ACTIVITIES FOR PIPE-RACK ERECTION

it depends what stage design is at.



I firmly believe that a definative estimate should be prepared as design issues IFC drawings.



This serves many purposes.



primarily to quantify what you are actually going to build.



and then to compare to what was budgetted,

IMHO, using tender estimates for resourcing is not a good practice.

Your project manager / erection crew can list their preference of resources.

Get quantity estimate from fabrication drawings.

You can use the production rates published in this website to calculate the resource requirements.

For structural steel piperacks, detail planning is required for erection sequence (approach, fabrication output, Crane lift and capacity and methodology etc).

HTH

Neeraj

Brennan,

Got the Photo’s. Pretty much like you described it



Ted,



First photo Total structural steel, can be erected by doing the columns and cross members, and preliminary alignment first. If bib enough crane available then erect the pre-assembled cages and place on columns. Otherwise build in sections as already suggested by Brennan.



Second Photo the white Pipe racks, I can’t see too well it seems it is all-concrete except for the top cage above the 4th level. Or it is also all structural steel but has been fireproofed.



Question of resourcing, your company must have estimated for this project get the man-hours from the project manager and estimate. The estimate should be up into Labor and skilled and give you a good indication.



How many Tons of structural steel has to be erected? in how long a period? How many sufficient tonnage cranes is at your disposal? answers that you must find out.



Hope this helps.

Hi,



I guess the existing plant is about to retire. I just hope you still got the original as-built drawings with you.



Oh, you will be working with live pipes & wires...



but you can always try excavation manually (that’s a lot of U.S. visa)

if u can see them then u can save them

think about it.... they are already on your hard disk somewhere.





i just emailed u the pictures if by chance u are viewing this forum on your pocket pc =)

eeerrrmmm, I’m not set for that otherwise I would not of made the request. Duuhhh.

errrrm.... just right click on them and choose "save picture as"

Ted.



Can you mail me the Photo’s at [email protected]



Thanks.

They are good photos



as you can see there are concrete footings, the photo at the bottom appears to be a concrete structure.



Structural Steel:

- columns

- Beams

- Infill Steel

Look at the modularisation, can sections be preassembled off site or away from the workfront?



You would want to put your long runs of pipe in with the structural steel, alternately you could feed it in from the end but this would be the second preference.



Once the pipe is in and fit up its time to weld out.There are published rates for butt welds.



hydrotesting and drying comes next (by the looks of it you are in a Gas plant which is particularly sensitive to moisture). You will need to talk to the gingerbeers to work out test limits and requirements.



Tie in planning is probably the most crucial part of the operation. In an existing plant this will require interface with operations staff to organise isolations.



Hope this helps

To answer your second question.. what activities can be start to start :

Only the linkage between starting activites of sections should be Start to Start like



"Section 1 Excavation" (SS+7days) "Section 2 Excavation" as

Finish of section 1 is not related to start of section 2.



All other activites in Pipeprack are of FS nature.



Regards

Neeraj

Ted,

You could divide the pipe rack length into sections, Section 1, 2 ,3 (generally your piping activities will define these sections).

Within section 1, if you have prefabricated columns and beams, start erection as soon as foundations allow it. otherwise calculate erection starting point from the rate of progress of erection w.r.t to the rate of pouring foundations. You dont want your erection crew idling on account of lack of foundations.

regards

Ted.



Are the Pipe racks complete concrete? or is it concrete and structural steel. What king of piperack is it, single, double, triple storey with stairs and gantries ? send a sketch. There are many types of piperacks that can be detailed.



Give PP some info to work with.