DNV-OS-F101 Design and API Procurement

[delia16]

Hi there,

I've done a bunch of calcs with DNV-OS-F101 for subsea petroleum piping and now that the wall thickness reports have all been issued we are told we can only buy API fabricated pipes (off the shelf). I've worked on projects before where this wasn't an issue (usually we just require extra testing, etc.) but on this project they are being particularly sticky and want to re-do the design using ASME (blech).

Does anyone have industry experience or any actual EVIDENCE that says it's ok to order API piping even if the design was carried out using API??


Thanks!

 

[London]

Hi Delia16,

Perhaps this post would get more of a response in the pipelines thread.. There are people there who would know the intricacies of validating API pipe with other industry standards.

I am interested in a similar topic personally, and will let you know if I uncover any more information!

Rgds

 

[BigInch]

Something wrong with your question. There is API pipe, but there is not an API piping or pipe design code. The common USA piping and pipeline design codes are ASME B31.1, B31.3, B31.4 and B31.8

Those ASME codes require that you use a pipe material made to a specification listed within those codes. One group of specifications for fabrication of pipe, not for design of pipe, listed within and approved for use by the ASME B31.4 and B31.8 design codes are the API 5L specifications.

If the DNV F101 design indicates that pipe with a certain level of yield stress is safe to be used, you could supposedly purchase API pipe with an equivalent or higher yield strength than was assumed for the design and it would normally be safe and sufficient. Check if the DNV F101 code allows the use of API 5L pipe and you should be OK. Let us know if DNV allows the use of API 5L pipe fabrication specification. I'm not sure about that. Otherwise you can sometimes purchase pipe that is multiply certified. Try to buy pipe that is certified to both the specification required by your DNV design and also certified to the API 5L specification.

I hate Windowz 8!!!!

 

[SJones]

DNV-OS-F101 linepipe requirements are based on ISO 3183 with a host of modifications and supplements. "Off the shelf" pipe is highly unlikely to meet all of these modified and additional requirements. The question then becomes: is the validity of the design compromised by using non-compliant pipe. Given the focus on offshore process safety these days, the majority of end users are likely to say yes, even without the intervention of a verification body, hence the instruction to use ASME design code with API Spec 5L linepipe.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.