"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 insulated junction, the potential is close to -5V CSE. If the station facilities potential is less than -0.90VCSE, it is necessary to consider whether the zinc grounding battery is short circuited, or whether the insulation joint is bad or not. At the same time, it is necessary to analyze the possibility of shorting 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 facilities causes the electric field near the reference electrode to be negative. When the power is suddenly cut off, the electric field potential is restored to the normal state, that is, the positive shift causes the potential of the reference electrode to rise and causes the potential difference between the reference electrode and the pipe to increase.
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 is some electrolyte in the transport medium, which leads to the insulation joint to lose insulation performance. For the reasons described above, the leakage point of the pipe will only occur at the junction of the protected pipe and the unprotected pipe, or at the insulated joint of the protected pipe. Therefore, in the inspection and maintenance process, you need to find the leakage point of the pipe, with the limitations of the above situation. However, if the underground pipe network in the construction environment is very complex, for example, when the pipeline is crossed with other pipelines, it will be very difficult to find the leakage point. Therefore, the maintenance of the cathodic protection system should be based on the actual situation at the scene, repeated measurements and multiple checks to make a comprehensive judgment, in order to find the true leakage point