Stress Analysis for Reinforced Thermoplastic Pipe
Stress Analysis for Reinforced Thermoplastic Pipe
(OP)
Hi All,
I want to ask for any expert here, how to perform stress analysis for above material and what kind of code/standard ? Is BS7159/UKOOA ( for GRP/GRE pipe) applicable for it ? The pipe will be buried with 8" size, 60 C.deg, and
2300 psig, with 30 km length as water pipeline.
Rgrds,
I want to ask for any expert here, how to perform stress analysis for above material and what kind of code/standard ? Is BS7159/UKOOA ( for GRP/GRE pipe) applicable for it ? The pipe will be buried with 8" size, 60 C.deg, and
2300 psig, with 30 km length as water pipeline.
Rgrds,





RE: Stress Analysis for Reinforced Thermoplastic Pipe
RTP is great looking stuff, but applying rigid pipe design to it won't work - in my opinion.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Stress Analysis for Reinforced Thermoplastic Pipe
RE: Stress Analysis for Reinforced Thermoplastic Pipe
RE: Stress Analysis for Reinforced Thermoplastic Pipe
Are you thinking of HDPE or RTP? The numbers you quoted are in the ballpark for HDPE (a little high, but with some derate of effective life, I can get there in water service). RTP is rated MUCH higher. FlexSteel has a 3,000 psig rated pipe in sizes up to 8-inch. FiberSpar has a 2500 psig rated pipe in up to 3.5 inch. Soluforce and FlexPipe both have products rated over 2,000 psig in 3-inch. I've used this stuff at 1400 psig with great results. I see no reason to think that you'd have problems at 2300 psig.
As to calculating hoop streses, take a look at API RP 15S or API RP 17J. I'm not sure how you go about doing a Caesar type analysis with this stuff. When I've tried to run it in Caesar II, I've gotten meaningless results.
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: Stress Analysis for Reinforced Thermoplastic Pipe
The latest version of CAESAR-II is able to perform a stress analysis of these systems.
I am also curious about "Reinforced Thermoplastic Pipe" at 2300 psig........ really ? What kind of plastic valves are you using at that extreme pressure ?
What is the wall thickness of the RTP piping for this pressure ???
MJCronin
Sr. Process Engineer
Venture Engineering & Construction
www.VentureEngr.com
RE: Stress Analysis for Reinforced Thermoplastic Pipe
It's all plastic pipe with loads of reinforcement as separate layers, some use steel, some kevlar and how you analyse it god only knows.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Stress Analysis for Reinforced Thermoplastic Pipe
As such, this material may or may not be permitted for use in CFR/DOT regulated piping systems only by filing for a special use permit issued by PHMSA for each particular installation, and only after public comments have been taken and the design and other peculiarities of the installation have been reviewed and approved by the agency, more with an eye towards allowing it under a proprietary "equipment" classification, rather than by proving adequacy by meeting any particular pipe design criteria of the various codes. As far as I know, there has been only one instance that might (or might not have) been approved for installation in a regulated system (in Los Angeles during the summer of 2012). I was following it for a time, but got busy on other things and never looked back to see if it was ever actually approved for use, or not. I suspect it was.... but I don't know for sure. You might look into the PHMSA online "special use permits granted" files to find out yourself.
Independent events are seldomly independent.
RE: Stress Analysis for Reinforced Thermoplastic Pipe
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: Stress Analysis for Reinforced Thermoplastic Pipe
RE: Stress Analysis for Reinforced Thermoplastic Pipe
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: Stress Analysis for Reinforced Thermoplastic Pipe
zdas04(Mechanical), how long have you use this kind of material, what's the size, P, and T, and how to conduct real time leak test/inspection if it is buried pipeline service ?