Coating on Duplex Underground Pipeline
Coating on Duplex Underground Pipeline
(OP)
Dear all,
is it right to coat an Underground Pipeline in duplesx material type S31803? I'm doing a project in Algeria for a gatering system to construct so the soil is prevalently constituted by sand. I suppose that corrosion mechansms could be done by differencial aeration or electrolites presence, but in the same time this material should be projected to resist to these environments.
In case of Cathodiic protection obviously i opt for a coating system in order to reduce current density demand.
In case of is always suitable coat the duplex pipeline which could be the coating system suitable for the scope? could Polyethylene or Polypropylene be suitable for the scope? I'm oriented on Polypropylene system coat of 3 mm in thickness.
Regards Vincenzo
is it right to coat an Underground Pipeline in duplesx material type S31803? I'm doing a project in Algeria for a gatering system to construct so the soil is prevalently constituted by sand. I suppose that corrosion mechansms could be done by differencial aeration or electrolites presence, but in the same time this material should be projected to resist to these environments.
In case of Cathodiic protection obviously i opt for a coating system in order to reduce current density demand.
In case of is always suitable coat the duplex pipeline which could be the coating system suitable for the scope? could Polyethylene or Polypropylene be suitable for the scope? I'm oriented on Polypropylene system coat of 3 mm in thickness.
Regards Vincenzo





RE: Coating on Duplex Underground Pipeline
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Coating on Duplex Underground Pipeline
many thanks for your reply. Client have decided for PP coating but anyway I will follow your advice principally for my knowledge.
I have another question for you, I have seen on ASTM for Pipe material A790 Grade S31803 that pipes, obviously, shall be fournisced in pickled conditions without any type of spot.
My question is the following
is rigth to require also the passivation treatment after pickling?
On ASTM is not mensioned the passivation, probably because we are speaking about a duplex material where the Cr quantity is to high that in a short time it will form a protective stable and uniform superficial oxide. Anyway in my opinion I will ask for a passivation treatment to the pipes supplier in order to be sure that the external layer will be omogeneus.
Thanks for all.
With my best Regards
Vincenzo
RE: Coating on Duplex Underground Pipeline
It should not be necessary to passivate this pipe.
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Plymouth Tube
RE: Coating on Duplex Underground Pipeline
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04