MEANS FOR AND METHOD OF DETECTING AND CONTROLLING PIPELINE LEAKAGES

Abstract: A liner pipe (2) which is resistant against the fluid flowing therein is inserted in an outer protective pipe (1) leaving a space (5) between them which extends over the length of the pipes. Any fluid leaking from the outside through the outer pipe (1) or fromthe inner pipe (2) will flow in said space to reach fluid detecting and controlling means arranged at intervals along the pipeline, at respective lowest points thereof, for analysis and removal. Preferably the outer pipe (1) is made of concrete, and the inner pipe is formed from a helically wound strip of ribbed plastics material. Spacers may be used to create said space (5). A method for introducing the liner pipe into the constructed outer pipe is described. Advantageous application for sewage pipelines.

Description: MEANS FOR AND METHOD OF DETECTING AND CONTROLLING PIPELINE LEAKAGES This invention relates to improvements in and to pipelines and :to a method of sensing to check the condition of the pipeline and to enable determination of the conditions of the pipeline. From DE 35 35 586 A1 there is known an arrangement for de¬ tecting leaks of a pipeline consisting of two concentric pipes defining an annular space between themselves. At about the lowest part of the slopingly installed pipeline, a tube connects said space to a control space underneath the pipeline with a window to show the presence of leak fluid. This arrangement is intended and useful for pipe¬ lines where at least the outer pipe is of steel, and a tight connection thereof with the control tube can easily be provided. It is already known to line pipes in sewer and fluid flow control means so that for instance a protective cover for the pipe carrying the actual fluid is given by an external pipe, the internal pipe for instance being con¬ structed of a liner material suitable to handle the fluid within the pipe line, the outer pipe providing the strength or protection for the liner. Past experience has shown that pipelines of concrete, reinforced concrete, clay, asbestos cement, cast iron, steel, plastic and composite materials used to date in the drainage, including the sewerage section, do not in- he long term meet the nonleakage requirements. This applies particularly to the pipe joints so that despite the best choice of materials and actual construction, exfiltration of wastewater must always be expected. For this reason, in protected water catchment areas, so-called double pipes are required in some cases. A problem with pipelines of this type is to be able to determine whether there is leakage into the pipe from a surrounding area, or out of the pipe to the surrounding area, and i£ is the principal object of this invention to provide a method of and means for detecting any such leakage. It is a further object to detect whether there is leakage fϊ-om the inner pipe, to the space between it and the outer pipe and also to detect whether there is leakage from the surrounding area into the space between the two pipes. It has been proposed to use for instance a concrete outer pipe and to wind into it a pipe formed of a plastics mate- rial such as by winding a plastics strip,especially a ribbed profile to helical form and joining the edges of the con¬ volutions, and it has also been proposed to expand such a pipe of plastics material into an outer pipe which may be formed of concrete or the like, or can itself be a pipe of the helically wound type, or formed of a plastics or simi¬ lar material in any other manner. It is also an object of the invention to readily detect and measure any leakage in the pipeline, whether it be into the space between the two pipes or infiltration of ground water, or exfiltration of drainage or the like handled by ' the pipeline. The object is achieved by providing a space at at least one cross sectional area of the pipes, disposed between the pipes of the pipeline or within the contiguous sur¬ faces of the pipes or within the cross sectional area of one pipe in a manner such that any leakage ' through either the inner or outer pipe or both will cause flow of the fluid into the space, means being provided at manholes or .the like to sense the presence of fluid in this space and thus to be able to determine readily whether either of the pipes of the pipe¬ line, or both are faulty. The system applies to multiple pipe configuration in general as more than one layer may be required. It is also possible to use this control space as pressur¬ ising means between the pipes to avoid inflow into the pipes from the surrounding area or to prevent outflow from the inner pipe to the area. The invention can be readily applied by shaping or dis¬ torting either the inner or outer pipe, such as by the pipe configuration or by the use of spacers or the like " and such configuration or spacers could for instance be positioned along a lower part of the pipes to give an area at which the fluid can flow and be detected. The invention also applies to pipes of the type previously referred to which are formed by winding a strip of any material, preferably plastics, to helical, or as it is •alternately termed, spiral form, which pipes usually have ribs projecting from the base of the strip for the purpose of providing the necessary strength and reinforcement of the pipe, and the invention extends to the use of such ribbed pipes where the ribs can be apertured or arranged to provide the necessary flow into the space between the ribs for sensing any presence of fluid. The apertures or configuration is such that any fluid leaking into the space between this pipe and the adjacent pipe of a compound structure will be sensed at a selected point such as at a manhole. It would of . course be possible to simply use such space between the ribs, even if the ribs are not apertured and are sealed to the adjacent pipe surface, because the helical or spiral winding affords a construction which will allow flow to take place longitudinally along the space provided that the height of the liquid or fluid is sufficient to reach the uppermost part of the flow path between the inner and outer pipes. It will be realised that the invention can readily be applied in the method known as the "Expanda Pipe" (Trade Mark) system in which a helically wound pipe is expanded or contracted to contact another pipe which may be of the same type or of other construction, and it is envisaged for; instance that a first helically wound pipe could be positioned, preferably during the winding process, into a sewer channel' or the like and expanded to line the channel and after that a second pipe is wound inside of the first pipe and expanded, to engage the first pipe, and if this second pipe is ribbed as described a sealed elongated helical space results in which any leakage which is either inflow or outflow can be detected and measured at a manhole or other area. Such a helically wound pipe however can itself be distorted during expansion by for instance placing a spacer such as a rod along preferably the bottom of * the outer pipe so that, during expansion, the expansion is limited adjacent to this spacer to leave a space in which any fluid which leaks into the space can flow to the detection locality. .The ribs of such a helically wound pipe could be undulated radially or otherwise formed at the extremities to still provide the necessary contact but ensure leakage past the ribs, or a series of spacers can be placed between the pipes to limit expansion of the inner pipe of the "Expanda Pipe" system. It will be realised that the method of carrying the invention into effect, as well as the form of the pipe and test apparatus involved, αan be widely varied according I to this invention but to enable the system to be fully appreciated the system in general will be referred to with reference to the accompanying drawings in which: FIG. 1 is a schematic view showing a double pipeline and showing a sampler connected to the pipeline which is arranged to detect fluid in the space between the inner and outer pipes, which sampler can be arranged to test pressures or type of fluid in the space or to pressurise the space when required, the sampler being arranged at any convenient locality such as a manhole in the case of a sewer line, FIG. 2 is a transverse section showing a heavy duty pipe having within it a flow channel, the pipe having a liner, FIG. 3 is a- view similar to FIG. 2 . but showing a series of spacers to provide .the cavity between the two pipes, FIG. 4 is " a view similar to FIG. 2 but showing a multiple construction comprising outer protective segments supporting a' liner pipe in which is positioned a second liner pipe with a longitudinal spacer at the bottom of the assembly to provide a flow path for any liquid which finds its way to between the two liner pipes,- FIG. 5 shows how the sampler " can be positioned in a manhole through which the inner pipe passes, the flow from the space between the pipes being into the manhole, FIG. 6 is a fragmentary sectional perspective view showing part of a compound pipe of the ribbed type formed by inter¬ connecting two pipes, one being shown of solid form, but providing a cavity between the ribs for the sensing of fluid in the cavities, FIG. 7 shows a similar form to FIG. 6 but of an alter¬ native ('construction using two helically wound pipes which for instance have been expanded into position, and FIG. 8 shows a form similar to FIG. 7 but modified to include a further membrane and perforations to allow flow into the channels defined between the ribs. The further membrane can be a solid plate with spaced apertures and the assembly can be reversed so that the plate is on the inside of a multiple wall pipe so formed. --- - FIG. 9 is a schematic view similar to FIG. 1 showing a section of a pipeline between two manholes, the space between the inner and outer pipes being sealed at each end of the section and provided with means to fill the space with a fluid to be pressurized. Referring to FIG. 1 the .outer pipe is designated 1 and the inner pipe 2 while the sampler is designated 3 and • the connection to the space is designated-4. As stated the sampler 3 can -take various forms and can be used for a number of purposes depending on the monitoring which is to occur of any flow, which appears in the space 5 between the-pipes or for control of the application of pressurising fluid where this is required for any purpose. In' FIG. 2 the outer pipe 1 has a longitudinal recess 6 formed in it so that any flow into the space between the outer pipe 1 and the inner pipe 2 is directed to the reces 6 and is then taken to the sampler or could simply be taken to a waste line to give for instance an indication of any leakage which is occurring. • Fig. 3 shows an embodiment similar to Fig. 2, but showing a series of spacers 7 to space the inner pipe 2 from the outer pipe 1. In any of the embodiments of Fig. 2, 3 and 4, the outer pipe 1 can be made of concrete, and the one or several spacers 7 in Fig. 3 may be formed integrally with the outer pipe 1 , during the fabrication process of the latter. FIG. 4 is a view somewhat similar to FIG. 2 but in this case the outer pipe 1 is segmented to form a protective channel and has in it a liner 8 against which the inner pipe 2 is positioned but in this case the inner pipe is distorted by having a spacer 9 at its bottom portion to provide on each side of it the recess for the fluid flowin into the space between the liner 8 and the pipe 2. FIG. 5 shows how such an assembly can be positioned in a manhole 10, showing again the outer pipe 1 and the inner pipe 2, the outer pipe terminating on each side at the edges of the manhole 10. The manhole in this case collect the fluid flowing into the manhole from the space between the inner pipe 2 and the outer pipe 1. Flow at this area can be taken to a sampler or other device whereby to give an indication of the presence of fluid in the space betwee the two pipes. The inner pipe 2 is preferably provided with a removable inspection plate 2A to give access into the pipe 2. FI G . 6 shows a fragmentary view of a lower section of outer pipe 1 and an inner, pipe 2, the outer pipe 1 being formed by a metal or similar member engaged by the inner pipe 2 which is of the helically formed type comprising a membrane 11 having upstanding ribs 12 with expanded ends 13, showing apertures 14 through the ribs of the helically* ormed strip from which the pipe is formed to allo flow longitudinally through the space formed between the base 11 of the' strip on which the ribs 12 are formed and the surface of the pipe 1 contacted by the expanded ends 13 of the ribs 12. FIG. 7 shows a modification of the form shown in FIG. 6 but in this the apertures are replaced by undulations 15 at the ends of the ribs 12, the undulations being shown only on the inner pipe 2, the outer pipe 1 in ' this case also being shown as formed by a helically wound strip. FIG. 8 shows a modification of FIG. 7 in which a membrane 17 extends over the outer pipe 12 to form a further series of channels between the ribs but with apertures through the membrane 17 and through the base of the strip 15 to allow draining into or out of the channels between the ribs. As stated earlier herein the assembly shown could be reversed to cause the membrane 17 to define the inner surface of the pipe. The membrane 11 of the pipe 1 also has apertures 19. FIG. 9 shows a pipeline similar to FIG. 1 extending between two manholes where the outer and inner pipe end, and at each end of the pipeline the space 5 between the outer and the inner pipe is closed by seals 20. The space 5 can be filled with fluid, e.g. water, by means of a* valve 21 and the water pressure can be read at a gauge 22 situated in the manhole and connected to the space 5. The invention allows, 1. 'The construction of new, maintainable sewer mains an d pipelines and of conduits for carrying water-polluting media j of double-pipe configuration, making use of outside or protective pipes of any preferred material and a liner pro d uced either by the spiral winding or the "Expanda Pipe" method. 2- τhe outside or protective pipe to be produced from any preferred material thus offering maximum cost advantage the protective pipe fulfilling the static functions and needs only be resistant to possible physical, chemical, biochemical and biological stresses from outside. 3. The liner to be of spirally wound ribbed plastics profile ("RIB LOC" - trademark) to represent the actual liquid carrier. 4. The liner to rest against the inner wall of the outer pipe by means of the "Expanda Pipe" (trademark) process and the T-ribs can create a defined annular space between liner and protective pipe. 5. The bottom of the protective pipe to be factory- -equipped with a checkable and cleanable channel which serves as a collecting and drainage channel for any waste- water exfiltrating through leaks in the product pipe, or groundwater infiltrating through leaks in the protective pipe. 6. The outside diameter of the liner to be smaller than the inside diameter of the protective pipe, ' and the annular space and the collecting and drainage channel can be formed by spacers. 7. The number and dimensions of the spacers on the inner wall of the pipe to depend on the pipe diameter. 8 . The spacers to be fitted to the inside of the pro ¬ tective pipe at the factory and to be continuous or inter ¬ mittent. 9. The spacers to be produced either on the spirally wound pipe with fixed or at first variable diameter ("Expanda Pipe" - trademark), during the winding process, or to be attached either to the spirally wound or "Expanda Pipe" -(trademark)-as prefabricated components. 10. The annular space, if required, to be sealed at the junctions in the manhole and those of the house con¬ nections and be filled with water. 11. The water in the annular space to be put under a pressure which generally prevents exfiltrations of for instance wastewater through possible leaks in the liner *.- and serves at the same time to locate leaks in the liner and to continuously or occasionally check the seal of the double-pipe system. 12. The water pressure in the annular space to be read off on a measuring device placed in the manhole-or another suitable location. 13. The annular space to ill with water in the case of pipelines lying in groundwater, due to infiltration through leaks in the protective pipe, and this case it is possible to measure and control the groundwater level and water pressure in the annular space. 14. The volume of water in the annular space to be con¬ trolled, that is increased or decreased by special filler and discharge nipples and the annular space to-be flushed for cleaning. 15. The continuous free flowing-off of for example ex- filtrating wastewater or infiltrating groundwater in the collecting and drainage channel of the protective pipe, making it possible to have a quantitative and qualitative check at the manhole. 16. The wastewater and/or groundwater flowing to the manhole to be collected and pumped away. 17. The rehabilitation of defective sewer mains and pipe lines and of conduits for carrying water-polluting matter to be effected by application of the double-pipe techniqu based on the "Rib oc" (Trade Mark) process with plastic ' profiles, the basic concept underlying this invention being to apply the double-pipe technique also to the re¬ habilitation of for instance defective sewer mains and pipelines. 18. In the case of repairing a sewer line, an "Expanda Pipe" (TM) to be inserted as a liner in the pipe tract requiring rehabilitation, and this liner takes over the function of the protective pipe and acts as a seal agains surrounding groundwater and fulfils a bearing function in relation to all acting external loads. Next it allows a second "Expanda" liner to be inserted as the product pipe for the collection and drainage of wastewater exfiltratin through the product pipe, or of groundwater infiltrating through the protective liner. It allows a special drainage fitting can be installed in the floor of the protective liner, but instead of the special drainage fitting it is possible to perforate the T-ribs of the Rib Loc profile in the factory in such a way that drainage to the manhole can take place, or the ribs can be otherwise shaped to achieve the required fluid flow. SUBSTITUTE SHEET Some of the advantages of the invention are as follows: A " The construction meets all requirements as regards controlled secure drainage of wastewater and water-poll- uting liquids. B The liner provides protection for the outside pro¬ tective pipe (e.g. corrosion protection for concrete pipes) and, there is no need in the sewerage sector for factory- made compound pipes e.g. concrete or reinforced concrete pipes with integral plastic linings and the attendant jointing problems . C The protective pipe need fulfil only static functions, the liner taking care of .physical, chemical, biochemical and biological demands generated by the medium. D The use of either spirally wound or "Expanda Pipe" ensures optimum adaptation of the liner diameter to the particular hydraulic requirements so that sedimentation is largely excluded. With sufficient nominal diameter of the protective pipe it is in the course of time possible to effect from the manhole, without difficulty and without excavation adjustments of the liner, diameter changes to meet changing hydraulic requirements . * - E Compared with conventional segmental liners, pipe joints and therefore the most significant weak spots of pipelines are eliminated. F compared with conventional continuous liners, there is no need for a trench as the liner can be inserted from the manhole without excavation and can ' if necessary be removed or replaced in the same way. G By sealing the annular space at the manhole and at the house connections, a constant or occasional leakage test of the protective pipeline and the liner is possible. ' H ' . Any wastewater exfiltrating due to damage of the liner, or groundwater infiltrating through the protective pipe, can be collected, led to the manhole and measured and analysed there. I The method meets all requirements of maintainable construction.

Claims: Claims 1. Means for detecting and controlling pipe leaks of a -pipeline consisting of an outer pipe and a concentric inner pipe, a space being provided between the outer and inner pipe, said pipeline being constructed with a gradient, and detecting means being connected to said space near to the lowest level of the pipeline, characterized in that the outer pipe. (1) is_a_.protective pipe. and the inner pipe (2) is resistant against the fluid within the pipeline, and that detecting and controlling means for sensing any fluid leakage into said space (5) are connected to said space. 2. Means according to claim 1 , characterized in that the outer pipe (1) is formed of concrete or re-inforced con- crete and the inner pipe (2) informed of plastics material. 3. Means according to claim 1 or 2, characterized in that the liner pipe(2) is formed of a helically wound strip of ribbed profile of plastics material ("RIB LOC" (trade mark)) . 4. Means according to claim 3, characterized in that the rib ' s: of the liner pipe (2) create a defined annular space between the liner pipe (2) -and the protective outer pipe (1). 5. Means according to claim 4, characterized in that each rib of the liner pipe (2) is provided with at least one aperture (14) at a point near the lowest part of said rib. 6. Means according to claim 1 or 2, characterized in that the outer pipe (1) is provided with an axially ex¬ tending checkable and cleanable channel (6) forming said space (5) which serves as a collecting and drainage channel • for any waste water exfiltrating through leaks in the liner pipe (2), or groundwater infiltrating through leaks in the outer pipe (1). 7. Means according to claim 1 characterized in that the outside diameter of the liner pipe (2) is smaller than the inside diameter of the outer pipe (1), and the space (5) and collecting and drainage channels are formed by at least one spacer (7 > 9), the number and dimensions of the spacers (7) being dependent on the diameter of the liner pipe (2) and the outer pipe (1 ) . 8. Means according to claim 7 characterized in that the spacers (7) are fitted to the inside of the outer pipe (1 or ' integral therewith, and are continuous or intermittent. 9. Means according to claim 7, characterized in that the spacers (7) form part of a spirally wound liner pipe (.2) or are attached to the liner pipe (2) as prefabricated components. 10. Means according to claim 1 , characterized in that the annular space (5) is sealed at junctions in a manhole and house connections and is adapted to be filled with a fluid. 11. Means according to claim 10, characterized by means to pressurise the fluid to prevent exfiltrations of for instance waste water through possible leaks in the liner pipe (2) and serving at the same time to locate leaks in the inner pipe (2) and to continuously or occasionally check the seal of the double-pipe system. 12. Means according to claim 11 characterized by means to read the pressure in the annular space. 13. Means according to claims 9, 10, 11 and 1 wherein the annular space is filled with water in the case of pipe¬ lines lying in groundwater, due to infiltration through leaks in the protective pipe, characterized by means to measure and control the groundwater level and water pressure in the space (5) . 14. Means according to claim 13, characterized by means to control the volume of water in the annular space and by means to increase-or decrease the water pressure to flush the said space for cleaning. ' 15. Means according to claim 1 characterized by means to allow continuous free flowing-off for example exfiltrating waste water or infiltrating groundwater from the space (5) to allow quantitative and qualitative check of the flow. 16. Means according to claim 1 characterized by means to pump away the waste water and/or groundwater. 17• The method rehabilitation of defective sewer mains and pipelines and of conduits for carrying water polluting matter characterized by positioning an inner pipe (2) in the defective sewer main or pipeline or con¬ duit (1) to provide a space (5) > connecting measuring and control means to the space (5), and manipulating conditions to monitor correct operation of the inner pipe (2) . 18. The method of claim 17 characterized in that the inner piβe (2) is formed from a plastics strip having a ribbed profile and means to interconnect the edges of the convolutions of the strip in a manner known per se- ' ("RIB LOC" (trade mark) system) . 19.. The method of claim 18 applied to repair a sewer line, characterized by inserting the inner pipe (2) as a liner in the pipe tract requiring rehabilitation to take over the function of the protective pipe and act as a seal against surrounding groundwater to fulfil a bearing function in relation to all acting external loads. 20. The method of claim 18 characterized in that a second liner formed from a helically wound strip of ribbed plastics material is inserted into the pipe tract and ex¬ panded at its final position to its final diameter to serve as the pipe for the collection and drainage of waste water exfiltrating through the outer pipe (1) or of groundwater infiltrating through the inner pipe (2). 21. The method of claim 19 or 20 characterized by in¬ stalling a drainage fitting in the flow of the inner pipe (2 22. The method of claim 18 wherein the ribs of the ribb profile are perforated or shaped to allow drainage to a man¬ hole to take place.

Inventors: MENZEL STANLEY WILLIAM OTTO, STEIN DIETRICH, MENZEL, STANLEY, WILLIAM, OTTO, STEIN, DIETRICH
Applicants: RIB LOC GROUP, STEIN DIETRICH, RIB LOC GROUP LIMITED, STEIN, DIETRICH
Application year: 1989
Main classification: F17D5
IPC codes: F16L9, F17D5, G01M3