Plot Plans

Just curious, I referred Roger Hunt. It refers to three distinct phases of plot plan.

1. Proposal Stage : Developed during estimate phase of the plant. It only indicates principal items of equipment, main supporting facility and overall dimensions. The sample shown did not show any equipment location dimension marked.

2. Planning Plot Plan : This is updated version of Proposal Plot Plan after awarding of the contract based on the latest data. The sample had dimensioning for major support structures etc. but no equipment location dimension.

3. Construction Plot Plan: The IFC plot plan issued to construction. This sample had all equipment location dimensions marked.

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I have a query in this regard:
If we choose to (we should not) show dimensions on Plot Plan then we have duplicated information a. Plot Plan b. Unit Plan (Equipment Location Plan) which 11echo has marked in his first response as I see now. Then at some point, we have to shift the equipment location then it will then become binding to update both documents. Will the plot plan (since we are revising) need the client approval again (every time)?

Ideally we should not repeat the same information on two different drawings.
Example-

To show the unit to unit or facility to facility dimentions we have a plot plan which shows it very clearly & when we need to know or convey what is there in each unit or facility we have a equipment layout which shows it with much clarity.

Repeat info is not at all a good practice as whenever we change one document we need to take care of the same change in other document as well....which will be additional work unncecessarily..!

Do you agree with me ?? We should try to avoid it..!

Where I work, Plot plans are classified into following:

-Site Plan (contains reference points and general locations of major facilities such as process block, utility block, common facilities, etc)

-General Plot Plan (applicable for multi-unit process block to locate different key units like acid gas removal,fractionation, liquefaction area, etc

-Unit Plot Plan (equivalent to equipment arrangement drawing), with reference coordinates and dimension to show location of equipment.

Site plan and general plot plan were developed/decided at the FEED and early EPC stage. After issuing it for construction, update would normally be required only if requested by site engineering staff.

Unit plot plans are decided on early EPC stage and issued for design and construction (mainly for early site development work) before detail engineering stage. After using 2D plot plan as based for 3D equipment and structural modeling, plot plan will be extracted from 3D model and a consistency check between model and 2D plot will be made. From time to time, an equipment arrangement may change mainly because of piping design development. Also, most vendor package data will be available only during detail engineering stage. IFC revisions of unit plot plans were issued for these cause and to release any hold items that were not decided or unavailable during initial IFC schedule.

Ideally you are correct when you say you should not duplicate dimensions and coordinates in any form. and you should show everything listed in the first post if applicable. But in reality it is the bosses decision. Not the he is going to be correct, usually not. I've work on many different job and not one has been the same unless I was the boss. So till your the boss you do what he says.

Boss is always right..! Of course ...
but we should be aware what is a good practice.........