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Air Blown Fiber Terminology

Light Brigade Air Blown Fiber Terminology

Compressed Air or Nitrogen​

  • Blow or “jet” fiber units or micro cables​

  • Typical rates are up to 300’ per minute​

Micro Cables​

  • 12-864F​

  • Distance 6600’ and beyond​

Fiber Units​

  • 1-24F​

  • Typical maximum distance 3300’​


  • Pathways for routing ABF​

  • Aerial, buried or in-building


A flexible tube for the installation and long-term protection of blown fiber bundles or micro cables. They are typically 5 to 20mm O.D., constructed from HDPE (High-Density Polyethylene) or LFH (low fire hazard) polymer. For outdoor applications, they are typically color-coded.​

Microduct Bundle​

An assembly of two or more microducts surrounded by a common sheath. Microducts can either be all the same size or a combination of diameters. (i.e. 12 tubes of 7/3.5 mm with thin sheath surround)​

Standard Duct​

A single path duct, normally of HDPE, having an OD of >= 25 mm/1”. Typically holds one or more microducts or microduct bundles (i.e. Commonly used 1.25”, 1.5”, and 2.0” HDPE/PVC ducts).

Blown Fiber Unit (FU)​

AKA blown “fiber bundle.” A fiber “mini cable” consisting of 1 to 12 fibers (1-12F) with a 0.8 to 2.4mm O.D., intended for air blown installation. As these designs are constructed without strength members, pulled installation is prohibited.​


A compact fiber cable typically containing between 12 and 864F, primarily intended for blowing into microducts. Microcables have diameters smaller than traditional duct-pull cables. This is due to the lack of central or aramid yarn strength members and the use of 200um coated fibers instead of traditional 250um. ​

Direct Bury (DB)​

When referring to microducts or microduct bundles, this term implies with “thick wall” construction (~ 2.0 mm). DB microducts and microduct bundles will tolerate narrow-trench or micro-trench “backfill” and compaction without deforming provided that sand blinding is applied around the apparatus according to installation “best practice.”​

Direct Install (DI)​

Referred to as “duct grade” meaning that it must be installed into the existing duct. Microducts in bundles with this description are of a “thin wall” design. While having good installation tensile strength, DI bundles are not suitable for direct burying.

Interested in taking our Introduction to Air Blown Fiber Training Course?

Light Brigade's Introduction to Air Blown Fiber Training Course is aimed at anyone interested in learning the basics of air blown fiber technology or those that have recently purchased blowing equipment and want to learn how and why to use it.

This course serves as an introductory level course focused on installation, maintenance, and machine operation. The two days will be a mix of theory and hands-on exercises that relate to the learned theory.

Subjects covered will be an overview of air blown fiber technology including terminology, components and equipment, best practices, setup, teardown, safety, communication, and various blowing methods and techniques. Hands-on exercises will include calculating fill ratios, duct and microduct joining, proper lubrication methods, duct cleaning, and preparation tests, as well as machine setup and blowing microcables and fiber units.

The primary focus of the content is aimed at OSP/FTTx installations; however, the basic principles can be applied equally to indoor applications and campus installations. This course will be taught by a field application engineer and is best suited to be delivered at a Light Brigade Academy or your facility.

This course will also serve as a preparatory measure for the soon-to-be-released four-day instructor-led ABF for Installers and Technicians class.

Contact Us

(800) 451-7128

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