Backing

[Venkateswaran]

 

As per ASME SEC IX ,we qualified PQR(SMAW/GMAW process) with 8mm/10 mm thickness plate full penetration welding( Root Land:1mm to 1.5 mm) as root ,hot and cap welding and then back/root side of plate was grounded(approx 2mm) to sound metal and one pass of cap welding was done in root side.

My question is whether is method is considered as welding with backing or with out backing it is considered as backing. how?

Regards,

kvr

[John Henning]

YES – it is welding with backing.

 

See QW-402.4, non-essential variable for both SMAW and GMAW and an essential variable for welder performance qualification for both processes per QW-416.

 

“QW-402.4  The deletion or the backing in single  welded groove welds.  Double welded groove welds are considered welding with backing.”

 

John

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[Karthik]

I think,this is not a backing,because this is to make sure for the welder confirmation. it is happen in normal practice that after welding of single v groove of plate and to be confirmed by visual to confirm the full penetration..and if the penetration is good...many(All) times the welder need to confirm by themself by grind to some depth after confirm by visual (1 or 2mm max..) to make it look good appearnce as well as to avoid any discrepancies in RT.(even it can accept in Rt without grinding)   As far as my experience and Customer,AI witness.. it was accepted as without backing... Thanks & Regards, (Karthik) Karthikeyan.S QA/QC Manager Getabec Energy Co.,Ltd. 379,Moo6,Soi8,Nikhomphatana, Rayong-21180, Thailand. Phone: 0066 38 897035-8 (Off) Fax: 0066 38 897034 Hand Phone: 0066 892512282 --- On Wed, 3/23/11, John Henning <jhen...@deltak.com> wrote:

[John Henning]

Karthik,

 

I beg to differ – any time you weld on the root side of the weld, for ASME Section IX it is considered welding with backing.  Whether you do it for cosmetic purposes, to fix suck back, or to remove & replace unsound material, you are still welding against some existing material  and (probably more important) you are not welding “open root”.  That said, this usually is not a problem, because it is considered easier to weld with backing than without.  A weldor qualified to weld without backing can make a weld with backing and, therefore, if your weldor was qualified for the open root weld he can correct the root side without issue – probably why your AI has no issue also.  Also since the use of backing is a non essential variable for the WPS, this too is not an issue other than making sure your pencil is sharpened.

 

John

[Karthik]

Dear Mr.John, This case called as back gouging not backing.This is not a Double welded type. As per Sec.IX,definition as below. backgouging: the removal of weld metal and base metal from the weld root side of a welded joint to facilitate complete fusion and complete joint penetration upon subsequent welding from that side.

Thanks & Regards, (Karthik) Karthikeyan.S QA/QC Manager Getabec Energy Co.,Ltd. 379,Moo6,Soi8,Nikhomphatana, Rayong-21180, Thailand. Phone: 0066 38 897035-8 (Off) Fax: 0066 38 897034 Hand Phone: 0066 892512282

[arijoy roy]

We are essentially doing GMAw welding on thick plates with single grrove with 2 m root face. . One way of checking penetration is to see whether an uniform  weld metal deposit has appeared on the bootom side. If it has then it is grinded and removed other wise gougins is done and welded again. I therefore agree that it is not backing.   Backing is done generally where appraoch from the other side is not available and whre full penetration is the requirement. Arijoy Roy R&D Telcon Jamshedpur --- On Wed, 23/3/11, Karthik <karth...@yahoo.com> wrote:

[kannayeram gnanapandithan]

Mr Karthik

 see the clarification, it is a back weld(double side), and i go with john

 

Pandithan, AWS-CWI,CSWIP 3.1

In-Charge/Welding Technology

Cethar Vessels Ltd

Trichy

[Karthik]

then what is back gouging? pls.see my last mail for the explanation for this mail.

Thanks & Regards, (Karthik) Karthikeyan.S QA/QC Manager Getabec Energy Co.,Ltd. 379,Moo6,Soi8,Nikhomphatana, Rayong-21180, Thailand. Phone: 0066 38 897035-8 (Off) Fax: 0066 38 897034 Hand Phone: 0066 892512282

--- On Sat, 4/2/11, kannayeram gnanapandithan <kgpan...@gmail.com> wrote:

From: kannayeram gnanapandithan <kgpan...@gmail.com> Subject: Re: [MW:10580] RE: 10463] Backing To: material...@googlegroups.com