In the 1966 science fiction thriller “Fantastic Voyage” the entire crew of a submarine are shrunk and (along with the sub) injected into the artery of a scientist, so they could make repairs to his brain. Although this technology has not yet been realized, it’s possible to send equipment into underground pipes to make repairs and clean things out. This is done with technology called pipeline pigging. Let’s take a closer look at the process to see how it works and why it can be so beneficial to businesses today.
What are Pigs?
This term is not meant to be confused with the barnyard animals of the same name. When we speak of pipe pigs we are talking about equipment sent through pipes to perform a specific job. There are two schools of thought on how pigs got their names. Some say it is simply an acronym for “pipeline intervention gadget” or perhaps “pipeline inspection gauge”. However, some believe it is from the squeal noise made by pipe pigs as they pass through the interior walls of pipes. In any manner, the term pipeline pigging has stuck and this is why the process is synonymous with pigs.
There are two basic classes of pipe pigs:
* Sealing – this smooths out pipe interior to allow for better seal for sweeping liquids out of the pipe.
* Cleaning – used to remove debris from inside diameters. Can also get rid of some forms of corrosion, buildup or clogs.
Within these pig classes, you can find several types. For example:
* Polyurethane – sometimes made from solid or foam polyurethane and may have abrasive material bonded to the outer surfaces. This provides a cleaning action.
* Mandrels – tube shaped pigs allow for different uses by mounting specific hardware on the mandrels.
* Inflatable – these pigs are round or spherical shaped and are inflated with water or a mixture of water and glycol.
* Geometric – measure and record inner conditions of a pipeline.
* Smart -high tech pigs designed to inspect and detect a wide range of conditions.
* Plug pigs – these pigs are used to temporarily close off a section of pipeline while repairs or maintenance is taken care of.
Pipeline pigging can be utilized for many different jobs and one of the most important functions involves entering pipelines and pulling a polyethylene lining into the pipe. This can seal and repair in one step and can save an enormous amount of money.
