Multiple PWHT allowed
Multiple PWHT allowed
(OP)
I had a PQR(P1G1 TO P1G2)done with 2 Hrs soaking time.I build a spool(CS, A105/A 106 Gr B) which has gone for 2 Hrs soaking time as well.Now customer wants me to weld a mounting on the spool.As per customer spec PWHT is needed for Min 2 Hrs.Service is sour.NACE MR0175 is applicable & max production hardness allowed is 200HB.
What I will need to do now?
Shall I weld the mounting on spool & do a localized PWHT for 2 Hrs again.By this way, one of the portion of spool will have a pwht for 4 Hrs.Will my existing PQR with 2 Hrs PWHT will support this?I have never done pwht beyond the PQR time earlier.
As NACE MR 0175 is involved i heard that production piece should go for same pwht cycle as that of original PQR coupon. is it true?
What I will need to do now?
Shall I weld the mounting on spool & do a localized PWHT for 2 Hrs again.By this way, one of the portion of spool will have a pwht for 4 Hrs.Will my existing PQR with 2 Hrs PWHT will support this?I have never done pwht beyond the PQR time earlier.
As NACE MR 0175 is involved i heard that production piece should go for same pwht cycle as that of original PQR coupon. is it true?





RE: Multiple PWHT allowed
Is your PQR qualified in accordance with ASME Sec IX?
Is the WPS impact qualified?
RE: Multiple PWHT allowed
The PQR is also qualfied with impact test.But the spool piece here does nor require imapact test.
RE: Multiple PWHT allowed
If impacts are not required for this application, your PQR will support a WPS with additional PWHT cycles.
I don't believe the additional PWHT will conflict with NACE MR0175.
RE: Multiple PWHT allowed
RE: Multiple PWHT allowed
Remember this is a minimum requirement and should not be construed to indicate that PWHT is not a crtical process. Your customer may have more stringent requirements.
RE: Multiple PWHT allowed