[hvn83]

Hi shrivallabha,

Thank you kindly for all your answers, theyve provided much help.

Regards,
Hubert

[hvn83]

I’m sorry but so far no one has really understood, nor answered, my question.
To put it in perspective again, here comes a new formulation of the same question:

If you use dual certified have 304/304L ASME B16.5 flanges, what is/are the max. temperature (limits) these flanges may be used to, and WHY?
B16.5 namely does not address any reasons why 304L flanges are limited to 425 deg C.
It only says 304 flanges may be used to 816 deg C, and 304L flanges up to 425 deg C.
Thus, what temperature limit should be used now for dual certified 304/304L?

PS: if Im making a mistake, i.e. my question has been answered, Im sorry if I understood the respective reply wrong. Just let me know where the answer is mentioned.

[hvn83]

Hi all,
im new to this forum,
i have 1 question ,due to lower carbon content in the ss304L(0.03%),is it restricted to use below 425 deg celcius or any other reason is behid this??
Can any one explain me wat is the Temperature range for SS304L ,SS304 ,SS304H???

I think the reason behind this is the carbon content indeed.
I’m not quite sure, but I believe (please correct me if im wrong) that it has something to do with the resistance to high temperatures @ low carbon containing stainless steels.

Tip: just Google ‘dual certified 304’ and look for a thread going @ engtips.com (I think its the first Google result)

[hvn83]

[quote]The post #4 by JamesKelly mentions Temperature suitability

[quote]Almost all “304” plate is dual certified. It may be 0.03 max carbon stuff dual certified 304L/304. This, meanins it has decent corrosion resistance as-welded and the tensile & yield properties of 304, at least near room temperature.1150F is in the creep range, for which you need dual certified 304/304H. This has a minimum of 0.04% carbon for strength, plus I think both grain size and minimum annealing temperatures. It is widely available.Dual certification is the common practice. The mill does not want to melt two or three different chemistries, i.e. 304L, 304 and 304H so they make two different chemistries do the work of these three. It is the magic of precise chemistry control by refining the melt in an Argon-Oxygen Decarburization vessel, where a little nitrogen brings up the yield strength of 304L to the requirements of 304. Great for room temperature but the dual-certified “L”grade is not usually considered strong enough for use in the creep-limited range.Clear as mud?

If you go by this post then you should avoid using Dual Certified Steel (L) at higher temperatures and should go for the other Dual Certified Steel(H).

See if this is of any help![/quote]

Thanks again for the explanation, but it still ist an answer to my question (I believe).
I’m talking specifically about the 0 deg C – 425 deg C (~ 842 F) temperature range, which is below the range mentioned in your last post.
Second, I’m dealing with flanges, not with plates.

See the corresponding ASTM and especially the ASME B16.5 design notes; then you’ll understand where my question comes from.

[b]Briefly; 304L flanges may only operate up to 425 deg C (per ASME B16.5).
So, may 304/304L flanges (say 150 lbs) operate up to 538 deg C then?
Why or why not?[/b][/quote]

Bump, anyone?

[hvn83]

The post #4 by JamesKelly mentions Temperature suitability

[quote]Almost all “304” plate is dual certified. It may be 0.03 max carbon stuff dual certified 304L/304. This, meanins it has decent corrosion resistance as-welded and the tensile & yield properties of 304, at least near room temperature.1150F is in the creep range, for which you need dual certified 304/304H. This has a minimum of 0.04% carbon for strength, plus I think both grain size and minimum annealing temperatures. It is widely available.Dual certification is the common practice. The mill does not want to melt two or three different chemistries, i.e. 304L, 304 and 304H so they make two different chemistries do the work of these three. It is the magic of precise chemistry control by refining the melt in an Argon-Oxygen Decarburization vessel, where a little nitrogen brings up the yield strength of 304L to the requirements of 304. Great for room temperature but the dual-certified “L”grade is not usually considered strong enough for use in the creep-limited range.Clear as mud?

If you go by this post then you should avoid using Dual Certified Steel (L) at higher temperatures and should go for the other Dual Certified Steel(H).

See if this is of any help![/quote]

Thanks again for the explanation, but it still ist an answer to my question (I believe).
I’m talking specifically about the 0 deg C – 425 deg C (~ 842 F) temperature range, which is below the range mentioned in your last post.
Second, I’m dealing with flanges, not with plates.

See the corresponding ASTM and especially the ASME B16.5 design notes; then you’ll understand where my question comes from.

Briefly; 304L flanges may only operate up to 425 deg C (per ASME B16.5).
So, may 304/304L flanges (say 150 lbs) operate up to 538 deg C then?
Why or why not?

[hvn83]

Hi shrivallabha,

Thank you kindly for your answer.
I already noticed that thread, but it doesn’t mention anything about the temperature range 304/304L may operate in, regarding the limits of 304L flanges.
Hence my question is still open.

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