Surface Engineering Forum

  • Alternative Forum Home PageSEF Portal
  • Old S E Message Board ArchivesOld Message Board Archives
  • Search
  • Member List
  • Calendar
  • Help

Current time: 02-16-2019, 08:19 AM Hello There, Guest! (Login — Register)


Surface Engineering Forum / Surface Engineering / Surface Engineering Threads v
« Previous 1 ... 26 27 28 29 30 31 Next »
/ arc spray metallizing vs PE coating




Post Reply 
Threaded Mode | Linear Mode
arc spray metallizing vs PE coating
02-18-2008, 02:53 PM
Post: #1
basakglkn Offline
Active Member
****
Posts: 18
Joined: Nov 2007
Reputation: 2
arc spray metallizing vs PE coating
Dear All,

Do you have any opinion of using arc spray metallizing zinc or aluminium+sealer inside of
Sea water pipeline instead of polyethylene coatings?

Have you ever come across such a subject in your projects?

Do you have any idea of year based resistance according to polyethylene coatings?

Your responses would be highly appriciated.
Thank you in advance.for your assistance.
Best Regards,

�. Ba?ak G�LEKEN
Metalurgical Engineer
Send this user an email Find all posts by this user
Quote this message in a reply
02-20-2008, 06:37 AM
Post: #2
Alexangel1226 Offline
Senior Member
*****
Posts: 94
Joined: Sep 2006
Reputation: 3
RE: arc spray metallizing vs PE coating
Basak,

Not so sure about PE coating, but Arc spray metallizing zinc/ aluminum provide genral corrosion resistance or for electrical insulation purpose other than its well known function, but to resist corrosion by sea water, I am not sure because generally arc spray coating is relatively rougher in surface profile and with higher tolerance of porosity within the coating layers. Chemical, water or fluidized aqueous may penetrate even with sealer applied on it after coating. Youprobably need a higher desity coating for sea water corrosion protection. As I am not expert in this area, would like to know more also.

I come across an interesting article or webpage of experiment conducted to studyThe Effect of the Thermal Spray Process on the Protective Behaviour of NiCr Alloy in Seawater, and the results of the electrochemical investigation of the corrosion properties of thermal sprayed Ni80Cr20 coating as compared to the behaviour of "standard" mass material. It is interesting to know that HVOF being the dense coating is contributing better protective value compared to APS, and most importantly the oxide level in the density has better corrosion resistence towards sea water.

With this study reference, maybe you could consider HVOF process using a better material instead of ARC spray process.

Pls see (link dead)

Regards,
Alexangel1226
Send this user an email Find all posts by this user
Quote this message in a reply
02-20-2008, 11:18 AM
Post: #3
jeffsays163 Offline
Active Member
****
Posts: 35
Joined: Dec 2007
Reputation: 2
RE: arc spray metallizing vs PE coating
Heard of Arc spray process for Sea water corrosion resistance, instead of PE. But not too sure about how many years it can stand. HVOF is certainly a great process for this application, the cost issue usually limits its expanding.
Send this user an email Find all posts by this user
Quote this message in a reply
02-20-2008, 12:31 PM
Post: #4
Stuart Milton Offline
Senior Member
*****
Posts: 61
Joined: Feb 2008
Reputation: 2
RE: arc spray metallizing vs PE coating
Please can you confiirm if you mean the pipeline is under the sea or if the pipe is to carry seawater?

As some of the other posters above, I do not have any information or knowledge of PR coatings. However, arc spraying is done inside pipes for various applications. The issues that you need to consider are the physical dimensions of the pipes themselves. For example, small diameter pipes (less than about 100mm) can only be sprayed internally with an arc extension to a depth of about 1.5m. If you need to go longer than that, the pipe would need to be around 450mm ID. You would have to mount an arc pistol on a fixture and preferable rotate the pipe and traverse the pistol along the inside of the pipe. Depending on the consistency of the pipe diameter, you can have problems doing this. If the pipe diameter is large enough to climb into, you can hand spray. In all cases, you have to consider dust extraction, otherwise you have safety risks and potential for bad dust inclusion in the coatings.

Regarding the material selection (zinc, aluminium or other more exotic materials), this depends on the environment and what the pipeline is carrying. To respond to Alexangel1226, aluminium is most commonly used in seawater applications. Many of the off-shore oil rigs around the world have their support jackets (steel sub-structures, cellar decks, super structures etc.) For a pipeline application with external coating, oil risers pipes that are used to transfer oil and mud products during off-shore drilling are commonly coated with aluminium (around 200 microns) and sealer (to full penetration). For atmospheric coating lifetimes, I suggest that you refer to EN ISO 14713 for independent life to first maintenance predictions for arc sprayed zinc and aluminium coatings.

So, in summary, arc spraying of pipe internal bores is possible, but you need to consider a lot of factors to do it successfully.

Stuart Milton
Metallisation Ltd
https://www.metallisation.com
Send this user an email Visit this user's website Find all posts by this user
Quote this message in a reply
02-20-2008, 03:40 PM
Post: #5
basakglkn Offline
Active Member
****
Posts: 18
Joined: Nov 2007
Reputation: 2
RE: arc spray metallizing vs PE coating
Stuart Milton Wrote:Please can you confiirm if you mean the pipeline is under the sea or if the pipe is to carry seawater?
..............
The issues that you need to consider are the physical dimensions of the pipes themselves.
Thanks to all for the replys.

The pipes are carrying sea water and their diammeter is app. 3m (far too large i think?)
Send this user an email Find all posts by this user
Quote this message in a reply
02-20-2008, 03:49 PM
Post: #6
Stuart Milton Offline
Senior Member
*****
Posts: 61
Joined: Feb 2008
Reputation: 2
RE: arc spray metallizing vs PE coating
In principle, with the information given, I think that a sealed aluminium arcsprayed coating should be fine against sea-water. You may need to re-consider if there are other contaminants in the sea water.

With a 3m diameter pipe, you could easily spray inside and this has been done. You still need to consider access for blasting and metal spraying then sealing. In principle, this is similar to an off-shore environment and when the pipe is not full, you will have a 'splash zone' where your corrosion is higher.

Still not sure about the benefits over PE coating though. It would be interesting to get other viewpoints regarding that.

Stuart Milton
Metallisation Ltd
https://www.metallisation.com
Send this user an email Visit this user's website Find all posts by this user
Quote this message in a reply
« Next Oldest | Next Newest »
Post Reply 




Possibly Related Threads...
Thread: Author Replies: Views: Last Post
  Spray fused coating cracks Arturas 24 12,317 12-07-2016
02:57 PM
Last Post: abhay
  THermal Spray and Hard Crome Coating Met.Eng. 4 2,776 07-11-2015
03:40 PM
Last Post: Met.Eng.
  Spray & Fuse coating for Boiler tubes Jaydev 7 6,129 06-25-2015
05:08 AM
Last Post: abhay
  Thermal spray coating for Nitriding shantanu 4 2,834 04-25-2015
08:47 AM
Last Post: Joris Kraak
  Metal Spray Coating for ID Fan Impeller RV_DMG 2 2,511 04-08-2015
06:54 PM
Last Post: Met.Eng.
  TAFA 45 CT arc spray coating shantanu 1 3,449 08-13-2013
12:36 PM
Last Post: Gordon
  what's the effect of the spray energy to the coating's hardness? Spark 3 3,242 07-10-2013
05:55 PM
Last Post: loriolo
  Thermal spray coating in Process Industries Chakraborty_P 8 6,786 08-29-2012
02:43 AM
Last Post: ehasan
  HELP TO DEPOSIT SPRAY & FUSE COATING OF STELLITE POWDER --- REG sreenuvundela 10 9,219 03-14-2012
11:46 AM
Last Post: Vijay Deshpande
  Plastic Coating over flow / over spray hafizAR85 0 2,022 02-20-2012
09:03 AM
Last Post: hafizAR85
  Glass flake coating by thermal spray sreenuvundela 1 3,541 09-29-2011
04:26 PM
Last Post: Vijay Deshpande
  thermal spray coating for Galvalume tank horsecheng 8 7,818 08-31-2010
04:25 PM
Last Post: loriolo
  thermal spray metco 204ns coating retlaw 2 7,266 09-11-2009
02:24 AM
Last Post: Gordon
  delamination of spray - fuse coating Arturas 10 8,798 04-01-2009
05:13 PM
Last Post: Gordon
  Maximum RPM for ARC Spray Coating Vijay Deshpande 1 2,998 02-15-2009
02:00 AM
Last Post: iwan-sedaryawan

  • View a Printable Version
  • Send this Thread to a Friend
  • Subscribe to this thread


User(s) browsing this thread: 1 Guest(s)





Surface Engineering Forum Sponsor - Alphatek Hyperformance Coatings Ltd

    Subscribe in a reader

    Contact Us | Thermal Spray Coatings | Return to Top | Return to Content | Lite (Archive) Mode | RSS Syndication

Powered By MyBB, © 2002-2019 MyBB Group.


© Copyright Gordon England