Pipe bursting requires the excavation of a launch pit and a receiving pit. The hydraulic pipe pulling unit is positioned within the receiving pit and a steel cable is fed from the unit through the existing pipeline. The cable is then connected to a conical pipe bursting head at the launch pit. The pipe bursting head is attached to the new pipe and the head is winched from the launch pit towards the receiving pit.
The hydraulic winch draws the bursting head through the existing pipe. As the bursting head progresses, the replacement pipe is advancing and displacing the old pipe. The process is complete once the bursting head and the attached new pipe reach the receiving pit.
Interflow’s pipe bursting unit uses the technique known as rope bursting which is different to the more commonly used rod systems. One significant advantage of this system is the increased worker safety provided as operators are not required to be within the pits during the pipe bursting.
Interflow is currently able to carry out pipe bursting operations for pipelines with diameters of 100–300 mm. The new pipe is able to be installed rapidly, however this is dependent on many factors such as subsoil conditions, the depth of pipeline and upsizing requirements.
Pipe bursting is an important pipe renewal option as it allows old pipelines with insufficient capacity to be increased. A pipeline may be considered undersized due to additional flow demand being placed on the network.