Matching System Components to Reduce Risk of Failure
One of the most critical activities before bursting is to ensure that the bursting system has sufficient power to burst the old run from the insertion shaft to the pulling shaft. The system must be able to overcome the friction between the soil and the outside surface of the new pipe and the soil with reasonable margin of safety to overcome unforeseen repair sleeves, clamps, etc.
The contractor should adhere to the sizing guidelines stated in the operations manual issued by the bursting system manufacturer to match the system with the needs of the job. The bursting system manufacturer should be consulted if there is any doubt regarding the adequacy of the system for that specific run in that particular conditions (soil, depth, type of pipe, etc.). Lubricating the outside surface of the pipe with polymer or bentonite (depending on the type of soil) can dramatically reduce the coefficient of friction between the pipe and the soil, and consequently, reduce the needed pulling force. In addition, the bursting system components should be appropriately matched to the need of the project; for example, the winch capacity is matched with the bursting head size and the conditions of the job.