POLYPROPYLENE STRESS ANALYSIS

[PIPING_DESIGNER]

I have to prepare a new stress analysis report of piping project which the pipe material is polypropylene.
As a software, I will use caesar ii.
I want to know about:
- which stress code should be used to best drive this analysis.
- mechanical properties of polypropylene (allowable stress, elastic modulus, yield strength)

Please, I wait your advices to best achieve this analysis.

 

[1503-44]

https://www.kebechem.com/images/pdf/PP_2.pdf

Code depends on what type of system it is.

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[PIPING_DESIGNER]

I would be grateful if you could help me.

 

[1503-44]

What are you building?

Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

"Stress code"?? You analyse the stress according to the design code the piping is built to. That is up to you / your designer, but could be ASME B 31.3 or indeed some other code. You need to ask them or look at the design basis.

Mechanical properties vary depending on the grade of pipe and sometimes who you buy it from,. So ask for the suppliers data sheet once you've decided which type of PP you are using.

Note that PP, like PE, has creep properties, is very temperature dependant in terms of mechanical properties and has a much higher expansion coefficient than steel ( about x 7-9 higher than steel pipe)

But you need to not think of this as another type of steel. It just doesn't work that way. The link by mr 44 is a good reference and you should read it carefully to understand how PP behaves under stress and what the impact is of temperature and long term creep.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[PIPING_DESIGNER]

Thank you for your reply.
Which code (ASME B31.3, ASME B31.1, ASME ND or ...) should I use for the study of polypropylene material.

 

[XL83NL]

Which code (ASME B31.3, ASME B31.1, ASME ND or ...) should I use for the study of polypropylene material.

The one that's spelled out in the engineering design of your contract. You don't get to choose, you have to follow.

Pipe stress analysis for plastics is different from metals and requires a different approach. If this is your first, I'd recommend you hire a consultant or subcontract the work to someone who can (also) train you on the job.

Huub
- You never get what you expect, you only get what you inspect.

 

[Alex Matveeff]

ASME B31.3 and B31.1 don't have any methods for pipe stress analysis of PP piping. And CAESAR don't have this feature
In this course I explain how to analyze it using DVS 2210 and 2205 codes

I'm the PASS/START-PROF Pipe Stress Analysis Software Developer

 

[XL83NL]

If you have the option to choose, consider the new ASME NM standards, piping standards recently developed specifically for Non-Metallic piping systems

https://resources.asme.org/nm-standards-manufacturing

Huub
- You never get what you expect, you only get what you inspect.