Pipe line design

[tbvn]

Gents,

Our team is taking over one platform which is under detailed engineering phase,there is an issue that we are facing with, and I need some your advise for this issue:

Previously our design for pipe line is suitable with riser 16" wt 25.4 API 5L X60 and MAWP is 238 bar ,however we are trying to reduce MAWP of pipe line to around 120bar.

Anyone knows what is the standard for this changing? what kind of material/parameters will be selected for this pipe line? and if we are changing this pipe line, can we perform pigging with this riser?

thanks for your advise.

 

[zdas04]

If you knew how to calculate the required wall thickness and pipe grade for 238 bar, why don't you know how to do the same calculation for 120 bar? The calculations should have been in the other company's files.

David

 

[tbvn]

Dear David,

Thanks for your advise,the problem here is I have not found the company's file yet.

Could you please provide some more information for this issue?

Thanks,

 

[zdas04]

From your mixture of units it is not possible to tell where you are. If you had said "we are in the UK part of the North Sea" or "a project in the Gulf of Mexico", then you might have gotten an ISO or ASME reference. Maximum Allowable Working Pressure is very much an issue about selection of standards and the requirements of jurisdictions. It is also about what individual companies are willing to tolerate (e.g., one multi-national that I've worked with won't allow hoop stress at normal operating pressure to be above 20% of SMYS, another won't allow hoop stress during a static test to be above 22% of SMYS--both values are far more conservative than the code allows).

Give us enough information to help and you might get some help.

David

 

[BigInch]

From the extent of the panic, I guess Indonesia.

Let your acquaintances be many, but your advisors one in a thousand’ ... Book of Ecclesiasticus

 

[tbvn]

All,

Mr Biginch is correct, I am in Jakarta indonesia now.

We are approaching company's file now ,so will collect more information in this.

Will get back to you soon.

Thanks.

 

[tbvn]

Dear Zdas04 and Biginch,

I just got some more information and need your help.

Our riser is 16” and WT is 25,4mm and the pipe line is 16” and wt 10,3mm.We are choosing the scraper pig for pigging this pipe line,do you have any document or standard to explain the selection of pigging?

Thanks,

 

[BigInch]

There could be a lot of reasons to do it, and selection will depend on which one. It is usually if for drying, gaging, cleaning, corrosion inhibitor or other treatment pushing, keeping the line liquid, or solid free, or sometimes just to segregate products. The type of pig will be choosen based on what the exact purpose of running the pig is, and maybe the type of "dirt" you expect to get.

Let your acquaintances be many, but your advisors one in a thousand’ ... Book of Ecclesiasticus