Sacrificial anode CP system 1

[midris]

Hello all,

I am designing a simple sacrificial anode cathodic protection system for a Gulf client. The protected structure is a 6", 27 m buried carbon steel in plant piping coated with liquid epoxy (pipe temperature doesn't exceed 40 degC).

I have specified Mg anodes and fink test posts with the necessary monitoring and connection cables for protection. However, the client as requested additional coupons and permanent reference electrodes to be installed.

This is where I am confused. To my knowledge, coupons and PREs are necessary for test stations on pipelines for monitoring. From an engineering point of view, is the requirement of coupons and PREs applicable for such a simple sacrificial anode system at all? Or is the initial arrangement I described above sufficient?

I have tried to search the literature at my disposal, but my understanding is based on past experience and engineering practices.

Appreciate your feedback,
Maen

 

[brimmer]

Well, if it was my project I wouldn't need the PRE's or coupons for this, but then it isn't my project. Typically you would install that equipment if you were at a suspected location of interference, and needed to monitor that / a location more frequently. With 27m of line, and the fact you are installing test posts so they can take a pipe to soil reading anytime (I assume you have a lead to the pipe at anode locations as well), I don't know why they need a PRE, especially also since the line is only 27m and they could easily hook onto a test post and get a reading anywhere on the line they wanted. The coupons, similar, however you could always use coupon data to help check levels of polarization, native potentials, etc.
Whether your initial arrrangement is sufficient, that is up to them to decide what they need. You can only go over with them why or why not the equipment is required and let them decide.

 

[LittleInch]

Gulf clients, or rather their engineering contractors managing projects, don't think, they simply apply the guidelines issued to them, sometimes a long time ago. Given the relative cost of this I wouldn't waste any more time and just include it, so long as it's not coming out of your fee. Is it required - No, Is it worth arguing about - No.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way