Re: [MW:15340] Repair after PWHT

Re: [MW:15340] Repair after PWHT - B 31.1

Dear gents,

Case-1: Normal practice

1.welding (with/without pre heat & post heat)

2.RT

3.Clear repair + RT

3.PWHT

4.RT

Case-2: Some agents are doing (with confidence of worker & Did not get a time fot RT)

1.welding (with/without pre heat & post heat)

2.PWHT

3.RT

4.Clear repair (with/without RT)

5.PWHT

6.RT

Solution of case-2: There is no problem for twice PWHT. It will not affect any meterial properties.

That is the reason, we are taking hardness test to meet requirement. Only time will take more.

Regards,

sabi

On Mon, Sep 17, 2012 at 10:01 AM, Muhammed Ibrahim PK <ibratech@gmail.com> wrote:

PWHT shall be done after repair. To avoid this issue better to perform RT before PWHT also.

Thanks & Regards
Muhammed Ibrahim PK

On 10 September 2012 09:10, sevak hiren <hirensevak80@gmail.com> wrote:

Dear Experts,

Piping Code : ASME B 31.1, Power Plant Piping, (P No.5A,11,12,15, 91 etc pipes) & ASME Sectin I

Contractor is doing piping fabrication stages in following manner,

Preheating & Welding of Piping joints then Post heating, then PWHT & then finally RT.

Contractor is arguing, RT is taken after PWHT to reveal the defects causing due to delayed cracking.

My question

If RT repair is done for particular joint after PWHT then is it compulsory to perform PWHT again for particular joint ? if yes then please mention the clause of code.

Thanks & Regards

Hiren Sevak

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