Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Welding Failures

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Dave,
This is NOT a duplication of effort. The contract documents prepared by the structural engineer indicate what the structural engineer intends. The shop drawings indicate the structural steel details including welding details. When the structural engineer indicates a CJP, he does not know what welding procedure will be used, what filler metal will be used, or what preheat will be used. That is the prerogative of the shop and is for the preparer of the shop drawings to indicate.

When I get shop drawings just saying CJP, I reject them. I want to see that the shop has a detailed welding procedure. The welder will need the welding detail and procedure as will the welding inspector.

If that exercise would have happened on the Hyatt Regency walkways, a competent detailer would have seen that it was impossible to get a butt weld CJP weld on the toe to toe channel. It MAY not have prevented the disaster, but it would have forced the steel detailers and the structural engineer to take a more detailed look at the connection.

From 1975 until 1980 I worked as a steel detailer. When I saw the symbol
for any type of CJP, I would detail the weld. I would indicate the procedure, the angle of the bevel, the finish, the backer, run off tabs, the root opening, etc. In the shop the inspector would check the root opening, the tolerances, the filler rod, the backing, etc. The welder would mark his weld. The shop inspector would verify the NDT inspectors qualifications per AWS. The NDT inspector would run his probe over the weld to verify that there were no weld discontinuities. As you can tell from the dates, this is nothing new.

Regards,
Harold Sprague





From: "dave lowen" <jatech(--nospam--at)kwic.com>
Reply-To: <seaint(--nospam--at)seaint.org>
To: <seaint(--nospam--at)seaint.org>
Subject: RE: Welding Failures
Date: Sun, 9 Apr 2006 14:32:23 -0400






On Apr 9, 2006, at 1:25 AM, Harold Sprague wrote:

> Personally, I expect the detailed weld symbol to show the procedure,
> the bevel, the preparation, the heat, the filler metal, etc.  And I
> check them.  Maybe I am a bit particular, but I have worked in about
> every area of structural steel and I am more than a bit cautious.


Harold

What you are asking for is a duplication of effort. Putting a weld procedure
number on a weld symbol is a great idea and to my mind should be mandatory.

But, the procedure itself contains all of the variables that you mention
i.e.; electrode, base metal, bevel angle, max thickness, position, wire
feed, gas flow etc. Also, the AWS does not require that much info on the
symbol.

Up here in the great white north, ALL shops doing structural work MUST be
sanctioned by the welding bureau, MUST have at the least, a retained welding engineer, MUST have one or more designated welding supervisors having passed
at least 5 different bureau exams and MUST have on hand a catalogue of all
the welding procedures the shop is allowed to do. Welding operators MUST
have tickets for each weld procedure they are allowed to do. Each ticket is
issued only after the operator has been physically tested and his weld
specimens have been tested. It becomes shop property, if the operator goes
to work in another shop, he/she must be retested.

In shops I have managed, fitters were required to draw the weld symbol on
the steel in chalk as most welding operators could not read drawings. The
welding supervisor would then check the chalk mark with the drawing and then check the weld for conformity. Incidents of misinterpretation were extremely
rare.

Dave



******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted
*   without your permission. Make sure you visit our web
*   site at: http://www.seaint.org
******* ****** ****** ****** ******* ****** ****** ********

_________________________________________________________________
Don?t just search. Find. Check out the new MSN Search! http://search.msn.click-url.com/go/onm00200636ave/direct/01/


******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* * This email was sent to you via Structural Engineers * Association of Southern California (SEAOSC) server. To * subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
* Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you * send to the list is public domain and may be re-posted * without your permission. Make sure you visit our web * site at: http://www.seaint.org ******* ****** ****** ****** ******* ****** ****** ********