Buildup in a pipeline can cause transmittal slows or plugging of the pipeline. Flaws and cracks can be disastrous as well. Pipeline pigging ensures that the line is running smoothly. It is a form of flow assurance for gas or oil pipelines or flow lines. A pipeline pig is a maintenance tool. It is introduced in the line through a pig trap. This includes a receiver and a launcher. The pig is forced through by product flow without interrupting it. It can also be towed by another device or cable. Pigs are general spherical or cylindrical. They sweep the line by scraping the sides of the pipeline and push the debris ahead. There are a number of functions that the pig can perform as it travels along the pipeline. It can clean the line and inspect the interior.
There are two main hypotheses for why the procedure is called pipeline pigging. One theory is that the word pig stands for Pipeline Intervention Gadget. The other theory is that a leather-bound pig was being sent through the pipeline. The leather squeaked against the sides of the pipe while it passed through the pipeline which made it sound like a squealing pig.
When selecting the proper pig for a pipeline, engineers must consider a number of criteria. It is important to define what tasks the pig will be performing. Operating conditions and size are important as well. Pipeline layout is integral to consider as well when selecting a pig.
There is not a set schedule for pigging a pipeline because every pipeline is different. The amount of wear and tear and quantity of debris collected in a pipeline can increase the frequency of pigging. Pipeline pigging is utilized during all phases of the life of a pipeline today.
Types Of Pipeline Pigs
The development of technologies have evolved the purposes of pipeline pigging. In the past, they were utilized to clear the line. Unwanted materials are removed from the pipeline by utility pigs. This includes removing wax from the line. They are inserted into the pipeline. The pipeline from the inside can be examined by inline inspection pigs. Specialty pigs are used to plug the line or isolate specific areas of the line. Gel pigs are a liquid chemical pigging system.
Utility pigs are used to clean the pipeline of debris or seal the line. This is similar to how you clean a plumbing line. Debris can accumulate during construction. The pipeline is pigged before production commences. Debris can build upon the pipeline. The utility pig is used to scrape it away. Sealing pigs are used to remove liquids from the pipeline. They also serve as an interface between to different products within a pipeline. The various types of utility pigs include, spherical pigs, solid cast pigs, foam pigs, and mandrel pigs.