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DM Drainage Limited
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Lining & Patch Repair

Patch and end to end liningA cured-in-place pipe (CIPP) is a trenchless rehabilitation methods used by DM Drainage LTD to repair existing pipelines. CIPP is a jointless, seamless, pipe-within-a-pipe with the capability to rehabilitate pipes ranging in diameter from (4"–110").

As one of the most widely used rehabilitation methods CIPP has application in water, sewer, gas, and chemical pipelines. A resin-impregnated felt tube made of polyester, fibreglass cloth or a number of other materials suitable for resin impregnation, is inverted or pulled into a damaged pipe.

Cured in Place pipe (CIPP) can be used to rehabilitate sanitary sewers, storm drains and pressure pipelines for water, gas and process effluents. Circular pipe from 100-2,700mm and a variety of noncircular pipe such as egg shapes, and box culverts can be lined. Lining with CIPP removes the pipe from service for the duration of the installation and reinstatement process so overpumping or provision of an alternate source of supply may be necessary. CIPP liners of non-woven polyester felt or fibre reinforced fabric are manufactured to fit the host pipe. The liners are impregnated with a polymer resin, which when cured will form a close fitting liner pipe within the host pipe. The liner may be designed with sufficient thickness when cured to sustain the loads imposed by external groundwater and internal service pressure, and by soil and traffic acting on the pipe.

patch lining drainage repairPrior to lining, the pipe must be cleaned by jetting to remove corrosion debris and detritus. Protruding lateral connections also must be removed. Local repairs may be required where the existing pipe is substantially deformed or damaged. After lining, the service connections or laterals are reinstated and the pipe is returned to service, usually within the same day. Lined water mains must be disinfected before returning to service.The liner is thoroughly saturated with polyester, vinyl ester epoxy or silicate resin using vacuum, gravity or other applied pressure. The resin includes a chemical catalyst or hardener to facilitate curing. The outermost layer of the liner tube is coated with a polymer film to protect the liner during handling and installation. The impregnated liner may be chilled for transportation to maintain stability until installed.

Where an installation of a full end to end liner is not necessary DM Drainage LTD can patch repair to a specific section by installing a short liner within the drain or sewer. Resin is impregnated onto a fabric mat and wrapped around an inflatable packer, positioned at the section needing repair. And is then filled with air to press the patch against the sewer/drain wall whilst the resin cures. Once the resin has cured, the packer is removed and the section will be explored by CCTV to ensure success before re-commissioning the pipe. Patch repair can be carried out in pipes from 100mm-450mm.