Repairing sewers, pipes, drains, culverts, conduits and tunnels without having to dig them up is an enormous advantage. Excavation is not only expensive in its own right but often results in additional collateral damage to above-ground structures, other buried services or the target pipeline itself.
Cured-in-place-pipes (CIPP) provide a very attractive alternative. Resin-saturated lining tubes are lowered or winched into position inside the existing pipeline. Once correctly positioned and inflated by air or water, curing of the resin is initiated by heat, steam, UV light or chemical triggers.
The new pipes often offer less flow resistance than the surfaces they replaced.
According to some estimates, Britain loses three billion litres of fresh water daily by leakage, and 40% of sewers have structural defects, so there is plenty of scope for improvement. CIPP is also widely used in the oil and gas industry, in agricultural drainage and for processing industrial effluents.
The Process
Service diversions may be needed while remedial work is undertaken. However, a great advantage of CIPP is speed. The liner is pre-built off-site and can often be in a serviceable condition within hours.
Clearing of obstructed conduits may also be necessary. Here too excavation can almost always be avoided by a drain lining company such as https://www.wilkinson-env.co.uk/sewer-repairs-drain-lining-concrete-cutting/ equipped with remotely controlled directional water cutters. These remove even stubborn concrete and other detritus.
Your drain lining company will also calculate strength requirements before fitting a new CIPP, considering the loads that might be applied to it by overhead traffic or groundwater pressures. In other cases, liners only need to supply enough additional support to seal existing conduits from infiltration or leakage.
After the lining has cured it has to cool before being cut flush with the conduit and tightly sealed. Hydraulic cutters can also be used to re-open side channels after a new liner hardens.
Limitations
Extensive damage inside old conduits sometimes has to be repaired before new liners can be safely hauled into place, and excessive water ingress must not interfere before the new liner cures. Otherwise there are few constraints.
Liners commonly range from 100mm to 3m in diameter and between 30m and 200m in length. Continuous runs of 900m have been successfully fitted, and there are ways of accommodating bends and turns. Short lengths to bridge a localised defect can also be fitted.
