Expander / Hammer Configuration

The typical pipe bursting configuration is termed a rear expander and consists of a nose section that fits within the existing host pipe and with the conical expansion section at the rear of the bursting head. This configuration aids the bursting and replacement process to follow the alignment of the existing pipe. For a static pull, there are no other moving parts. For a pneumatic process, the hammering mechanism fits within the bursting head and may be an integral part of the bursting head. Sometimes, in order to work within small arrival manholes, it is advantageous to use a bursting head with the expansion section at the front of the bursting head and this is termed a “front expander”. If the impact mechanism is kept separate from the bursting head itself, it is possible to remove the front expander in the arrival manhole and retract the impact mechanism to the starting manhole.