Separating the Facts from Fiction in Process 'Pigging' Technology

Product recovery (often called ‘Pigging’) is a long-established technology that delivers a wide range of benefits to companies that process liquids.

Despite these benefits, which include increasing yields, reducing waste, improving environmental sustainability and making business processes more efficient, there are still myths and misconceptions surrounding pigging technology. And it’s about time they were busted!

Here’s a selection of the most common myths about pigging systems:

Pigging Myth Number 5
“Pigs Contain Solid Magnets, Which Can Break or Shatter”

One of the most popular concerns associated with pigging is that the solid projectile or plug (the ‘Pig’) contains solid magnets. Pigs containing any solid metal within them can cause problems, because broken or shattered magnets, as well as ripped or torn fins, can damage equipment and cause product contamination and other issues.

However, this is not true for all process pigs. In fact, some contain a flexible magnetized silicon core with no solid magnets. At the same time, some pigs don’t contain fins or complex external profiles. Instead, they are simpler in shape, which makes them more robust, reliable and efficient.

Pigging Myth Number 4
“Pigs Get Stuck in the Pipes”

Another common myth regarding pigging technology is that the pig (or pigs) can get stuck and stall in the pipelines.
However, this isn’t true. In fact, Pigs rarely get stuck.

Peter Elgar, Group Marketing Manager of HPS explains, “As long as you haven’t overused the pig and exceeded the recommended usage, then there’s always a logical reason why the pig doesn’t reach its destination. It could be anything from insufficient propellent pressure, pipeline faults, leakage from a pipe connection or even something as simple as a closed valve which prevents the pig from going any further. Either way, you can always get the pig to its destination".

Pigging Myth Number 3
“Pigs Can Only Travel in One Direction and Are Unable To Navigate Bends”

Another myth that’s incorrect. The design of the HPS process pig allows it to travel in both directions (i.e. they are fully bi-directional). Also, the flexible nature of the HPS pigs allows them to comfortably navigate 1.5 D – 90° bends.

Pigging Myth Number 2
“You Need to Pig a System Several Times"

Although this depends on a number of factors including the type of system and application, generally HPS pigging solutions can achieve high product recovery rates of up to 99.5% in a single run. Therefore, there is usually no need to pig the system several times, as a single run is typically sufficient.

Pigging Myth Number 1
“Pigging Systems Don’t Work”

This is another unfortunate myth that is certainly not true.

As a matter of fact, a correctly designed and implemented pigging solution will work. They are extremely effective, proven, reliable, safe and can be implemented quickly and efficiently into existing or new plants with minimal downtime.