Micro-ducts and Micro-duct Assemblies

Micro-ducts and micro-duct assemblies are available for several installation environments such as direct buried installation, into existing pipes or for indoor installation.

Basically two type of outdoor micro-duct assemblies are available:

• Thick Walled Ducts (TWD)

• Tight Protected Ducts (TPD)


Thick Walled Ducts (TWD) are characterised by heavy wall micro-ducts and a relatively thin outer sheath. The micro-ducts themselves are rugged enough to protect the fibre cables inside. Typical dimensions for TWD are (OD/ID): 7/3.5 mm and 14/10 mm.


Tight Protected Ducts (TPD) are characterised by one or several sheets that protect the relatively thin walled micr-oducts. The sheets form a thick protective layer that in combination with the micro-ducts protect the fibre cable or blown fibre. Typical dimensions for TPD are (OD/ID): 5/3.5 mm and 12/10 mm


Tight protected ducts have a substantially higher impact resistance compared to thick walled ducts and are therefore a safer choice in many installations. Thick walled ducts simplify jointing and branching of ducts which results in a slightly lower installation cost.


Micro-ducts and microd-uct assemblies for certain installation types, e.g. aerial installation and indoor installation are only available as TPD. However, TWD and TPD may be connected in the same network using reduction connectors.