Need a book? Engineering books recommendations...

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

RE: Welding Failures

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Your are correct. The filler metal is not on the weld symbol, and preheat is in the weld procedures.

My observation (and it varies with the shop) is that I will show on the structural contract drawings the generic CJP symbol. When I get the detail drawings back, they often times show the same generic symbol. That is OK for a fillet weld, but not a CJP weld.

I want to see all of the information on the shop drawings regarding throat thickness, finish, bevel angle, single/ double sided, root opening, backing, position, shielding, process, etc. A lot of ambiguity goes away with indicating the joint designation in the tail. That is a detailed prequalified weld.

I have had occasion that the shop drawings indicated a B-U3c-S (which is a sub arc) for a vertical weld in the field. Obviously that is a mistake in that sub arc welds can only be done in a flat position. Just showing CJP would not have allowed me to catch it. That is the kind of thing I was writing about.

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: Tue, 11 Apr 2006 19:25:42 -0400

Harold,

I think we may be talking about 2 different things. You mentioned in your
first post that you wanted to see the heat and filler metal on the weld
symbol. The AWS makes no provision for adding this information to a weld
symbol.

Shop fabrication drawings traditionally have the material grade(s) and the
electrode(s) required listed in the B/M or notes. If they don't, they should
have.

I have never come across a shop drawing that specified pre heat or post
heat.

Regards,
Dave


-----Original Message-----
From: Harold Sprague [mailto:spraguehope(--nospam--at)hotmail.com]
Sent: April 9, 2006 8:30 PM
To: seaint(--nospam--at)seaint.org
Subject: RE: Welding Failures

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
******* ****** ****** ****** ******* ****** ****** ********




******* ****** ******* ******** ******* ******* ******* ***
*   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 ******* ****** ****** ****** ******* ****** ****** ********