HDPE Pipe wall thickness calculation

[Shahbaz_ME]

Hi members!
I am working on a pipeline project in Libya. We are to design, analyze and procure HDPE pipe for approximately 25 KM in length. I am concerned about HDPE pipe design code / standard. Is there any code, standard for calculation of pipe wall thickness? Your guidance in this regard will be highly appreciated.
Design parameters are as follows;

Transported Fluid Water
Design Pressure 200 psig
Design Temp 93 0C
ASME Class Rating 150 #

 

[LittleInch]

The thing leaping out here is 93C.

I don't think you'll find anyone supplying HDPE at that temperature.

Even at 30C you get de-rating and at 50C it's something like 40% of what the base pressure rating id

But if you want a code use ISO 4427

https://www.iso.org/standard/72183.html

Most PE pipe goes in the EN PN pressure rating system so PN16 is about the most you can get.

Try looking at UHMW PE e.g.

http://www.sunnysteel.com/ultra-high-molecular-weight-polyethylene-pipe.php

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

 

[SJones]

https://www.awwa.org/Store/Product-Details/productId/6743

https://www.asme.org/codes-standards/find-codes-standards/nm-1-thermoplastic-piping-systems

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[HTURKAK]

the length of pipeline approximately 25 Km .It should be buried pipe...I think the temperature 93 shall be
93 ℉ rather than 93 ℃ . HDPE pipe is not applicable for pressure pipelines for temperature higher than 60 ℃.

You can look to the following documents for codes and standarts:

AWWA C906 Polyethylene (Pe) Pressure Pipe & Fittings 4 In (100 Mm) Thru 63 In (1,575 Mm) For Water Distribution And Transmission

AWWA C 901 Polyethylene (PE) pressure pipe and tubing

AWWA M55 PE pipe _ design and installation-American Water Works Association (2006)

Moreover, you can visit Plastic Pipe Institute for free of charge documents :

https://plasticpipe.org/publications/,

https://hdpe.ca/technical-data/

 

[Shahbaz_ME]

@HTURKAK actually temperature is 90C and pipeline is buried

 

[LittleInch]

actually temperature is 90C and pipeline is buried

Then fundamentally PE is not the correct material for this use, either as a liner or as a the main pipe material

Find out which person suggested this and ask them to provide you the information or indeed any vendors willing to supply it. In the deafening silence which will ensue go find another material, probably metal.

But 90C is hot and you're going to run into expansion and stress problems for a buried line.

BTW PE has an expansion coefficient about 8 times that of steel so it is much much worse in that respect.

what sort of hot "water" are you transporting? Full of nasties and corrosive or benign and just very hot for some reason?



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

 

[HTURKAK]

@HTURKAK actually temperature is 90C and pipeline is buried

If the design temperature 90 ℃ , HDPE pipe can not be an option...Change the material at least for the portion of PL which the temp. is higher than 50 ℃.. You are saying the PL is buried 25 Km and the temperature still 90 ℃ ..Typical velocity for the water transmission pl's in the range of 1.0m/sec. That is, transmission time will be around 7 hours.. If the upstream side temperature 90 ℃ , downstream should approach to soil temp.

 

[alchemon]

OP - I seriously, seriously, seriously doubt you are going to get an ANSI 150 out of the PIPE, but I have my popcorn ready to see it happen.

Also - google the plastic pipe institute P.E. handbook.

 

[Shahbaz_ME]

Guys as per your suggestions, i have consulted my process dep. and they have provided following process design conditions;

Maximum Shut-off Pressure 1479 kPa
Extreme Transient Temperature 65 0C
Maximum Operating Temperature 45 0C
Minimum Operating Temperature 25 0C

Under above mentioned conditions, do you still think that choice of PE pipe is not correct ?

 

[LittleInch]

"do you still think that choice of PE pipe is not correct ?" - In a word Yes.

At 45C you're in the 70% derating region for most normal PE100 pipes.

most PE100 (sometimes called HDPE) pipes don't go beyond 16 bar (SDR 11), so you are down to 11 bar. At best you can get 25 bar, but that is really thick pipe and then you're down to 17 bar pressure rating

You can probably use this a liner at that temperature, but 25km is a bit of a stretch for a lined pipe.

what diameter are we talking here?
What sort of "water" is this?

But also don't neglect the expansion / thermal stress issues - expansion coefficient is about 1.3 x 10-4 per degree C so about 10 times that of steel so your buried effective pressure rating could suffer.

Or you could end up with a porpoise of a pipeline.

Like all things, PE is a great material, but only in the right place. Hot water at high pressure isn't one of them. And don't start thinking about GRE either - that's even worse.



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

 

[alchemon]

LittleInch and others - have you seen any Polyamide (PA12) being used? I have yet to lay any, but it looks like it will be coming sooner rather than later.

I wonder if that may be worth looking into. I have not heard of anyone marketing PA12 for water usage, but know it has been used in the European market much longer.

 

[SJones]

https://airborneoilandgas.com/tcp-trackrecord

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[LittleInch]

I had to go look up PA12, but looks like it's a competitor for distribution gas systems which isn't where I do my work.

That industry is pretty conservative so I suspect it will take a long time or a large advantage to get people to change their standard pipe materials.

And there is no water usage I can find.

Sjones - That looks interesting stuff, but usually for onshore projects, the advantages you get offshore aren't there to the same extent and this stuff is never cheap. But nice to know it exists.

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