Flexible Conduits: Types and Uses
Electrical conduit is the tubing used to route cables and wires in electrical installations. It comes in different types of materials and shields the conductors inside from adverse environmental factors. Conduits are used in residential, commercial and industrial wiring applications, and come in two basic types – flexible and rigid. Rigid conduit has traditionally been regarded as the more heavy-duty option, but with advancements in materials and design, flexible conduits are steadily taking over.
Types of Electrical Conduit
Different types of rigid and flexible conduits, in different materials and diameters, are used. Let’s take a closer look at what’s available:
- EMT or Electrical Metal Tubing, also known as thin-wall conduits, are lightweight conduits made of thin metallic walls. They are easily shaped and bent to fit around irregular areas like piping. EMT consists of galvanised steel or coated aluminium, making it rust, heat and moisture resistant, so is often seen outdoors in both residential and commercial buildings.
- RMC or Rigid Metallic Conduits are made of wider, thicker metal tubes and are typically used in heavy-duty applications, like high-voltage industrial wiring. They are difficult to form, but the thickness provides better protection for cabling and wires than EMT.
- IMC or Intermediate Metallic Conduits are rigid conduits used as a cost-effective substitute for RMC. They can carry the same amount of wiring but are made of thinner steel walls.
- Rigid PVC conduit is one of the cheapest conduit types and is used in either underground cable routing, often in thicker orange variants, or as a coated grey conduit for indoor and above-ground uses. It is easily formed to suit the installation type.
These are types of rigid conduits that are mainly used in industrial settings for their perceived strength and longevity. However, for residential and commercial uses, and where flexibility is necessary and negotiating tight areas often is the case, flexible conduits are the better choice. Read on to see why.
Types of Flexible Conduit
- FMC or Flexible Metal Conduit consists of interlocking metallic coils, generally galvanised steel or coated aluminium, so it’s easy to bend and install in new or existing electrical installations. Variations using different coating materials allow FMC to be used in situations where added protection is needed. PVC and nylon, for instance, make flexible metal conduits suitable for high-temperature settings and where there is exposure to hazardous materials. Nickel or brass fittings connect the ends to other pieces.
- ENT or Electrical Non-metallic Tubing is a type of flexible conduit made of different grades of corrugated nylon. Thicker types are worthy and inexpensive substitutes for EMT in industrial applications. Non-metallic tubing is connected to other parts by nylon or brass fittings.
Why Use Flexible Conduit?
For the same length, flexible conduits are a lot cheaper but don’t miss out on the protective qualities of traditional rigid conduits. Flexible conduits are effective, safe and functional cabling solutions for a wide range of applications. The metallic or nylon outer casings are treated to provide the best possible protection. This includes protecting cables from adverse weather or environmental factors, like moisture, liquids, steam, various chemicals, or UV radiation. Flexible conduits also need to be tough and withstand direct impact, scraping, and not deform under sudden movement. They must remain unchanged in all temperatures and resist damage in case of fires. Since they are used in residential and industrial installations, flexible conduits need to be adequately shielded against micro-organisms and bacteria, mould buildup, livestock and house pests and stand up to explosions, vibrations, electrical shocks and magnetism. Any ruptures or damage to internal cabling can cost you dearly, especially in industrial processes.
Benefits Over Rigid Conduits and Other Cable Routing Systems
Flexible conduits require little in the way of expensive routing accessories, particularly in corners or surfaces with obstructions. This means no specialist tools are needed in installation as opposed to those regularly used in forming and bending rigid conduits. Individual pieces are easy to cut and the lightweight materials mean less physical stress. Flexible conduits can be used in the same or similar environments as rigid conduits, but need less work and come at the fraction of the cost.
When compared to cable glands, flexible conduits are more efficient, with fewer terminations needed. They are also quicker to install, can be retrofitted, and circuits and conductors are easily upgraded if the need arises. They also save you money in this aspect as no specialist cables are required. Compared to armoured cables, flexible conduits are simple to cut and can be used to combine multiple cable types in a single system. In both cases, you save time, space and money.
Uses
Flexible metallic and non-metallic conduits are widely used in the construction of private and public facilities like schools, airports, hospitals, warehouses, hotels and more. Here the provision of critical services is dependent on reliable electrical supply and conduits to prevent the risk from electrical faults or failures. Mechanical shielding in conduits means cabling is protected in hazardous materials applications, railway networks, demanding production and automation processes and other areas regularly exposed to high levels of chemicals, corrosion and high vibration. Sealed fittings and attachments also provide protection in processes and environments subjected to high hygienic requirements.
In commercial or residential settings, flexible conduits are used in a multitude of instances including lighting, HVAC systems, switchgear and distribution boards, heating and cooling systems and general cabling. Flexible and rigid conduits and accompanying attachments and accessories are sold by respected suppliers of industrial and residential electrical equipment throughout Australia.
