The International Society for Trenchless Technology

Void which is created to receive a pipe, conduit or cable.

Manual or hydraulic tool used to connect or break tool joints at access points forward of the drill rig.

Excavation along the drill path to relieve excess pressure that has created hydrolock.

Term used for square end jacking pipes.

A principal module of a shield microtunneling or tunnel-boring machine (TBM). Trailing cans may be used to faciliate steering. It may also be referred to as a trailing tube.

Pipe to be rehabilitated by any trenchless rehabilitation method.

Bore in which a pipe, usually a steel sleeve, is inserted simultaneously with the boring operation. Usually associated with auger boring or pipe jacking.

A pipe to support the bore. Usually not the product pipe.

General trenchless technology term that refers to methods for closing joints within a pipeline or between lining segments.

Spray-on coating used primarily for corrosion protection of small diameter metal pipelines. Cement mortar and concrete linings can also provide structural and leak protection benefits in larger man-entry pipes or tunnels.

Method for the treatment of the ground around a shaft or pipeline, using non-cementitious compounds, to facilitate or make possible the installation of an underground structure.

Renovation method which seals a length of pipeline between two access points by employing a chemical solution pumped into the pipe and surrounding ground. Such systems perform a variety of functions including sealing of cracks and cavities, the provision of a new wall surface with improved hydraulic characteristics or ground stabilisation.

A system of centrifugal pumps, tanks with baffles, shakers screens, de-sanding and de-silting hydro cyclones for the removal of cuttings from the slurry for recycling and reuse.

Method of lining with a continuous pipe for which the cross section is reduced to facilitate installation, and reverted after installation to provide a close fit to the existing pipe.

Video cameras mounted on small tractor devices or sleds and driven or pulled through a pipeline commonly used to inspect repairs and to assess the condition of the pipe.