SA 240 316L Post forming heat treatment

[vessexst]

I have a vessel (vertical) that is made from SA 240 316L. The EFE of the head (2:1 ellipsoidal) is at 8.5%. I am confused if there is any post forming heat treatment required for this head. If I look into Table UHA 44, the temperature ranges for 316 grade are given. But, it does not mention anything about 316L. Now, on further probing this, I found out that the temperatures required for stress relieving are above the maximum temperature given for 316L in ASME sec II, Part D.

My question is, what should be the EFE percentage to go for post forming heat treatment in this case??

Design temperature is 600 Deg C.

Moreover, does the code not require any post fabrication treatment for any percentage of EFE for design temperatures less than 580 Deg C for SS grades 304 etc specified in the table UHA 44??

 

[DriveMeNuts]

Have a look at this:

https://www.eng-tips.com/viewthread.cfm?qid=380626

 

[vessexst]

@DriveMenuts: Based on this thread link shared, it seems my understanding of the matter is correct. There is no limit on EFE percentage calculated according to UG-79 for SS grades of 304 etc at design temperatures less than 580 Deg C. Since, the 580 Deg C is above the maximum temperature permitted for 316L material, therefore there is no requirement of heat treatment for this grade at any EFE percentage (say 50% for example)

 

[kiad]

You should also see what your client's spec states.in some specs even when for example the material of transition/obround nozzle of header of air cooler is 316L PFHT is required for that nozzle.