Hi Arvinda,
What's the service environment gaseous /flammable liquid or gases or any chemicals or steam/water. What's the design code of the component which is to be repaired by Temper bead welding technique.
Welding is only a part of the hot tapping process. There are two established guidelines in the industry for hot tapping :-
- API-RP-2201-Mostly used for hot tap on oil and gas pipelines.
- ASME PCC-2- provides methods for repair of equipment and piping and vessels within the scope of ASME Pressure Technology Codes and Standards after it has been placed in service.These repair methods include relevant design, fabrication, examination, and testing practices and may be temporary or permanent, depending on the circumstances.As per PCC-2, Hot Tap on pipelines shall be done to API RP-22.Temper bead weld repair is accepted by this document. Note API-510 also accepts temper bead weld repair, but subject to the verifications of operating media, not across the board. 01
One has to qualify a temper bead repair technique with the guidelines of QW-290(Sec-IX).Follow the guidelines of QW-290.4 to establish the welding procedures. For meaningful temper bead weld repair a PQR shall be qualified under simulated conditions, worst condition would be more proven. Temperbead welding is a substitute for PWHT, hence it's a serious issue.
Thanks.
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Declan Foley
Sent: Monday, October 04, 2010 6:22 AM
To: materials-welding@googlegroups.com
Subject: Re: [MW:7350] hot tap and temper bead
I don't have a copy of spec here, so am not sure. The fact that you are putting a split tee on means that it is a reasonable size hot tap. If you are doing this with no procedure, might I recommend that you not stand too close to this when they retract the drill, particularly if this is a lethal or explosive service............
Declan
On 04/10/2010 04:01, arvinda shan wrote:
----Thanks for your response.One more clarification. In our project, for hot tapping activities, split tee welding is going on with out any procedure qualification. As per sec IX QW290.4 , fluid backing, heat input etc... are essential for temper bead welding. For that essential variables no PQR has been qualified.Need separate procedure for doing these activities or no need? Plz clarify.On Mon, Oct 4, 2010 at 12:54 AM, Declan Foley <declan1foley@eircom.net> wrote:
Arvinda,
No relationship.....temper bead is a welding process.........hot-tapping is a mechanical process, which involves drilling into a vessel or pipeline!
temper bead is the welding process usually ( but not always ) employed when welding the hot tap fittings (usually weldolets, split tee's etc....) onto the vessel or pipeline as part of the hot tap process.
As regards qualifying welders, you should be very careful here, because depending on service, this can be a hugely critical operation, and doing it wrong can have catastrophic results. Its a while since I have done any but as far as I can remember the best specs are British Gas ( Transco ) PS-P2 & PS-P9
regards
Declan
On 03/10/2010 11:13, arvinda shan wrote:--Dear all,
What is the relation between temper bead and hot tapping? Is there any specific procedure to qualify for hot tapping or only welders to qualify downhill progression?
arvinda
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
No comments:
Post a Comment