How we replace pipes
Choosing the correct method of pipe replacement is key to delivering a project at the agreed cost with the minimum disruption to our customers.
Several stages of planning take place prior to confirming the method:- A full street-by-street survey is carried out.
- Trial holes and pipe samples are installed to determine ground conditions and to find out if other utility services' pipes and cables are running through the area.
- We work closely with partner agencies such as the highways authorities and other utilities, to ensure are activities our joined up and disruption is minimised.
How it's done
Directional drilling
In certain situations it may be more appropriate to use directional drilling rather than replacing the pipe in a trench, or inserting a new pipe.
This involves drilling a pilot tunnel with a precision-guided drilling rig, then pulling the new pipe back through the tunnel.
Pipe bursting
Most mains replacement work is done underground, with only two small pits dug at each end of the section of pipe that is being replaced.
We push a steel rod into the old main and then use the rod to pull a cutting tool back through the pipe.
This breaks up the old pipe as the rod returns, and at the same time we pull a new pipe into the space left by the old pipe.
Inserting new pipes
Wherever possible, new plastic pipes are placed inside the old metal ones.
Although the new plastic pipes are smaller, the smoother surface ensures the amount of water carried through the pipe is not reduced.
Replacing old pipes
If we cannot insert a new plastic pipe, we will dig a new trench and replace the old pipe completely with a new plastic one.
