Which type of flexible conduit is best?

• 11th October 2021

Conduits provide an inherent mechanical barrier for vulnerable electrical cables, wiring, and fibre optics. Without an effective form of cable management, they will be exposed to external elements and are at serious risk of wear and tear.

Flexible, rigid, metallic, non-metallic, split, solid – they are all types of conduit that come with their own unique features and benefits for specific installations.

As a specialist supplier of metallic and plastic conduit systems, we’re confident that you’ll find the products you need to protect and contain electrical cables here at Flex-It.

But the question is – which is best for your application?

Here we look at the different types of flexible conduits, including their pros and cons, to help you make an informed decision.

Metallic vs. non-metallic flexible conduits

Flexible conduits can be made from composite metal or plastic.

Both types are designed to provide the same level of protection as rigid conduits and are typically used in installations where flexibility is required for connections.

They come in handy where electrical cables may be subjected to shock and vibration, and provide easy routing of cables around obstructions.

Pros of metallic conduits

Flexible metal conduits (FMC) have a spiral construction that makes them easier to snake through walls and other structures.

They are super simple to install and can be twisted and turned without the need for any additional hardware or specialist tools. Ideal for areas where rigid conduits prove difficult to install.

Suitable for dry indoor locations, flexible metal conduits protect electrical wiring in commercial and industrial buildings and are a brilliant choice for vibrating machines, i.e. heating and cooling units.

Liquid-tight metallic conduits (LFMC) – a special type of FMC – have a waterproof plastic coating which makes them perfect for outdoor use.

Cons of metallic conduits

A flexible metal conduit is designed for use where flexibility is required due to movement or vibration, or where bends and offsets make the installation process tricky. It’s not intended for use in wet locations unless conductors are specially approved for the conditions.

Besides short runs, for wiring outdoor air conditioning equipment and wiring under kitchen sinks, the use of LFMC in residence is pretty limited.

Metal conduits, particularly steel braided, are more expensive than other types of conduit systems.

Pros of non-metallic conduits

Non-metallic conduits are typically less expensive than other options and are made from PVC (polyvinyl chloride), PA6, or polypropylene.

PVC is a high-strength thermoplastic that’s extremely durable, resistant to weathering and chemicals, and doesn’t conduct electricity. It protects cables against punctures, cuts, and other damages, preventing electrical accidents further down the line.

PA6 is a specially modified polyamide that has countless advantages over steel braided conduit, including:

• ease of cutting and installation
• reduced installation time and costs
• no sharp edges, ensuring safer handling
• a high degree of mechanical protection
• suitable for static and dynamic applications

Polypropylene flexible conduits are non-corrosive and offer an economical solution for cable assemblies, underfloor wiring, and general cable tidying.

Available split or solid, these corrugated conduits are lightweight and easy to install. They can withstand any toxic materials that pass through the cables, making them perfect for harsh environments. The split variety also makes it easy for you to insert and replace cables should they become damaged.

Cons of non-metallic conduits

One of the most notable disadvantages of PVC conduits, when compared to metallic flexible conduits, is their physical weakness.

PVC can break when exposed to physical stress, and it needs additional support when installed in longer cable runs to prevent sagging.

Though non-metallic conduits are an economical choice – and used to run cables below the ground or in an area exposed to dust and water – metal conduits are best suited to applications in the basement or garage. These can offer protection from rats, mice, and other impacts.

Which will you choose?

Unsure which flexible conduits are best for you? Need an expert opinion? Fear not, the team here at Flex-It is always on hand to assist and will be more than happy to guide and advise you.

Of course, the type of conduit you need will depend on the installation and environment where cables will be routed. However, we will take into consideration your specific requirements and budget before recommending a suitable size and type.

If you would like to learn more about the flexible conduits we stock, don’t hesitate to get in touch. Either call 01530 812 195 or email sales@flex-it.co.uk, and we’ll get back to you as soon as possible.

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