Materials & Welding

Dear Sir, Yes you can do it if your other specifications is not restricting the same. That will not be a code violation. Regards  Hareesh K V Mechanical Engineer  On Wed, 9 Sept, 2026, 4:43 pm sridhar cn, < sridharcn305@gmail.com > wrote: Dear Mr. Chatterjee, You have not indicated whether it is an H₂S  service or a general type.  P WHT can itself introduce or  reveal  problems  such as reheat/stress-relief cracking in susceptible weldments, dimensional distortion, cracking associated with high hardness/microstructural conditions and  defects that were not detectable before PWHT. So, if it is an NACE/H₂S  service line , the project specification may require a  final NDE after PWHT,  even though  B31.3 itself does not mandate it for P-No. 1.   Welding → RT/UT ...

Dear Mr. Elavaran, 1.   Although all three materials are treated as P-No. 1, Gr No. 2 for ASME Section IX qualification, ASME B31.3 fabrication      requirements and the sour-service specification are more restrictive. Your project requires welding of           API 5L X65 Pipe with 535 MPa to A350 LF2 Flange with 485 MPa.            API 5L X65 Pipe with 535 MPa to A860 WPHY 65 Elbow with 620 MPa.          WPHY 65 Elbow with 620 MPa to A350 LF2 Fl with 485 MPa.          Hence, we can consider them under two PQRs.                ...

Hi Ranajit,  Here are some suggestions regarding your requirement, Yes. For P-No. 1 carbon-steel materials, ASME B31.3 does not impose the same mandatory “examine after heat treatment” requirement that it explicitly imposes on P-Nos. 3, 4, 5A, 5B, 5C and 15E. 1. What B31.3 clause  341.3.1(a) actually requires In the current B31.3 wording, Clause 341.3.1(a) states that for P-Nos. 3, 4, 5A, 5B, 5C and 15E, examinations are to be performed after completion of heat treatment. P-No. 1 is deliberately not included in that list. Therefore: | Material          | B31.3 clause  341.3.1(a) specific post-heat-treatment requirement | | ------------      | -------------------------...

For P -1 material , there is no restriction, you can conduct either before or after. Check the client spec if anything mentioned On Tue, Sep 8, 2026 at 5:04 AM 'ranajit chatterjee' via Materials & Welding < materials-welding@googlegroups.com > wrote: Dear Sirs, As per ASME B31.3 clause no.341.3.1(a) mentioned P Nos.3,4,5A,5B,5C AND 15 materials examination(RT/UT) shall be performed after completion of heat treatment. But no information for P1 material whether NDT performed before or after PWHT. Please advise can we perform NDT(RT/UT) before PWHT activity for P1(NACE/H2 service) material or not. Regards, Ranajit Chatterjee 9995018265 -- https://materials-welding.blogspot.com/ https://www.linkedin.com/groups/122787 --- You received this message because you are subscribed to the Google Groups "Materials & Welding" group. To unsubscribe from this group and stop receiving emails from it, send an email to materials-weldi...

Hi KG, Here is my reason for your question; The reason to do NDT after PWHT for alloy steel is to verify the weld after the heat treatment has finished, because PWHT itself can create or reveal defects that were not visible right after welding. Main reasons: - Reheat/stress-relief cracking: Alloy steels, especially Cr-Mo types, can develop cracks during PWHT. - Delayed cracking: Hydrogen-related cracks or other delayed defects may appear after welding and only become apparent later. - Defect growth or opening: Existing small discontinuities may grow or become detectable during thermal cycling and stress relief. - Final acceptance condition: The inspection must ensure the component is fit for service before it is put into operation....

It's a because present stabilizing element as well high content of alloying element like Cromium. On Tue, 8 Sept 2026, 15:21 Kannayeram Gnanapandithan, < kgpandithan@gmail.com > wrote: What is the reason to do NDT after PWHT for alloy steel.  THANKS & BEST REGARDS, KG.PANDITHAN, BE, IWE,   ISO 9712 Level 2 in VT, ASNT-Level II in PT,MT,RT & UT, LA ISO 9001-2015, ISO 3834, EN 1090 & EN 15085,  International Welding Engineer.  CONSULTANT-WELDING & QUALITY ...

Dear Mr. Chatterjee, You have not indicated whether it is an H₂S  service or a general type.  P WHT can itself introduce or  reveal  problems  such as reheat/stress-relief cracking in susceptible weldments, dimensional distortion, cracking associated with high hardness/microstructural conditions and  defects that were not detectable before PWHT. So, if it is an NACE/H₂S  service line , the project specification may require a  final NDE after PWHT,  even though  B31.3 itself does not mandate it for P-No. 1.   Welding → RT/UT → PWHT → final RT/UT → hardness check, where h ardness control is an important means of  controlling SSC susceptibility in carbon and LA steel weldments. The first RT/UT is useful for finding weld defects.   PWHT changes the weld metallurgy and residual stress  condition.  Final RT/UT (f or a sour-service line with mandatory PWHT) could b...