aboveground GRP water pipeline analysis

[netjack]

Dear All,
I wonder whether pipeline analysis programs such as Ceasar, AutoPipe etc are enough to satisfy the requirements stated by standards like BS7159, ANSI31.3,ANSI31.3 etc. In other words, would anyone need detailed finite element analysis or analytical calculations to meet the criteria.

Regards,
Gurol Ipek

 

[KernOily]

Compliance with any code is ultimately the responsibility of the owner and/or his agents. The owner is responsible for showing that his piping systems are in compliance with any applicable codes. Usually the owner and/or his insurers will state any requirements to that end.

Having said that, most of the computer-aided stress analysis programs out there will do the calculations using the Code equations, i.e. they will calculate the Code stresses as well as the non-COde stresses, displacements, etc.

The Code says that the system must comply with the requirements. How the owner gets to compliance is his business. Most people nowadays use CAESAR or equivalent to do the calcs simply beacause it's a lot faster and a more efficient use if the analyst's time.

What CAESAR does NOT do is remove the element of engineering judgment. I have this discussion with folks all the time: a smart chimpanzee could be taught to run CAESAR and get an output. The hard part is (1) making sure the model is an acceptable portrayal of reality (2) that the output, even if it says f < Sa, is still realistic and not trouble in some other way.

The use of FEA is called for when the situation at hand cannot be accurately modeled by a beam-column-element program like CAESAR. Experience and judgment are usually required to make this call, but obvious situations for FEA are thick flanges, unusual pipe branch connections/reinforcements, unusual pipe-to-equipment connections, unusual vessel supports, pipe trunnions, thin wall-large OD pipe, tank shell nozzles, etc. For example, I use FEA all the time to analyze tank shell and roof nozzles on tanks not covered by API 12J.

An FEA program would do everything CAESAR will, but CAESAR has all the built-in Code equations and it's much more suited to the piping task since it was purpose-built for that job. Thanks!
Pete
P. J. (Pete) Chandler, PE
Principal Engineer
Mechanical, Piping, Thermal, Hydraulics
Processes Unlimited International, Inc.
Bakersfield, California USA
pjchandl@prou.com

 

[stanier]

Algor's Pipepak software covers FRP specifically. Check out

http://www.pipepak.com