Re: Nitrogen as preservative
We use Nitrogen to purge refrigerant or water lines in our HVAC work. Usually,
the target is the moisture remaining in the line. Whether it will take out
remnants of water depends on the pressure used plus resistance to the flow such
as bends, etc. After purging, the line is pressurized to about 10 - 15 psi and
the N2 is allowed to stay to make sure there is no leak in the system and to
prevent ingress of moisture from outside. This usually lasts for a day or two
(not years) or until such time we are to introduce refrigerant gas or water
into the line, as the case maybe.
I think this will be costly if used on long water lines. Also, N2 being inert
will probably not prevent corrosion, it that is the objective. A
biocide/herbicide and rust inhibotor mixed with water will probably be a better
choice.
Good luck.
Tas Grajo
PipingDesign@yahoogroups.com wrote:
There are 11 messages in this issue.
Topics in this digest:
Message: 1
Date: Thu, 26 Aug 2004 15:11:48 -0000
From: "aomodu"
Subject: 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
Message: 2
Date: Thu, 26 Aug 2004 11:29:36 -0400
From: "Paul Bowers"
Subject: New at Piping Design Central: Design Theory
Visit the Piping Design Theory page and click the appropriate links for the full articles:
http://www.pipingdesign.com/designtheory.html
The Accuracy of Calculations, by ABZ, Inc.
<design processes, it is commonly thought that engineering calculations are very accurate. However, while engineering software can eliminate mathematical errors and perform calculations with greater speed than hand calculations, there are many factors that must be acknowledged which can result in the calculated values being substantially different from actual measurements. This article will discuss some of the factors that can make calculations vary from measured results, including factors related to system construction as well as to system modeling. These factors can then be considered during system design to ensure that the design will meet all necessary requirements. In addition, consideration of these factors is also prudent when troubleshooting existing systems to avoid drawing unwarranted or incorrect conclusions.>>
Dynamic Susceptibility Method for Piping Vibration, by SST Systems, Inc.
<the specific requirements, nor the analytical tools and technical references typically available for other plant equipment such as rotating machinery. Typically, piping vibration problems only become apparent at the time of commissioning and early operation, after a fatigue failure or degradation of pipe supports. Discovery of a problem is then followed by an ad hoc effort to assess, diagnose and correct as required.>>
Message: 3
Date: Thu, 26 Aug 2004 11:49:12 -0400
From: "Paul Bowers"
Subject: 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"
To:
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
Message: 4
Date: Thu, 26 Aug 2004 16:48:22 EDT
From: KoechigC@aol.com
Subject: Re: Use of Nitrogen as a pipeline preservative
One thing I can tell you about Nitrogen, as an inert gas, when i braze copper pipe in the field for refrigeration, the gas neutralizes the oxygen to prevent the black scale debris that will cause the system to burn out if left unchecked
[Non-text portions of this message have been removed]
Message: 5
Date: Thu, 26 Aug 04 23:34:58 -0500
From: Christopher Wright
Subject: Re: Use of Nitrogen as a pipeline preservative
> the gas neutralizes the oxygen to
>prevent the black scale debris
There's no chemistry involved. The nitrogen simply shields the fusion
zone and keeps oxygen away.
Christopher Wright P.E. |"They couldn't hit an elephant at chrisw@skypoint.com | this distance" (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)http://www.skypoint.com/~chrisw
Message: 6
Date: Fri, 27 Aug 2004 22:31:44 +1200
From: "Steve McKenzie"
Subject: RE: 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"
To:
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
http://www.pipingoffice.us/ =========================================Main site: http://www.pipingdesign.com
Yahoo! Groups Links
Message: 7
Date: Fri, 27 Aug 2004 10:38:10 -0000
From: "Steve McKenzie"
Subject: spamattack
Gents+1
for my last 2 postings I have immediately received a serving of spam from
FDHNotes02/SRV/Dornier/DASA/DE@eads.com; on behalf of; Campus@dornier.eads.net
Obviously they are a total failure as an educational/employment organisation, but I am wondering if anyone else has received unsolicited email from these rats.
Cheers
Steve
Message: 8
Date: Fri, 27 Aug 2004 07:43:11 -0400
From: "George McKinney"
Subject: Re: spamattack
Steve:
It must be at your end - haven't gotten anything here. (Sorta hesitant to reply,
now watch me get spammed)
George McKinney
----- Original Message -----
From: Steve McKenzie
To: PipingDesign@yahoogroups.com
Sent: Friday, August 27, 2004 6:38 AM
Subject: [PipingDesign] spamattack
Gents+1
for my last 2 postings I have immediately received a serving of spam from
FDHNotes02/SRV/Dornier/DASA/DE@eads.com; on behalf of; Campus@dornier.eads.net
Obviously they are a total failure as an educational/employment organisation, but I am wondering if anyone else has received unsolicited email from these rats.
Cheers
Steve
Yahoo! Groups Sponsor
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c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]
Message: 9
Date: Fri, 27 Aug 2004 23:58:26 +1200
From: "Steve McKenzie"
Subject: RE: spamattack
Thanks George
mystery to me; it comes back with my copy of the message I post. So I
should get one when I receive my copy of this posting.
Lets see.....
Cheers
Steve
-----Original Message-----
From: George McKinney [mailto:gmckinney@augustaeng.com]
Sent: Friday, August 27, 2004 11:43 PM
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] spamattack
Steve:
It must be at your end - haven't gotten anything here. (Sorta hesitant
to reply, now watch me get spammed)
George McKinney
----- Original Message -----
From: Steve McKenzie
To: PipingDesign@yahoogroups.com
Sent: Friday, August 27, 2004 6:38 AM
Subject: [PipingDesign] spamattack
Gents+1
for my last 2 postings I have immediately received a serving of spam from
FDHNotes02/SRV/Dornier/DASA/DE@eads.com; on behalf of; Campus@dornier.eads.net
Obviously they are a total failure as an educational/employment organisation, but I am wondering if anyone else has received unsolicited email from these rats.
Cheers
Steve
Yahoo! Groups Sponsor
ADVERTISEMENT
a.. To visit your group on the web, go to: http://groups.yahoo.com/group/PipingDesign/
b.. To unsubscribe from this group, send an email to: PipingDesign-unsubscribe@yahoogroups.com
c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]
http://www.pipingoffice.us/ =========================================Main site: http://www.pipingdesign.com
Yahoo! Groups Links
Message: 10
Date: Sat, 28 Aug 2004 00:03:24 +1200
From: "Steve McKenzie"
Subject: RE: spamattack
Yep
its still there 15 secs after my confirmation message.
Will wait to hear from Paul before I do anything about it.
Cheers
Steve
-----Original Message-----
From: George McKinney [mailto:gmckinney@augustaeng.com]
Sent: Friday, August 27, 2004 11:43 PM
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] spamattack
Steve:
It must be at your end - haven't gotten anything here. (Sorta hesitant
to reply, now watch me get spammed)
George McKinney
----- Original Message -----
From: Steve McKenzie
To: PipingDesign@yahoogroups.com
Sent: Friday, August 27, 2004 6:38 AM
Subject: [PipingDesign] spamattack
Gents+1
for my last 2 postings I have immediately received a serving of spam from
FDHNotes02/SRV/Dornier/DASA/DE@eads.com; on behalf of; Campus@dornier.eads.net
Obviously they are a total failure as an educational/employment organisation, but I am wondering if anyone else has received unsolicited email from these rats.
Cheers
Steve
Yahoo! Groups Sponsor
ADVERTISEMENT
a.. To visit your group on the web, go to: http://groups.yahoo.com/group/PipingDesign/
b.. To unsubscribe from this group, send an email to: PipingDesign-unsubscribe@yahoogroups.com
c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]
http://www.pipingoffice.us/ =========================================Main site: http://www.pipingdesign.com
Yahoo! Groups Links
Message: 11
Date: Fri, 27 Aug 2004 09:16:06 -0400
From: "George McKinney"
Subject: Re: spamattack
DAMN! Now I've got it, too! - Kind of like fleas...I guess they are squatting on the site (parasite?)
George
----- Original Message -----
From: Steve McKenzie
To: PipingDesign@yahoogroups.com
Sent: Friday, August 27, 2004 8:03 AM
Subject: RE: [PipingDesign] spamattack
Yep
its still there 15 secs after my confirmation message.
Will wait to hear from Paul before I do anything about it.
Cheers
Steve
-----Original Message-----
From: George McKinney [mailto:gmckinney@augustaeng.com]
Sent: Friday, August 27, 2004 11:43 PM
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] spamattack
Steve:
It must be at your end - haven't gotten anything here. (Sorta hesitant
to reply, now watch me get spammed)
George McKinney
----- Original Message -----
From: Steve McKenzie
To: PipingDesign@yahoogroups.com
Sent: Friday, August 27, 2004 6:38 AM
Subject: [PipingDesign] spamattack
Gents+1
for my last 2 postings I have immediately received a serving of spam from
FDHNotes02/SRV/Dornier/DASA/DE@eads.com; on behalf of; Campus@dornier.eads.net
Obviously they are a total failure as an educational/employment organisation, but I am wondering if anyone else has received unsolicited email from these rats.
Cheers
Steve
Yahoo! Groups Sponsor
ADVERTISEMENT
a.. To visit your group on the web, go to: http://groups.yahoo.com/group/PipingDesign/
b.. To unsubscribe from this group, send an email to: PipingDesign-unsubscribe@yahoogroups.com
c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]
http://www.pipingoffice.us/ =========================================Main site: http://www.pipingdesign.com
Yahoo! Groups Links
Yahoo! Groups Sponsor
ADVERTISEMENT
[Non-text portions of this message have been removed] Received on Sat Aug 28 00:23:00 2004
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