Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Polypropylene piping support design stress consideration

Status
Not open for further replies.

Vishakash

Mechanical
Apr 6, 2023
5
IN
Hi,
I'm working on strength design of PPH piping and its supports using Ansys. The piping systems is required to be design for elevated temperature say 65°C. I'm considering the creep stress and strain at specified temperature for strength values as recommended by standards. But one of the party asked us to include thermal stresses in design analysis using thermal coefficient of expansion as well which is resulting in significant deformation even before loading. I'm confused on validity of consideration? Is it correct? Or should I only consider the creep stress at specified temperature? Can someone provide some supporting argument or reference ?
Thanks in advance.
 
Replies continue below

Recommended for you

Thanks @mk3223 for link. But I couldn't find anything helpful.
The PPH pipe is meant for industrial application. Basically it sprays water to clean the contaminants inside the vessel during operation. The vessel is having contents at high temperature.
 
Can you share a drawing and details of the vessel and internal spraying PP line?
Why not to use the same material for vessel and spraying line?
 
[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1712640444/tips/Internal-Mist-Eliminator-Applied-in-Flue-Gas-Desulphuration-FGD-of-Power-Plants_wy51dg.webp[/url]

Here's the picture of similar spray line that I could find from internet. The pipes are straight run pipe with supports at particular span. Nozzles are attached at bottom of pipe for spraying.
I can't change the material as same is project requirement.
 
IMO, this is a design of the simple water spraying header using the plastic pipes. The specific creep strength of the material at the higher temperature is to be considered for designing the support type and with span without too much deflection. Also, the thermal expansion stress may be considered in the axial movement of the pipe as needed.
 
PP piping expands a lot (10 × more than steel) and you need to let it move. The picture looks like it is simple supports and clamps which just stop it lifting off but allow it to slide.

Don't use U bolts as fitters tend to clamp them down. Bad move.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor