Materials & Welding: RE: [MW:23918] Bulge P-91 Pipe after PWHT

Tuesday, November 24, 2015

RE: [MW:23918] Bulge P-91 Pipe after PWHT

Hi Pradip,

Thanks for emailing us the temperature-time chart.

However, we still need a sketch or drawing of the heater and thermocouple arrangement.

You stated that you utilized 2 thermocouples, 180^o apart. However, where were they relative to their heaters and relative to the header-tube weld?

Specifically:

1. What are the diameters and thicknesses of the header and tube(s)?

2. What size heaters were attached to the header, and where were they and their control thermocouples relative to the location of the header-tube weld?

3. What size heater was attached to the tube, and where was it and its thermocouple relative to the header-tube weld?

4. The fact that the softened, bulged section of tube was 140 mm from the header-tube weld indicates that the temperature of the tube at that location may have exceeded the PWHT soak temperature.

5. Your sketch/drawing of heater sizes and thermocouple locations will help diagnose the cause of your problem.

Regards,

Dennis

From: pradip kumar Sil [mailto:pradipsil@gmail.com]
Sent: Tuesday, November 24, 2015 6:45 AM
To: Thompson, Dennis; materials-welding
Subject: Re: [MW:23914] Bulge P-91 Pipe after PWHT

Dear Dennis,

Pls find the PWHT chart & in 10" we used two nos of thermocouple with equal distance i.e 180 degree. We checked the hardness in the weldment as well as HAZ zone & found 210 to 238 HB but in bulge zone ( Parent Material ) which is 140 mm away from weldment is coming 155 to 175 HB.

Thanks in advance.

Regards,

Pradip

On Tue, Nov 24, 2015 at 4:22 PM, Thompson, Dennis <Dennis.Thompson@teaminc.com> wrote:

Hi Pradap,

Please email us a drawing of the heater and thermocouple arrangement that was employed for your PWHT, along with a copy of your temperature-time chart. Both are needed to help diagnose your failure.

Regards,

Dennis Thompson, P. E.

Team IHT Technical Support Manager

973-885-2148

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of pradip kumar Sil
Sent: Tuesday, November 24, 2015 5:37 AM
To: materials-welding
Subject: Re: [MW:23914] Bulge P-91 Pipe after PWHT

It is not possible to do PWHT horizontally because spool piece is welded at location

On Tue, Nov 24, 2015 at 3:25 PM, VHEER RAJHU <rajuveera2011@gmail.com> wrote:

Mr shanmugan,

Job is kept in vertical condition where and when the job is heated locally the material softens at that particular area where all the weight of the job is acted on that softened area which leads to bulging locally

Preferred to do PWHT HORIZONTALLY

On 24 Nov 2015 14:46, "shanmuganathan .subbiah" <shanmuganathan.subbiah@gmail.com> wrote:

Dear

Both end closed or not during PWHT?

On Tue, Nov 24, 2015 at 12:26 PM, pradip kumar Sil <pradipsil@gmail.com> wrote:

Dear Expert,

In P91 Material ( HRSG header Joint ) after pwht one joint is bulge.We did Preheating ,Welding , Post Heating,& PWHT in proper way.

Can anybody explain why this bulge occurs & remedy.

During fit-up inspection & weld visual inspection all round the joint is perfect but after PWHT pipe is bulge 140 mm away from the weld ment

Pic Attached

Regards,

Pradip