Hi all, I've just get the latest edition of ASME B31.3 2014 edition.
Referring to PWHT scope, I found a big difference from previous edition (2012 edition) which said an exact number of temperature for thicker material (over 20 mm).
Instead at latest edition, there're an exemptions to mandatory of PWHT (table 331.1.3) which in my opinion is we can prevent to use PWHT if some additional requirements is fulfilled (ex. for P-1 all groups, we can apply high preheat and do multiple layers for exemption from PWHT)
My question is, if we work with thicker goods let say 22 mm or above. Can we substitute the use of PWHT with only high preheat temp? I think these two treatment is for different use. How can we get a stress relief with only using a high preheat temp?
Thanks in advance.
Referring to PWHT scope, I found a big difference from previous edition (2012 edition) which said an exact number of temperature for thicker material (over 20 mm).
Instead at latest edition, there're an exemptions to mandatory of PWHT (table 331.1.3) which in my opinion is we can prevent to use PWHT if some additional requirements is fulfilled (ex. for P-1 all groups, we can apply high preheat and do multiple layers for exemption from PWHT)
My question is, if we work with thicker goods let say 22 mm or above. Can we substitute the use of PWHT with only high preheat temp? I think these two treatment is for different use. How can we get a stress relief with only using a high preheat temp?
Thanks in advance.