Overlap of reinforcement pad with existing pipe circumferential Joint

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Hafiz Ali Alvi

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Jul 13, 2015, 11:00:50 PM7/13/15
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Deal All,

I have a question about Overlapping of RF Pad With an Existing Weld Joint.

We have a situation where hot tapping (NPS 36) to be performed on existing NPS 60 hot flare header. The branch connection was specified as Stub On with Reinforcement Pad as per ASME B31.3. There was a note specified on the ISO drawing to verify the hot tap location before executing the job. The contractor (perhaps overlooked the ISO note) weld the NPS 36 branch pipe and when they were about to weld reinforcement pad, they notice the reinforcement pad overlap with existing pipe weld.


Now the contractor has proposed to reduce the reinforcement pas width to 60mm to avoid overlapping with existing weld. I need you opinion on this proposed solution. Can we accept it.

What can be other possible solution keeping in view the welding requirements.

Design Code : ASME B31.3
Pipe Material : ASTM A672
Design Temp. 180 deg C
Design Pressure : 3.5 kg /cm2 g
Corrosion Allowance : 3.2 mm
Header WT: 15.3 mm
Header size : 60 inch
Branch size : 36 inch
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george....@gr.bureauveritas.com

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Jul 14, 2015, 4:43:03 AM7/14/15
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To the best of my knowledge, it is not prohibited to weld a pad or a saddle on a weld.
 You may check in chapter 382.5 and more particularly in 328.5.4.
Check 341.3.1 for inspection requirements

best regards

Dr. Georgios Dilintas

Authorized Nuclear Inspector
Authorized Inspector Supervisor

I&F REGIONAL TECHNICAL MANAGER
BUREAU VERITAS PIRAEUS - GREECE

Tel: +30 210 40 63 113 /4 /5
Fax: +30 210 40 63 118
Cell: +30 69 44 64 62 04


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Bijay

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Jul 14, 2015, 9:23:10 AM7/14/15
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As per site condition you can accept it. But before welding please be sure that the haz of rf pad and joint are apart from each other. 
 
What is the size of rf pad?  Is it 1.5 or 2 time of branch 

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From:"Hafiz Ali Alvi" <alima...@hotmail.com>
Date:Tue, 14 Jul, 2015 at 8:30 am

Subject:[MW:23156] Overlap of reinforcement pad with existing pipe circumferential Joint

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Hafiz Ali Alvi

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Jul 14, 2015, 11:01:57 PM7/14/15
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Hi Bijay,

Width of pad is 18 inch, half of branch size.
And after reduction it will be of 16 inch size at the side of circumferential joint.

Regards

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Shaik Basha

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Jul 15, 2015, 1:57:02 AM7/15/15
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you can take RT of that weld joint and can make overlap.

same also mentioned and allowed as per ASME VIII

Qc Engineer

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Jan 19, 2017, 5:44:06 AM1/19/17
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Dear All,

I am laso having similar issue RF pad covers circumferential weld by 150 mm. (72" PIPE WITH 24" WELDOLET CS THINNESS 26MM,  FOR ASME B31.1) issued  NCR to engineering, but still i wont get satisfactory closed out,

waiting for your valuable comments

Regard's

Faizur Rahman
QA/QC ENGINEER
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