FRP fiberglass piping analysis in Caesar

Posted by: KemalK

FRP fiberglass piping analysis in Caesar - 12/23/10 01:17 PM

Hello to all,

Does anybody has experience with analysis of FRP fiberglass piping systems with caesar.

Which code is it. I am using C II 5.10


Posted by: CraigB

Re: FRP fiberglass piping analysis in Caesar - 12/23/10 04:09 PM

The same design code that applies to all of your other piping systems will apply to fiberglass piping systems.

But the major problem design engineers have with fiberglass piping systems is assembling a competent set of design properties. Fiberglass pipe for a given size, design pressure, and design temperature can have a very wide range of bending stiffnesses.

A proper stress analysis of a fiberglass piping system requires you to obtain a great deal of this (proprietary) information from the vendor. It is not possible to do a competent analysis of a fiberglass system until you know any of these. And since the properties can be controlled by the particulars of the winding of the glass fiber, they can be changed to accommodate the requirements of the project.

Therefore, determining the most suitable properties for the fiberglass pipe is an iterative process. If you, as an independent (not an employee of the pipe manufacturer) design engineer attempt to do the detailed analysis on your own, there will be several iterations before you have a final set of material properties that work for your layout. This can be quite slow, and the pipe vendor can use your analysis time as the basis for an additional charge for external contract delays.

The fastest and most cost effective way, by far, to deal with this situation is to give the vendor coordinates, thermal movements, and allowable loads for all terminal points, and design conditions for the piping, and require him to submit the report and get it approved before he ships the pipe. That way, the iterations on design requirements vs. manufacturing requirements can happen within the same organization, and one driven by the desire to get the report filed and approved so they can ship the pipe and get paid.
Posted by: corne

Re: FRP fiberglass piping analysis in Caesar - 12/24/10 12:42 AM

There are a lot of topics in this forum regarding the codes to be used for FRP analysis.
Currently there are three codes (UKOOA, BS7159 and ISO14692) supported by C2. B31.3 has a chapter on non-metallic piping (so do other piping codes), but this is not effective for analysis. Firstly because it's incomplete, secondly because C2 uses the steel part of the code for the analysis.

I disagree with CraigB regarding the problem getting the correct piping properties. Especially vendors with certified product ranges (like Ameron and Wavin) have all the info you need available in their datasheets.

What is much more important is that you have knowledge of the behaviour of this specific material. There is a great deal of difference between steel and FRP and this also results in different piping designs.

First make sure you understand material behaviour and the way the code you're using handles this behaviour. Then start finding material properties and carefully start your first analysis.
Posted by: KemalK

Re: FRP fiberglass piping analysis in Caesar - 12/24/10 04:25 AM

It is firewater underground piping, not high temperature. I do not know why stress analysis for that piping.

This is request is request:

1. Hydrostatic thrust
2. Thrust due thermal expansion
3. Thrust block design and construction.

Posted by: corne

Re: FRP fiberglass piping analysis in Caesar - 12/26/10 02:31 AM

For underground piping there are a couple of difficulties, just like with steel underground piping:
- stiffness of the pipe in combination with soil load and vessel axel loads
- axial (non)-restriction of the pipe

The first thing can't be checked with C2. The second issue can.
Posted by: AnirbanDatta

Re: FRP fiberglass piping analysis in Caesar - 12/28/10 11:28 AM

You may please consult the engineering guides published by GRP/FRP pipe vendors, like Future Pipe, etc.