For the pipeline parallel to the small distance of the strong electric line, the magnetic induction coupling is the main way, in the fault state of the strong electric line and the long-term unbalanced state, the induced voltage generated by this coupling is still very dangerous, the light continuous interference causes the AC corrosion of the pipeline, and the heavy threatens the safety of the pipeline and the operator, which can not be underestimated.
In addition to maintaining an appropriate distance during the design phase, protective measures should also be taken from the pipeline itself, mainly grounding drainage, of which sacrificial anode grounding drainage is the best. The sacrificial anode cathodic protection in this state not only plays the role of grounding and draining the exchange, but also provides cathodic protection for the pipeline.
Grounding discharge is good, but after the pipeline is grounded, it will have an impact on the original cathodic protection system, so it is necessary to have a direct separation link between the pipeline and the grounding body, mainly a polar drain with embedded drains, capacitor drains and diodes. Diodes and sacrificial anodes are widely used at home and abroad for discharge protection.
With the exception of sacrificial anodes, all grounding electrode materials can be galvanized steel. According to the practice of drainage, the grounding resistance of the grounding electrode should be less than the grounding resistance of the pipeline, otherwise the effect of the discharge is not obvious. In addition, according to the theory of magnetic induction, insulating flanges should be used for isolation.