From lubricants and liquids to various other products, industrial pipes carry a variety of mediums that often leave residuals somewhere in the pipeline system. Seeing as these products often hold a high value, recovering every drop is essential to increasing yields, eliminating waste, and preventing cross-contamination risks. This is where pipeline pigging comes in to facilitate total product recovery by pushing out any residual product it comes across as it travels through the entire length of pipelines.
That said, pipeline pigs must be well-kept to serve their purpose well. Otherwise, it could lead to unpiggable pipelines – they could contaminate the leftover product they are designed to recover and possibly render it unusable or reduce its quality once it gets out of the pipe. Read on as we provide a quick overview of how to ensure your pigs are kept clean, stored properly, and ready for use at any time.
Pipeline pigs come in a variety of types to suit many different pigging applications. The most common types include foam pigs, mandrel-bodied pigs, and urethane pigs. Out of these three, urethane pigs, in particular, require the most care as urethane components are generally vulnerable to deterioration under certain conditions like UV light, heat, and humidity. Hence, proper maintenance and storage is key to guarantee their optimal performance and condition.
As mentioned, heat and humidity are a couple of the main factors that cause urethane pigs to deteriorate far more quickly. Therefore, it is recommended to store these pigs in an environment where the relative humidity is less than 60% and temperature is right around 27℃. Naturally, they should also be kept away from direct sunlight.
Should the urethane components be exposed to extremely cold temperatures, make sure to warm them up between 10℃ to 27℃ first before use to prevent them from becoming brittle. Pig parts, especially pig cups, should also be stacked to prevent their shape from deforming.
When it comes to storing pigs, the ideal storage setup would be to use a two-stand structure where the former holds the pigs while the latter supports the weight of each pig. Pigs that feature brushes, blades, springs, or urethane cups should be stored standing on end, as placing them on their sides may cause these components to get deformed with no quick means of putting them back in shape.
If a pipeline pig comes with removable plug components, they must also be properly stored. It is perfectly fine to stack urethane pig cups as long as their weight does not cause the lower cups to become distorted. This stacking method applies to urethane discs as well.
Any urethane parts that have been in storage for six months or more must be inspected for any defects in their physical properties before use. These defects typically cause urethane components to darken in colour, crumble, flake, and soften. Any parts that have these properties need to be immediately discarded.
Besides a visual examination, it is also best to check the hardness of each component by pressing a sharp tool into the urethane. The amount of give or penetration caused by the tool should be minimal. For those who want a more accurate measure of non-metallic hardness, a durometer gauge is the best solution to verify whether cup or disc components have retained a hardness level within manufacturing specs. If the reading states they are no longer within the threshold, they must be discarded.
Pigs need to be cleaned as soon as possible once they come out of the pipe. If a pig gets heavily packed with paraffin due to the medium, most of it can be easily removed by scraping down the pig immediately. When doing so, don’t forget to submerge the scrapper into heated water (ideally reaching 70℃) first for no more than an hour. Once most of the paraffin is off, you can use a high-pressure water jet to remove any remaining residue.
Alternatively, you can also use steam cleaning for pigs but only for the spring assemblies and metal parts they may have. Set the maximum water temperature to 85℃ and steam clean for up to 30 minutes only since going any hotter or longer may damage the exposed urethane. Lastly, you can use solvents like kerosene or diesel fuel to clean your pigs, as urethane components will be fine when wiped with or immersed in either.
Industries that rely on pipe pigging should stay on top of their pipeline maintenance procedures and their pigging equipment. By observing proper cleaning and storage practices, they can ensure that the cleaning systems keeping their pipelines running efficiently will always perform as expected.
Apart from good upkeep and storage, choosing high-quality pigs and pigging equipment like the ones we offer here at Pharmchem Engineering is another factor that contributes to reliable pipe pigging systems. As the leading brand for industrial engineering parts, you can always count on our tried and tested hoses, dry disconnect couplings, expansion joints, and more to meet your application requirements and exceed expectations.
Discuss your project with us today, and we’ll help you find the best engineering solutions that fit the bill. Otherwise, we can also provide something custom-made to your exact needs should we not have it in stock.