Hi,
For a short length of buried pipeline, I will use a galvanic cathodic protection system by connecting a Mg anodes. Is it necessary to place an isolating kit on the extremity of the pipe or this is not required because it is not a ICCP system.
The factors that drive the need for isolation are not generally dependent upon the type of CP system deployed. It should be noted that the finite life of a sacrificial anode system tends to lead to greater emphasis on correct isolation.
In my case, I have a piping system located in a terminal station, several small separated parts of the pipe are buried . A galvanic cathodic protection system is deisgned to protect these small portion of buried pipe.
Is it necessary to place isolating kit between the buried and aerial parts?
From what you describe above if accurate, the general answer to the question would be no. You won't loose any protection below ground because you have an above ground section, assuming that the above ground sections are not connected to anything else that goes below ground.
the attached Image resume the exact situation that i'am dealing with. I understand that normaly in this case there is no cathodic protection loss but my client is not convinced and would like a reference or a standard confirming this point.
please If someone of you has the reference that I seek
May refere to NACE RP-286, the Electrical Isolation of CP Pipelines, for the use of the CP isolation.
IMO, the galvanic anode CP system is the current flowing through the electrolyte. The electrolyte of the buried pipeline is the soil. For the aboveground pipeline section, there is no cathodic protection since the current won't flow in the air. The isolation kit on the aboveground pipe won't be needed.
The NACE standard is SP0286. Section 3 details considerations in determining whether isolation is required, or not. If the client has no specific requirements amending this standard, you could remain in stalemate. ISO 15589-1 is a little more specific.
You need to be a little more detailed with your diagram. Where does that pipe go after the flange? Does it connect to anything below ground again? If so you will need isolation, if not then no isolation. I would ask your client why he thinks there will be leakage to the other area? In the big picture what are we talking about, one isolation kit on one flange. Who cares, if they want a kit, put a kit there...