곽동현
2007-11-02 11:06:37
2
532
배관용접의 열처리 중 ASME B31.1 후열처리 사항을 보면, P. NO.: 4 일때 두께가 13이상, 호칭경이 4인치 초과하는 재질에 대해 열처리를 하게 끔 되어있습니다. 그럼 BRANCH 배관의 경우 BRANCH JOINT부는 열처리을 해야하는지, 예)HEADER가 20"에 SCH 140일 경우 BRANCH 관이 11/2"일때 이 BRANCH JOINT부 열처리 여부,,,,
MAIN 배관이 용접하니깐 해야한다고 하는데, 이것에 대한 근거집이 있는지 궁금합니다.
감사합니다.
MAIN 배관이 용접하니깐 해야한다고 하는데, 이것에 대한 근거집이 있는지 궁금합니다.
감사합니다.
First of all you may have to confirm the applicable code because as far as I know ASME B31.1 (or 31.3) does not have the size limitation (i.e., 4 NPS and above) for P. 4 materials while ASME VIII has it.
In B31.1, Table 132, the PWHT is not required in all of the following conditions;
(1a) Nominal thickness of branch pipe [for SET ON TYPE with groove weld] of 1/2” (13 mm) thickness or less or
(1b) Nominal thickness (44.5 mm) of main pipe [for SET THROUGH TYPE with groove weld] of 1/2” (13 mm) thickness or less and
(2) Carbon contents of two metals (main and branch), 0.15wt% or less, and
(3) Minimum preheat, 120C
For more detail governing thickness to define the thickness of PWHT requirements, you can find the instruction at ASME B31.1-2004, para. 132.4 (or ASME B31.3-2004, para. 331.1.3)
You may also have to find the client’s spec because most company standards have the mandatory PWHT requirements for P 4 materials regardless of thickness and/or joint configuration.
Please email me (thomaseun at hanmail.net) if you have further questions.
In B31.1, Table 132, the PWHT is not required in all of the following conditions;
(1a) Nominal thickness of branch pipe [for SET ON TYPE with groove weld] of 1/2” (13 mm) thickness or less or
(1b) Nominal thickness (44.5 mm) of main pipe [for SET THROUGH TYPE with groove weld] of 1/2” (13 mm) thickness or less and
(2) Carbon contents of two metals (main and branch), 0.15wt% or less, and
(3) Minimum preheat, 120C
For more detail governing thickness to define the thickness of PWHT requirements, you can find the instruction at ASME B31.1-2004, para. 132.4 (or ASME B31.3-2004, para. 331.1.3)
You may also have to find the client’s spec because most company standards have the mandatory PWHT requirements for P 4 materials regardless of thickness and/or joint configuration.
Please email me (thomaseun at hanmail.net) if you have further questions.
공지사항
즉, 두께가 두꺼울수록 잔류응력이 많아지게 되어 그걸 해소하기 위해 열처리를 해 주는 것이지요
따라서 Branch여부를 떠나서 해당 용접부가 두껍다면 열처리를 해주는 게 올바른 해석이 되겠습니다.