Thermaflex® S-TL Flexible Duct

Flexible Air Duct

Non-insulated UL181 Class 1 flexible air duct, extremely strong with heavy fiberglass cloth fabric permanently bonded to a corrosion resistant spring steel wire helix. For all pressure heating and cooling systems. A superior alternative in applications where insulated duct is not required or cannot be used, e.g., clean room applications. Unlike connector-rated products, S-TL is not limited to length of run.


  • Reduced total installation cost
  • Long standard lengths help reduce waste
  • All components are self-extinguishing

S-TL Specs

Diameter 2-20 inches ID
Pressure Rating (WG)
Positive 16 inches (2˝-10˝ ID)
10 inches (12˝-20˝ ID)
Negative 1 inch (2˝-20˝ ID)
Velocity 6000 FPM
Temp. Range -20°F – 250°F cont.