UCS 66 materials

[waliq]

Hello,

If I refer to UCS 66 curve note 3 (b), it says, "all materials listed in 2(a) and 2(c) for Curve B if produced to fine grain practice and normalized, normalized and tempered, or liquid quenched and tempered as permitted in the material specification, and not listed for Curve D below".

Does it mean that SA 105 if produced to fine grain practice will be in Curve C??
I am reviewing vendor calculations where for nozzles,SA 105 flange, the minimum temperature that shows in report is -29 Deg C
However, for body flange channel side, the blind cover is of SA 105, but the MDMT is shown for a curve C material and is reduced till -38 deg C

Any comments will be appreciated

 

[david339933]

Does it mean that SA 105 if produced to fine grain practice will be in Curve C??

No. The note states "AND normalized, normalized and tempered"..etc.

 

[SnTMan]

waliq, as david339933 says, it must be both. About your vendor calculations, it is possible that the body flange can be shown via the MTR that the material is FG & N, and therefore Curve C while the nozzle flanges cannot be so proven and so MDMT is governed by UCS-66(c).

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[waliq]

Thanku both of you

Yes i missed to mention the normalized part

@snTman: Arent the nozzles governed by UCS 66b since Sa 105 is a curve b material??
This is what I am asking. Nozzles cannot be proven by mtr to be fg and N so curve B applies to them and min temperature goes to -29 Deg C
However, in case of a SA 105 body flange, we can take curve C, since it can be proven through mtr to be fg and N
Is my understanding correct of what you said??

 

[SnTMan]

waliq, "nozzles" may be made up of several components, each of which must be evaluated separately. Your OP stated "SA-105 flange" which I took to be a standard flange, B16.5 for example. This is why I cited UCS-66(c), it specifically exempts these flanges to -29 C. The nozzle pipe (if any) is evaluated on its' own merits.

And yes, if body flange is known to be FG & N, it can be assigned Curve C. Back to the nozzle flanges, standard parts may not be supplied with a complete MTR, so it may not be possible to say whether it is FG & N.

Regards,

Mike



The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[waliq]

@smTman: Thanksss!!!
It was really helpful

 

[SnTMan]

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[waliq]

@Sntman: I need help in one more thing?

I was designing a vessel on PV Elite. There, in the design tab, i checked the option of Hydrotest as per UG 99 C. Then, below I also checked the option of corroded hydrotest. The idea behind doing this was, that I thought it would now test the vessel according to UG 99 C in new and cold (shop test) and also according to UG 99b (hot and corroded) based on MAWP.

My thickness based on internal design pressure was 8 mm.
C.A of 3.2 mm
When I checked the option of corroded hydrotest, my vessel got overstressed such that it was passing at a thickness of 14 mm. However, if I unchecked this option of "corroded hydrotest" and selected hydrotest as per UG 99b above instead of UG 99C, the thickness of 8 mm was sufficient.

This was opposing my initial thought that if I checked the option of corroded test below would evaluate the hydrotest on the basis of UG 99b.

My question is that what does it mean by a corroded hydrotest?
Does UG 99b not ask for a corroded hydrotest to be performed for all vessels since it says 1.3*mawp*sa/s?? Because, MAWP is calculated max pressure on the basis of corroded thickness. Am i interpreting this clause wrong?

 

[SnTMan]

waliq, might have been preferable to start a new thread, but...

Yes, UG-99(b) is based on MAWP, hot & corroded, UG-99(c) most often on MAP, new and cold. I don't often run PVE so what it is doing I have no idea. I do know that it has very useful documentation, I'd start there. The user help is generally pretty good as well.

Might let us know what you find out, and good luck.

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[kiad]

about your body flange... You may know you can reach MDMT lower than -38 deg C you mentioned for curve B material without impact test.of course it depends on design condition.see ucs 66 b1(c),ucs 66 b1 (b) and ucs 68(c).

 

[waliq]

@kiad: Thanksss!!