What are the different types of fiber optic metal spiral tubes

Fiber optic metal spiral tubes, also known as Fiber in Metal Tubes (FIMTs), come in various designs including stainless steel tubes, spiral steel armored tubes, and interlock or square-lock armored configurations, each offering specific protection and flexibility for optical fibers.

Fiber in Metal Tubes (FIMTs)

FIMTs are hermetically sealed metal tubes that house optical fibers, providing crush resistance, corrosion resistance, and high fiber density. They are available in different sizes, wall thicknesses, and metal types, allowing customization for applications such as downhole cables, subsea installations, cryogenic environments, and industrial monitoring. The tubes can be further protected with outer buffering to enhance durability and environmental resistance (Fibercore) .

Stainless Steel Fiber Optic Tubes

Stainless steel tubes, sometimes called FIST (Fiber in Steel Tube), are designed for harsh environments. They are often flooded with a thixotropic filling compound and hermetically sealed to protect fibers from moisture, chemical exposure, and mechanical stress. These tubes are commonly integrated into armored cables and subsea umbilicals, ensuring flexibility, optical signal integrity, and long-term durability (AFL) .

Spiral Steel Armored Tubes

Spiral steel armored tubes consist of a helically wound steel strip around the fiber optic core. This design provides exceptional flexibility, ease of installation, and protection against rodent damage, UV radiation, and mechanical stress. Spiral steel armor is widely used in outdoor and industrial applications, where cables are exposed to challenging environmental conditions (Anfkom) .

Other Armored Configurations

• Interlock Armor: Uses interlocking metal strips to provide enhanced tensile strength and crush resistance, suitable for outdoor and industrial installations.
• Square-Lock Armor: Features a square-profiled metal strip tightly wound around the cable, offering flexibility and abrasion resistance, ideal for applications requiring frequent cable movement (Anfkom) .

Summary

Fiber optic metal spiral tubes are designed to protect delicate optical fibers while maintaining flexibility and signal integrity. The main types include:

• FIMTs: Hermetically sealed metal tubes for high-density fiber protection.
• Stainless Steel Tubes (FIST): For subsea and harsh environments.
• Spiral Steel Armor: Helically wound steel for flexibility and outdoor durability.
• Interlock and Square-Lock Armor: Provide additional mechanical strength and abrasion resistance. These variations allow engineers to select the appropriate tube type based on environmental conditions, mechanical stress, and installation requirements.