Protective treatment for bare carbon steel

[kjy313]

Three vessels will be shipped oversea after hydrotest.
There are the uncoated carbon steel internals in these three vessels.
I worry that the internals can be corroded during sea transportation and storage. I expect that the vessels will be serviced after 6 months later.

Could any one recommend the protective treatment on surface internals from corrosion, in case that N2 purge is not avaiable?

 

[unclesyd]

Checkout this company. The have all the material for Vapor Phase or Coatings for shipments.
It is best to make a personal contact as they have a number of different approaches.

http://www.cortecvci.com

 

[eyec]

what are the vessels end use?
does a slight coating of oxidation matter?
use of a nitrogen blanket is pretty much standard. where that is not chosen some are using "shrink wrap".

 

[kjy313]

These vessels are separators for oil and gas plant.

Mr. eyec, could you explain "shrink wrap" in detail?
It sounds a cousin of food wrap.

If hydrotest will be undertaken with alkine water, is it possible for the carbon steel internals to be passivated?

 

[eyec]

yes, it is similar to "food wrap". they cover the entire piece of equipment in heavy duty plastic and apply vacuum/heat to draw the plastic closed.

 

[SJones]

Typically, vapour phase inhibition (VPI) is an accepted substitute for nitrogen blanketing. Wrapping would be seen as a supporting measure for the VPI. Consult BS 1133 Section 6 for guidance. The VPI will be flushed by the hydrotest water and may, dependent upon specific type and concentration, render some degree of corrosion protection during this operation although it cannot be considered a substitute for normal hydrotesting practices and post test drying.

Steve Jones
Petroleum Development Oman LLC
Muscat
Sultanate Of Oman

 

[1969grad]

A cheap solution is having the interior surfaces spray coated with a light oil after hydrotest.

In addition, all connections should be plugged or have flanges with gaskets.

If the light oil solution is not acceptable to you then the next solution would be to pressurize with nitrogen.

Shrink wrap is usually reserved for smaller items like control panels.

 

[eyec]

we received an entire generator (150Mw+/-) for a CCCT plant!

the generator was shiped via boat and train and looked good when it arrived. haven't seen it in a while but after sitting on a rail spur for a couple of months it was still nicely covered.