The reason you coat the underside of flush mount anodes is to remove the low resistance path to the structure. This would then result in hot spot cathodic protection, which is generally only really a problem with ICCP systems.
Steve,
If you are trying to protect Auminium, then you are going to have to go for something like magnesium as the sacrificial alloy. When you start looking at Mag as the alloy for subsea systems, you are then looking at whole areas of concern, such as hydrogren embrittlement...
I concur with the suggestions above regarding B7M studs etc. I would like to add that I have had good experience with using washer faced nuts to ensure continuity across bolted connections.
Regards
Andrew
Gator1991,
I've had a look at the paper (managed to find it by typing the title into google).
I want to calculate the temperature of a pipe that is exposed to sun light. Where do I put the heat loading into the equations?
hb (equation 5) appears to be a boltzmann type equation, but I am not...
Dennis,
What formulas have you used to perform the calculation. I would like to calculate the 'black steel' temperature of a pipe that is exposed to sunlight.
Any assistance would be appreciated.
Regards
Andrew Lindsay
Steve,
While the type of steel will influence the number of anodes, by far the largest factor will be the amount of exposed steel.
The selection of the coating system to minimise the amount of anodes is going to be the best option in most cases. This is also important when you are looking at...
TSA can be a good coating, but as with all coatings, it may be difficult to get a good coverage items with small details. Likewise, it may be difficult to coat items that are already installed with TSA. Perhaps a high build epoxy, though not ideal, would give adequate service with a minimum of...
I concur with Steve. You really need to look at the economics of the pipeline that you are wanting to build. Carbon steel can be very cost effective, especially if it is only a short life that you want to have. If the asset is expoected to have a much longer life, then it may be prudent to...
You've really got to coat the stainless steel parts if they are not going to be permanently immersed.
There are a number of issues that you will have anyway with the selection of 304 stainless steel. As 304 does not have any molybdenum, its resistance to chloride pitting is going to be much...
Pipelinermike,
Why do you need to isolate the 304 from the carbon steel?
I would have CP applied to the 304 section as well as the carbon steel, so making them continuous is a very pragmatic solution. If you are concerned about internal corrosion, then I would have to ask what is going to be...
There has been much research done into the requirements for cathodic protection of stainless steels compared to carbon steels over the past 30 years. Under most situations, it is likely to be OK to use standard carbon steel design guidelines.
Care should be taken however in selecting the CP...
