Key Components of a Pigging System

What Does a Product Recovery System Do?

Liquid product recovery systems can be found in operation throughout the world at plants and factories that process liquids. These include food, beverages, cosmetics, personal care, pet food, homecare, paint processing plus more.

Also referred to as ‘pigging’, the main purpose of the technology is to recover or remove residual liquid remaining in the pipelines of process systems. This is achieved using a specialist projectile (the ‘pig’). Because the pig recovers so much product from the pipeline, it reduces costs, CIP cycles, cleaning chemicals, and the amount of effluent sent to waste.

The pipeline pig is an integral part of a pigging system. However, it’s not the only important part. From single-pig pigging systems to double-pig and tank-drop off systems, pigging systems are made up of a variety of different parts and components. Each of these components plays an important role in the running, effectiveness and safety of a pigging system.

What are the Key Components and Parts of a Pigging System?

Because virtually every processing plant is different, so is nearly every pigging system. Therefore, HPS pigging systems tend to be bespoke and designed around the precise needs, aims and objectives of each customer.

Nevertheless, despite the bespoke nature of pigging, the key components of the technology are typically the same. In most cases, they include the:

High-Performance Process Pig Fundamental Component of Pigging System

The most important component of a pigging system is the hygienic process pig. This is a specialist projectile that has a diameter slightly larger than the pipeline that it is pigging. Typically, in hygienic and sanitary applications, pigs range from 1 inch to 8 inches in diameter.

The pig is propelled through the pipeline, by either water, other liquid, compressed air, carbon dioxide or nitrogen gas or the next product being processed. As the pig makes its way through the pipeline, it recovers or removes the remaining product.

To reap the optimal benefits of a pigging system, its important that the pipeline pig used is well-designed, efficient, and offers high-performance, reliability, and quality.

HPS Pig – Recovery Efficiency of Up to 99.5%

The performance of the HPS magnetic pig is extremely high, as it will typically recover up to 99.5% of product from the pipeline (in some cases, this figure is more!). The HPS pig’s robust, cylindrical style design allows it to maintain full body contact with the pipeline walls, which maximises efficiency and eliminates issues such as product bypass.

The HPS pig also differs from other pipeline pigs in the process pigging industry as it contains a flexible magnetised silicone core. Not only does this unique feature enable the pig to be accurately and reliably detected in the pipeline (using HPS non-intrusive pig detectors), but it massively increases safety and minimises contamination risks.

Pigs that contain solid magnets pose a major risk in hygienic or sanitary applications. If the pig gets worn or damaged, the solid magnet, or parts of it, can break apart from the pig and contaminate the line or product resulting in costly downtime.

Here’s even more information about HPS magnetic pigs and our guide to choosing the right pipeline pig for process, hygienic and sanitary applications.

HPS pipeline hygienic (sanitary) pig

The HPS Process Pig

Pig Detection System – Non-Intrusive, Accurate Pig Detection

The pig detection system (or pig detector) is another important part of a pigging system. You may have also seen or heard the pig detector referred to as a pig signaller or pig sensor.

The main purpose of a pig detector is to reliably determine the presence and location of the pig. Typically, pig detectors can be found near the launch and receive stations and are mounted externally on the pipe being pigged. HPS pig detectors use magnetic detection, which makes them non-intrusive as well as easy to set up and remove.

HPS Pig Detectors Enable Semi or Full Automation

HPS pig detectors work in the way that when the pig passes the detector, the detector picks up the pigs magnetic field. As the pig travels past, visual indication (an LED on the detector flashes red) alerts operators to the pig’s presence.

As well as determining the presence of the pig, HPS pig detectors provide a signal that PLC and control software can use to enable semi or full automation of your pigging or product recovery process.

Watch the space, as HPS have a new pig detector in development, which will be available in 2019!

HPS PIG DETECTOR

The HPS Magnetic Pig Detector

Automatic Pigging Control Software Increases Process Speed, Efficiency and Productivity

Most pigging systems are either semi or fully automated, therefore another fundamental component of a pigging system is the control software. The control software, controlled by PLCs with either HMI or SCADA systems, can either be supplied as a standalone or can be integrated into your existing setup.

The purpose of the control system (as the name indicates) is to control and run the pigging system, and importantly, send the pig through the pipe to clean it and recover product.

The benefits of including automatic pigging control software in your pigging system include increasing process speed as well as ensuring high levels of safety, operational efficiency, and reliability.

Automatic Pigging Systems

HMI Pigging Control

Pig Launchers and Pig Receivers Fundamental Components of Any Pigging System

The pig launchers and pig receivers are a fundamental part of any pigging system. Also known as pig stations, their main purpose is to introduce the pig safely into the product line, propel the pig to and from source and destination, and store the pig when it’s not in use.

Pig launchers and receivers are nearly always bespoke and comprise of specialist valves which control the pig propellent and the pig. While the pig launch station introduces the pig into the line, the pig receivers send the pig back again once it has reached its destination.

pig receive station

Pigging Receive Station

Pig Housing Stores the Pig When Not in Use

When the pig is not in use, it resides in a special housing usually at the launch station (and sometimes a receive station).

The HPS pig housing is designed so it is slightly larger than the pig. This enables the pig to be easily and safely removed for inspection and maintenance. At the same time, its design ensures there’s enough room for water and cleaning fluids to flow around the pig for cleaning and CIP.

HPS pig launch stations also allow operators to access the pig during normal processing operations. So, if the pig does need replacing, this can be done easily without any disruption and downtime to production.

Pig receive stations don’t usually contain a pig housing. That’s because in most cases they don’t store the pig. However, occasionally some pigging systems such as multi-destination and double-pig pigging systems, have been known to include housings in the launch and receive stations.

pigging system launch station

Pigging system launch station

System Valves, Supports/bracing and Fittings – Important Parts of Pigging Systems

Other important components of a pigging system are the valves as well as the supports and fittings. Although the types of valves can vary from solution to solution, they all share a similar purpose. This being to enable smooth and efficient routing of the product and pig.

Certain valves are used as on/off valves whereas other valves can be used to divert the flow of the pig and product through the process pipelines. Types of valves include the 3-way Solid Seat Ball Valve (SSBV), 2 and 3-way Inflatable Seal Ball Valve (ISBV), Butterfly valves and 2-way ball valves.

Valves are chosen based on the pipeline routing as well as the hygienic requirements of the customer for the product.

Piggable Diverter Valves

Solid Seat Ball Valve (SSBV)

Let’s Not Forget the Pigging System Pipework!

And of course, a fundamental part of any pigging system is the pipework. Without any pipework, pigging wouldn’t be possible.

HPS work with a wide variety of pipe codes and standards, including ASME, ANSI, ASTM, AGA, API, AWWA, BS, ISO, DIN plus more.

Importantly, the pipework needs to be in good condition and free from dents and damage along the length of the pipe you are intending to pig.

Here’s even more about the pipeline infrastructure for pigging systems.

pigging system pipework

Pigging System Pipework

Thanks for Reading

We hope you’ve found this blog useful. If you have any questions, then please don’t hesitate to get in touch.

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