Re: Use of Nitrogen as a pipeline preservative

Likely someone with more field experience will chime in, but you will probably want to do a high pressure N2 purge of the line (watch out for the low points) followed by the usual system overpressurization. Maybe a dynamic purge setup would be useful in order to compensate for the inevitable leaks/detection of pressure loss.

Paul

From: "aomodu" <aomodu@yahoo.com>
To: <PipingDesign@yahoogroups.com>
Sent: Thursday, August 26, 2004 11:11 AM Subject: [PipingDesign] Use of Nitrogen as a pipeline preservative

> My question is this a new pipeline is to be preserved for 3 years
> prior to coming on stream. We have decided to introduce biocide,
> oxygen scavenger and inhibitor into the hydrotest water prior to the
> test and afterwards dewater the line. Nitrogen will then be
> introduced as a preservative for the line.
> 1. Will the introduction of the above chemicals and oxygen
> scavenger/inhibitor actually prevent pipeline corrion, since no mater
> the effiency of our dewatering mechanism there will still be some
> traces of water left in the line?
> 2. Will the presence of N2 as a preservative actually prevent the
> little traces of water left in the pipeline from corroding the
> pipeline?
> 3. How do we contain the leakage of N2 from the system since I
> understand that this is a usual occurence.
> 4.The pipeline is designed to ASME/ANSI B31.8 CODE, will this code of
> design be adequate to prevent N2 leaking from the system?
>
>
>
> THANKS
>
> Adolphus Omodu
> Mechanical Engineer
Received on Thu Aug 26 11:49:00 2004