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Ultimate Guide to Flexible Conduit: Everything You Need To Know

Jun. 12, 2024

Flexible Metal Conduit (FMC)


Flexible Metal Conduit (FMC) is a type of flexible conduit used in electrical installations. Made from spiral-wound metal strips, typically galvanized steel or aluminum, FMC provides a robust and versatile solution for protecting and routing electrical wires and cables in various applications.


Usage of Flexible Metal Conduit:

FMC is used in a wide range of electrical installations where flexibility, durability, and mechanical strength are required. Some common applications include:


1. Commercial and Industrial Wiring: FMC is commonly used in commercial and industrial settings, such as factories, warehouses, and office buildings, to protect wiring systems from physical damage and provide a conduit pathway for electrical wires.


2. Outdoor Installations: FMC is well-suited for outdoor applications, including outdoor lighting, signage, and equipment connections. Its durable construction helps protect electrical wiring from moisture, UV exposure, and other environmental factors.


3. Machinery and Equipment: FMC is often employed in machinery, equipment, and control systems where movement, vibration, or mechanical stress is present. It provides a flexible conduit solution that can withstand the rigors of industrial environments.


4. Retrofitting and Renovations: FMC is an excellent choice for retrofitting or renovating existing structures, as it can be easily bent and routed around obstacles or existing infrastructure. This flexibility allows for the installation of new wiring without the need for major modifications.


Benefits of Flexible Metal Conduit:


Flexible Metal Conduit (FMC) offers several benefits in electrical installations, including:


- Flexibility: FMC is highly flexible, allowing for easy bending and routing around obstacles and corners. It offers greater flexibility compared to rigid metal conduits, making it suitable for installations in tight spaces or areas requiring frequent movement.


- Durability: Made of sturdy metal materials, FMC provides excellent mechanical strength and protection for electrical wiring systems. It can withstand impact, vibrations, and exposure to harsh environments.


- Corrosion Resistance: FMC is typically coated with a layer of corrosion-resistant material, such as galvanized steel or aluminum. This coating protects the conduit from rust and corrosion, extending its lifespan.


- EMI/RFI Shielding: The metal construction of FMC provides inherent electromagnetic interference (EMI) and radio frequency interference (RFI) shielding properties. This makes it suitable for installations where electromagnetic compatibility is a concern.


- Easy Installation: FMC is relatively easy to install, thanks to its flexibility and compatibility with standard fittings and connectors. It saves time and effort during the installation process.


How to Install Flexible Metal Conduit?


1. Plan the Installation: Determine the required length and size of Flexible Metal Conduit (FMC) for the project.


2. Cut the FMC: Use appropriate tools to cut the FMC to the desired length.


3. Bend the FMC: Bend the FMC either by hand or with bending tools to fit the installation path. Avoid sharp bends that may restrict wire movement or cause damage.


4. Install Fittings and Connectors: Attach compatible fittings and connectors to the ends of the FMC. These fittings allow for connections to junction boxes, electrical panels, or other conduits.


5. Secure the FMC: Use straps, clamps, or hangers to secure the FMC at regular intervals. Follow local building codes for spacing and support requirements.


6. Pull the Wires: Pull the electrical wires through the FMC using proper techniques to avoid damaging the wires or the conduit. Lubricants designed for wire pulling can be used to reduce friction.


Flexible conduit

Liquid-Tight Flexible Conduit


Liquid-tight Flexible Conduit is a type of conduit that, as the name suggests, provides a liquid-tight seal around the wires it houses. It comes in two main types:


Liquid-Tight Flexible Metal Conduit (LFMC): LFMC is made of corrugated metal with a liquid-tight plastic jacket, offering exceptional durability for challenging environments. It withstands physical abuse, moisture, chemicals, and oils, making it ideal for outdoor applications, machinery connections, car washes, and food processing plants.


LFMC finds extensive use in various applications, including outdoor installations, wet locations, and areas requiring flexibility and liquid resistance. It is commonly employed in industrial settings, commercial buildings, and outdoor lighting applications.


Liquid-Tight Flexible Non-Metallic Conduit (LFNC): LFNC is made of non-metallic materials, typically PVC, and features a liquid-tight outer covering that protects against moisture, oil, and other liquids. Constructed from a smooth PVC core and a liquid-tight outer jacket, LFNC offers a lightweight and cost-effective alternative to LFMC. It also provides corrosion resistance.


LFNC is commonly used in residential and light commercial applications where flexibility and liquid-tight properties are required. It is suitable for outdoor installations, wet locations, and areas prone to corrosive environments like attics, basements, and kitchens, providing protection from moisture and dust.


Benefits of Liquid-Tight Flexible Conduit


- Watertight Seal: Maintains a seal against liquids and moisture, safeguarding your electrical system from corrosion and short circuits.


- Durable Protection: Withstands abrasion, crushing forces, and chemicals, ensuring prolonged performance and reliability.


- Flexibility: Easily bends and twists, facilitating straightforward installation in tight spaces and around obstacles.


- EMI Shielding: Certain types of LFMC offer electromagnetic interference shielding, protecting sensitive electronics.


- Fire Resistance: Provides an additional layer of safety in the event of a fire.


How to Choose the Right Flexible Conduit


Selecting the appropriate flexible conduit for your specific application involves considering several factors. Here are key considerations to guide your decision-making process:


1. Application Requirements: Understand your application's specific needs, including the environment (indoor or outdoor), exposure to moisture, chemicals, or extreme temperatures, and the required level of flexibility and mechanical protection.


2. Material Compatibility: Ensure compatibility between the conduit material and the wires or cables to be installed. Different conduits are designed for specific wire types (metallic or non-metallic) and have varying temperature ratings, resistance to chemicals, UV exposure, and corrosive substances. Confirm that the conduit material suits the installation's environmental conditions.


3. Flexibility and Bend Radius: Evaluate the flexibility needs of your installation. Determine if the conduit must bend easily around obstacles or tight corners. Consider the manufacturer's specified minimum bend radius to ensure the conduit's flexibility meets your project requirements.


4. Conduit Sizing: Choose the appropriate conduit size based on the number and size of wires or cables to be installed. Ensure that the conduit can accommodate the wiring adequately and leave room for future expansions or additions if necessary.


5. Code Compliance: Familiarize yourself with local electrical codes and regulations. Ensure that the selected flexible conduit meets the standards and requirements for your application. Compliance with codes is crucial for safety and to avoid legal or regulatory issues.


6. Durability and Protection: Evaluate the conduit's level of protection. Consider factors such as impact resistance, corrosion resistance, UV resistance, and its ability to withstand environmental hazards. Select a conduit that offers sufficient protection for the wires or cables in the given application.


7. Installation Considerations: Assess the ease of installing the flexible conduit. Consider factors such as the availability of compatible fittings and connectors, the installation method (snap-in, compression, adhesive, etc.), and the overall installation process. Choose a conduit that aligns with your installation requirements and capabilities.


8. Budget: Consider the project's budget. While cost should not be the sole deciding factor, it's essential to strike a balance between quality and affordability. Compare different brands and types of flexible conduits to find the best option that meets your needs within your budget.




Flexible conduit plays a vital role in electrical installations, offering flexibility, durability, and protection in various applications. It is essential to grasp its uses, advantages, properties, and installation methods to select the appropriate conduit for different projects. Adhering to proper guidelines and local regulations ensures that installations are safe and reliable. By understanding the nuances of flexible conduit, you can confidently meet the electrical needs of diverse projects while prioritizing safety and efficiency.

Flexible conduit