The patented Impactor process is another system that combines the HDD with pipe bursting as shown in the
figure below. The bursting head (Impactor) receives air through the HDD stems. The HDD is connected to
the air supply and positioned to drill out to an entry manhole. Then the HDD stem is pushed through old
pipe to the next manhole and drilled back to the entry manhole. The Impactor device, after it is attached
to the drill stem and to the replacement pipe, is pulled into the old pipe. While pulling back, the
Impactor system is activated and bursts the old pipe. The combined actions of pulling using the HDD
rig and of hammering by the Impactor breaks up the old pipe and replaces it with the new pipe. The
Impactor system can reduce excavation and overcomes blocked old pipes.