Specifying cable protection for pharmaceutical applications
05 October 2020
Pharmaceutical applications demand stringent hygiene and contamination control to avoid downtime and maintain quality standards across the entire supply chain. Processors are investing heavily in automation solutions and equipment to deliver these objectives, resulting in an increasing reliance on the continuity of power and data cabling.
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As a result, it is vital that essential cabling is protected appropriately with flexible conduit solutions that perform safely and adhere to stringent hygiene and safety requirements.
Alex Smith, Flexicon Technical Director discusses the areas to consider when specifying flexible conduit systems to protect critical power and data cabling from multiple and diverse hazards in hygienic applications. This will include practical advice on the areas to consider when specifying a conduit system, including the choice between non-metallic or metallic systems.
Why flexible conduit?
Flexible conduit provides an inherent mechanical barrier for cabling, overcoming traditional installation challenges while delivering unrivalled product performance too. To understand the importance of selecting the appropriate conduit specification for the application(s) in question, it is necessary to first establish the reasons why quality standards are deemed so critical in the industry – and how the appropriate equipment can help to mitigate against the risks of downtime, product recalls and the likelihood of expensive financial penalties.
EU legal framework
The production and distribution of pharmaceutical and medicinal products for human consumption is governed by regulations designed to guarantee high standards of quality and safety.
Similar to the food processing industry, where there are strict controls around hygiene standards to prevent the risk of contamination, the pharmaceutical industry’s key aim must be to safeguard public health during the manufacture of products.
As a result, there are a number of common, potential hazards to be managed effectively. These include biological agents, such as pathogens or micro-organisms, chemical agents, including cleaning and disinfection products and any foreign bodies that may come in to contact with the pharmaceutical product during manufacture.
Robust hygiene considerations
Operators should specify systems that prioritise hygienic design to stop bacteria from spreading, taking the following nine areas into account:
1. Corrosion resistance
Materials can often fail due to corrosion, leading to serious issues with equipment. From pitting corrosion to crevice corrosion and deposit attack, its impact should not be underestimated. For this reason, stainless steel is often used in the industry due to its high levels of corrosion resistance. However, this resistance can be compromised when exposed to chlorides, which are prevalent in supply waters and detergents. Furthermore, the grade of stainless steel will also dictate its effectiveness, with Grade 316 often specified where there is risk of pitting and crevice corrosion.
Elastomeric materials are commonly used for seals and gaskets, but performance properties can vary depending on the compound mix. Chemicals present in cleaning agents and processing fluids can also determine the performance of elastomeric materials and their resistance to corrosion.
High temperatures can cause materials to degrade faster and significantly reduce service lifespan, while low temperatures can make materials brittle and even potentially lead to cracking. Elastomeric materials, in particular, can expand or contract depending on the ambient temperature, requiring special consideration if used in conjunction with metallic products.
Processing plants often need to move goods via lifting equipment, manual handling or other machinery, and the material composition needs to be able to withstand impact – to avoid piercing protective coatings, deforming profiles and or crushing cables.
4. Wear and abrasion
For equipment that might be moving or contain moving components, abrasion resistance is key to limit any damage to protective coatings or the potential compromise of ingress protection.
5. Surface finish
Rougher surfaces are generally more complex to clean and there is greater opportunity for matter to stick. The processing method used to achieve a material’s surface finish – whether it’s turning, milling, mechanical polishing or casting – can also affect the rate that contaminants build up.
Materials can suffer symptoms of fatigue, such as cracking and brittleness, if constantly moving. This needs to be considered carefully at the specification stage.
7. Chemical composition
Materials and coatings need to be durable, resist damage and abrasion, and be easy to clean.
While manufacturers typically publish data demonstrating a material’s relative performance against attack from one chemical, should a combination or greater concentration of chemicals occur, then this needs to be taken into account. The impact elevated temperatures can have on chemical composition is another important consideration.
For plastic materials, the colour blue is generally used to offer increased visibility, in order to identify foreign bodies that might be present.
‘Soil’ defines any material that is out of place, which might occur during cleaning. Whether a material is cleaned manually or soaked, spray-washed or steam cleaned, the opportunity for soil and how this will be managed needs to be considered.
The benefits of flexible conduit for increased hygiene standards
Flexible conduit used for cable protection allows efficient cleaning while providing system integrity in hygienic applications. Cleaning regimes are an important and essential process to ensure the safety and quality of a company’s output and goods. However, while machinery is being cleaned or maintained, production to service output is zero.
With this in mind, it is clear that cleaning time should be swift and effective, alongside ease of installation and maintenance, without compromising product safety and quality. Manufacturers offer a wide range of solutions to facilitate this, ensuring critical power and data cabling in hygienic environments are well protected. The benefits offered by using flexible conduit solutions include:
Speed of installation
By grouping cables into one hygienic and flexible conduit, there is only one system to route and fix, as opposed to multiple cables with alternative systems. This means installation time for flexible conduits is reduced against other options, with less holes to drill, fewer fittings to terminate and minimal enclosure entry points to maintain. Furthermore, a flexible conduit system provides easier access for cleaning and maintenance.
Any manufacturer will want to futureproof equipment as much as feasibly possible, to cope with changing demands and offer a competitive advantage over time. A flexible conduit system can be replaced or added to with minimal effort and disruption. Should more circuits need to be installed in the future, this can be achieved using the existing conduit system – as long as the space is available inside – rather than having to drill out new entry points in the enclosure. This also eliminates having to purchase new hygienic cable glands or create new fixing and routing for new cabling, or even having to purchase larger enclosures.
Fixing and routing
Alex Smith, Flexicon Technical Director
A flexible conduit system is not only easier to clean, but easier to fix and route onto a machine too. The alternative is numerous cables routed individually or bundled together. The bundling of exposed cables must be avoided to allow sufficient space for cleaning. Multiple cables mean multiple surfaces to clean and maintain, posing a serious risk.
As well as ensuring hygiene standards are maintained, explosion protection is also a key concern; particularly resulting from the presence of airborne fine dust particles from ingredients and chemicals used during manufacture. Users should ensure that electrical cables are protected adequately and terminated using appropriately rated hazardous area fittings such as Ex e or Ex d rated fittings.
In addition to the specific installation benefits of a flexible conduit system, it is also important for operators to select the appropriate material for the application, typically selecting between hygienic non-metallic and metallic systems.
With no exposed metallic content, non-metallic conduits do not rust or corrode thus maintaining performance and appearance over time. They are often quicker to install than metallic options as they are easier and faster to cut. Non-metallic fittings will typically be one piece and simply push on and twist to secure.
The conduit and fitting interface must be able to withstand tensile stress caused by the weight of the cabling, or dynamic loads caused by movement or vibration.
Metallic and composite systems
Metallic systems are ideal for applications that require a very high compression or pull-off strength, or where there is the need to protect cables from exposure in hazardous environments. These systems typically have a higher level of crush resistance, high mechanical strength and can provide excellent EMC screening properties.
Hygienic flexible conduit systems can offer numerous benefits for pharmaceutical installations to protect critical power and data cabling. Time saving, simplicity of installation and future proofing can all be achieved by using hygienic conduits to group and protect cables from end to end.
With multiple and diverse hazards, cabling needs protection to maintain system and process functionality. The correct specification of flexible conduit can help save time and money while meeting the stringent hygiene demands of the pharmaceutical industry.
About the author:
Alex Smith is Technical Director at Flexicon. Having graduated from the University of Warwick with an MEng in Mechanical Engineering, Alex joined Flexicon initially as Development Engineer, before becoming Engineering Manager and latterly, Technical Director. Holding an MBA, he has responsibility for new product development, specification and quality, with a passion for integrating digital technology and software to drive continuous improvement.
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