Piping Stress Analysis Software Recommendations

[sircrashahlot72]

Trying to select the best, most applicable stress analysis software for subsea piping (manifolds and tie in structures), but having a hard time coming to grips with what is actually out there.

Various other offices within my company use either CAESAR II or AutoPIPE with great success, but these generally tend to be larger plant systems onshore or topsides. My systems are generally very small (less than 15 spools per structure usually), but have many different load cases and influences, from current and wave effects, temperature/pressure variations (both internal and external), marine growth, cathodic protection etc. Existing systems seem to be both overkill and simplistic at the same time. Consultants using AutoPIPE for us, have often had real challenges getting good results out of the software, and minor changes to the piping arrangement can take quite a bit of time to implement as we are not designing our piping in a full plant PDMS system (as why would we need to with 15 spools?). Also getting geometry into AutoPipe seems archaic, and it is considered one of the more user friendly. Does anyone know a good pipe stress system that has a good user interface?

I also think that with the power of modern PC's, using simplified beam elements for piping is again an overly simplified approach. I would think that modern mechanical FEA packages (Ansys, CREO Simluate, Solidworks Simulate, etc.) would be able to handle the load cases, and the actual math to generate stress and deflections accurately for the components. The other question is how to apply these results to the ASME B31.3 or B31.8 (or other codes) requirements. Is anyone out there using these standard mechanical FE packages for piping design?

Again, coming from a more straight forward analysis background, my preference is for a mechanical FE package, so any hints or roadblocks that others have run into would be appreciated.

Thanks,

Andy Harbin
Mechanical Systems Lead

 

[BigInch]

Sure FEA can do it, but you haven't lived until you tried it. The idea is obviously to keep it simple an do not over-analyze, especially for such small systems, but I think nothing's too small when it comes to FEA. Even a small bit can become huge.

you must get smarter than the software you're using.

 

[XL83NL]

Jsut my 2 cents re AuoPIPE.
- love the interface. user-friendly, allows for easy changes. so I tend to disagree on

Also getting geometry into AutoPipe seems archaic

and

minor changes to the piping arrangement can take quite a bit of time to implement

- no experience on the dynamic part you mentioned, so cant comment on that
- from what Ive seen in webinars, AP can do offshore work
- what design codes is applicable to your work?
- review B31.3 para 300(c)(3) to see what B31.3 requires of you when you use 'your own design rules'
I think you're far from home leaving B31(.3) for what it is and using FEA.

 

[Gator]

"...minor changes to the piping arrangement can take quite a bit of time to implement as we are not designing our piping in a full plant PDMS system..."

How is the piping being laid out (i.e., which software)? You can import piping geometry into most stress programs fairly easily (PCF and other formats IIRC), although many stress analysts prefer to recreate the system themselves with AutoPIPE or Caesar (to 'familiarize with the routing' or to avoid potential glitches in export/import of the digital file).

Piping Design Central

 

[TGS4]

One of the issues with a general-purpose FEA program is the Code compliance checks. Converting from FEA-stress-space to Code-stress-space is a lot more complicated than you might think.

 

[sircrashahlot72]

Gator - We are using Inventor for all of our structure and piping modeling, and AutoCAD for laying out the ISO's. The piping is usually built off a line skeleton that could be exported, but our consultant has always re-created the geometry in AutoPipe from the ISO's. Causes a lot of back and forth on the design as he finds stress issues, or we need to make mods to account for valve sizes or other structural concerns.

TGS4 - The code compliance check is really the basis of my post. I'm trying to see if anyone out there has solved the riddle of doing a 'proper' FEA on a piping system and getting a code check from the same model. The more I dive into this, the harder it appears to be, but I think it is possible, and the right way for me to go.

XL83NL - Compared to a proper 3D modeling or drafting package, AutoPipe is bad. This is why I'm loath to consider other software, even though I know of calculation issues within AutoPipe. You are absolutely correct on the statement from the code, and generally my client isn't that educated on what needs to be done, so this is a potential issue as well.

Looking forward to more input on this...

Andy

 

[Gator]

Are you redrawing isometrics with AutoCAD that you've already modelled with Inventor? I'm not sure of the price difference between, say, AutoPLANT/CADWorx/AutoCAD Plant 3D and Inventor.

With the above-mentioned piping software, isometrics are (semi) auto-generated by Isogen from the model.

Last time I looked, AutoPIPE was part of the AutoPLANT suite of programs.

Piping Design Central

 

[XL83NL]

re

Compared to a proper 3D modeling or drafting package, AutoPipe is bad

A discussion on this subject is more personal than factual. Compared to 3D modelling its bad yes, but its comparing apples with bananas.
In terms of pipe stress programs, AP might be the best out there when it comes to ease of use for adjustment, (re-)modelling, adding in/removing parts, etc.
I route a piping more quickly in AP than in e.g. SolidWorks. Im not as fast in routing in AP as our piping engineer is in Plant3D, but hey, I dont need to. He also cant do it quicker e.g. using SolidWorks.