Chlorinated Rubber v/s Zinc Rich Epoxy Paint 2

[ak1965]

I wish to paint Liquid Nitrogen Bullets in my plant. I have options of chlorinated rubber paint and zinc rich epoxy paint. Which is better and why ?

Thanks

 

[CoryPad]

Do you mean a tank (pressure vessel)?

Of what is it made?

What are the requirements? Corrosion resistance, wear resistance, appearance, etc?

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[ak1965]

Yes these are huge vertical cylinderical liquid Nitrogen tanks with an annular space for vacuum. Serivce temp. inside the tank is -170 deg c, however due to vacuum insulation, tank surface temp. remains around ambient.

Protection is expected from atmospheric corrosion, the plant location is coastal and weather remains rainy for 6 months.

 

[unclesyd]

The chlorinated rubber (CR) will work but it will not last as long as an epoxy + urethane top coat (EU). Though you don't have a need for toughness the EU is far superior to the CR. We have a LN2 plant on site along with 8 storage tanks and all are coated with EU.
At one time CR was our site standard based on similar requirements as yours, located on salt water bay. We tried a straight epoxy system based on our at the time our paint supplier's recommendation, no good chalked rapidly. We then went to EU system based on KTA panel results. Our first supplier of the EU system was Carboline. They are other good suppliers out there. R was phased out quickly after adoption of the EU system mainly due to some issues with CR solvent at the time. In KTA testing the only monocoat coat epoxy that stood up to our environment was Sears epoxy deck paint.

I've heard that there are now some very good monocoat epoxies on the market.

Here are the systems we used for a number of years.

http://www.carboline.com/docs/generic_systems_2006.pdf

 

[JStephen]

For storage tanks in general, some form of epoxy + urethane is the most common coating, and has been for years. The zinc is an upgrade to that, and you can also apply clear overcoat for additional protection.