UHA 44 Post fabrication requirements for SA 240 316L

[waliq]

Hi,

I was reviewing Table UHA 44. I could not find the material 316L listed there. 316 is listed but 316L is not. Is there any specific reason?? In case, the allowable elongation range for an elliptical head of SA 240 316L is to be seen, does the code provide any reference for it?

 

[kiad]

Max temperature limit of SA 240 316L as per ASME II D is lower than the design temperature condition specified in table uha-44 for the austenitic chromium nickel.

 

[waliq]

@kiad: In my case, the vessel (O.D of 610 mm), but being made from plate of SA 240 316L rolled to the specified diameter and temperature of 87 Deg C, is having an ellipsoidal head EFE of 12.667%.

Does it mean that SA 240 316L (having a maximum temperature of 850 Deg F does not require heat treatment at any temperature regardless of the amount of strain developed as per Table UG 79-1??
Am i missing something in the code??

 

[waliq]

Moreover, If I see for 316 also, table UHA 44 gives the requirement of heat treatment at temperatures more than 580 Deg C and the corresponding strain limit exceeding etc.
From this, I understand that even for 316 only, the post fabrication heat treatment is not required at temperatures less than 580 Deg C.

So, by this I understand that, since the max temperature of 316L is 455 Deg C (850 Deg F), heat treatment for 316L is exempted irrespective of the amount of strain developed as per Table UG 79-1

I hope I am interpreting the clause correctly.

 

[waliq]

Any comments guys??

 

[MECH993]

@Waliq - Yes you are right, as per UHA-44 PFHT not required for head with MOC SA 240-316L.