacketed pipe. It allows calculation of compound stiffness and weight for core pipe, contents, jacket and insulation, axial force and buckling checks and local stresses in the closure plate.

Go to www.pipemill.com for a free demo download.

Thanks
MoverZ & John Breen
For your valuable suggestion & information.

Regards

Habib

MoverZ,

I must respectfully disagree. I am working on steam jacketed sulfur piping now. In discussions with the operations people, it has been made clear that the system will be brought up to temperature with steam before any sulfur is introduced. I have had some local issues to be concerned with, such as right off the sulfur condensers, where the core temperature is a good be higher than the steam jacket.

In my case, it's also been made clear that, if the sulfur core gets plugged/frozen, the spool is going to have to be pulled out that blasted clear.

While we certainly need to be cognizant of the scenarios and design for them appropriately, as engineers we also need to use the information available to make sure that we are making informed decisions to arrive at practical solutions.

Edward,

The last sulphur plant I worked on (in Saudi) had 1.4km between the recovery plant and the truck loading depot and pumps. That was definitely designed to unfreeze the solid with steam, since it would be impossible to locate a plug. Thus I think my concerns about short term conditions were in that case, well justified.

Hi Friend,

I am working for Jacketed Piping for Sulphur application.
We are using CAESAR II for pipe stress analysis of jacketed piping.
Could you please let me know how to perform the stress analysis of jacketed piping (steam jacketing) using CAESAR II?

Also from your discussion forum, it is said that this procedure is included in the CAESAR MANUAL. Also In addition to that we make manual calculation for buckling failure & core-jacket interface weld joint failure based on temperature differential between core pipe & jacket pipe.

Could you please help me out for this jacketed piping along with some tutorial?

many thanks in advance for your great support.

You can find a “jacketed” example in the Applications Guide – page 8-69. Note this isn’t a real system. The purpose of this model was to show how to create a jacketed model in CAESAR II. You can find the actual job file in the \examples directory, it is installed with the software.

Please note that pipe stress programs do not perform buckling computations, so yes you would need manual calculations to address interface weld joint failure.

Hello sir,

sir i am confused about modeling of jacketed piping.please send me one example of CII file for sulpher jacketed piping with some good technical notes on jacketed piping.my email id is sumitkadam@gmail.com

Thanks in advance