Lining of passageways

#This invention relates in general to the lining of passageways and more particularly pertains to a method of lining passageways such as sewers and underground pipes while those structures remain in place. There is a need for a suitable method to restore to use sewers, underground pipes and other conduits which have corroded or crumbled from use or from other causes. Hitherto it was usual to replace such structures even where access to them was difficult and required substantial excavation or removal of intervening material. The invention permits the restoration of such structures while allowing them to remain in place by providing a method for lining the passageway with a rigid and strong shell.

#The invention resides in a method of lining passageways in which a flexible tubular member is progressively fed into the passageway and is pressed by fluid pressure against the surface to be lined. The flexible tubular member is of a material that is impregnated with a synthetic resin in the liquid state. Upon hardening, the resin causes the tubular member to form a rigid lining in the passageway. The walls of the passageway are not simply sprayed with a liquid resin to build up a hardened inner shell because solid resin tends to be brittle or to have poor structural strength or to crack under stress or to have other disadvantages which prevent its use in that manner. The resin impregnated material is therefore needed to form a liner having the requisite durability, strength, and impact resistance.

#The objective of the invention is to provide a method of lining a passageway in situ with a rigid and durable inner sleeve without requiring the disassembly or dismantling of the passageway. In the practice of the method, a fluid impermeable tube carrying in its interior a tubular member of resin absorbent material impregnated with a settable synthetic resin is introduced into the passageway at one end in such a manner that the impermeable tube and the tubular member evert as they progress into the passageway. To accomplish the eversion, the impermeable tube is anchored at the entrance of the passageway and is then fed through the anchored end into the passageway so that the tube turns inside out as it progresses into the passageway. As it everts, the impermeable member presses the resin impregnated tubular member against the walls of the passageway. Fluid pressure is employed to move the impermeable tube and the resin impregnated tubular member along the passageway and to cause those tubes to evert so that the impregnated member lies between the impermeable tube and the passageway surface. The fluid pressure is produced by at least partially filling the everted impermeable tube in the passageway with liquid so that the uneverted impermeable tube and its enveloped impregnated member are buoyantly supported by he liquid and are able to move along the passageway without appreciable contact between the uneverted portion of the impermeable tube and the everted portion of the impermeable tube. The resin is permitted to set and become hard while the fluid pressure is maintained to cause the everted impermeable tube to hold the resin impregnated liner against the walls of the passageway.

#Embodiments of the present invention will now be described by way of example, with reference to the accompanying diagrammatic drawings, wherein

#FIG. 1 is a sectional side view of the end of a flexible composite tubular structure or laminate.

#FIG. 2 is a sectional end view of the laminate shown in FIG. 1;

#Referring to the drawings, and firstly to FIG. 1 and FIG. 2, in these Figures there is shown a flexible composite tubular laminate 10 which is made up of a tubular member 14 of an absorbant material such as fibrous material, for example a needled felt, or a woven material or other absorbent flexible structure, and this member 14 is wetted out with, so as to be immersed in, a synthetic resin such as an epoxy resin which sets hard or can be caused to set hard.

#Surrounding the member 14 is a barrier tube 16 which is of water impermeable synthetic plastics material such as polythene or polyvinyl chloride.

#Basically, the tube 14 forms the internal impact reinforcement of a pipe to line a pipeline and the barrier tube 16 may form part of the finished pipe or may be removed as desired.