"Contact: Li Chunpeng Tel: QQ:1327077391 13930752103" in the insulating joint and ground battery is good, the facilities in the workstation should be nature potential potential, even if the zinc earthing cells missing part of current station facilities, potential may decline, but not less than -0.90VCSE. At the insulation joint, the potential is close to -5V CSE. If the potential is less than -0.90VCSE in the station, it is necessary to consider whether the short circuit of the zinc grounding battery or the poor performance of the insulation joint. At the same time, it is also necessary to analyze the possibility of short circuit through other paths. The insulating joint short circuit may cause the power output increase, if the reference electrode near the insulating joint, in order to make the reference electrode can meet the requirements of the potential, the potentiostat output will increase a lot, make it possible for the cathodic protection to increase the protection distance. If the insulation joint leakage is very serious, in the case of cathodic protection station, breakpoint potential more negative than the electric potential.
The reason is that the leakage of the grounding equipment causes the electric field near the reference electrode to be negative. When the electric field is suddenly cut off, the electric field potential returns to the normal state, that is, the forward shift, and the potential of the reference electrode is increased.
Two. Failure or leakage of insulation joint
The failure of insulation joint effect or leakage, the insulation joint in use after a period of time the quality problems, insulation parts damage or deterioration caused loss of flange insulation performance, so that the current pipeline cathodic protection is no longer limited. Or there are some electrolyte in the transmission medium to make the insulation joint conductive and lose insulation performance. According to the above description, the leakage point of the pipeline will only occur at the intersection of the protected pipe and the unprotected pipe or in the insulating joint of the protected pipeline. Therefore, in the process of inspection and maintenance, the need to find the leakage point of the pipeline with the limitations of the above. However, if the construction of the environment in the underground pipe network is very complex, for example, the protection of the pipeline and a number of other pipelines crossing the place will lead to find the leakage point of the work is very difficult. Therefore, the maintenance and overhaul of the cathodic protection system should be carried out according to the actual situation of the site to carry on the comprehensive judgment of the repeated measurement and the multi-directional inspection to find the true leakage