Flange Connection at Zone 1 Pipeline

[ammp]

Dear Expert,

I'm a pipeline engineer looking for advise from you guys.

Our company is planning to do a flange tie-in at the middle of a 200km pipeline, due to government requirement in one of the country in south east asia. We won the 200km pipeline but we had to surrender half of the portion to the local company in order for us to operate in that particular area.

However, client rejected our proposal to add tie-in flange connection at the middle of pipeline as it is only allowed for spool. I wonder, is there any requirement stated in DNV or any design code that allow flange tie-in at Zone 1 pipeline? FYI, the tie-in location is at 45m water depth and for us to perform AWTI is quite difficult with current barge specification and 14inch pipe with 72mm CWC.

Appreciate your advice on this.



rgds

 

[BigInch]

No code prohibits it.

 

[ek4putr4]

I did so many sectional pipeline replacements with lot of flanges and mechanical connectors in the middle of pipeline. No issue with the Authority approval. We also have other pipeline HPHT that having U expansion spool in the middle of the pipeline.

 

[TensionvsTorque]

Are you using ASME recommended parallel joint closure or are you welding the flanges?

Ever thought of using ASME reaction washers to make job hands free, and eliminate bolt side loading?