3 replies to this topic

[chinbas]

I work in a very new and novice EPC company. I wanted to know about actual workflow in major EPC companies.

After tender is float we do following things.

Besed on clients PFD or P&ID & tender document with process engineering knowledge we prepare our preliminary P&ID (without sizing).

In the meantime we do our process simulation using HYSYS. Then we crosscheck major Equipment with Pro II.

Then we go for major equipment sizing.

When some or all of the vessel sizing is done we pass those datasheet to our senior for chechking and approval to pass it to mechanical engineers for thickness calculation, nozzle positioning (stress calculation) PVelite (Vendor), codeware compress.

Then we do control valve sizing.

In the same time we start doing psv sizing and flare header calculation.


After theses sizing HAZOP team starts doing HAZOP study.

At this time we finalize the P&ID. Submit for clients approval.

In the meantime mechanical engineers start building 3d cad drawing for GAD in AutoCAD plant 3d.

Then we do pipe stress calculation.

After GAD is done we relese all the datasheet and drawing to prcurment team for consuatation with equipment vendor and fabricator.


I have included many software that we use or try to use. Would appreciate if you share your valuable experiance.

[chemproc]

seems like you covered most of what is done in an EPC company.

[processengbd]

Thank you for your reply.

 

It is not possible to write all the work done by an EPC in page I just wanted to check my understanding with you.

 

There are more things like Electrical engineers do load calculation, ladder diagram for control system.

 

I also missed pipe sizing. Piping arrangement calculations. 

 

We are facing one difficulty in cost estimation of the projects. Like before bidding it is does on preliminary calculation. But when we do detail sizing it differs considerably with the previous calculation. How can we resolve this please advice. 

 

Regards

[gegio1960]

processengbd (or chinbas?),

generally speaking you shouldn't have significant differences in equipment size between bid and project phases.

For a better understanding you should say which kind and size of plants you're speaking of.

good luck!