Impact Test For SA-179 1

[stesw90]

Dear all ,
I would like to know were i can find specification for impact test of SA-179 used as tubes for heat exchangers,
I couldn't find any statement regarding impact test in Section2 A SA-179 as well as in SA-450 were as in PV elite it shows that it can be used with impact test up to -55°F ,
I have placed a material requisition requiring impact test report at -55°F based on report shown by pv-elite.

 

[metengr]

Do you realize that impact testing is exempt for carbon steel tube material less than 0.394" in thickness down to -55 deg F per Section VII, Div 1?

 

[gr2vessels]

metengr,
I think I know a few things, but this time I have to throw up my arms;- where is actually the clause you cited because the SA-450 is listing the optional Impact Test on SA-179 without any qualification. I am also willing to learn!
Cheers,
your humble gr2vessels

 

[doct9960]

SA-179 tubes less than 0.237" thick are exempt from impact test for metal temperatures of -155 deg F and warmer. Refer to UCS-66(d).

 

[stesw90]

Thank you all for making me aware of ucs-66(d),
i clearly understood the first part which says less than 2.5mm can be used up to -55°F without impact test,
But the i didn't understand very much clearly about,

For vessels or components made from NPS 4 (DN 100) or smaller tubes
or pipe of P‐No. 1 materials, the following exemptions
from impact testing are also permitted as a function of
the material specified minimum yield strength (SMYS)
for metal temperatures of −155°F (−105°C) and warmer:
[ul]
[li][/li]
[/ul]SMYS, ksi ( MPa) Thickness, in. ( mm)
20 to 35 (140 to 240) 0.237 (6.0)
36 to 45 (250 to 310) 0.125 (3.2)
46 (320) and higher 0.10 (2.5)

 

[stesw90]

And the second part i am not able satisfy in pv elite calculation every time for sa-179 with normalized condition maximum it shows up to -55F below that it is not taking the the second part in consideration it just shows MDMT failure below -55.
which client demands for calculation review.

 

[metengr]

If you have the MTR for the tube material, the SMYS is noted and can be used based on thickness to go from -55 deg F down to -155 deg F with UCS-66 (d).

 

[stesw90]

I have found that when you r designing exchangers in pv elite it is not showing MDMT for tubes coming under the range of SMSY and thickness mentioned in the table concerned to ucs-66(d) i think it is based on UCS-66(d) and the tube material passes up to -155°f,
and in the calculation report also its not mentioning that it is not using ucs-66(d), all it mentions is tht it doesn't use ucs66(g)&(i),
but now the confusion is statement that is showing in ucs-66(d)
i.e

[highlight #CC0000]For vessels or components made from NPS 4 (DN 100) or smaller tubes
or pipe of P‐No. 1 materials[/highlight], the following exemptions
from impact testing are also permitted as a function of
the material specified minimum yield strength (SMYS)
for metal temperatures of −155°F (−105°C) and warmer:

as mentioned above vessel or vessel components can be exempted if within the range mentioned in the table for ucs-66(d)
but when i am trying to design a vessel keeping all the values within the range as mentioned in ucs-66(d) it is showing MDMT failure,
[highlight #EF2929]Now my concern is does ucs-66(d) covers vessel or only the vessel components in it.[/highlight]
Thank you very much for the idea,
Regards,
Stephen Wilson

 

[EdStainless]

SA-450 is a general spec, it lists all of the tests possible for covered product specs.
You have to look in the product spec to know if the test is required or not.
And yes, all of these exemptions are difficult to keep track of.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[SnTMan]

stesw90, it is a matter of knowing what the Code permits, what the software is doing, and if what it is doing is what you need. As to MDMT calculations, there are usually a number of ways to get to your desired temp. No software can be counted to exploit every one of them. In particular my faith in PVElite's MDMT calcs only goes so far. As EdStainless says "And yes, all of these exemptions are difficult to keep track of."

Study the Code first, your software second.

Regards,

Mike

 

[stesw90]

Yes I understand that it is difficult keep the tack of all exemption,
and as u said code is first ,
but as per current trend client first ask the calculation report from pv elite,
so after studying the code and comparing it to software analysis i have found some deviations which i just wanted to confirm before making a comment about the report, so just discussed here.
Thank you very much for your comment,

Regards.

 

[SnTMan]

stesw90, one of my dislikes of PVElite / Codecalc is the AMOUNT of output, for which I am ultimately responsible. It's a trap. Too much to carefully review. Way more than I want to supply a client. But if I edit it, then I have to keep track somehow so that I can reproduce the document if necessary. Yuk.

Regards,

Mike