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RE: Welding Of Steel Moment Connections

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See below for reply.

Harold Sprague, PE
Krawinkler, Luth & Assoc.


-----Original Message-----
From:	Rick.Drake(--nospam--at)fluordaniel.com [SMTP:Rick.Drake(--nospam--at)fluordaniel.com]
Sent:	Thursday, June 25, 1998 7:30 AM
To:	seaoc(--nospam--at)seaoc.org
Subject:	Welding Of Steel Moment Connections

     It is my understanding that welding electrode coatings produce a 
     gaseous shield to exclude air and stabilize the arc.  Consequently, 
     the work area must be protected from wind to preclude dissipation of 
     the protective shielding gasses.  However, in practice, I rarely see 
     the Structural welding work areas shielded in construction projects.
     This raises a few general questions.
     [Harold Sprague]  Your understanding is correct for shielded metal arc welding (SMAW) and flux core arc welding (FCAW).  There are other processes that use an external gas.  I will focus on SMAW(stick) and FCAW because they are the most common in the field.  The G indicates that external gas is required.

     1) Do AWS D1.1 and UBC allow field welding (wire not stick) with no 
     provisions for shielding the work area from a 20 mph wind at a dusty 
     site?
[Harold Sprague]  There is no wind speed limit for SMAW or FCAW-S there is a limit on FCAW-G.  I have required FCAW-G in lieu of FCAW because of the problems I have observed with maintaining the shield for FCAW-S.  If FCAW-G is used a wind shelter is required and the wind can not exceed 5 mph.
     
     2) Does the lack of any noted indications from subsequent UT 
     inspection of these welds mean they are OK?
[Harold Sprague]  If the inspector does his work properly, the welds should  be O.K., but keep in mind that typical fillet welds do not require UT.
     
     3) Do the answers change if these welds are the beam flange to column 
     flange welds of a "Reduced Beam Section" moment connection design?
[Harold Sprague]  These usually are full pen welds which will require UT.  Just require UT and special inspection on these connections.  That way you will get an inspection on the process as well.  If the process is wrong, you could get a very brittle weld or the wrong electrode.  (UT will not detect this.) The inspector should check to see if they are using a wind shield, proper electrode, preheat, etc.  I know the code requires this anyway, but if Fluor is doing a project in China it will not have ICBO requirements.
     
     Rick Drake, SE
     Fluor Daniel, Irvine

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