Research On Optimization Of In-service Inspection Scheme For Natural Gas Station Pipeline Based On RBI

As an important part of the natural gas pipeline system,the natural gas station process pipeline equipment serves as the hub and heart of the gas pipeline system.However,due to its complex structure and laying conditions,especially its geographical location is permanently located in densely populated areas.Compared with long-distance pipelines,once a pipeline leak or explosion accident occurs,it will cause serious economic,environmental losses and social harm.The pipeline inspection activities mainly diagnose the safety status and functional performance of the pipeline facility system by finding out the potential failure mechanism and defect level of the equipment.And through reasonable maintenance,replacement and transformation to reduce the overall risk level of the system to avoid accidents,so that it can extend the service life as long as the risk is acceptable.In-service inspection,as a supplement to statutory inspection,is becoming more and more important in pipeline safety management due to its characteristics that can be performed under non-stop conditions.However,the current regulations and standards dedicated to pipeline in-service inspection are basically blank.The formulation of in-service inspection schemes is subject to the professional level of the inspection agency and the safety input level of the pipeline operator,which cannot guarantee the safe operation of the pipeline in the station.From the perspective of risk evaluation,this paper applies the risk-based inspection(RBI)evaluation theory and combines the characteristics of natural gas station pipelines with risk assessment to establish a set of risk assessment models suitable for station pipelines.Through the example of the process pipeline in the HZ sub-transmission station,quantitative analysis is made on the possibility and consequences of the pipeline failure.Based on the RBI evaluation conclusions,adjust the inspection scope,inspection frequency,inspection method and inspection proportion of in-service inspection,and optimize the in-service inspection scheme.Avoid the problems of “under-inspection” and “over-inspection”,and promote the scientific and standardization of in-service inspection programs.