Inventions: A UNING SYSTEM AND METHOD FOR INSTALLING A PLASΗC UNER

SPECIFICATION

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. Patent Application Serial No. 08/348,652, filed 2 December 1994, which is a continuation-in-part of U.S. Patent Application Serial No. 07/977,853, filed 17 December 1992. These patent applications, and European Patent Application No. 92 114 244.4 EPO, filed 20 August 1992, are incorporated herein by reference. All patents and patent applications mentioned herein are hereby incorporated by reference. BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to a method of installing plastic liners within pipelines, either initially or as a repair, for renovating structure of the pipelines or rehabilitating a functional performance of the pipelines, therefore, protecting the pipeline from deterioration. The invention further relates to a method of producing deformed pipe from continuously extruded thermoplastic material having the anchors "nubs" or generically named

"protuberances" spread over the surface of the plastic sheet (such a plastic sheet "panel" being patented in U.S. Patent No. 5,167,895). The protuberances can be co-extruded into the sheet, and in the factory or at the site the sheet can be welded into a closed circular shape, and coiled on a spool by bending the deformable circular shape of the extruded sheets flatly toward inside of the circular shape thereof and without elongation to maintain the wall thickness of the circular shape to be used as a thermoplastic liner pipe. The invention also includes apparatus to carry out a grouting process in the installation of the grout through a specially perforated insert tube (or/and multiple tubes) which remains a part of the grouted entity when installation is completed. The field installation is facilitated by a variable set of rollers used in pre-insertion for the purpose of the cross section shaping to pass into and

through the existing pipe applied to the folded or flattened liner immediately received from the coil. This is a method of handling the thermoplastic material as a deforming tube of a flexible nature rather than a deformed pipe known as prior art. And not utilizing the temperature at a deforming level for the tube shape change, being prior art utilized in constructing "historic time memory," but a mechanical folding, this would be a part of the "thin wall" method of installation. Where a thick wall liner is required a temperature constructed "historic time memory" can be utilized in the process of deforming, making the anchor tube a deformed pipe capable of being processed as a reformed product with heat and pressure means. The invention further relates to a method of grouting a re-shaped plastic liner in positions where a radial liner separation from the existing pipe is filled-grouted and where an anchor position is utilized in firmly fixing the liner as a part of the overall composition consisting of the old pipe structure bonded by grout and anchored to a liner structure. Where warranted a non-bonded grouting with anchored liner can be used for pipe rehabilitation or renovation.

One method and a respective liner for protecting the interior of pipelines is disclosed in the pending applications Nos. WO 93/21398 and WO 93/21399 by Huls Troisdorf hereby incorporated by reference. In those publications there is disclosed a liner for relining conveyor lines like pipelines with an internal inliner and an external inliner, whereby the internal inliner forms a stiffened internal pipe after insertion into the external inliner and the external inliner is arranged at such a distance from the internal inliner that an open flow section is formed between the internal and external inliners as an inspection chamber to detect and, where necessary, remedy leaks in one of the liners, the above being particular to a patent application No. WO 93/21398.

Particular disclosure in patent application No. WO 93/21399, relates to a system and process for relining channel pipe sections with several hose-like inliners. The internal hose-like inliner of thermoplastic material has on its outside, e.g. a plurality of protuberances as spacers for an external liner (being a "plurality of protuberances" also particular to the invention described in U.S. Patent No.5, 167,895, Dec. 1, 1992 to Agru). The patent application proposes

that first a preliner and then an internal inliner externally fitted with protuberances be drawn into the channel to be repaired. A quicksetting mortar (sealant) is inserted into the annular chamber defined by protuberances and is allowed to set. Fundamental to the overall function of the invention is the space created by the protuberances.

One method and a respective liner for protecting the interior of pipelines is disclosed by French Patent No. 81 07 346 to Laurent. In that patent there is disclosed a cylindrical liner of plastic material having historic time memory properties, i.e. shape memory characteristics, the liner being deformed to a predetermined reduced overall diameter at an appropriate temperature. The deformed liner is introduced into a pipeline, and hot steam or fluid is forced into the liner sufficient to obtain an average crystallization temperature of the material so that the deformed liner assumes its original cylindrical shape. Pressure is then applied within the liner to conform the liner to the interior contour of the pipe.

Other patents were filed to extend the applicability and innovation with the same method for U-Liner Pipe: U.S. Patent Numbers 4,863,365, No. 4,985,196, No. 4,986,951, No. 4,998,871, No. 5,091,137, No. 5,112,211. All these methods are generic to a deforming/reforming process but not descriptive and proprietary to a final product, i.e., U, V, C and other shapes.

Another method for installing a plastic liner within a pipe is described in Japanese Patent Specification J5 3009-878. This known method is for lining metal pipe with a plastic pipe using a plastic pipe with projections or ribs on outer surface. The metal pipe lining is done through use of an adhesive layer coated on the outer surface of the plastic pipe, the plastic pipe has projections or ribs on its outer surface. The projections eliminate air pockets between the metal and plastic pipes. By use of the compressed air the liner is pressed against the metal pipe.

Another method for installing a plastic liner within a pipe is described in British Patent Specification 1 580 438 or in PCT application

PCT/AU86/00362. This known method uses liners of semi-rigid and non-standardly plasticized material, and provides the following steps: forcibly

mechanically collapsing (folding) the liner so as to form at least one longitudinally extending depression (fold), fixing a longitudinally extending tearable strap to or about the liner so as to maintain the collapsed configuration, introducing the collapsed liner in its maintained collapsed configuration into the pipe for a desired distance along and within the pipe and releasing the strap in order to restore the tube to its original shape, thus making use of the spring rebounding effect of the liner material.

U.S. Patent No. 5,034,180 discloses a method for installing a liner of plastic material in a pipe. The method of this patent uses a thin flexible tubular membrane providing a heat containment tube for insertion into and inflation within an underground conduit to be repaired. The thermally deformed liner is inserted into the tube while hot and flexible. The tubular membrane is pressurized to exclude unwanted fluids from within existing conduit. Then, hot steam is injected into the tube to heat the pipe for its full length externally and internally until it assumes its original circular shape, the liner being thereby expanded against the walls of the pipe, with a flexible tubular membrane therebetween.

All of these known methods rely on the deformation or mechanical collapsing of the plastic liners, and to the respective deformation of the deformed liner in the pipe. The thermoplastic liner using the material property "historic time memory" relies on this unique property which is then utilized in the reforming process to constitute the pipe within a pipe. These processes are restricted to liners which do not exceed a pre-given wall thickness and this affects the reliability of the lined pipe in some cases. The present invention provides a composite lining product, utilizing a thermoplastic sheet with protuberances (one or two sided on a single sheet) made into a tube, capable of being coiled in a flattened form for transportation and installation, folded or deformed into a compact shape with reduced cross section for insertion through an existing pipe, and a method for grouting consisting of the grouting tube (or/and multiple tubes) with perforations and grout application lengthwise at numerous points of the pipe and a method for a grout control lengthwise with internal /external pressure

monitors. This way a large size pipe reduction is converted into a manageable small size compact pipe prior to insertion into a host pipe, which affords increased management of the liner in the process of the pulling through pipes, bends, reduced sections, and other local imperfections, ability of multiple lining, increased length of the pipe with jointless connections. Where the deformed liner is concerned, the present invention allows reforming into a tight fit liner pipe by application of a thermo-pressure process at crystalline temperature, and forming a structural bonded or non-bonded composite liner with a given structure of the existing pipe. The present invention of the plastic liner composite pipe product includes a tubular liner with protuberances (one sided or both sided protuberances) of deformable thermoplastic material, the external diameter of the liner corresponding to internal diameter of the lined pipe (or computed circumference) reduced an amount to compensate for the created annulus resulting from the extended size of the protuberances, to establish a cavity for grouting and providing space for a permanent grouting tube (or/and multiple tubes). Installation of a thin wall liner with protuberances is done by means of utilizing pressure plugs capable of sustaining at least a pressure of 75 psi (,52MPa), which is necessary to provide resistance for the plugs against the internal pressures used in the liner processing and used to counteract the pressures of grouting. The means of closing the ends of the liner by use of rubber plugs can be substituted by an internal restraining spring with a membrane capable of sustaining an same pressures. The water pressurization or air pressurization can be applied for thin liners and where a deformed/reformed type thick wall liner is used a heat/pressure combination is utilized. The thermo-pressure process used in installation can be achieved at a rapid rate of heat permeation and the liner reconstitution in a fit shape can be achieved at the crystalline point.

The deformation of the cylindrically shaped tube into a compact shape is a process under controlled deforming temperature of approximately 77 deg. C (for HDPE material, other deforming temperatures for other materials apply accordingly), at which temperature in a continuous movement the deforming

rollers force the tube to move into the direction of the deformed formation (the shape of the form being prior art); these rollers have the ability to adjust to a level where a control for the wall separation is secured and pipe fusion is prevented; the above described roller assembly can be augmented with more rollers as case may be for production of the larger sizes. The process can be automated by use of a computerized method or manually adjusted or both.

The first step of manufacturing thermoplastic sheets with protuberances, by extrusion is prior art. The welding and putting the sheets into a tubular shape is novel. The continuation of the process to coiling is prior art too. While "U", "H", "X", "W" and "V" shapes are considered prior art the flattened shape was also considered prior art. Exception and distinction must be made for similarity with protuberances utilized for double-containment pipe as prior art. That invention represents fused liners having protuberances necessary for the process of fusion and without benefit of anchoring features as claimed in this patent application. The shapes annotated as prior art were not recognized for the benefits with incorporated protuberances nor were they technically analyzed as such, for a specific benefit that a protuberant feature can be used for anchoring and by sporadic anchor distribution for preventing the liner sheet to resist movements otherwise common to the thermoplastic sheets where installed as liner pipe. The present method is concerned with anchoring the liner, preventing concrete and liner movement, providing a high abrasion resistant surface in contact with a transported fluid, and securing the smooth interior surface in the shape fitting tightly to the given shape of the existing pipe, and maintaining its composite structure resistant to imposed loads from outside and inside the renovated or rehabilitated pipe.

The coiling of the liner with protuberances where a thin wall liner is used is related to the mechanical folding action by application of the torque force on the coiling machine and tightly packing the liner tube on the coil. The principles of coiling for a thick wall tube with protuberances has to be done by a method of controlled heat of the material for reason of "historic time memory" of the material. The coiling of the deformed tube with protuberances is specially related to the temperature of the material. There shall be a

range of temperatures suitable for coiling from as low as ambient to a temperature of deforming of 77 degrees C, for example in case with HDPE, never to exceed the temperature of crystallinity of the material. As a rule a higher temperature will produce thermal residual stresses and in combination with strain residual stresses will compress the coiled pipe. While this may require longer relaxation time in the installation process, it may be beneficial to compress the coiled pipe assembly. The chosen temperature is part of the process of manufacturing and shall be according to criteria set for the anticipated function of the pipe. It is therefore a general object of the present invention to provide a method for installing plastic liners with protuberances into an existing pipe, manufacturing of a particular plastic liner with protuberances from sheets into a tube, coiling of such plastic liner, installation with grouting and anchoring the liner in a composite structure tied to the existing structure by means of bonding or as a free restraining structure, wherein the method and manufacturing adds to the family of the products distinguished for lining the pipes with increased reliability, safety and risk control of the lined pipe.

It is a further object of the present invention to provide a tubular plastic liner of a specific shape under such drastically deformed cross section that can be practically pulled through an existing pipe with a great liberty of unconfinement, with increased reliability safety and risk control as compared with known liners of large pipe sizes.

These and further objects and advantages of the present invention will become apparent upon reference to the following specification, appended claims and drawings.

BRIEF DESCRIPTION OF THE DRAWING FIGURES Figure 1 is a side view of the diagrammatic process for co-extrusion of the plastic sheet with protuberances. This machine is prior art and the product is described in U.S. Patent No. 5,167,895; Figure 2 is the plan view depicting the spread of the protuberances in

"V" shapes in a staggered formation on a flat plastic sheet; such spread is variable and has as its purpose to provide anchors for a strong connection

with the grouting;

Figure 3 is a detail of a protuberance in "V" shape; Figure 4 is a side view of the "v" shape protuberance; Figure 5A is an isometric detail of the "V" shape distribution of protuberances, showing a 2-ply sheet 20C;

Figure 5B is a side view of the 2-ply sheet 20C of Figure 5A; Figure 6 is a re-formed tube showing protuberances from the outside of its envelope and the seamed joint used in manufacturing of the tube with protuberances; Figure 7A is a detail of the cross section through the joint and the detail showing the "V" shape protuberances;

Figure 7B is another type of the joint which utilizes a welded connection applied between the edges of the plastic sheet and fused by the pre-manufactured shaped fusion wire which electrofuses the sheet ends; Figure 8 is a cross section showing an existing pipe to be lined with a deformed or folded liner with protuberances and the outer liner which is optional where bonding is not required with the existing pipe;

Figure 9 is a cross section of the liner with protuberances in the position ready for grouting; Figure 10 is a diagrammatic presentation of the liner with protuberances winched through a manhole directly from the coil.

Figure 11 is a cross section of the liner with protuberances being winched through a manhole, and showing the skoocum sheaves arrangement for initial folding of the liner into a U" shape for unconfined entry into the existing pipe;

Figure 12 is a diagrammatic presentation of the liner with protuberances winched through a manhole and through a curved pipeline; Figure 13 is a cross section showing a principal arrangement for the injection of the grout; the measuring instruments are diagrammatic indication of the combined processing pressures applied from inside the liner with protuberances and pressures within the annulus resulting from the grouting operation; a continuous perforated tube used in grout application is strung

through the annulus and positioned in various arrangements, the straight one being the most common, in order to distribute the grouting with balanced pressures in all cavity spaces; the pressure drop resulting from voids in grouting is registered with instrumentation for internal pressure; such information is then an indication to the installer to modify the pressures of the grout application;

Figures 14A and 14B are cross-sections of plugs or loggyballs used as end mandrels for closing the liner with protuberances prior to pressurization; one type (Figure 14B) is composed of a loggyball with steam pipe for the injection of water or air and the other type (Figure 14A) is a curtain plug with a restraining ring and an injection hose attachment; alongside is the arrangement for the end fixation of the liner with protuberances, the grout injection perforated hose, and an existing pipe;

Figure 15 is a detail showing the anchoring properties of the liner with protuberances and the grout bonding with an existing pipe;

Figure 16 is a detail showing multiple liners with protuberances grouted in single or multiple grouting pressurization through continuous perforated grouting hoses; the grouting hoses remain as a part of the grout;

Figure 17 is a picture of the end mandrel arrangement with the continuous grouting hose exiting alongside the loggyball;

Figure 18 is the finished product - the grouted liner with protuberances in a sample egg shaped pipe; the shapes and sizes of the pipe may vary;

Figure 19 is a cross-section showing a liner with protuberances bonded to a pre-existing pipe 40 in the ground 70 with grout 50, with the grout 50 filling in gaps in the original pipe 40 as well as anchoring liner 20 to pipe 40; and

Figure 20 is a cross-section showing a spirally wound liner 20B grouted in place in a pre-existing pipe 40.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to a present preferred embodiment of the invention, an example of which is illustrated in the accompanying

drawings.

Figures 1-4 are taken from and are described in detail in U.S. Patent No. 5,167,895.

Referring now the drawings, the present invention is concerned with lining new and old pipes, preferably concrete and clay, forming part of complete pipelines with two or more generally concentric liners with protuberations and grouted to a fixed position, and bonded or non-bonded to an existing pipeline. The general presentation here relates to a lining system with protuberances and grouting employing one liner, i.e. liner with protuberances and grouting, and as a mentioned alternative a preliner can be used where no bonding requirements are set, but it will be appreciated that additional liners may also be employed in like manner. The prepared wall of an existing pipe, after passing inspection, is lined by a pulled-in liner with protuberances from a coiled position above ground. Where preliner is concerned, the liner with protuberances is pulled in sequences, in such a way that a flattened position of the liner on the coil passes through a shaping arrangement of shieves which provide for the "U" shaping the liner with protuberances prior to its entry into the inlet of the pipeline. In such a way the reshaped liner is drastically reduced in cross section of its envelope and easily pulled through the existing pipe in an unconfined manner.

The grouting process provides a bond, where required, with the existing pipeline and fills in a controlled manner the cracks and deformities, therefore, repairing the existing pipe, and by anchoring the liner with protuberances into the grout, the structure becomes connected in the pipeline to one another to provide a single unitary stable structure tightly fitting together. The liner with protuberances can be made of suitable plastic material which can be folded or deformed and subsequently returned to its original cross-section, or cross-section adaptable to a given shape of the existing pipeline, either by shape, i.e. , historic time memory properties of the material or by inherent elastic properties of the material.

Important to the process and of a great significance is the process of applying the grout and the proprietary grout mix. The perforated tube, which

remains grouted from inside and as such becomes a part of the annulus grouting component, is the continuous pipe sufficiently small to fit the annulus and being provided among protuberances can occupy a position suitable for the spiral, straight line, and other grouting positions. The pressures applied in grouting and annulus pressures are an indirect control providing information about the spread of the grout around the circumference of the pipeline, and when combined with pressure readings for internal reforming of the liner with protuberances represents indications of fullness of the grouting operation, whose objective is to provide a uniform grouting around a total circumference and the total length of a pipeline.

The prime application of this liner with protuberances system is in its thin-wall lining composition combined with grouting. As a thin-wall system the average wall thickness of the liner sheet can range from 3mm to 6mm to 12mm as per design requirements. The objective for lining large size pipes is set from 20 inches (50.8cm) to 60 inches (152.4cm) and where special conditions warrant and by the design considerations larger sizes too. The ancillary objectives are in lining only the bottom of an existing large size pipe or/and a tunnel structure, where the liner sheets with protuberances used are with fixed ends lengthwise and grouting is done in like manner. Such other ancillary conditions may consist of the spirally wound layers of the liner with protuberances; in a multiple-layered liner structure, grouting is either continuously connected through a spiral arrangement of the liner with protuberances or disconnected grouting layers where one liner is provided inside the other liner in a tubular shape. When tightly fit in its reformed state within the pipe, the liner 20 with protuberances 10 may have an exterior (inner) diameter generally corresponding to the internal diameter of the pipe minus twice the height of the size of the protuberance. However, this sizing may vary depending on the design requirements where more of the grout thickness is required, then the liner size becomes reduced and the result is the contraction of the internal diameter and separation of the protuberances from the wall of the existing pipe. Such a requirement may be desirable where an internal cross section of

the lined pipe may be reshaped to a more uniform and, e.g., more circular and smoother curvilinear shape. If a pre-liner 30 is used as a separator from the existing pipe 40, and as a grout containment barrier between the existing pipe 40 and the liner 20 with protuberances 10, the pre-liner 30 shall be either inserted prior or at the same time with the liner 20 with protuberances 10.

Referring now to Figure 8, there is illustrated a cross-section of a liner 20 with protuberances 10 in its folded (collapsed) or deformed state, and which has reduced overall diameter as compared to its diameter when in a cylindrical configuration. In accordance with a preferred embodiment of the invention, the liner 20 with protuberances 10 is formed of plastic material, e.g., high-density polyethylene, with historic memory properties or just folded, where a thin liner is concerned, in such a shape. When using such material where memory is of issue, the liner 20 with protuberances 10 is deformed into a generally "U" shaped cross-section by mechanically initiating and processing the deformation at a temperature range between the deforming temperature and the crystallization temperature of polyethylene material, i.e., for example, between 75 and 113 deg. C. When the material is cooled down, the liner with protuberances preserves its deformed shape, so that it can be pulled into a pipe, as in Figure 10. The prior art for deforming the plastic liner into a generally "U" shape is disclosed in U.S. Patent No. 4,998,871, issued March 12, 1991 to Pipe Liners, Inc. Further referring to Figure 8, there is illustrated a pre-liner 30 just for general information and not to be interpreted as a primary way of installing with the liner 20 with protuberances 10.

Referring now to Figure 6, the inner tubular liner 20 with protuberances 10 is provided with co-extruded radially outwardly extending, circumferentially spaced, and randomly in longitudinal direction as depicted in Figures 1 through 5, protuberances 10 of various sizes and proportional to the required thickness of the liner 20 with protuberances 10.

Referring to Figure 7A and Figure 7B, the positive welded connection is established for the sheets with protuberances where one method of fusion-welding is done by overlapping (Figure 7A) while another method (Figure 7B) uses a specially pre-manufactured electrofusion locking strip 21,

set in the grooved ends and by electric activation of the plastic material at a fusion temperature positive connection is established. This type of fusion eliminates the distortion resulting from overlapping and provides more uniformity to the liner tube 20A. The process of using a set-in locking strip is a manufacturing process done in the factory or a field process done with a portable equipment.

Referring to Figure 13, the liner with protuberances is open by forced- under-pressure steam, water or air. This steam or fluid has a temperature sufficient to obtain the average crystallization temperature of the plastic material so that the liner gradually starts to form itself in the tight-fit shape either permitted by the shape of the existing pipe 40 or by the maximum diameter of the pre-measured liner 20 with protuberances 10. In case of a thin wall liner with protuberances, the liner is only forced into the like positions with the help of unfolding force where it has to be maintained through the completion of the process. During this process, the annulus void is pressurized by means of application of grouting into a void-annulus and among the protuberances. The pressures of grouting are associated with the grouting component and only the test pressure with air can be applied in case where annulus shape needs to be compressed against the internal pressure resulting from the liner with protuberances processing.

When the original cylindrical shape is recovered, the liner 20 with protuberances 10 fits against the existing pipe 40 or it is expanded to its designed diameter, being under circumferential compression, as in Figure 9. In its restored shape, the liner 20 with protuberances 10, having rigidity and stability, is grouted with the pressurization grouting in a sensitive reactive relationship to the internal pressures.

When the grouting operation is finished, the anchoring of the liner 20 with protuberances 10 is finished, the movement of the liner 20 is minimized, and the bonding is established with the existing pipeline 40. The grout distribution is controlled by a fail-safe control pressurization and the grout bonding is the repair and new added structure to the existing pipeline. This structure can be multiplied with the addition of the multilayered liners 20 with

protuberances 10 as depicted in Figure 16. In addition of having the continuous perforated grouting hose 60 embedded into the grout 50, a leak detection system may be embedded too for future monitoring of the pipeline's performance and potential for breakage. Referring to Figures 14A and 14B, the system for end mandrels necessary for blocking the ends of the liner with protuberances is shown in two types: one (Figure 14A) is a standard rubberized plug structure or loggyball 80A with incorporated steam and pressure hose 82A for application of steam, water or air through the blocked ends, and the other (Figure 14B) is curtain wall structure 80B restrained against the wall of the existing pipe by a spring expanded metal ring 81B. The curtain wall structure is also provided with connections 82B for steam and pressure. Such system is adjusted in position by a mechanism controlled through the steam attachment opening prior to its connection to the steam boiler or generator. In both types the compression is made to the extent of approximately 75 psi (.52MPa) and under the temperature ranges from 80 to 125 deg. C, necessary to resist the movement of the plug and the plug resistance necessary with the friction factor to provide a firm grip with the existing pipe. The components squeezed are the liner 20 with protuberances 10, the perforated injection hose 60 and the applied mastic material in-between to preserve the shape of the liner's protuberances without squashing.

When the liner 20 with protuberances 10 is used as a thin-wall liner, the liner may be produced of elastic material having spring rebounding properties and no shape memory properties. The liner 20 with protuberances is then mechanically collapsed, and maintained in its collapsed configuration on the coil until it is in position to enter the pipeline inlet, or shortly before that, where the liner 20 with protuberances is shaped in "U" formation for insertion by pulling.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent

arrangements included within the spirit and scope of the appended claims. WHAT IS CLAIMED IS: