Re: [PipingDesign] Cost Estimation

From: <Paul>
Date: Tue Oct 12 2004 - 22:42:00 EDT

Absolutely, I agree.

What I was referring to was small projects (say, just a couple of pumps and a storage tank, etc.) where the client may not even have piping specs or where the piping itself is a very minor portion of the facility. Often in those type of jobs all kinds of silly stuff gets added to the P&IDs like pipe anchor points, pipe couplings and manual valve handwheels drawn-in, unconventional symbols being used...

Then there's the arguments about how to notate reducers; is it a 4"x3" or a 3"x4"? Or insisting that the schematic follow the proposed physical routing.

Paul

Paul

George McKinney wrote:

> Paul:
> Good natured argument:
> Maybe I mis-read your sequence flow, but you say PFD goes to P&ID, and then
the trouble starts? For me, the PFD really needs to be the root document, that gets examined and approved by the customer, and ALL parties in the project. I worked for most of my useful life in a major gas transmission company. After being retired, I am now with a "hired gun" engineering company, frequently working with my old company. We do a lot of compressor station rebuilds, complete with all auxiliary systems. As such, the PFD is absolutely necessary to get everyone to agree that we have covered all the possible flow paths, support systems, etc. Once we do this, with all the valves indicated, the automation guys have a much simpler job of defining the valve control requirements, control feedbacks, etc. Then, when we start to do the P&ID, we're not trying so much to define equipment requirements - already been done and agreed. At the P&ID stage, it becomes a matter of what brand/model/c olor we want to use.
>
> George
> ----- Original Message -----
> From: Paul Bowers
> To: PipingDesign@yahoogroups.com
> Sent: Saturday, October 09, 2004 7:28 PM
> Subject: Re: [PipingDesign] Cost Estimation
>
>
> Bingo. This is still true even though we now have amazingly powerful
> "thinking machines" to help us.
>
> I hope to start a good-natured argument with the comments below, so take
> everything I say in that light.
>
> The PFD (which most people never even see) leads to the P&ID with all
> the nice lines and logical layout. Unfortunately, then the real world
> interrupts.
>
> If we work backwards from a well-installed, properly-functioning process
> piping facility, we get to the drawings from which it was built.
>
> Engineers typically do not understand that one hours' work (calculation,
> analysis perhaps) on their part can easily mean 10 hours work for the
> person that is creating the model/drawing.
>
> What I have found with many engineers (me having over 20 years of
> experience) is that they don't really know what they want until they see
> it. They seem to be able to visualize *their* ideas but cannot
> appreciate the time it really takes to make the drawings.
>
> Engineers that typically work on smaller jobs are especially bad in this
> regard. What they really need/want is a plumber that can draw pictures
> for the client presentation, not a piping designer.
>
> Paul
>
>
> Steve McKenzie wrote:
>
> > Right on
> >
> > piping has a history of having the largest cost overrun on projects,
> > even when professionally estimated and locked into fixed (ha ha) price
> > contracts. For some guidelines, look at John S Page's books published by
> > Gulf, but tread warily.
> >
> > Cheers
> >
> > Steve
> >
> > -----Original Message-----
> > From: Al [mailto:alwynk@shaw.ca]
> > Sent: Friday, October 08, 2004 4:53 AM
> > To: PipingDesign@yahoogroups.com
> > Subject: RE: [PipingDesign] Cost Estimation
> >
> >
> >
> > dear amit,
> > trust us on this one
> > thats exactly why estimators have gainful full time employment. if it
> > was as easy as you ask, they would have no job. would you hand over all
> > the knowledge of your job so you could become unemployed? besides you
> > have to seriously question the value and accuracy of data given to you
> > in the way you ask. Estimating is a serious skill and many serious
> > decisions are based upon it. If you are trying to cut so many corners
> > what value is the attempt you are making going to have. Theres no harm
> > in building your own knowledge base of costing, but dont pretend its any
> > more than that when you are starting from scratch. For one thing it
> > changes constantly and only a professional estimator is up with the play
> > In the long run you will save money by letting a skilled estimator do
> > it. this is from experience, Paul knows our recent case. I've seen many
> > botched estimates and they just cause grief.
> >
> > ** Altecheng@shaw.ca
> >
> > ' 001(780)465-9762
> > 6 Fax/Msg(780)465-9762
> >
> > * .
> >
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> >
> >
> > -----Original Message-----
> > From: anant panchal [mailto:panchal_ak@yahoo.com]
> > Sent: Wednesday, October 06, 2004 3:46 AM
> > To: pipingdesign@yahoogroups.com
> > Subject: [PipingDesign] Cost Estimation
> >
> >
> >
> >
> > Hello all,
> > I am getting problems in calculating cost for Pipes,
> > Pipe fittings, flanges valves etcs.. I dont have data
> > of rates for many items ..As sending querries to
> > related manufacturing companies for many different
> > components with diff materials is very tedious and
> > reply are also not so quick. Can anybody put some
> > light for getting tentative rates from any internet
> > sites or some other source so that the estimation
> > process could be fast
Received on Tue Oct 12 22:42:00 2004

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