Maintaining clean pipelines in liquid process industries can be of the utmost importance, especially if the product being manufactured must adhere to strict hygienic (sanitary) standards. Process industries may also clean their pipelines to prevent cross-contamination with the next product.

For example, paint manufacturers producing a different shade of paint will often clean the lines between batches to prevent colour-mixing.

Sanitary and hygienic pipeline cleaning is often a time-consuming and wasteful process. Not only is product wasted during the first stage of cleaning procedures, but water and chemicals can be used in large quantities to ensure cleanliness. Additionally, companies that use hot water will have to heat the water, which will use large amounts of energy.

Many companies will benefit from reducing the amount of time spent on cleaning procedures and reducing the amount of waste product they create.

This is where liquid product recovery technology, also known as pigging, comes in.


There are several ways that manufacturers can perform pipeline cleaning procedures. Pipeline cleaning can differ based on the specific industry or the product being produced, but a common method of cleaning is flushing.

While hygienic and sanitary pipeline product recovery itself does not clean pipelines, it can reduce the length of time that CIP procedures take by removing large quantities of product from the line.


Flushing is a wasteful way of cleaning pipelines, particularly those of significant length and diameter. Flushing works by sending water through the pipeline, followed by large quantities of CIP chemicals. A chemical flush may be followed by another water flush to remove traces of the chemicals before introducing the next batch of product.

The quantities of water and chemicals that are used in flushing are often unmeasured, with companies feeling it better to err on the side of caution and over-flush to guarantee cleanliness.

Additionally, water and chemical flushes mix with any remaining product in the line (which can be a large amount) and contaminate it. Companies can lose hundreds, or even thousands, of pounds (or dollars or Euros) in raw materials and product every time they perform a changeover.


Rather than flushing product, water and chemicals down the drain, companies should consider pigging. Saving product and reducing effluent creation are just two benefits of pigging.

Pigging for the liquid process industry is a technology that sends a specialist projectile through a pipeline, pushing the remaining product to the end of the line. It can then be sent on for further processing or packaging, as it remains in a usable condition.

Pigging is a quick process that can help companies speed up their cleaning processes. Though the exact length of time that a pigging run takes will vary according to product viscosity, pipeline length, and other factors, changeovers will take less time than traditional CIP procedures.

HPS liquid product recovery pigging system

The removal of up to 99.5% of product from full pipelines means that there is less product to be removed during CIP procedures. This speeds up the rest of the cleaning process, allowing more time for production and reducing the amount of water and chemicals required for cleaning.

By removing most of the product from the pipeline using a projectile, less water is needed to move the product along. Chemical usage is also decreased for a similar reason.

It is worth noting that though the amount of water and chemicals required are likely to decrease, the contact time requirements may still stay the same – we will be able to give you further advice on how pigging impacts cleaning and changeovers when you get in touch.

Depending on your company’s needs and product(s), it may be beneficial to have an HPS dual-pig pigging system put in place, which will allow you to send a measured amount of cleaning fluid, be it water, chemical, or solvent, through the line, cleaning as it goes.

Our process system experts will be able to help you choose which pigging system or piggable liquid transfer system is best for your process.

Types of Pigging System


HPS have over 28 years of experience in designing and commissioning pigging systems for the liquid process industry.

We’ve developed a range of pipeline pigging products that are designed to optimise your liquid product recovery efforts, including a hygienic (sanitary) pig that has a full-body interference fit and a recovery rate of up to 99.5%.

Our systems are designed according to each client’s individual needs, and with HPS there’s no such thing as an off-the-shelf system. If you can pump it, we can pig it.

Contact an Expert