Influence of Stray Current and Electric Drainage Technology

The stray current is also called missed current which is a kind of current flowing outside the stipulated loop. The metallic corrosion generated by the stray current, due to its features of fast corrosive speed, strong strength and concentration on the local position, becomes the  harmful metallic electrochemistry corrosion. 

1) Once the stray current flows to the underground metal and then out from the underground metal into the ground or water, the part where the current flows out will be seriously corroded.

2) 1A corrosive current happens in the pipeline. About 9KG of the pipeline erodes every year.

3) Especially for the underground metallic pipeline with the anti-corrosion coating in a long distance, the stray current flowing to the pipeline is large and concentrated on the local part. It flows out from the defect point of anti-corrosion coating and the local part takes the serious corrosion. 

According to the source, the stray current can classified into D.C stray current, A.C stray current and earth magnetic sense stray current. According to the point whether the current amplitude and flow path change over time, it can classified into the statistic stray current and dynamic stray current. 

The stray current is influenced by many factors. It is quite difficult to directly make the measurement. At present, the measuring technologies commonly used include the pipe-to-soil potential, soil potential gradient test, current probe test and detection of intelligent stray current detector. 

External Anti-corrosion Leaking Point Orientation

Measurement of Soil Resistance

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Record of Stray Current Detection

Forced Electrical Drainage of Deep Well Anode Ground Bed

The deep well anode ground bed has the following features: small covering area, small ground resistance and never generating the ground potential gradient mutation. It is applied to the long-distance pipeline A.C interference protection project, which has achieved quite good effect. Because the anode ground bed is under the ground, it needs small covering area. So, it can save the cost of temporary land acquisition. The anode is located in the region with quite low soil resistance. It has quite good drainage effect. 

Application of New Polarity Electric Drainager  

It can well eliminate the influence of the over voltage or over current generated by D.C and A.C stray current to the pipeline cathodic protection and prevent the exacerbation of the corrosion of the pipeline due to the electromagnetic interference so as to effectively protect the pipe equipment. 

◆ A.C/ D.C interference product integrating with the A.C/D.C drainage, surge protective device and spark gap has quite high AC failure current breaking capacity and low voltage protection level.

◆ It has the function of protecting the pipeline from the A.C and D.C interference and corrosion.

◆ It is equipped with the function of prevent the large current release while the direct lightning hits the pipeline.

◆ It applies the seal structure. The arc will not be easy to escape. It has the explosion-proof effect.