High pressure Hydrogen Pipeline ASME B31.12 1

[amyra--]

Hello, I'm currently involved in a hydrogen pipeline project where the design pressure is 350 barg. According to ASME B31.12, this pressure level is excluded for pipeline design. However, in Table GR-2.1.1-2, there's a note that states:

"The maximum operating pressure (MOP) shall not exceed 21 MPa (3,000 psi) for all materials unless otherwise noted, provided the material is deemed suitable as demonstrated by tests in hydrogen, such as per ASME BPVC, Section VIII, Division 3, Article KD-10."

I'm facing a dilemma because while ASME B31.12 sets a limit of 21 MPa for the Hf factor in the wall thickness formula, I'm unsure if I can design my pipeline according to ASME B31.12 given the discrepancy in the code. I'm currently utilizing API X70 material. Any advice would be greatly appreciated. Thank you.

 

[EdStainless]

please do not double post

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[1503-44]

It's worse than you think. There is no discrepancy.

Pipelines are limited to 3000 psig as per PL 1.3

X70 material, as well as X65 and X80 are limited to 1,500 psig.
Because they are noted otherwise in Table 2.1 1.2, see Note #1 stating 1,500 psig max operating pressure .

If you do design a pipeline to operate at greater than 1500 psig, you should select X60 or lower alloy grades. That is because of the warnings of hydrogen embrittlement of high strength alloys as discussed in the first sections of this code. At 5000 psig the wall thickness will be pretty high. Your welding will be very expensive. Preheating the weld area will probably be required. That gets even more expensive for all the welds you must do for a typical pipeline. Your high operating pressure should probably be reviewed more carefully, if this will be a long pipeline. It may not be economical, but I don't work with H2. And I didn't see the temperature, but you seem to be in the supercritical phase. How did you decide to use a mop of 5000 psi?


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

 

[amyra--]

@1503-44 : Thank you for your response. However, concerning the note under the table GR-2.1.1-2, it appears that it does allow us to use the specified materials at pressures exceeding 3000 psi if they have undergone testing according to KD10. Your guidance on this matter would be greatly appreciated.
PS : 5000psi is a given value by process team.
Amyra

 

[LittleInch]

You need to have a discussion with your process team and project manager and tell them that this sort of pressure, presumably onshore?, will be next to impossible to get permission and build economically.

Anything much over 100bar results in a impact distance which makes it impossible to route.

Also H2 has this nasty habit of catching fire or exploding, especially if released in a large amount.

How big a pipe?
Where in the world?

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

 

[amyra--]

The pipeline is 4inch & 300m of lengh.( it is a flowline NOT really a pipeline...)

 

[1503-44]

Possible GOOD NEWS here. Wait for it.

My interpretation is that you could use low strength grades, X60 or less, to reach op pressures of up to 3000 psig, however anything built with high strength, high alloy materials, X65, X70 or X80 will always belimited to op pressures of 1500 psig or less.

If it is not a pipeline, you should select materials using the GR tables.

Note that pipe lengths if 300m do not typically fit the B31 definitions of pipelines. Pipelines are those pipes that are involved with the point to point transportation or distribution of fluids over much longer distances, especially those which have parts or portions constructed outside of company controlled property.

Also note that "flowlines" are those pipes that typically connect a well to a facility or other pipelines that make up a gathering system. All pipe in a gathering system carry fluids that have generally not been processed in anything more than a gas/liquid separator and not yet treated, or entered a gas/liquid "field processing plant", or a pump, compressor, or metering station where custody has transferred from one company to another. Such pipes are engaged in collection and gathering within a production field, being distinct from those other pipes engaged in transportation, or distribution activities.

If you have this 300m pipe entirely inside a plant, or all within fenced, or highly company controlled property, then it falls within the definition of "plant piping". A "PI" type, not "PL" type.

Being that it is only 300 m of pipe, you won't be spending so much time on welding as I thought, so you can consider using thick walled pipe.


HERE Is the possible GOOD NEWS.
IF IT IS NOT A "PIPELINE", I do not see where there is any maximum operating pressure limitation. Apparently you can have any operating pressure you want, up to 15,000 psig, or 4500 or 6000 psig limits if you do not demonstrate material suitability I have not read this code before today, so please read every paragraph to ensure that none apply. I don't see it, but I have not read this code throughout.



The thick wall welds will be expensive, but that's just a problem for the owner's cheque book.



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

 

[amyra--]

Ok thank you again but what about the note that states that when the material undergo tests according to KD10 of ASME DIV3 , then we can consider working with higher pressure ( more than 3000psi) Note (a) Table GR-2.1.1-2

 

[1503-44]

Right. Correct. I just decided to check the fine print in those notes myself and have just edited the last comment above to include them.

If its not a pipeline, 5000 psig is allowed, with material suitability demonstrated.



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

 

[amyra--]

And ifit is considered as pipeline (since it can cross a non company proporety) , can i say that when the material undergo tests according to KD10 of ASME DIV3 , then we can consider working with higher pressure ( more than 3000psi) Note (a) Table GR-2.1.1-2 (PL)
Thank you again for your advices

 

[1503-44]

No. 1500, or 3000 psig when using Lower alloy are the pipeline limits.



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

 

[1503-44]

I admit it gets complicated. The wording is a bit strange, but
I think the "unless otherwise noted" you see there applies only to those materials that specifically have a note, Those notes which are limiting pressure to 1500 psig.

Effectively making the statement to be
3000 max, unless a material is specifically limited to 1500 psig.

That appears to be in line with what Little Inch says above, and to which I agree, 5000 psig H2 in a pipeline will scare a lot of people and would probably never get a construction permit anyway. There's a lot of potential Hindenburgs in a H2 pipeline.

Somehow you're going to have to put a fence around all of it and call it plant piping.
And don't forget the warning signs on the fence.

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

 

[1503-44]

If you are outside the USA, the definition of pipeline may not be so legally defined.
Check for applicable national, or local laws. Maybe, with a good lawyer, you can get your 300m pipe classified as "plant piping" even if it crosses into land owned by others.

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

 

[1503-44]

Page 8 of this slide presentation indicates 3000 psig as a Max for pipelines is intended.

https://www.energy.gov/sites/prod/files/2014/03/f12/hpwgw_code_hayden.pdf

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

 

[1503-44]

Qualification of H2 pipeline materials

https://www.pipeline-journal.net/ejournal/ptj-1-2021/#42

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

 

[1503-44]

And

https://arvengtraining.com/en/differences-between-codes-b31-12-and-b31-3/

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

 

[amyra--]

Just for information , the pipeline will be underground.

 

[1503-44]

OK. Put a bigger fence.

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