Internal coating for high pressure / temp

[engrom]

Looking for a suitable coating system for vessel internal at high pressure and high temperature. Norsok M-501 coating system 3 provides info for Pressure < 7Mpa, Temp < 80deg C. Is there any proven coating system for high pressure 12Mpa, Temp=200C (This is the design condition of the vessel, however operating conditions are much lower)?

 

[SJones]

Before you get a flood of recommendations telling you to use this coating, that coating, or to contact this supplier or that supplier, it would be best to define what you expect to see in the way of information to justify 'proven'. See also the following:

Which Temperature - Design Or Operating
There is a nice debate stirring, I hesitate to say raging, on the NACE web/e-mail forum regarding the basis for selecting and specifying coatings. I've precised the exchange as follows:

"Dear NCN members,

Which is the best to consider and recommend the paint system for equipment Desing Temperture or Operating temperature. Please guide me

thank you

Kumar KV
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While selecting painting system for any piece, which is subject to internal high temperature, we have always considered the design temp. (The design temperature is always higher than operating temperature).

The reason for :
1. While testing, commissioning and during refurbishment the piece will be subject to design temperature.

2. During complete life time of piece, there are always chance that, due to any abnormalities, piece will subject to design temperature.

3. If insulation is there on painting, failure due to heat not visible readily.

4. The paint specification of Exxon, FD, Shell, Woodside etc., which I has used in past, they recommend to considering paint system based on design temp.

5. If painting is having performance guarantee for longer period and paint fails (selected based on operating temp.), the replacement and repairing will be very costly.
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While recommending a paint system we should always consider the design temp.The design temp is always higher than the operating temperature as the designer always adds the safety factor while designing any fabrication.This is applicable to all type of equipments,structures etc.
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The question is, essentially: when selecting and specifying a coating, does one regard the "coating design temperature" to be identical to the "mechanical design temperature" of the item to be coated. It should be noted that, with instrumented controls etc, the actual maximum achievable temperature during operation could be lower than the "mechanical design temperature." Therefore, if one is confident that this lower, maximum operating temperature would never be exceeded, it could be beneficial to adopt this temperature as the "coating design temperature." Another thing to bear in mind is that one could also get smart with respect to whether the mechanical design temperature has simply been set by fluid temperature allowing some fancy heat transfer calculations to arrive at the actual temperature experienced by the external surface to which the coating is to be applied. When coating something like a subsea christmas tree, this temperature differential could be several tens of degrees celsius under transient conditions and make a significant difference to the coating selection requirements.

It could also be argued that the question is: "how lucky do you feel?!!", or "how much do you trust the process engineer and the mechanical engineer?!!!"

Steve Jones
Materials & Corrosion Engineer

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