We know that just running a pig through a pipe and calling it "clean" just doesn't cut it! When you run an inline inspection tool through the system, you expect your pig to reduce or eliminate lift off, allowing a more accurate result from magnetic flux leakage inspection. One also expects the pipeline's efficiency to be greatly improved after thorough pigging.
To achieve the most thorough cleaning and ensure the system is in peak condition, it is imperative to engage the services of a qualified pipeline-cleaning service company such as Professional Piping Services, Inc.
Mechanical pigs started out as pretty rustic devices thrown together from bailed fabric and barbed wire, and have matured into today's polyurethane marvels. Each manufacturer will choose their own types and ratios of pre-polymers and curatives that combine to create a castable product with various foam densities, abrasion resistance, elasticities and other variables that impact effectiveness and durability in given applications.
What kinds of Pigs are available?
The types of pigs, and the functions they provide, are as diverse as the piping industry itself. In general, pigs are sized with a 1.5 length to diameter ratio. This explains the importance of keeping your bends, or ells, to a minimum of 1.5D if you want them to be easily piggable. It is possible to use tandem pigs to navigate the tighter ells, if retrofitting an existing system is not an option.
In addition to Polly Foam or Urethane pigs, steel mandrel discs and cups can be used for certain applications.
The Polly foam types are generally made to match the Outside Diameter of the pipe. These pigs can navigate tight radius ells, miter bends, "T" intersections, multi-diameter piping systems and reduced port valves. Polly Foam Pigs can incorporate wire strip brushes for more thorough cleaning, a nose pull rope to assist in propulsion, transmitter cavity, making it a smart pig, and other accessories as may be required.
Unibody, single-body cast-polyurethane pigs, are designed to more aggressively clean than other Polly Pigs. They are commonly used to remove liquid from wet gas systems and liquid pipelines, reducing paraffin buildup in oil transport systems, clearing multi-use pipes between products and as a pre-clean between the construction process and initial use.
When using an ILI, it may be required to provide data before the ILI tool is introduced into the system. This data can be captured using a caliper pig. The Caliper pig and identify welds, taps, valve, Bends, wall thickness and more.
A smart pig was mentioned before, but let me explain. A smart pig (my client calls it Sherlock Pig. I don't know if that's a brand name, or just what they call it.) helps re-map the entire system. A pipeline's construction doesn't always go to plan, so the original documents may not provide an accurate picture of the finished system. The smart pig can identify lost branches and valves, changes in diameter, and can even specify depth in earth or water.
There is much more to this topic than the author can address at this time. When you need help with your piping system, don't trust me, trust my client, Professional Piping Services, Inc.
The author of this article has referenced source(s) from the internet including an article from pgjonline.com. The client for whom this is written is much more knowledgeable about the topic than the author. Any inaccuracy or error should be attributed to the author, and not the Poly Pig Specialists themselves, or the referenced article(s).