[MW:10615] RE: 10612] help in solving a problem regarding Welding Procedure Qualification

You have not read far enough into the specification.  If you read SFA-5.1 Annex paragraphs A7.6.7.1 and A7.6.5.4, you will find that E7018, E7016, and E7015 are all, all position, low hydrogen, electrodes which may be used with downward progression for diameters 5/32 inch (4.0mm) and less (typically).  E7048, addressed in A7.6.10 is specifically compounded to be used in the vertical position with downward progression and therefore may be preferred but is often not readily available.  Vertical progression down with E7018 and E7018-1 has been used successfully in welding of tanks and water towers for many, many years.  Welding with downward progression takes special expertise and practice in order to handle the flux and obtain sound welds.

 

John

 

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Suresh Babu
Sent: Wednesday, April 06, 2011 3:44 AM
To: materials-welding@googlegroups.com
Subject: [MW:10612] help in solving a problem regarding Welding Procedure Qualification

 

Dear Gents,
The objective of writing this post is seeking your precious help in solving a problem regarding Welding Procedure Qualification
It is required to qualify a Welding Procedure specification for welding the bottom shell plates of an Oil storage tank.
Is it possible to use ESAB ATOM ARC 7018 electrode for Vertical down welding of the shell plates?
As per the AWS 5.1 -2004 Table-1 Electrode Classification, this electrode cannot be used for Vertical down welding and only E7048 can be used for vertical down welding.
According to ASME SEC IX, ( WELDING VARIABLES PROCEDURE SPECIFICATIONS (WPS) Shielded Metal-Arc Welding (SMAW) ) QW-253 the Position QW- 405 is a supplementary essential variable only.
Now the contractor has successfully completed the Welding Procedure Qualification Test using ESAB ATOM ARC 7018 in the vertical down position and submitted for approval.
Kindly advise, is it fair to accept it?  Will there be any quality related problems in using this WPS and the ESAB ATOM ARC 7018 for welding Oil storage tanks as per API 650 standards?
The relevant portion of the ASME SEC IX extract, the brochure of ESAB ATOM ARC 7018 and the AWS 5.1-2004 are attached along with this.
Thanking You
Regards

Best Regards,

Suresh.

 

QW-253Error! Filename not specified.WELDING VARIABLES PROCEDURE SPECIFICATIONS (WPS) Shielded Metal-Arc Weldi

QW-410

Error! Filename not specified.

Paragraph   Brief of Variables   Essential Supplementary Essential   Nonessential     QW-402 Joints .1      Groove design     X .4 −    Backing     X .10      Root spacing     X .11 ±    Retainers     X     QW-403 Base Metals .5      Group Number   X   .6 T Limits impact   X   .8      T Qualified X     .9 t Pass > 1⁄2  in. (13 mm) X     .11      P-No. qualified X             QW-404 Filler Metals .4      F-Number X     .5      A-Number X     .6      Diameter     X .7      Diameter > 1⁄4  in. (6 mm)   X   .12      Classification   X   .30      t X     .33      Classification     X   QW-405 Positions .1 +    Position     X .2      Position   X   .3      ­¯ Vertical welding     X   QW-406 Preheat .1 Decrease > 100°F (55°C) X     .2      Preheat maint.     X .3 Increase > 100°F (55°C) (IP)   X     QW-407 PWHT .1      PWHT X     .2      PWHT (T & T range)   X   .4 T Limits X       QW-409 Electrical Characteristics .1 >    Heat input   X   .4      Current or polarity   X X .8      I & E range     X   .1      String/weave     X .5      Method cleaning     X .6      Method back gouge     X .9      Multiple to single pass/side   X X .25      Manual or automatic     X .26 ±    Peening     X .64 Use of thermal processes X

Technique

 

 

 

 

Legend:

+  Addition	>  Increase/greater than	­  Uphill	¬  Forehand	Change
−  Deletion	<  Decrease/less than	¯  Downhill	®  Backhand

 

 

 

 

 

 

 

22

 

 

 

QW-253.1

Error! Filename not specified.Error! Filename not specified.WELDING VARIABLES PROCEDURE SPECIFICATIONS (WPS) Shielded Metal-Arc Welding (SMAW)

Error! Filename not specified.Special Process Variables

 

Paragraph Essential Variables     Nonessential Variables for HFO and CRO   Hard-Facing Overlay (HFO) (QW-216)   Corrosion-Resistant Overlay (CRO) (QW-214) QW-402 Joints   .16   <           Finished t   <           Finished t       .20                P-Number                P-Number     .23                T Qualified                T Qualified

QW-403

Base

Error! Filename not specified.Error! Filename not specified.Metals

QW-404 Filler Metals	.12	Classification
	.37		A-Number
	.38			Diameter (1st layer)

 

QW-405                  .4          +           Position                                         +           Position

Error! Filename not specified.Positions

Error! Filename not specified.QW-406                  .4

Dec. > 100°F (55°C) preheat                       Dec. > 100°F (55°C) preheat

Error! Filename not specified.Error! Filename not specified.Error! Filename not specified.Preheat                                            >  Interpass                                                >  Interpass

QW-407 PWHT	.6	PWHT
	.9		PWHT

 

QW-409 Electrical Characteristics	.4	Current or polarity	Current or polarity
	.22	Inc. > 10% 1st layer	Inc. > 10% 1st layer
QW-410 Technique	.1			String/weave
	.5			Method of cleaning
	.26			± Peening
	.38	Multiple to single layer	Multiple to single layer

 

Legend:

+  Addition	>  Increase/greater than	­  Uphill	¬  Forehand	Change
−  Deletion	<  Decrease/less than	¯  Downhill	®  Backhand

--
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.