Close Fit Pipe Lining

Overview Close Fit Pipe Lining is an internationally recognised technique which involves inserting a compact pipe or sleeve into an existing pipe. The main advantage of this form of technology is that there is a minimum of disruption caused by surface digging. An entry and exit pit is excavated and the old pipeline is cleaned before work commences. Once the old pipeline is clear of debris, the compact pipe is prepared to be pulled through the existing pipeline using a winch.

The compact pipe roll is moved into position at the head of the launch pit. The roll is approximately 450 metres in length depending on the diameter of the pipe being used.

The new pipe is prepared to be pulled through the existing pipe line.

The winching cable is attached to the halter on the pipe itself and then the new pipe is slowly winched into the old existing pipeline.

The compact pipe is winched through the launch pit and guided into the old pipe. A steel guide (below) protects the new pipe as it flows into the old pipe.

The compact pipe can be seen emerging from the existing pipe line.

During manufacture the compact pipe is collapsed into a kidney shape. However it retains a memory which will be restored once the pipe is heated with steam to 80°C and then cooled with compressed air. It will then retain its regained round shape indefinitely.

Before steaming end caps are welded to the new pipe. A connection is fitted to the pipe to allow steam and compressed air to be pumped into the compact pipe

Water is taken from an existing outlet and fed to the boiler mounted in the steaming container.

After only a few hours and with the temperature still below optimum already the change in the pipe shape is obvious.

The kink in the new pipe where it enters the old pipeline is still obvious in the picture on the left On the right the kink is gradually filling out as the pipe regains its memory

The pipeline will continue filling out over the course of 6 to 7 hours and then will hold its shape indefinitely. The new pipeline is discrete and structurally sound, therefore where parts of the old pipe line were removed, no additional covering is required. The new pipe can stay in the ground for its 50 year estimated lifespan. The total time frame from the start of the preparation of the launch and receiving pits, to the complete laying of the new pipe is approximately 48 hours. This form of trenchless technology is therefore ideal for use in busy urban areas THE END