Pipe liner (pipe rehabilitation)

Hose liner for street sewer pipe

The pipe liner process is a method for rehabilitating lost or damaged pipelines. The term hose liner is used to describe the new pipe pulled into the pipeline in need of renovation.

Hose liners - also called "inliners" by the craftsmen - are used for the trenchless rehabilitation of drainage pipes outside of buildings, so that streets or sidewalks above the drainage pipe to be rehabilitated do not have to be broken up. The excavation of soil material and the subsequent backfilling of the pipe trench are no longer necessary. The pipe liner process can be used if the pipes to be rehabilitated have cracks, breaks, fragments or socket misalignments. The open construction method must be used in the event of pipe sags, counter-slopes or collapses.

The process saves time and money. When used in public spaces, long-term traffic obstructions and total closures can often be omitted or at least significantly minimized. In addition to the excavation and backfilling of the soil, you also save on the restoration of a possibly asphalt or paved surface.

It can be used to renovate sewer and rainwater downpipes within a building , so that there is no need to pry open walls and floor slabs. In the case of multi-family houses, there is also the fact that no complicated arrangements are necessary with the individual tenants and all bathrooms and drains can be used again after a short time.

In general there are different procedures:

Hose liner (hose relining process): Starting from a sewer shaft , a downpipe or drain, a synthetic resin-soaked textile hose is inserted into the defective drainage pipe (e.g. inverted). The synthetic resin is mixed from two components immediately before processing. Under constant air or water pressure, the pipe liner lies against the old, damaged pipe wall and hardens there within a few hours. By adding heat, warm water, steam or UV light sources, the curing time can be significantly reduced. This creates a seamless "pipe in a pipe system". The method can be used for pipes between DN 50 and DN 2000. It is suitable for circular and oval profiles , but also other types of profile . The installation length can be 200 m in one piece, depending on the local conditions. Existing house connections and inlets, which have been closed with pipe liners, are milled out again with pinpoint accuracy using a sliding or mobile milling robot. The entire renovation only takes a few hours. This means that the channel can be used again immediately after work is finished. For the durability of the rehabilitated pipe, the executing companies usually guarantee for a certain period of time , to what extent the stated durability of several decades is actually achieved, must remain open at the moment, since the process has not been practiced for that long.

Partial pipe liners (short liner method / repair method) are suitable for repairing punctual damage to sewage pipes where the majority of the rest of the pipe is undamaged.