Hi Guy's,
with regard to the 'Golden Weld' theories
going around, the latest bit of info is that such
welds are now called 'Closure Welds' as the old term
is not representative, in this technically correct
world of today.
Anyway, being an 'old bod' I will stick to the term
for the sake of continuity.
In my experience with Golden Welds is that they were
always treated with the utmost repect for the obvious
reason, that they were not proof tested by going
through the hydrotest process.
As for the substitue measures that can be taken with such welds, there are many and usually there is a method statement generated and approved by the Client to spell out the process for completing such welds.
I have in the past been involved with the witnessing of such welds and it is usually up to the Welding Engineer to decide on what length to go with these joints, in the past I have had to follow a whole variety of stringent controls to ensure that the welds were carried out in the best possible way.
Some of the measures are as follows:
1). A qualified Inspector being present throughout the
welding operation to confirm the visual condition of
the weld at all stages of completion.
2). A visual inspection of the root of the weld, this
was achieved by leaving the final length of root bead
open, (100mm), for a visual inspection with a pen
light, to ensure defects such as lack of root fusion
were not present.
3). Controlled sequential welding was applied to
lessen the unnecessary stress that could be put into
the weld by not applying such method.
4). The Hot Pass of the weld was sometimes MPI'd or
DPI'd, dependant on the pre-heat requirements or the
material being welded.(never the root as it is too
sensitive an area and it is best to be covered over
with the hot pass bead as quickly as possible for
added strength).
5). Heat inputs were sometimes taken at certain
intervals during welding by the Inspector, as would be
during a Weld Procedure Qualification test, using
'Tong testers'/stopwatch/tape measure/calculator, to
ensure that the welder was working within the
peramaters stipulated in the relevant welding
procedure.
6). Joint interpass temperatures would be taken with a
digital thermometer at the end of each pass, to ensure
that the interpass tempareture was in line with the
welding procedure tolerances.
7). Finally, when the 'Golden Weld' was completed
there would be a whole range of NDE to complete such
as Visual inspection, MPI or DPI, Radiographic AND
Ultrasonic Inspection, both prior to and after Post
Weld Heat Treatment, (if PWHT was applicable).
Still being in the business after 35 years, I look in dispair today when it is notedthat such critical joints are not treated with the same respect today.
It is in my book better to be safe than sorry by going the extra yard with the controls, in such critical instances.
Hope this mail is food for thought and enlightens some..........?
kdo.
> Hi all,
>
>
> In a new piping fabrication/installation/replacement
> jobs, generally all
> the weld joints are hydroteted (along with other NDT
> methods) in phases.
> However, sometimes due to some layout/site problems,
> it is almost impossible
> to do hydrotest of the final weld joint. We refer
> that weld joint as golden
> joint.
>
> Generally, Dye penetrant test of root weld,
> radiographt etc.. is used for
> quality control of that joint
>
> Say, something like a hook-up to an existing line
> etc..
>
> Regards
>
> Chakra
>
>
>
> -----
>
>
>
> [Non-text portions of this message have been
> removed]
>
>
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