Re: Use of Nitrogen as a pipeline preservative

There are also N2 generators (albeit at lower levels of purity) that are alternatives to high pressure N2 cylinders.

This is a good page that illustrates what is available: http://www.airliquide.co.za/en/business/products/gases/onsite/floxal_n2/index.as\ p
if you need nitrogen. From what I recall, there was no need to provide 99 and 4 nines purirty, so other production methods were invented.

(Disclosure: I have a previous relationship with Air Liquide)

Paul

• Original Message ----- From: "Steve McKenzie" <mechproj@xtra.co.nz> To: <PipingDesign@yahoogroups.com> Sent: Friday, August 27, 2004 6:31 AM Subject: RE: [PipingDesign] Use of Nitrogen as a pipeline preservative

> Hi Adolphus
>
> why not leave the line full of your solution? You would need to check
> out the biocide carefully as some can have unexpected corrosion
effects.
> If you use nitrogen, it will be important to maintain slight
> overpressure. Compressed nitrogen cylinders with pressure reducing
valve
> could be used, but it may not be economic if the line is leaky.
>
> Cheers
>
> Steve
>
>
> -----Original Message-----
> From: Paul Bowers [mailto:pbowers@pipingdesign.com]
> Sent: Friday, August 27, 2004 3:49 AM
> To: PipingDesign@yahoogroups.com
> Subject: Re: [PipingDesign] 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?
Received on Mon Aug 30 16:48:00 2004