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ANSON
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Join Date: Jul 2012
Posts: 9

Welding Flange On Existing Butt Weld End Connection Valve

07/29/2012 4:45 AM

IS welding the flanges on butt weld end valve allowed?

In my project at present there are motorised valve having butt weld end connection, can i weld flanges to these butt weld end connection valves. We are facing maintenace issue regarding butt weld valve. These valves are installed on water & steam line of waste heat boiler. The line has design pressure 54 bar and design temp 425 degree celcius. Valve body material is ASTM A216 WCB. Please provide any codal refernce if any.
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PennPiper
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#1

Re: welding flange on existing butt weld end connection valve

07/29/2012 7:37 AM

Think about this logically.

As for the valve it does not care what you weld to it's end, be it pipe, a flange or a vessel nozzle. It is all the same to the valve.

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ANSON
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Posts: 9
#8
In reply to #1

Re: welding flange on existing butt weld end connection valve

07/31/2012 5:36 AM

Thanks
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lyn
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#2

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/29/2012 11:28 AM

Although I have zero time as a piping engineer, what PennPiper says seems logical.

It's a butt WELD valve. So weld it already.
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MJCronin
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Location: Central Midwest
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#3
In reply to #2

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/29/2012 1:37 PM

Suggest that you use a weld-neck flange of the appropropriate class for this change.

What is the pressure class of the valve itself as well as any other.

Do you have a piping line specification ?

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ANSON
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Join Date: Jul 2012
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#10
In reply to #3

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/31/2012 5:37 AM

Thanks
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ANSON
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#9
In reply to #2

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/31/2012 5:37 AM

Thanks
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ANSON
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Posts: 9
#11
In reply to #2

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/31/2012 5:38 AM

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ian mcintosh
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#4

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/30/2012 3:32 AM

No problem with the correct WPS and a weld neck flange.
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ANSON
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#12
In reply to #4

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/31/2012 5:38 AM

Thanks
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PWSlack
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#5

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/30/2012 4:32 AM

Follow the valve manufacturer's instructions to the letter. In particular, take care that any components inside the valve that may be damaged or destroyed by the heat of welding are removed from the valve before doing the weld.

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user-deleted-1100
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Good Answers: 3
#6

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/30/2012 5:40 AM

You have the answer in your question. If seat of the valve fails, what cost you are going pay for replacement. It is a claver more welding WNF flange tovalve. One has to watch grade of vave and flange.
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ANSON
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#13
In reply to #6

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/31/2012 5:39 AM

Thanks
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ANSON
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#7

Re: Welding Flange On Existing Butt Weld End Connection Valve

07/31/2012 5:36 AM

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sivabalan
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#14

Re: Welding Flange On Existing Butt Weld End Connection Valve

08/06/2012 1:31 PM

You can weld with correct WPS and you have to very clear while choosing the flange rating... since pressure plays major roll here.. is there any space constraint for welding the butt welded valves?? .. if not welding directly is the better option. It is economy also..
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Users who posted comments:

ANSON (7); ian mcintosh (1); lyn (1); MJCronin (1); PennPiper (1); PWSlack (1); sivabalan (1); user-deleted-1100 (1)

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