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Frequently Asked Questions

Here are some of the most common questions we get asked about Ice Pigging and industrial pipe cleaning. You can also view a full and extensive list of FAQs here. If you have any questions which you can't find the answers to then please get in touch and we are happy to have a chat.

Frequently Asked Questions

Ice Pigging in general

  • What is Ice Pigging?
    Ice Pigging is a highly efficient technique that uses a thick ice mixture to offer high levels of cleaning in pipelines and is offered as an alternative to other pipe cleaning techniques.
  • How does Ice Pigging work?
    The ice is simply pumped into the pipe forming a plug profile (the Ice Pig) in the pipe. The nature of the ice mixture means that it is flowable and can be pumped as liquid but also takes on the properties of a solid plug within the pipe. The plug flow establishes high levels of wall shear stresses resulting in significant cleaning improvements over flushing techniques. The Ice Pig is propelled along the pipe and removed at the outlet.
  • What will Ice Pigging clean?
    The Ice Pig provides a soft, non-abrasive clean on pipe surfaces that will remove and carry any fouling and debris. It is non-abrasive and so will not remove well adhered material. As a rule of thumb, if you are able to remove the material by rubbing it with your finger then Ice Pigging is likely to be effective. If you need to use a tool to chip or scratch away the material then Ice Pigging will not be well suited to your needs.
  • How long does the Ice Pigging process take?
    The Ice Pigging process is very quick and is typically completed under 30 minutes and in some cases less than 5 minutes. Ice is pumped into the pipe and then propelled to the outlet where it is removed from the pipe. The exact timing is dependent on the injection flowrate and propelling flow rate.
  • Who uses Ice Pigging?
    Ice Pigging is used in many applications. It is used to clean drinking water pipe systems and also wastewater systems in many parts of the world. Ice Pigging is also used in industrial and manufacturing applications such as: Personal Care sector – hair and body products, creams, gels, etc; Food sector – more viscous and adhesive food products and ingredients; Pharmaceutical sector – ultra pure water cooling loops; Paints and coatings sector - base materials, polymer; Precision engineering applications – such as used in automotive and aerospace; Maritime and the Defence sector; Chemical – water cooling loops.
  • How does Ice Pigging compare to water flushing?
    Water flushing is commonly used to clean pipework. High flow velocities typically between 1.5 – 3.0 m/s are required to create the turbulent flow needed for sufficient scouring effect at the pipe surface (water flushing is not effective at low flow velocities). In many situations, especially larger diameter pipes, it is just not possible to reliably achieve this flow velocity throughout a system. Due to the solid like plug flow of the Ice Pig, Ice Pigging is able to generate high levels of cleaning even at very low flow rates so it is much more effective and also saves water, time and money.
  • How does Ice Pigging differ to conventional pigging?
    Ice Pigging differs from conventional solid pigging in that it can be used where conventional pigging cannot. The Ice Pig is capable of navigating complex pipework found in most installations including changes in pipe diameter and bends that a conventional pig would not be able to navigate. For certain applications where pipeline permits, conventional pigging may be better suited than Ice Pigging, this may include hot pipelines and product recovery applications. The two technologies can be complementary, we have experience using a conventional pig to clear the pipe for recovery followed by an Ice Pig to clean the pipe.
  • Can Ice Pigging be used for product recovery?
    Ice Pigging can be used for certain product recovery applications. The plug flow associated with the Ice Pig reduces mixing with the product compared to water flushing. Compared to product recovery using water, we are often able to achieve between 10 – 40% additional recovery. Best suited products for recovery are generally cool, viscous products. Conventional pigging is better suited for product recovery applications however this is only applicable if the pipeline can support conventional pigging.

Ice Pigging: The finer details

  • What diameters and lengths of pipework can Ice Pigging be used for?
    Ice Pigging can be used for a large range of pipe diameters and lengths found in industrial applications. Ice Pigging is generally used on pipe diameters between 25mm (1”) and 100mm (4”) from short lengths of less than 5m through to lengths of up to 500m. Using a standard Nivalis machine, Ice Pigging has been used successfully with diameters down to 5mm and up to 150mm (6”).
  • What about bends and different pipe sizes?
    The composition of the Ice Pig allows it to flow like a liquid and navigate complex pipework including bends and changes in pipe diameter. The Ice Pig will change shape when shear is imposed, for example a bend or diameter reduction, and will quickly reform and fill a pipe, in the case of a pipe expansion.
  • Will the Ice Pig go through a pump and other equipment in my line?
    The Ice Pig flows like a liquid and will flow through most process equipment including different pumps (including centrifugal, diaphragm, lobe and progressive cavity), valves and past sensors. Ice Pigging is not suitable for small flow cross-sections typically less than 5mm. This may include spray balls, nozzles and most commonly inline strainers/filters.
  • Can I use Ice Pigging to clean tanks?
    Ice Pigging can only be used to clean pipes and conduits that are enclosed and can be pressurised. Ice Pigging can be used to clean small tanks that can be pressurised and simply represent a large diameter pipe. Ice Pigging cannot be used to clean large tanks where sprayballs are typically used.
  • How much ice do I need?
    This is dependent on a number of factors for the pipeline including temperature, length, diameter, pipe material and cleaning requirements. The initial section of the Ice Pig is sacrificial, melting to cool the pipe to the temperature of the ice. At this point, the remaining ice carries out the cleaning process and removes debris/fouling from the pipe. Short, cool pipes that are easier to clean will require less ice than longer, hotter pipes that are challenging to clean. A good estimate for a minimum ice required would be 1/3 of the pipe volume. With key details about your application, Nivalis are able to provide estimates of ice requirements for your application.
  • Is the ice hygienic?
    The NIV500 is built to hygienic guidelines following best practice and suitable materials. Stainless steel 316 is used for tanks and pipework and suitable elastomers are used for hoses and seals. The NIV500 has a built in CIP (Clean-In-Place) cycle allowing automated cleaning processes of the machine to be carried out. We work closely with you to review and understand your particular hygiene requirements and can tailor CIP cycles for your requirements. For particular applications Nivalis have carried out equipment hygiene audits reviewing design principles, material selection and microbiological testing.
  • What do I do with the ice at the end of the process?
    The ice cannot be re-used and so must be disposed of or recycled for alternative use. If required, we will work with you to determine different options for storage and processing. The options are generally dependent on the additive used.
  • How long does it take to make the ice?
    The standard NIV500 generates between 1200 – 1500 kg ice per 24 hour period. The tank size is 500kg allowing typically 2 refills per day. Nivalis offer larger industrial Ice Pigging equipment solutions that are able to generate larger volumes of ice.

Ice Pigging: "what ifs" and machines

  • What happens if the Ice Pig gets stuck?
    Ice Pigging is a low risk activity, if the Ice Pig were to get stuck it will simply melt given time.
  • Will Ice Pigging mechanically damage my pipe?
    Some of our systems have been in use in factories for over 10 years. In this time we have never had a report of any physical damage to pipe systems. The Ice has a crystal structure and offers increased shear wall stress (when compared to flushing) but in short it is a “soft” clean. Ice Pigging can remove loose materials and softer material “stuck” to the pipe wall, it will not however remove material such as scale, this would require a chemical or physical clean.
  • How big is the equipment?
    The NIV500 is a compact, skid mounted system with outer dimensions of 2.8m (L) x 1.6m (W) x 2.1m (H).
  • Can I have a bespoke machine?
    The NIV500 has been designed to suit most plant applications with pipework between 1” (25mm) and 4” (100mm). Nivalis supply a range of larger industrial systems that may be better suited to different environments. Nivalis are able to offer tailored options for control, key components and connection types. Options are also available for remote mounting of condensers away from the machine.
  • Can Ice Pigging be integrated into my plant?
    The NIV500 can be used locally in isolation or can be fully integrated into a factory SCADA environment. We work closely with you to understand your requirements in order to develop and design a Functional Design Specification (FDS) to fully optimise the Ice Pigging process.
  • Where should the machine be located?
    We would generally recommend installing the NIV500 in a plant room or similar environment. Ice is then pumped to the point of application elsewhere in the site. This means that Ice Pigging can be non-intrusively used in challenging environments, for example ATEX or open food production environments, without the equipment having to fully comply to stringent regulations.
Have any more questions about pipe cleaning with Ice Pigging?

Have any more questions about pipe cleaning with Ice Pigging?

For a more extensive list of frequently asked questions please click below, or alternatively get in touch to chat through your queries with one of our helpful team members.

Find out how Ice Pigging could work for you

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