Knowing When to Use a Liquid Tight Conduit

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A conduit can be especially helpful in making the installation of electrical cables easier and less expensive, but when it comes to the protection of the wiring or cable that is installed in these conduits, some of them, such as the liquid-tight conduit, is absolutely necessary. Some installations, in fact, make it mandatory to use these conduits. Many of these conduits are so specialized that it becomes necessary at times to know which of the conduits will be a better fit for use in certain environmental and material conditions. In some of these applications, the liquid-tight conduit will be a perfect fit.

Moist Environments

In environments where moisture and water are likely to be present and where tight connections against moisture intrusion are desired or needed, this type of conduit works well, especially when it is combined with liquid-tight fittings.

Use in Corrosive Environments

Those users who require a flexible conduit in a corrosive or damp environment will find the liquid tight conduit to be an ideal product. This may be especially true where condensers for air conditioning units and electric motor connections are used.

External Applications

Where conduit is to be installed in external applications, the liquid-tight metal conduit can be used. The outer sheathing, which is composed of PVC and includes stabilizers made of carbon black, make it resistant to UV, and, therefore, suitable for use in external applications.

Conduit Bending and Vibration

In applications where conduit bending is anticipated, the liquid-tight conduit can be a good choice. Its resistance to bending and vibration is made possible by an inner core that is made more flexible by using electro-galvanized steel. This core is also coated with plasticized PVC that is resistant to oil and higher temperatures. This contributes to the prevention of wrinkling when the conduit is bent.


The conduit coating, which is PVC, has a smoother surface that allows certain compression fittings, such as those that are liquid-tight to provide for more secure connections. In this type of conduit, you will typically find greater mechanical strength, as well as protection from dust and certain liquids.

Direct Burial

In applications where a cable is to be buried and is subject to crushing, certain sizes of liquid-tight conduit will usually meet established specifications. To meet the required qualifications in these applications, these conduits usually cannot exceed a diameter size of 1 inch. Nor will conduits of a larger diameter usually be approved for encasement in concrete. Typically, to identify a conduit that is approved for this encased concrete or direct burial applications, the conduit will be marked, DIR BUR.

Conduit Fittings

In some applications, liquid-tight conduits will need to be used with liquid-tight fittings that will need to be threaded onto a connection. These connections can also be made in a junction box.