QW 406 , preheat maintenance

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rajesh s. mhaske ,Engineer Welding ,PUNE,INDIA

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Jun 20, 2014, 8:29:50 AM6/20/14
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   Dear sir
               thickness and  OD : 323 od* 70 mm thk
               welding process : GTAW+SMAW
               Material : SA106 Gr B
               Preheating : 100 deg c
               weld deposition : for GTAW : 4 mm, SMAW : 66 mm


   Question  :
                  1) Is the preheat maintenance (post heating ) is required for  above material
                  2) If YES, what is time and temp  plz send the back up
    

Shashank Vagal

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Jun 21, 2014, 5:08:22 PM6/21/14
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Always during welding the joint temp has to be maintained between preheat and interpass  temps.
 
With Best Regards,
Shashank C Vagal


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Mahantesh Loni

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Jun 26, 2014, 5:40:21 PM6/26/14
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Post heating. Not required

Kannayeram Gnanapandithan

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Jun 27, 2014, 1:01:36 AM6/27/14
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since max welding is taken place SMAW, it is better to go for POST Heat . temp 50degree above ur preheat temp and time for minimum 30minutes

THANKS & BEST REGARDS
KG.PANDITHAN, AWS-CWI, CSWIP 3.1
CONSULTANT-WELDING & QUALITY

george....@gr.bureauveritas.com

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Jun 27, 2014, 2:32:24 AM6/27/14
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Preheat maintenance, according to ASME IX,  is not post heating
Preheat maintenance means that you do not cool down before perform PWHT
B31.1 requires preheat maintenance for Pno15E unless engineering provides differently

    best regards

    Dr. Georgios Dilintas

    Authorized Nuclear Inspector
    Authorized Inspector Supervisor


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Inactive hide details for Kannayeram Gnanapandithan ---27/06/2014 08:01:37---since max welding is taken place SMAW, it is betteKannayeram Gnanapandithan ---27/06/2014 08:01:37---since max welding is taken place SMAW, it is better to go for POST Heat . temp 50degree above ur pre

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rajesh s. mhaske ,Engineer Welding ,PUNE,INDIA

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Jun 27, 2014, 3:39:09 AM6/27/14
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Sir,
     Any reference document for below statement. I have to give it to third party inspector.
Now we are doing same but don't have document for reference.

ABHISHEK SINGH

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Jul 9, 2014, 11:41:32 AM7/9/14
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No for this material post heating is not required.
 
Regards
Abhishek Singh

Kannayeram Gnanapandithan

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Jul 10, 2014, 12:50:56 AM7/10/14
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Do not see type of material alone for POst heating. we have to consider, Thickness, Welding Process etc

THANKS & BEST REGARDS
KG.PANDITHAN, AWS-CWI, CSWIP 3.1
CONSULTANT-WELDING & QUALITY


george....@gr.bureauveritas.com

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Jul 10, 2014, 5:35:49 AM7/10/14
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Preheat maintenance is not  "post heating".
This non essential variable applies only if PWHT shall follow
This variable (non essential) is not applicable to GTAW.


    best regards

    Dr. Georgios Dilintas

    Authorized Nuclear Inspector
    Authorized Inspector Supervisor


    I&F REGIONAL TECHNICAL MANAGER
    BUREAU VERITAS HELLAS

    Tel: +30 210 40 63 113/4
    Fax: +30 210 40 63 118
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pras ari

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Sep 28, 2014, 3:43:24 AM9/28/14
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Dear Sir,

Preheat maintenance, according to ASME IX,  is not post heating.
If it should be carried out NDT or not sure welding joint perfect, you can cool down before PWHT.

Preheat maintenance means that you do not cool down before perform PWHT



Jawaid

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Nov 12, 2017, 11:09:53 PM11/12/17
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As per ASME SEC IX
preheat maintenance: practice of maintaining the minimum
specified preheat temperature, or some specified
higher temperature for some required time interval after
welding or thermal spraying is finished or until post weld
heat treatment is initiated

mithlesh kumar

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Oct 9, 2023, 2:54:58 AM10/9/23
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Then what is the difference between post heating and pre heat maintenance.

Kannayeram Gnanapandithan

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Oct 12, 2023, 12:37:34 AM10/12/23
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Preheat maintenance, Maintain the Preheat temp till completion of welding, due to short term power cut etc.  Post heating/ Hydrogen Bake out, is after completion  of welding,  The weldment shall be held at temperature above the preheat temperature  for some time to release the hydrojen
THANKS & BEST REGARDS,
KG.PANDITHAN, BE, IWE,  CSWIP 3.1,
ISO 9712 Level 2 in VT,
ASNT-Level II in PT,MT,RT & UT,
LA ISO 9001-2015,
International Welding Engineer. 
CONSULTANT-WELDING & QUALITY
Mobile no: +919940739349



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