The Pcm Method Coating Detection Rating Parameters Selected

Pipeline delivery is the best way of the flow state to transport for long-distance the material, occupy the important position in petroleum gas industry. It is to initiate one of the invalid main factors of the pipeline to bury the corrosion of the ground steel pipeline, the oil gas pipeline especially to that those time on active service is longer, Grasp its corrosion guarantee the safety of the tubes is an important link.The pipeline is corroded and is lived in the environment to change to metal physics caused of multifactor function such as metal physics, chemistry - chemistry by the pipeline. The commonly used method of effective prevention of corrosion is to protect floor and isolate environment superficial direct. To master the buried steel pipeline coating properties of the state and its timely detection, quantification Coating situation, the degree of security classification for effective evaluation.PCM is the abbreviation of Pipeline Current Mapper, electric current method or many electric current method in charge of frequently, in charge of, it judges the antiseptic state of layer outside the pipeline by calculating the antiseptic layer of insulation once exceeded 1000km with the pipeline that this method was measured, but found in using actually, certain difference exists to the antiseptic appraisal result on floor and actual conditions in this method, can make the mistake to judge in the battle state of pipeline, increase the dangerous hidden danger or cause the waste of safeguarding. So must analyze to the reason causing the error, study the solution.Through the finding, lead to the fact the antiseptic main reason thinking the result inconsistent with real state on storey is: The pipeline and ground distribution capacity C, the pipeline is distributed inductance L and thought the result of great impact to antiseptic floor while dealin So, excavate and check and find live, according to the recommendation value (L is 0.003mH/m that the software provided, C corrodes the situation and does not accord with with the antiseptic reality on floor of the pipeline for that, The antiseptic actual conditions of layer have better result than appraisal of software.This article research results, revision electric current law appraise pipeline and ground distribution capacity C that software provide and pipeline distribute person who give a recommendation, L of inductance, in charge of frequently more, Make the appraisal result that PCM measures agree with the reality of Chongqing area of Hechuan even more, Have offered scientific basis for grasping the safe state of the pipeline accurately.