Gentlemen,
Weld production may also be a function of the alloy being welded for
instance P91 is a very difficult "superalloy" pipe to weld and once
you start welding a spool you are best off if you weld continuously
until ALL the welds are complete... In other words 3 shift
production... P91 is so tough to get right the EPRI folks have written
a paper on how-to fabricate on it. So plain old Carbon steel most
commonly used @ walls less than 3/4" welding can be stopped and then
re-started but something like P91 nope....
- In PipingDesign@yahoogroups.com, Paul Bowers <pbowers@p...> wrote:
> Thanks, Siva.
>
> I assume that means (generally, since there are the other factors you
> mentioned that can vary) that butt welds over 20" diameter require
> multiple shifts. Can a partially-completed butt weld be left
"overnight"
> and be continued the next day?
>
> I'm referring to field welding, common Sch. 40 carbon steel.
>
> Interesting that you mention climatic conditions. Some facilities have
> ambient construction temperatures that are lower than the usual -20
> degrees F.
>
> Paul
>
>
> B.Sivasubramanian wrote:
> >
> > Dear Paul,
> >
> > The productivity of the Welds in Piping Works is a subject it
self. The production rate depends on the following factors
> >
> > 1) Whether the Weld is done in Fab Shop or Field
> > 2) If in field whether it is Unit Piping or on Racks or on Pipes
> > 3) MOC
> > 4) Thickness of the Pipes (Schedule)
> > 5) Pre weld / Post Weld heat treatment requirements
> > 6) Welder's skill
> > 7) Electrode Diameter used
> > 8) Current used for Welding
> > 9) Type of Welding Process (Manual / Semi Automatic / Orbittal etc)
> > 10) Climatic Conditions
> >
> > etc.
> >
> > Just to give a guideline, if the work is in a typical hydrocarbon
facility on an average (say in a plant where the total quantum of
works is 400,000 ID) you may consider 20Inch Dia per Welder Day ( 1
Welder Day = 8 hours of Work)
Received on Fri Apr 15 07:24:00 2005