Purposes of PIGs

Pipeline inspections Gauges, or pigs, are extremely important to the pipeline industry. These are the devices that keep pipelines clean, safe, and efficient by removing debris, allowing hydrostatic testing, controlling corrosion, chemically cleaning, and locating imperfections such as dents or buckles. Without these tools, the productivity of our network of pipeline transportation would be far lower as well as more costly.
Following the construction of a pipeline, the line must be rid of any debris from the process, such as tools, welding icicles, etc. This will not be the only time a pig will be used for this purpose. Pipelines require regular servicing to maintain efficiency and control corrosion. As time goes by, it may even be necessary to use a PIG for a chemical cleaning of the pipeline. There must be no obstacles or obstructions within a pipeline. Any resistance may cause a multitude of problems.
PIGs are also used for hydrostatic testing which involves filling the pipeline with water to test the seals and pressure tolerance. This is an extremely important test regarding pipeline safety. If the pipeline as the potential to leak, it is in this phase it will be discovered. A PIG must also be used to remove the water or any testing material from the pipe.
The geometric integrity of a pipe can be studied using PIGs, as well as the level of corrosion or metal loss within a pipeline. When pipelines are used to transport more than one type of fuel, PIGs are utilized to separate those products and clean the way for the next product such as a different gasoline grade or fuel type.
As you might imagine, there are several categories of PIGs that are used for various jobs. The PIG that is used for cleaning debris is not usually the same PIG used to check for dents or imperfections. The three major categories of PIGs include conventional, geometric, and ILI (In Line Inspection) tools. ILI PIGs test for corrosion and metal loss, while geometric PIGs check for dents and blemishes. The most common, or conventional, PIGs are used for routine cleaning and testing seals.
Pigging technology has increased productivity and safety of pipeline transportation. As pipelines increase in their complexity, so more PIGs must be developed to maintain and support them. Without the ability to check run multiple materials, or clean debris without digging up pipeline, the entire industry would be simply cost ineffective, and the price of all fuel would be much more incredible. PIGs and pipeline provide the transportation we need to continue to fuel our industries, our homes, and our economy.

About the Author: Bob Jent is the CEO of Western Pipeline Corporation. Western Pipeline Corp is a successful, private independent producer of oil and natural gas.