Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1998-10-28
2001-10-16
Ball, Michael W. (Department: 1733)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S094000, C156S287000, C156S294000, C156S273700
Reexamination Certificate
active
06302983
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for renovation of underground pipelines preferably for sewage, comprising introduction of a lining pipe into an existing pipeline, said lining pipe having a length corresponding to the length to be renovated, and consisting of a fusable polymer in a folded condition, and unfolding of the lining pipe in order to line the pipeline.
2. Description of the Invention Background
Folded pipes have already been used for lining pipelines for example according to SE-911948-9, where above all a combination of PE and PVC has given the prerequisites of the use of the concept relating to folded pipes. The basic concept of this technique is that a length of coiled prefabricated folded pipe material without transverse welding is transported successively into e.g. a manhole and is located in an existing pipeline to be lined, said pipeline connecting to the manhole. Introduction of a pipe in a folded condition makes possible to line with a pipe having the same outside diameter as the inside diameter of the existing pipelines. Thereby the capacity of the pipeline substantially can be maintained, no additional arrangements for fixing the pipe in its longitudinal direction being required and the connection of so called service pipelines being facilitated. When lining larger pipelines (Ø≧300 mm) this technique has, however, not been possible to use, mainly due to difficulties in handling folded pipes of souch dimensions. This as a consequence of larger handling forces being required as well as problems with cracking in the fold areas of the pipes of larger dimensions. Moreover, the coils of the folded pipes have also been difficult, if not impossible, to handle in a normal environment, not the least of which is transportation on a truck, as a consequence of the dimensions of the folded pipes. This means, generally speaking, that the diameter of such a coil be in order not to require special transport, must not be larger than 2400 mm. In order to unfold lining pipes according to conventional methods it has also been necessary to preheat the lining pipe to a temperature of between 100° C. and 120° C. Moreover, at the lower temperature it has been necessary to apply an inner over-atmospheric pressure of about 5 bar, which for large dimensions sets high demands on security arrangements around the lining operation.
SUMMARY OF THE INVENTION
According to the invention described herein there is presented a solution to the problem of lining existing underground pipelines having a diameter >300 mm with a continuous lining pipe introduced into the pipeline, the lining pipe being built up by introducing lining layers into the pipeline to be lined, pressurising the layers and successively fusing them together by exposing each layer to fusion heat from a heat source which is carried along the inside surface of the innermost layer of the lining built up so far. The consecutively introdused lining layers may alternately be opaque and translucent to heating enegy to make fusion of more than two layers possible in one fusion step.
The method described makes it possible to line existing pipelines having a diameter up to at least 800 mm.
By the use of the method and the use of a smaller relative wall thickness equipment, such as coils of lining material etc., will be leas bulky and easier to handle.
It will also be possible to build up the pipe wall material for any application in an environmentally or cost optimised way so that only the outer layer may provide structural tensile properties and durability, while intermediate layers may provide only tensile properties and the inner layer/layers may be adapted to the medium the pipline is intended for. A proper example is the use of PEX (Cross-linked Polyethylene) crosslinking during fusion after its introduction into the pipeline. Another example is the use of a foam as one of the layers, which is caused to react by means of fusion heat.
A lining according to the invention eliminates the risk for subsoil water penetrating between the existing pipeline and the lining due to the existing pipeline being in a too bad condition. In the worst case this may lead to the lining floating on the surface of the water with the consequence that sooner or later it may rupture due to abrasion or fatigue.
REFERENCES:
patent: 3560291 (1971-02-01), Foglia et al.
patent: 4386628 (1983-06-01), Stanley
patent: 4394202 (1983-07-01), Thomas et al.
patent: 4781780 (1988-11-01), Hannover
patent: 4867921 (1989-09-01), Steketee, Jr.
patent: 4871413 (1989-10-01), Hyodo et al.
patent: 5205886 (1993-04-01), White
patent: 5366669 (1994-11-01), Maine et al.
patent: 5395472 (1995-03-01), Mandich
Agren Lennart
Dickinson Alan John
Jarvenkyla Jyri
Jormakka Veli-Pekka
Leo Harri
Ball Michael W.
Harris Beach LLP
Piazza Gladys
Uponor Innovation AB
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