Let's talk about conduit. A conduit is a channel through which something is conveyed. Conduits take many shapes and forms, but in the electrical field, conduit has a more specific and narrow definition: it's a tube, pipe or trough that protects and routes electrical wiring. That said, not all electrical conduit is created equal: there are miscellaneous types that have different applications in the field. Let's look at some of the conduit offerings out there.
But first, what makes conduit preferable to other wiring options? Since it's fully enclosed, it offers excellent protection to outside damage from things like moisture, abrasion, chemicals and other perils. It can even keep out fire when properly sealed. It can be modified to be waterproof or can be submerged, with certain types able to be encased within concrete. Metallic conduit helps shield cabling from electromagnetic interference and makes it easier to add or remove cables as needed.
However, it can be more costly than other open wiring methods, so if the added protection isn't needed, it may be more advisable to take a more economical approach such as cable trays or support rings. Additionally, heat dissipation can be an issue with fully enclosed conduit, meaning that if you have multiple cables in a single pipe, you may need to lower the current capacity of your conductors.
NON-FLEXIBLE METAL CONDUIT
There are several types of non-flex metallic conduit often made of steel, stainless steel or aluminum. RMC (rigid metal conduit) is thick-walled with threaded ends for fitting and coupling. GRC (galvanized rigid conduit) is galvanized steel with a wall thick enough to accommodate threading, though it may not always be threaded. EMT (electrical metal tubing) is thin walled, which makes it less expensive and lighter than other metallic rigid conduit types. IMT (intermediate metal conduit) — as its name implies — is lighter than RMC but heavier than EMT.
EMT is the type of metallic non-flex conduit we offer at CableOrganizer.com. Since it's thin walled, it cannot be threaded, which means fittings must be clamped in place. Though it's the thinnest walled of the rigid conduits, it still provides ample protection in most applications except where serious damage is anticipated. Its light weight makes it easy to handle and alter as needed. It's often used in commercial or industrial applications.
FLEXIBLE METALLIC CONDUIT
Flexible conduit is ribbed, giving it a look like corrugated wire loom. It can bend and flex freely (though it does not hold a bend permanently as a bent pipe would). For areas where obstacles would require rigid conduit to make too many turns and use an impractical number of fittings, flexible conduit may be an ideal choice. Flexible metallic conduit (FMC) provides the protection of rigid metal conduit without being confined to traveling in straight lined sections. It also provides vibration isolation when connecting to motors or other devices prone to movements, where rigid conduit would be easily jarred.
It should be noted that FMC, due to the interlocking coils that allow it to bend, is not liquid tight unless it features a waterproof plastic coating. This type of conduit is known as LFMC (liquid tight flexible metallic conduit).
FMC should not be confused with FMT (flexible metallic tubing). It is used in lighting fixtures and other plenum applications; and is liquid-tight despite not having a jacket. Visually, it features tighter, thinner “ribs” than FMC.
NON-METALLIC FLEXIBLE CONDUIT
There are many varieties of non-metallic flexible conduit, but most share basic properties. They are often constructed of PVC and feature a corrugated exterior. Varieties exist to handle communication cables, fiber optics and other low-voltage cabling. Depending on the type, it may be UV resistant for outdoor use or suitable for burying. Since it's typically made from a solid piece of material, it's watertight, but resistance to chemicals and corrosives will vary. PVC flexible conduit is found in riser applications, HVAC areas, water treatment systems and many other applications.
Visit CableOrganizer® for our full selection of conduit, tools, fittings and accessories.