Glass Flake Lining

[Simdro]

Hi everybody,

I have to purchase some pressure vessels and some filters which shall contain well water.
The process specification says that the Vessel can be designed and manufactured taking into account as main material Carbon Steel plus 3mm of corrosion allowance plus glass flake as internal lining. Moreover all internals (vortex breaker, internal baffle,etc...) shall be made by super duplex or plastic material.

Does anyboby have experience with this type of internal lining applications?
Are there some precautions or limitations in applaying this type of lining in some cases like us high pressure apllications, small diameter vessel, etc..?

Furthermore for small diameter housing filters (500mm) could be better to make the internal lining in Super Duplex Material, considering the internal lining glass flake costs and application?

Which kind of NDE can be performed on these lined Vessels?

Any clarification on the matter would be greatly appreciated.

 

[vesselfab]

gee whiz...ask the lining guys

actually the inside surface needs to be ground smooth at all wells but not neccesarily flush.

small nozzles can be a problem but the fabricator should take that into effect when bidding since he will be responsible.

I would at a minimum LPT all the internal duplex to carbon welds since they will be covered with flake.

you may wonder/ask what the extent of flake will need to be.

ON FLANGE FACES?

if so gasket selection will be critical

 

[SJones]

Somebody has to work out why the vessel needs corrosion allowance and coating. The implication is that the water will be corrosive and that uncoated steel will not achieve the design life. Having decided that, the next step is to understand that the coating will not last forever and will require maintenance. Two issues arise: firstly, as you point out, pressurised service may not be good for coatings particularly when depressurised rapidly; secondly, the vessel has to be accessible to maintain the coating; i.e. of a suitable size. You seem to be aware of these issues so you need to investigate them further.

PS - you will be using CP as well?

See also thread338-250080

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[Simdro]

Hi guys,

First of all thank you for yours prompt replies.

The issues underlined by Vesselfab are surely so interesting. I hope that the selected manufacturer will be able to do this type o lining on internal shell, internal nozzles and on flange face as well.

Do SJones think that the provided corrosion protection (3mm of CA + Glass Flake lining) is not enough strong to guarantee a design life of 15 years?
I inform you that my company gave the material selection study as subcontract and the selected materials were taken from it.

From my point of view the lining restoring should be scheduled only after the expected design life, even though so difficult to be carried out on filed.

As I have already read on some spread sheet, this type of lining is suitable for applications where the medium salt concentration can achieve the galvanic corrosion phenomenon, so in this way I can erase the coupling of dissimilar metals (CS vs. Super Duplex).

Hoping to find the best solution before to begin the BID phase,
I would like to thank you again for your availability.
SD

 

[stanier]

International Coatings have such a lining.

Use of CP with super duplex is something to be concerned with as hydrogen embrittlement may occur as the alloy has ferrite avaialble.

 

[SJones]

If you have selected the materials you have to live with them. All I can say is: make sure you pick the correct coating and coating supplier. How to do that has already been pointed out.

CP can be an issue for super duplex when it is a highly stressed pressure boundary item which vessel internals shouldn't be (they also shouldn't be welded to a carbon steel shell).

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04