PWHT
PWHT
(OP)
As per ASME B31.1 2014 edition, where is the thickness specified above which PWHT is mandatory for P1 material. In the older versions, 19mm was mandatory. In the 2014 version if I do not meet the exempt requirements , is PWHT compulsory for all P1 material ?





RE: PWHT
RE: PWHT
RE: PWHT
RE: PWHT
Refer to table 132.2
RE: PWHT
RE: PWHT
Is that requirement noted in B31.1 as well ?
RE: PWHT
No, per the 2016 edition of ASME B31.1, Table 132.2 and Notes.
...The mandatory preheat has been
applied Specified carbon content of the base
materials ≤0.15% Multiple layer welds are used when the
nominal material thickness >3⁄16 in.
(5 mm)
See Note (6)
(6) Single layer or single pass welds may be exempted from PWHT, provided the WPS has been qualified using single pass welds with ±10% heat input and that all other conditions for exemption are met
RE: PWHT
Is the OP's carbon content of 0.18% not greater than the allowed 0.15% noted ?
RE: PWHT
RE: PWHT
I thought "specified" is supposed to be actual. The Sa requirements should be treated as minimum and maximum.
RE: PWHT
RE: PWHT
132.3.2 The postweld heat treatment exemptions
of Table 132.2 may be based on the actual chemical composition
as determined by a ladle or product analysis
in accordance with the material specification in lieu of
the specified or maximum specified chemical composition
limits.
For carbon steel P-No 1 in Table 132.2
A preheat of 200°F (95°C) is applied
prior to welding on any nominal material
thickness >1 in. (25 mm)
Multiple layer welds are used when the
nominal material thickness >3⁄16 in.
(5 mm)
See Note (6)
Apparently, when I copied the information it was for P-No 5A and not P-No 1.
My error, so there is no 0.15%C limit for P-No 1 BM.
The above would apply for P-No 5A for information.