Greetings,
Refer below interpretations are useful for your subject? as i have very short time i cannot scrutize your subject but still i will get back to you.
Interpretation: VIII-81-110
Subject: Section VIII, Division 1, UCL-34 and Table UCS-56
Date Issued:
File: BC81-492
Question: Is it required under the provisions of UCL-34 and UCS-56 to postweld heat treat a vessel made of SA-516 Grade 70 base material which is 1 5/16 in. thick, arid has l/4 in. thick integral nickel clad-ding?
Reply: Yes.
Interpretation: VIII-1-86-37
Subject: Section VIII, Division 1; UCS-85, Heat Treatment
Date Issued:
File: BC85-606
Question: During the fabrication of a nonimpact tested pressure vessel made from SA-516 Grade 70 that is 5 in. thick, normalization of the material is conducted by the fabricator as a part of a hot forming process. In order to satisfy the requirements of UCS-85:
(a) are mill test specimens required to have the heat treatment associated with the hot forming simulated?
(b) is it required that the manufacturer define for the mill the anticipated cooling rate from the critical temperature during the hot forming operation?
Reply:
(a) Yes.
(b) Yes.
Interpretation: VIII-1-86-222
Subject: Section VIII, Division 1, UCS-79
Date Issued: May 11, 1988
File: BC88-048
Question: A 2:1 semielliptical head is hot formed by pressing at temperatures in the normalizing range, from SA-516, Grade 70 plate 1.38 in. thick. Is it required that the head be postweld heat treated after forming?
Reply: No.
Interpretation: VIII-1-95-37
Subject: Section VIII, Division 1 (1992 Edition, 1992 Addenda); UW-40(f)(5)(c), and Tables UCS-56 and UHA-32
Date Issued: January 20, 1995
File: BC93-735
Question (1): UW-40(f)(5)(c) in Section VIII, Division 1 states that shell thickness is the controlling value for postweld heat treatment when attached to a flat head. No mention is made of material. A flat head is attached to a shell with a joint as shown in Fig. UG-34(g), with the addition of an integral backup bar. The head is 2 1/2 in. thick and made of SA-516 Grade 70, the shell is 1 1/4 in. thick and made of SA-240 Grade 304. Is it acceptable to weld the shell to head using a 200° F preheat without performing PWHT?
Reply (1): Yes.
Question (2): The same conditions apply as in Question (1) except that the shell material is also of SA-516 Grade 70?
Reply (2): Postweld heat treatment is not a mandatory requirement.
--For a pressure vessel designed with stamped under ASME VIII Div.1, there is a requirement that: "Hardness values should not exceed 200 brinell for the welds / material of shell."
Shell material is specified as SA516 Grade 70.
I am concerned the requirements for hardness and material will automatically require stress relief for all pressure vessel parts.
Would SA516 Grade 70 have hardness lower than 200 Brinell?
Thank you.
Regards,
RKD
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