protection failure

[psozot]

we have impressed current cathodic protection system on our lines. yesterday pipeline ( 8" dia under ground) got leaked. after checking CP system it was revealed that no current was flowing from transformer rectifier (TR).we turn it off, disconnect the cable and then turn TR ON again. now vary the resistance gradually, the voltmeter shows deflection as the resistance varied. pls help how to restore the system and what was the cause. i ruled out cable damage during excavation as the excavation was done 5 km away from plant

 

[EdStainless]

When was the last survey for this section of pipe? You take current measurements, open the curcuit and take voltage and current readings, re-close and check again. Do you do this regularly?
It could be many things, I would first look at interfearnace from other structures.

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Corrosion never sleeps, but it can be managed.

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