Cleaning a pipeline will increase pipeline flow efficiency by increasing the effective internal cross section area of the pipeline. Therefore the system can reach the nominal flow rate at lower pressures. There are two types of pipeline cleaning programs, mechanical and chemical.
Mechanical cleaning is referred to running mechanical pigs along the route of the pipeline in order to remove debris from the pipeline. Most debris in the pipelines are located around 5 to 7'o clock position due to gravity. Mechanical pigs are used to move and distribute debris along the route and circumference of the pipeline.
Chemical cleaning is referred to the method where diluted liquid cleaner is pushed through the pipeline using mechanical pigs. The volume of the cleaning batch should be high enough to be able to carry the solids out of the pipeline. The cleaning batch should also be able to keep the solids in suspension and not to allow them to settle before being expelled from the pipeline.