Metal-containing polymeric reinforced pipe, method for manufacturing same and pipeline produced using said pipe

Abstract

The polymeric pipes reinforced with a metal casing are used for transporting oil and gas, acids, alkali products, drinking water and industrial water, and also in the transportation of aggressive and neutral pulps. A metal-containing polymeric reinforced pipe includes a welded metal casing and a polymeric matrix having an amorphous-phase-based molecular structure. The metal-containing polymeric reinforced pipe is produced by extrusion moulding with simultaneous feeding of a polymer melt and the reinforcing metal casing into the mould cavity, followed by intensive cooling of the internal and external surfaces of the pipe being moulded. The invention increases the quality and endurance limit in the radial direction of the metal-containing polymeric reinforced pipe, productivity of the process for manufacturing the pipe, and also the strength and technological effectiveness of a pipeline constructed from the pipes produced.

Claims

1. A method for producing a metal-polymeric pipe by extrusion molding, comprising the steps of: feeding a polymer melt from an extrusion head into a mold cavity being comprised of a heat-resistant non-metal bush, a mandrel after the bush, and an external mold barrel around the bush and said mandrel; welding a metal reinforcing framework comprised of longitudinal reinforcement elements and transverse reinforcement elements, the step of welding being comprised of: coiling said transverse reinforcement elements around said longitudinal reinforcement elements; constantly pressing said transverse reinforcement elements to said longitudinal reinforcement elements by a roll electrode with a force applied by a hydraulic actuator; and synchronizing mutual crossing of said longitudinal reinforcement elements and said transverse reinforcement elements with pulses to said roll electrode; simultaneously feeding of said welded metal reinforcing framework into said mold cavity so as to form a molded pipe; and cooling an internal surface of said molded pipe within said molded cavity and after the bush, and after said molded cavity, and an external surface of said molded pipe after said molded cavity so as to produce a polymer matrix with a molecular structure based on an amorphous phase.

2. The method according to claim 1, wherein said polymer matrix comprises an amorphous phase in an amount of 60-90% of total polymer volume.

3. The method according to claim 1, wherein the step of cooling further comprises the steps of: compressing air and a cooling liquid into a cooling agent as a mist so as to cool said external surface of said molded pipe; feeding a cooling liquid into an inner cavity of said molded pipe; and filling a space between said mandrel and a plug arranged within said molded pipe so as to cool said internal surface of said molded pipe, said mandrel being between the bush and said space, said space being between said mandrel and said plug.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is illustrated in FIGS. 1-13.

(2) FIG. 1 shows the structure of the claimed metal-polymeric pipe in a longitudinal sectional view.

(3) FIG. 1A shows the structure of the claimed metal-polymeric pipe in a cross-sectional view along A-A line.

(4) FIG. 2 shows a general schematic view of the device for continuously making a metal-polymeric pipe.

(5) FIG. 3 shows a schematic view of a section of the extrusion head with the welding machine arranged thereon.

(6) FIG. 4 shows a schematic view of the arrangement of one welding roll electrode on the carousel of the welding machine.

(7) FIG. 5A shows a graph illustration of curves of cooling a polymer melt during production of the claimed metal-polymeric pipe and according to the prototype.

(8) FIG. 5B shows a graph illustration of dynamics of increasing costs for production of the claimed metal-polymeric pipe with increasing pipe diameter, as compared to a non-reinforced polymeric pipe.

(9) FIG. 6 shows a schematic view of a pipeline constructed of the claimed metal-polymeric reinforced pipes.

(10) FIGS. 7A and 7B show schematic views of the connecting element and its arrangement on one end of a metal-polymeric pipe.

(11) FIG. 8 shows a schematic view of a welded connection of metal-polymeric reinforced pipes in a pipeline.

(12) FIG. 9 shows a schematic view of a welded connection of metal-polymeric reinforced pipes in a pipeline, the connection being reinforced with reinforced metal-polymeric sleeve.

(13) FIG. 10 shows a schematic view of a detachable flange connection of metal-polymeric reinforced pipes.

(14) FIG. 11 shows a schematic view of a detachable sleeve connection of metal-polymeric reinforced pipes.

(15) FIG. 12 shows a schematic view of a transition to a metal pipe.

(16) FIGS. 13A-13C show schematic views of embodiments of a T-piece and branch pipes for constructing the claimed pipeline.

DETAILED DESCRIPTION OF THE DRAWINGS

(17) A metal-polymeric reinforced pipe, as shown in FIG. 1, has a polymer matrix 1 and a welded metal framework made of longitudinal reinforcement elements 2 and transverse reinforcement elements 3. The framework is produced by spirally winding transverse reinforcement elements 3 onto longitudinal reinforcement elements 2 and their welding to each other in each point of their crossing. The metal-polymeric reinforced pipe is produced by extrusion molding during which a welded reinforcing framework is fed to a mold cavity, while simultaneously feeding a polymer melt to the cavity, and after a molded pipe leaves the mold cavity, it is subjected to intensive double-side cooling wherein a cooling agent is fed both on the inside and outside.

(18) The device for continuously producing a metal-polymeric pipe, as shown in FIGS. 2 and 3, comprises an extruder 4 mounted on a base 5 and provided with an extrusion head 6. Reels 7 and 8 are used, respectively, for feeding longitudinal and transverse metal reinforcement (in particular, wire). A jig 9 with slots along which the longitudinal reinforcement elements 2 are moved, is mounted onto the extrusion head 6 (FIG. 3). A mandrel 10, which is continuously cooled by a liquid on the inside, is secured to the extrusion head 6 via a heat-resistant bush 11. The housing (not shown in the Figure) of the welding machine is provided with a drum 12 having an individual rotary actuator (not shown in the Figure) on which the reels (bobbins) 8 for the transverse reinforcement elements 3, a guiding mechanism 13, a roll electrode 14 for welding the transverse reinforcement elements 3 to the longitudinal reinforcement elements 2 are arranged with the possibility of rotating freely. The drum 12 accommodates a stationary barrel 15 forming together with the mandrel 10 an annular mold cavity 16 for molding a polymer exiting the extruder. The cooling agent generator 17 is rigidly arranged on the outside of the mold barrel 15. A welding unit consisting of one or more roll electrodes 14 connected to power sources (not shown in Figures), an eccentric lever 18 and the actuator are arranged on the drum 12. For the purpose of continuously feeding the longitudinal reinforcement elements 2, as unwound from the reels 7, and outputting an extrudate from the extrusion head 6 a pulling mechanism 20 with adjusted force of tracks 21 is arranged after the head 6 in the direction of moving a molded metal-polymeric pipe 19.

(19) For the purpose of making pipes having a certain length a cutting device 22 is provided. A signal for starting the cutting process is supplied by a position sensor 23 arranged on a gravity roll carrier 24. The gravity roll carrier 24 has several guiding rolls and serves as the support for finished products; its structure also provides a system for collecting a cooling liquid and returning it to the cooling system.

(20) An extrudate, that is a melt of an extruded polymer, which exits the extrusion head 6, falls onto a continuously moving metal framework welded from elements of longitudinal reinforcement 2 and transverse reinforcement 3. The process of filling the framework with the extrudate is performed in the mold cavity 16 restricted along its internal surface by the mandrel 10 and the sleeve 11 arranged before it and the mold barrel 15 along its external surface.

(21) In order to produce the pipe internal surface of required quality (geometrical arrangementcoaxiality of the inner circumference, the external circumference and the framework; surface roughness) the mandrel external surface is polished, and the mandrel structure has the possibility of being positioned on the extrusion head due to an increased bore diameter.

(22) The longitudinal reinforcement elements 2 are tensioned and moved by the pulling device 20. The geometrical arrangement of the longitudinal reinforcement elements 2 relative to the pipe body is determined by slots disposed concentrically on the jig 9. The outer coil of the reinforcing framework is formed by simultaneous movement of the drum 12 feeding the transverse reinforcement 3 and translational movement of the longitudinal reinforcement 2. A coil of the transverse reinforcement 3 has a definite pitch, in accordance with the method, in the range of s-6 s (where s is the transverse dimension of the outer reinforcement) and is welded to corresponding, in succession crossed longitudinal reinforcement elements 2 by the roll electrode 14. The profile of the longitudinal reinforcement and the transverse reinforcement may have any section and is selected according to set properties of a pipe to be molded. The transverse reinforcement 3 is unwound from the reels 8 arranged on the housing of the drum 12, which reels rotate freely on bearings, and is fed to welding rolls 14 via a system of the guides 13. The hydraulic actuator and hydraulic control valves together with the eccentric lever 18 perform the function of pressing the roll electrode 14 to the transverse reinforcement coil. The welding roll 14 is pressed and a welding current pulse is fed simultaneously for contact welding, the time of feeding welding current pulses from transformers to the roll electrode being installed in several ways, for example:

(23) a) mechanically, with the use of a counting device and position sensors;

(24) b) automatically, on the basis of determination and coordination of: pulling speed of a pipe molded, rotational speed of the drum, voltage and strength of current supplied to the roll electrode 14. Feedback sensors are used for determination of most effective current parameters that are set earlier, on the basis of tests. In order to synchronize shock pulses and welding current pulses, the welding machine is provided with feedback sensors connected to a processor for the purpose of automatically determining optimal current parameters.

(25) In order to achieve an optimal structure of the polymer matrix (based on the amorphous phase), during production of a metal-polymeric pipe it is necessary to ensure continuous cooling of the extrudate after it exits the mold cavity 16. In order to cool the internal surface of a molded metal-polymeric pipe 19, a system for feeding a cooling agent to the mandrel 10, which is used for calibration of the inner diameter of a pipe produced, is provided. A cooling agent is fed through a tube 25 passing within the extrusion head 6. As the cavity within a molded metal-polymeric pipe 19 is filled, pressure is created there which is maintained by a bleeder valve arranged in a plug 26 installed within the pipe. For cooling on the outside the cooling agent generator 17 is used that supplies a cooling agent consisting of a pressurized gas and a cooling liquid onto the external surface of a molded metal-polymeric pipe 19. When a polymer melt fills the annular mold cavity 16 restricted by the mold barrel 15 on the outside, a cooling agent, which is sprayed from holes located on the inner side of the coil of the generator 17, is supplied directly from the outside onto the molded metal-polymeric pipe 19.

(26) If polymers that do not relate to the polyolefin group are used for molding a pipe, it is possible to use a cooling mixture including a cooling liquid and a pressurized gas with a temperature of a produced cooling agent below 0 C.

(27) After exiting the welding machine, a molded metal-polymeric pipe 19 passes through the pulling device 20, a pressure of the tracks 21 of which, for the purpose of avoiding defects in the pipe geometry or insufficient force of the said pressure, is adjusted manually or automatically. Then the pipe 19 is fed to the gravity roll carrier 24 and, while moving on rollers, reaches the position sensors 23 which locations on the gravity roll carrier is determined by a pipe required length. The sensors 23 feed a signal to the cutting device 22 which, while moving simultaneously with the pipe along the guides, cuts the finished metal-polymeric pipe. All the production process is continuous and cyclic.

(28) The melting temperature of polymers, which are most frequently used for continuous production of a metal-polymeric pipe, is in the range from 130 C. to 280 C. In order to mold a polymer, it is necessary to heat it above its melting temperature. Reinforced metal-polymeric pipes have increased long-term strength and, at the same time, maintain their flexibility in the system metal framework-polymer.

(29) According to the state of the art, slow cooling of a pipe after a polymer leaves the extrusion head contributes to the process of the polymer matrix crystallization which results in that the polymer structure of the pipe taken as the prototype consists of crystallites by 70-90% and is characterized by low flexibility and plasticity.

(30) Quick and deep cooling, which is used in production of the claimed pipe, enables to achieve a polymer structure consisting not more than by 10-30 Vol. % of fine-grain crystallites and by 70-90 Vol. % of amorphous zones. In a long time the crystallite factor in the polymer structure will become slightly higher due to an increase in the crystallite sizes, but this will not entail significant changes in the properties of a pipe produced, since the diffusion processes are very slow in solid polymers. The achieved macromolecular structure of a finished pipe has sufficient flexibility, since a main volume is occupied by amorphous zones that are plastic under action of loads; they deform, but not disintegrate.

(31) Production of a metal-polymeric pipe of high quality and strength opens prospective fields of its application both in pipeline transport and for creation of strong, relatively light load-bearing structures having perfect corrosion resistance. However, in order to use the claimed metal-polymeric reinforced pipes in pipeline structures, e.g. as shown in FIG. 6, and in other structures, it is necessary to develop reliable means for connecting metal-polymeric reinforced pipes therebetween.

(32) FIG. 7B shows that for connecting metal-polymeric reinforced pipes to construct a pipeline, it is first necessary to provide the ends of each pipe 19 with so-called end pieces, i.e. connecting elements 32 made as a sleeve produced from the same polymeric material as the pipe itself. The sleeve of the connecting element 32 covers a definite length from the end of the pipe 19 as well as covers visible portions of the metal reinforcement 33, thus precluding appearance of corrosion on open elements of the metal reinforcement. The connecting element 32 corresponding to the claimed invention may be made by making blanks in injection molding machines. Such a cast blank has certain allowances and technological elements that will be removed during subsequent machining, and a blank will have the finished appearance of a cylindrical sleeve with a collar along the inner circumference.

(33) According to another embodiment, a blank for making the connecting element 32 may be produced by extrusion as a non-reinforced (single-component) polymeric pipe, then such a pipe is cut into portions, and thereafter a connecting element in the form of the end piece shown in FIG. 7A is made out of each portion by lathing.

(34) The material used for producing the connecting element 32 is a welded polymer. Preferably, the same material is used as for production of connected metal-polymeric reinforced pipes; this helps to avoid problems with different coefficients of thermal expansion. However, in order to connect pipes made of different polymers, a material for the end piece may be selected with due regard to the optimal combination of materials used.

(35) The connecting elements 32 are made non-reinforced; they should be rigidly fixed at the pipe ends, in order to ensure a reliable connection of the latter in a pipeline. For this purpose thread 34 is made on the upper polymer circumference, this thread having a pitch, tooth height and start angle that allow to avoid appearance of the reinforcing framework elements on the surface. A device for making thread may include a tapping die with handles and a guide, or, in a case of making this process mechanical, a unit with a drive for rotating and moving a tapping die and guides. After thread is made, the connecting element 32 is screwed onto the pipe 19, which, on its inner contact surface, already has thread with the parameters corresponding to those of the thread on the pipe. The process of repairing a pipeline with the claimed connecting elements may be performed in field conditions, since there is no necessity of dismounting a pipe to be repaired and no additional special equipment is required.

(36) FIG. 8 shows a welded connection of metal-polymeric reinforced pipes in a pipeline. A connection of two metal-polymeric reinforced pipes 19 and 36 in the claimed pipeline may be made with the use of the connecting elements 32 and 37, respectively, at the ends of such pipes. In order to make a welded connection, pipes should be arranged butt-to-butt by the end faces of the connecting elements 32 and 37 with the possibility of heating the end faces with a flat heater of iron type arranged therebetween. After removing the heater, the welded connection 38 is achieved by pressing the pipes by way of translational movement in the opposite direction.

(37) FIG. 9 shows a welded connection of metal-polymeric reinforced pipes in a pipeline, which is strengthened with a reinforced metal-polymeric sleeve. In order to make this connection, the connecting elements 32 and 37 are mounted onto the end faces of the metal-polymeric reinforced pipes 19 and 36 in the way described above, which connecting elements 32 and 37 are welded to each other along their end surfaces, thus obtaining a weld 38, then thread 39 is made on the external surface of the sleeves of the connecting elements 32 and 37. A metal-polymeric pipe length having a diameter that is greater than that of the pipes is used as a connecting sleeve 40, and the internal surface of the sleeve on its two sides is provided with complementary thread corresponding to the thread 39 on the external surface of the sleeves 32 and 37. Then the sleeve 40 is screwed, with the use of its thread 39-41, onto the connecting elements 32-37 welded therebetween for achieving threaded sleeve strengthening of the welded connection of the metal-polymeric reinforced pipes. For the purpose of protection against corrosion polymeric rings 42 are arranged on the end faces of the sleeve 40, which cover metal reinforcement portions visible on the faces.

(38) FIG. 10 shows a detachable flange connection of metal-polymeric reinforced pipes, which is used for strengthening welded connections in a pipeline. For this purpose the external wall of the connecting elements 43 is provided with a groove with a chamfer 44 for arranging flanges 45 having the shape of a ring with holes arranged circumferentially, and the inner annular surface of the flanges is provided with a complementary conical surface having a cone angle corresponding to the angle of the chamfer 44 made at the respective connecting element 43. The pipes 19, 36 are connected by tying the flanges 45 with the use of studs 46 and nuts 47.

(39) FIG. 11 shows a detachable sleeve connection of the metal-polymeric reinforced pipes 19 and 36, which is achieved with the use of the connecting elements 32 and 37 mounted onto the ends of these pipes. The external surface of the sleeves of these connecting elements is additionally provided with thread 39 for a sleeve. A length of a metal-polymeric pipe with a diameter greater than that of the pipes to be connected may be used as a sleeve 48. For this, the internal surface of the sleeve 48 should be provided with complementary thread on two sides, which will enable to screw the sleeve 48 onto the sleeves of the connecting elements 32 and 37. The sleeve 48 is additionally provided with the protective polymeric rings 42 covering reinforcement on the ends.

(40) When making a sleeve connection in a pipeline, thread on the external surface of the sleeves of the connecting elements 32 and 37 may be, for example, cylindrical. In such a case, this connection in the pipeline comprises a sealing ring 49 which is arranged between the end faces of the connecting elements 32 and 37.

(41) According to another embodiment, the external surface of the sleeves of the connecting elements 32 and 37 may be provided with conical self-sealing thread. In this case no sealing ring is required between the end faces of the connecting elements.

(42) FIG. 12 shows a transition from a metal-polymeric pipe 19 to a metal pipe 50, which transition may be used in the claimed pipeline if the latter is connected to a common pipeline of a city network.

(43) A connection between the metal pipe 50 and the metal-polymeric pipe 19 is made with the use of a polymeric connecting element 51 arranged at the end of the metal-polymeric pipe 19 on thread. The external surface of the sleeve of the connecting element 51 has a conical chamfer 52 for the mounting surface of an additional metal sleeve 53 covering the connecting element 51 on the external side. The external surface of the additional metal sleeve 53 is provided with thread 54. Complementary thread 55 is made on a transitional barrel 56 into which the metal pipe 50 to be connected to the pipeline is inserted and secured, e.g., by welding 57.

(44) The above-described connections of metal-polymeric reinforced pipes are shown in FIG. 6 within a length of the claimed pipeline, which length is made in one branch pipe with a transition to the metal pipe 50 and in another branch pipe with a transition to a polymeric non-reinforced pipe 58. The pipeline shown in FIG. 6 comprises a connection 59 made by butt welding of the connecting elements (as shown in FIG. 9), which connection is strengthened with a reinforced metal-polymeric sleeve arranged on the elements from above on conical self-sealing thread 60. Further, the pipeline comprises, as a stop valve, a wedge plug 61 mounted with the use of a flange connection 62. Further, a welded connection 63 is made that is shown in FIG. 8. Then, a branch is made with the use of a T-piece 64. Further, a sleeve connection 65 is shown that is made detachable with the use of cylindrical thread. Then, a detachable sleeve connection 66 is mounted that comprises the sealing ring 49 arranged as shown in FIG. 11. Further, a transition to the metal pipe 50 follows that is made as a detachable connection 67 shown in FIG. 12. In order to change the pipeline direction branch pipes 68 are used that are made as connecting elements according to various embodiments.

(45) FIG. 13A shows one embodiment of a composite T-piece 64; and FIGS. 13B-13C show several embodiments of the branch pipes 68 for constructing the claimed pipeline.

(46) When pipelines are built, there exists a necessity of solving process tasks, such as making network branches, connecting to the main pipeline, constructing a bypass pipeline and many others.

(47) The present technical solution proposes a composite T-piece that is shown in FIG. 13A and intended for a pipeline made of metal-plastic reinforced pipes. The T-piece material is a composite of a metal and a polymer, and the T-piece comprises a metal T-piece 69 that is covered by a polymeric casing 70, that is, a metal T-piece is included into a polymeric T-piece. Short lengths of a metal framework 71 having a cylindrical shape are welded to three ports of the metal T-piece 69. For the purpose of making a composite T-piece a metal (stamped, cast, welded, etc.) T-piece 69 is mounted into a welding jig. Lengths of a metal framework 71 are in succession welded to its three ports, which lengths correspond to the framework of the metal-polymeric pipe 19. Also, in order to strengthen a weld, in some cases it is possible to use metal shells that are welded over the metal framework 71.

(48) After the metal centerpiece is made, it is placed in a mold where the polymeric body, i.e., casing 70, of the T-piece is molded. Then, the finished part is processed, i.e., process gates and burrs are removed, and the part is processed by lathing.

(49) This composite T-piece is used for constructing pipelines from the metal-polymeric reinforced pipes 19. It is connected to the pipe 19 via the connecting element 32 completed with the connecting sleeves 40 or 48, or by butt welding of two connecting elements 32, or with the use of a flange connection which is shown in FIG. 10. Also, it is possible to use it for connecting the claimed pipeline to a pipeline made of pipes of other type, such as glass-reinforced plastic, polyethylene, with the use of respective connecting elements 32.

(50) Strength of this composite T-piece 64 is similar to the strength of a metal-polymeric pipe 19. It enables to use the composite T-piece 64 in pipelines constructed from metal-polymeric reinforced pipes without reducing the operating pressure.

(51) FIG. 13B shows a composite branch pipe 73 made according to the same technology as the above-described composite T-piece 64. It comprises a metal branch pipe 74 enclosed in a polymeric casing 75. When forming a metal centerpiece, lengths of a metal framework 71 are welded to ports of the metal branch pipe 74, which lengths correspond to the framework of the metal reinforced pipe 19. Also, in order to strengthen a weld, in some cases it is possible to use metal shells that are welded over the metal framework 71. Then, a polymeric casing 75 is made in a mold.

(52) According to another embodiment of the branch pipe 68, as shown in FIG. 13C, it is formed from two or more lengths of a metal-polymeric pipe (depending on a turning angle) onto which, at its two ends, the connecting elements 32 are mounted.

(53) In order to obtain a required turning angle, the connecting element is either made in a mold with the use of which an end piece with a certain angle of the end cut is made, or the connecting element is processed by cutting for the purpose of obtaining a set angle of the end cut.

(54) It should be noted that the connecting element 32 may be used not only on metal-polymeric reinforced pipes, but also for connecting a pipeline made of metal-polymeric reinforced pipes 19 to glass-reinforced plastic pipes as well as to other types of pipes 58, primarily pipes made of plastic materials, e.g., pipes made of a polymer reinforced with a metal foil, and/or pipes made of a polymer reinforced with a metal band, and/or pipes made of a non-reinforced polymer.

(55) The dimension range (outer diameter) of a metal-polymeric pipe 19, which is used for constructing pipelines in accordance with the present invention, is from 50 mm to 1,000 mm with the pitch of 1 mm (for diameter). The claimed connecting element 32 is made according to the same range, its inner diameter being equal to the outer diameter of pipes to be connected with due regard to allowances and seating fits.

(56) The best embodiments of connection for metal-polymeric reinforced pipes are explained below as Examples, which, in a combination, enable to construct a pipeline of an unlimited length that will be optimized for a specific variant of its application.

EXAMPLE 1

(57) A metal-polymeric reinforced pipe is produced by a method of continuous extrusion molding with the use of the device shown in FIG. 2.

(58) In order to prepare a polymer melt for molding, granulated polyethylene was loaded into the extruder 4, and the polymer melt was fed from the extrusion head 6 via the passage for outputting polymer into the mold cavity 16 formed by the cooled mandrel 10 and the external molding barrel 15, simultaneously feeding a welded reinforcing framework made with the use of one roll electrode, as shown in FIG. 4, into the said cavity. The distributor 27, which guides a melt flow in parallel to the internal surface of the extrusion passage, is arranged before the entrance into the mold cavity 16. The heat-resistant non-metal bush 11, which is mounted before the mandrel 10, is secured to the distributor 27. The heat-resistant bush 11 is made of a material with low heat conductivity. It protects the cooled mandrel 8 against direct thermal action of a melt going out of the passage. At the same time, this bush 11, due to properties of the material it is made of, have no effect on a temperature mode of a moving melt. The selection of a material with low heat conductivity (polymers, ceramics, etc.) for making the heat-resistant bush 11 is conditioned by its intermediate position between the cooled bronze mandrel 10 and the extrusion head 6 which arbor is heated to a temperature of a polymer melt prepared for molding (190-240 C.). The function of the heat-resistant bush 11 is to preclude direct heat transfer from the extrusion head 6 to the mandrel 10, which improves temperature conditions for molding a metal-polymeric pipe.

(59) After the metal-polymeric pipe 19 left the mold cavity 16, its inner and external surfaces were cooled intensively. The curves of cooling the polymer melt during molding the pipe are shown in FIG. 5A. Curve 1 corresponds to the prototype; Curve 2 corresponds to the claimed method. The cooling time of the polymer from the molding temperature to the room temperature according to the prototype was 245 seconds, and according to the claimed method86 seconds. Quick cooling enabled to form, primarily, an amorphous structure of the polymer matrix of the reinforced pipe, due to which the long-term strength of the pipe made according to Example 1, as measured during cyclic temperature changes from 40 C. to +80 C., was more than 1,200 cycles, and that of the pipe according to the prototype was from 130 to 245 cycles.

(60) Furthermore, it should be noted that, in order to ensure higher strength, during welding a pressing force and shock pulses were supplied to the roll electrode 14 by the hydraulic actuator, which were synchronized with the time of mutual crossing of the reinforcement longitudinal elements 2 and transverse elements 3, as well as with the time of supplying a current pulse to the roll electrode 14.

(61) To supply shock pulses the shock mechanism 28 (FIG. 4) was used, which comprised a hydraulic cylinder arranged within the rod 29 connected to the hydraulic actuator. That is, a shock pulse is supplied to the shock mechanism 28 by the hydraulic actuator, which pulse is transformed into translational movement of the rod 29 to the opposite end of which the eccentric lever 18 with the roll electrode 14 is secured. Thus, the welding process was combined with forging, which improved strength of each welded connection of the reinforcing framework. The shearing strength of a welded connection of the reinforcing framework longitudinal and transverse elements in each connection point was at least 35 kgf.

(62) Furthermore, in order to continuously press the roll electrode 14 to the reinforcing framework elements to be welded, a pressing device was used that was made as a spring 30 arranged on the rod 29 of the hydraulic cylinder and resting against the lever 18 of the roll electrode. That is, when making a reinforcing framework as a means for forming a coil of the transverse reinforcement elements 3, the roll electrode 14 was used which roll ensures continuous pressing of the transverse reinforcement elements to the longitudinal reinforcement elements due to a force provided by the hydraulic actuator. Steel wire (Steel 3) of round section and having the diameter of 3 mm was used as the transverse and longitudinal reinforcement elements. The guiding device 31 was used for guiding the wire directly under the roll of the electrode 14.

(63) Steel wire (Steel 3) of round section and having the diameter of 3 mm was used as the transverse and longitudinal reinforcement elements.

(64) The dimension range (in outer diameter) of the metal-polymeric pipe thus produced was from 50 mm to 1,000 mm with the pitch of 1 mm (per each diameter).

(65) The following dimension ranges of the reinforcing framework for producing the said pipe were selected: reinforcement section: 0.2 to 16 mm, pitch 0.1 mm; pitch between the transverse reinforcement elements (coil)s to 6 s, where s is the transverse reinforcement section (coil), in mm.

(66) It should be noted that the pipe dimension is calibrated according to its inner diameter, contrary to the conventional production technologies for producing polymeric pipes and profiles according to which calibration is performed according to the outer diameter of the product.

(67) The experiments carried out with specimens of the pipes produced in accordance with Example 1 as well as an analysis of the macromolecular structure of the pipe polymer matrix enabled to draw a conclusion that simultaneous use of intensive internal and external cooling gave the possibility of adjusting the speed and depth of polymer cooling for obtaining the pre-determined structure of the polymer matrix based on the amorphous phase of the molded polymer.

(68) Residual stresses in microvolumes of the produced pipe polymer matrix were not more than 2 kg/cm and, practically, had no effect on its durability.

(69) During prolonged operation these insignificant stresses in the polymer matrix relax.

(70) A breaking load during axial tension of the produced pipe is more than 2 times greater than the normative value for metal-polymeric pipes.

(71) Long-term stability of a metal-polymeric pipe produced according to Example 1, as measured at cyclic temperature changes from 40 C. to +80 C., is more than 1,200 cycles.

(72) Long-term stability of the produced pipe made with a butt-to-butt welded connection, when tested at wall stresses 6 MPa and at +80 C. is at least 1,000 hours; at stresses 13.4 MPanot less than 170 hours; and at stresses 19 MPanot less than 100 hours.

(73) The metal-polymeric reinforced pipes, which are produced as described above, show high resistance against the action of corrosive agents both of natural and industrial origin, such as sulfurous gas with concentration from 20 to 250 mg/L per day, chlorides with concentration less than 0.3 mg/L per day, various acids and alkalis as well as to the action of sea water and soil-corrosive environment.

(74) The metal-polymeric reinforced pipes, which are produced in accordance with Example 1 with the wall thickness from 11.0 to 12.5 mm, are characterized as having operating pressure of 40 atm, operation temperature mode in the range from 50 to +95 C., impact strength at the level of 427.4 kJ/m.sup.2, fatigue ratio of, at least, 0.46.Math.10.sup.7 cycles, number of cyclic loads at 0.4 MPa with frequency of 25 Hzat least 3.Math.10.sup.6 cycles, thermal expansion coefficient of 2.Math.10.sup.5, tightness at constant pressure for one hourat least 5-10 MPa (depending on pipe diameter) and safety factor from 2 to 4.75 (depending on pipe diameter in the range from 95 to 225 mm).

(75) The physical-mechanical properties of the pipes produced in accordance with Example 1 are shown in Table 1.

EXAMPLE 2

(76) Metal-polymeric pipes reinforced with a welded metal framework were produced in the same way as in Example 1. The material for molding the pipe polymer matrix was polyethylene corresponding to GOST 16338-85, and various variants of metal-roll, rods and wires were used as the longitudinal and transverse reinforcement elements.

(77) A metal wire or rod of round section with the diameter of 3 mm, of square section with square side of 2.7 mm, of trapezoid section with base of 3 mm and sectional area of 7.1 mm.sup.2, of oval section with minimum diameter of 2.5 mm was used for the longitudinal and transverse reinforcement elements. Steels of various grades or alloys based on ferrous and non-ferrous metals, in particular, chrome-, nickel- or copper based alloys were used for producing the longitudinal and transverse reinforcement elements. An alloy for producing the reinforcement was selected under the condition of suitability for electrocontact welding and depends, mainly, on the purpose of a finished product.

(78) The properties of the metal-polymeric pipes reinforced with a welded metal framework produced in accordance with Example 2 are shown in Tables 2-4.

(79) An analysis of the findings shows that the presence of even one flat face in the longitudinal and transverse reinforcement elements increases the contact area during welding of the reinforcing elements therebetween and improves the strength of the whole welded framework as well as indices of allowable axial tensile load and ultimate collapsing pressure for the pipe produced.

(80) The claimed method for producing metal-polymeric pipes reinforced with a welded metal framework, as it is described below, may be carried out with the use of various polymers for forming the body (matrix) of the pipe, in particular, with the use of fluoroplastic, polyesterketone, polyestersulfon, polyurethane, thermoplastic vulcanized elastomers, polyamides and other polymers.

EXAMPLE 3

(81) Metal-polymeric pipes, reinforced with a welded metal framework were produced in the same way as in Example 1. But, as the material for molding the pipe polymer matrix, fluoroplastic-4 was used which had density of 2.12-2.17 kg/m.sup.3 and tensile yield point of 12-20 MPa. Fluoroplastic was selected as a polymer having higher chemical stability and heat resistance in comparison with other polymers. In the process of processing fluoroplastic-4 components are added to it that enable to raise the level of polymer cold flow, without compromising its physical-chemical properties. Such additives include graphite, metal sulfides and other antifriction materials.

(82) A pipe was produced that had the outer diameter of 115 mm and could be used at an operation temperature in the range from 150 to +260 C. The ultimate collapsing pressure for this pipe was 7.0 MPa, the allowable axial tensile load was 14.6 tons-force. The pipe properties are presented in Table 5.

EXAMPLE 4

(83) The method for producing metal-polymeric pipes reinforced with a welded metal framework was carried out with the device (FIGS. 2-3) in the same way as in Example 1. For forming the pipe polymer matrix polyesterketone (PEKK) was used that had density of 1.28-1.31 kg/m.sup.3 and tensile yield point of 91-112 MPa.

(84) A pipe was produced that had the outer diameter of 160 mm and could be used at an operation temperature in the range from 90 to +260 C. The ultimate collapsing pressure for this pipe was 14.0 MPa, the allowable axial tensile load was 20.4 tons-force. The pipe properties are presented in Table 6.

EXAMPLE 5

(85) The method for producing metal-polymeric pipes reinforced with a welded metal framework was carried out with the device (FIGS. 2-3) in the same way as in Example 1. For forming the pipe polymer matrix polyestersulfon (PES) was used that had density of 1.36-1.58 kg/m.sup.3 and tensile yield point of 83-126 MPa.

(86) A pipe was produced that had the outer diameter of 140 mm and could be used at an operation temperature in the range from 100 to +200 C. The ultimate collapsing pressure for this pipe was 16.0 MPa, the allowable axial tensile load was 16.0 tons-force. The pipe properties are presented in Table 7.

EXAMPLE 6

(87) The method for producing metal-polymeric pipes reinforced with a welded metal framework was carried out in the same way as in Example 1. But, the material for forming the pipe polymer matrix was polyurethane of TPU grade that had density of 1.12-1.28 kg/m.sup.3 and tensile yield point of 12-70 MPa.

(88) A pipe was produced that had the outer diameter of 115 mm and could be used at an operation temperature in the range from 70 to +170 C. The ultimate collapsing pressure for this pipe was 14.1 MPa, the allowable axial tensile load was 15.0 tons-force. The pipe properties are presented in Table 8.

EXAMPLE 7

(89) The method for producing metal-polymeric pipes reinforced with a welded metal framework was carried out with the claimed device in the same way as in Example 1. The material used for forming the pipe polymer matrix were thermoplastic elastomers TPV (based on polyolefins) that had density of 0.97 kg/m.sup.3 and tensile yield point of 2-28 MPa.

(90) A pipe was produced that had the outer diameter of 200 mm and could be used at an operation temperature in the range from 60 to +130 C. The ultimate collapsing pressure for this pipe was 9.4 MPa, the allowable axial tensile load was 24.0 tons-force. The pipe properties are presented in Table 9.

EXAMPLE 8

(91) The method for producing metal-polymeric pipes reinforced with a welded metal framework was carried out with the claimed device in the same way as in Example 1. The material used for forming the pipe polymer matrix was suspension polyvinylchloride (PVC-S) having density of 1.13-1.58 kg/m.sup.3 and tensile yield point of 4-7 MPa.

(92) A pipe was produced that had the outer diameter of 115 mm and could be used at an operation temperature in the range from 10 to +70 C. The ultimate collapsing pressure for this pipe was 14.4 MPa, the allowable axial tensile load was 13.8 tons-force. The pipe properties are presented in Table 10.

EXAMPLE 9

(93) The method for producing metal-polymeric pipes reinforced with a welded metal framework was carried out with the claimed device in the same way as in Example 1. The material used for forming the pipe polymer matrix was polyamide (of PA-6, PA-12 grades) having density of 1.02-1.13 kg/m.sup.3 and tensile yield point of 80-100 MPa.

(94) A pipe was produced that had the outer diameter of 225 mm and could be used at an operation temperature in the range from 60 to +115 C. The ultimate collapsing pressure for this pipe was 18.6 MPa, the allowable axial tensile load was 10.2 tons-force. The pipe properties are presented in Table 11.

EXAMPLE 10

(95) In order to use for constructing the pipeline, as shown in FIG. 8, a welded connection was made of the metal-polymeric reinforced pipes 19 and 36. For this, the connecting elements 32 and 37 were mounted on thread on each pipe. Then, a flat heating iron (not shown in the Figure) was placed so as to be between the end faces of the connecting elements 32 and 37, the iron was squeezed with the pipes 19 and 36, and then the end faces of the connecting elements 32 and 37 were heated simultaneously. After reaching the required temperature the pipes 19 and 36 were separated to a small distance, the iron was removed, and the two pipes were pressed with opposite forces; in the result a weld 38 was produced. After the connection reaches the ambient temperature, it may be used.

(96) The long-term stability of a polyethylene reinforced pipe made with the above welded connection, when tested with wall stresses of 6 MPa and temperature of +80 C., is at least 1000 hours; at stresses 13.4 MPaat least 170 hours; and at stresses 19 MPaat least 100 hours.

EXAMPLE 11

(97) For the purpose of constructing a pipeline a welded permanent connection for metal-polymeric reinforced pipes 19 and 36 was made with subsequent strengthening of the welded connection with a reinforced sleeve 40, as shown in FIG. 9.

(98) This embodiment of the connection enables to construct a pipeline from metal-polymeric reinforced pipes of large diameters (from 275 mm and above), owing to the joint use of a welded connection and threaded connection. This method is most effective for using in pipelines and casing columns of large diameters, since with increasing a pipe outer diameter a load at a connection is also increased.

(99) After mounting the connecting elements (end pieces) 32 and 37 onto the pipes 19 and 36, they were welded at their end faces with the use of a heating iron, in the same way as in Example 10, for producing the weld 38, and the external surface of the welded connecting elements 32 and 37 were provided with thread 39. The next step is screwing of a connecting sleeve 40. As the sleeve 40, a length of a metal-polymeric pipe with a diameter greater than that of the pipes 8 and 9 to be connected may be used, i.e., an inner diameter of the sleeve 40 is equal to the outer diameter of the connecting elements 32 and 37. Complementary thread 41 is made on the internal surface of the sleeve 40 on two ends, which enables to screw the sleeve 40 onto the bushes of the connecting elements 32 and 37 for the purpose of strengthening the welded connection 38 of the pipes 19 and 36. In order to protect the reinforcement against corrosion, the sleeve 40, which is made as a length of a metal-polymeric pipe, comprises protective polymeric rings 42 covering reinforcements visible at the end faces.

EXAMPLE 12

(100) This Example (FIG. 10) presents a detachable flange connection of the metal-polymeric reinforced pipes 19 and 36, which is made with the use of the claimed connecting elements 43.

(101) The connecting elements 43 are processed for arranging flanges 45 by making an external groove with a chamfer 44, as shown in FIG. 10. The flange 45 is a ring with holes disposed circumferentially. The internal annular surface of each flange 45 is provided with a conical chamfer with a cone angle corresponding to a cone angle of the chamfer 44 on the external side of the connecting element 43.

(102) The two pipes 19 and 36 provided with the flanges 45 are assembles into a pipeline with the use of studs 46 and nuts 47. In order to seal the pipe flange connection, gaskets 76 are used that are arranged in annular grooves made in the end faces of the connecting elements 43.

EXAMPLE 13

(103) For the purpose of constructing a pipeline a detachable sleeve connection for the metal-polymeric reinforced pipes 19 and 36 was made (as shown in FIG. 11) with the use of the connecting elements 32 and 37. The external surface of the connecting elements 32 and 37 was provided with cylindrical thread 39. As a connecting sleeve 48 a length of a metal-polymeric pipe with a diameter greater than that of the pipes 19 and 36 to be connected was used. The inner diameter of the sleeve 48 corresponded to the outer diameter of the connecting elements 32 and 37. The metal reinforcing framework of the sleeve 48 is protected at its ends by welded rings 42 made of the same polymeric material as the sleeve 48. The internal surface of the sleeve 48 is provided on its two sides with complementary thread corresponding to thread 39 on the external surface of the connecting elements 32 and 37.

(104) A polymeric ring 49, which is installed in the connection, serves as a seal as well as enables to eliminate a pocket in the longitudinal section of a pipeline.

EXAMPLE 14

(105) This Example illustrates a transition in the claimed pipeline from a metal-polymeric pipe 19 to a metal pipe 50 with the use of a connecting element 51 fixed at the end of the pipe 19 by using a threaded connection, as shown in FIG. 12.

(106) The rear portion of the connecting element 51 is provided with a chamfer 52 for the tapered mounting surface of a metal bush 53 covering the external circumference of the connecting element 51 and tight fit onto the latter. A metal barrel 56 is screwed onto the bush 53 along thread 54, 55 until stop. After the bush 53 and the barrel 56 are mounted, the barrel 56 is welded to the metal pipe 50 along the external contour with a weld 57.

(107) According to another embodiment, the connecting element 51 and the bush 53 are secured to each other with thread (not shown in the Figure).

EXAMPLE 15

(108) This Example illustrates possibilities of the claimed metal-polymeric reinforced pipes for constructing a pipeline having an adapter connection shown in FIG. 6 at an upper branch of a pipeline, which connection comprises a transition from a metal-polymeric pipe 19 to a polyethylene non-reinforced pipe having the outer diameter () of 200 mm, the inner diameter (Di) of 150 mm and designed for an operating pressure (Po) up to 12 atm. The connection is made by butt welding of the end face of the polyethylene pipe 58 and the connecting element 32. The welded connection is strengthened by a sleeve mounted on thread over the welded connection according to the procedure described above.

(109) The pipeline is constructed with due regard to the requirements for a water supply pipeline (as well as for pipelines for sewers or hot water supply). For these purposes polymeric pipes, which are made of polyethylene or polypropylene, pipes of glass-reinforced plastic, pipes of metals (iron alloys) or pipes of composite materials, are used. Agents transported through these pipelines include water, water having solid inclusions, vapor. The pipeline operating pressure is up to 16 atm, working temperature in from 5 to 75 C.

(110) Let's consider advantages that may be obtained by constructing a water supply pipeline with a transition to the claimed metal-polymeric pipe from a polyethylene non-reinforced pipe 58 having the outer diameter of 200 mm, the wall thickness of 25 mm (wall thickness index SDR=pipe diameter/wall thickness=9). A water supply pipeline made of polyethylene of PE-100 grade, according to calculations involving material strength and pipe wall thickness, has the operating pressure of 12 atm (1.2 MPa). In order to make a connection, we select a metal-polymeric reinforced pipe with the corresponding inner diameter (nominal bore) equal to 180 mm, with the wall thickness of 12.5 mm, Di-155.

(111) In this case the main advantages of the metal-polymeric pipe 19 over a polyethylene pipe are great strength and great flexibility at equal throughput. The strength of a metal-polymeric pipe is measured by its resistance to axial, radial and other loads. In this case the metal-polymeric reinforced pipe MPT-180 may withstand inner pressure P max=80 atm, and the resistance in the axial direction is F=227.5 kN (a polyethylene pipeapp. 58 kN).

(112) Meanwhile, it is necessary to take into account that a metal-polymeric reinforced pipe, with due regard to its strength, has sufficient flexibility for compensating external loads. This is possible due to the framework-polymer system that works in a reinforced pipe. A polyethylene non-reinforced pipe has no sufficient flexibility, and this factor is reduced in proportion to an increase in the wall thickness. The metal framework, on the contrary, is strengthened proportionally to an increase in the pipe diameter due to an increase in a number of longitudinal reinforcing elements, while the wall thickness of the pipe may remain unchanged.

(113) An increase of a transported product pressure within a pipeline constructed from the claimed metal-polymeric reinforced pipes enables to raise the efficiency of using such a pipeline, reduce costs and increase profitability.

(114) A comparison of material costs for producing one linear meter of the pipe is shown in FIG. 5B. This comparison is based on calculation of a specific weight and prices for corresponding materials. In the production of a metal-polymeric pipe the cost of steel St3 for making a framework is 28 RUR/kg and the cost of polyethylene of grade 100 is 67 RUR/kg, and, thus, we obtain that the cost of one linear meter of a metal-polymeric pipe MPT-180 is 588.60 RUR, and that of a polymeric non-reinforced pipe PE-100 is 676.70 RUR. The weight of one linear meter of the pipes is 13.5 and 10.1 kg, respectively.

(115) An increase in the wall thickness of a polymeric non-reinforced pipe leads to an increase in the polymer volume that should be spent for its production; this means an increase in the material cost for producing one linear meter of the pipe. Thus, if it necessary to increase the pipe inner diameter, the construction of a pipeline from the claimed metal-polymeric reinforced pipe is more advantageous from the economic point which is illustrated by Curve 4 in FIG. 5B. Curve 3 in FIG. 5B shows a leading increase in the cost of a polymeric non-reinforced pipe with an increase in the pipeline inner diameter.

EXAMPLE 16

(116) This Example illustrates advantages that may be obtained, if a gas pipeline is constructed with a transition to the claimed metal-polymeric pipe from a polyethylene non-reinforced pipe 58 with the outer diameter of 500 mm.

(117) A pipeline constructed from polyethylene non-reinforced pipes (having the outer diameter of 500 mm, the inner diameter Di=388.8 mm; design operating pressure Pn=12 atm) may be equally replaced by a pipeline made of metal-polymeric reinforced pipes MPT-450, which has the following physical-technical characteristics: outer diameter450 mm, Di416 mm, wall thickness17 mm, operating pressure Pn30 atm. The comparative weight of one linear meter of the pipes: MPT-450 is 40.7 kg, and that of the polyethylene (non-reinforced) pipes PE-500 is 78.32 kg.

(118) This comparison proves a reduction of the total weight of a pipeline constructed from metal-polymeric reinforced pipes and an increase of the operating pressure of a product transported therein. Furthermore, as was already mentioned, a polyethylene non-reinforced pipe loses its flexibility and capacity to withstand elastic deformations with an increase in its wall thickness, which, in this case, is one more negative factor for assessing the pipeline strength. The reinforcing framework of metal-polymeric reinforced pipes enables not to increase the pipe wall thickness with an increase in the inner diameter, since it takes most loads, while preserving sufficient flexibility and capacity to relax stresses in the pipe body.

(119) Gas-supply networks made of metal-polymeric reinforced MPT pipes are scores of times more reliable than polymeric and composite pipes, especially in seismically dangerous regions with a complex geological situation.

EXAMPLE 17

(120) This Example illustrates advantages that may be obtained, if an oil pipeline is constructed with a transition to the claimed metal-polymeric pipe 19 from metal pipes 50 having the outer diameter of 500 mm (inner diameter Di=468 mm; operating pressure Pn=20 atm).

(121) As compared to a metal pipe (materialSteel 20), metal-polymeric reinforced pipes have the following advantages: chemical stability, corrosion resistance, weight and cost.

(122) In order to replace the said metal pipe, the metal-polymeric reinforced MPT-500 pipe is selected (outer diameter500 mm; inner diameter Di=464 mm; operating pressure Pn=20 atm).

(123) The weight of one linear meter of a metal-polymeric pipe MPT-500 is 46.8 kg; and that of a pipe made of Steel 20 with the diameter of 500 mm is 191.2 kg. A great weight of a metal pipe, as compared to that of a metal-polymeric MPT pipe, is a significant disadvantage during mounting, operation and repair of a pipeline.

(124) The cost of the materials required for making a metal-polymeric MPT-500 pipe is 2,191.8 RUR/linear meter; that of a pipe made of Steel 20 with the diameter of 500 mm is 5,353.6 RUR/linear meter.

(125) It follows from the above data that a metal-polymeric reinforced MPT pipe is not inferior to a metal pipe as to the radial strength. The polymer chemical stability enables to operate such a pipeline without a major repair and replacement for much more time than a similar pipeline made of metal pipes.

(126) If, for the purpose of increasing the operation period of a steel pipeline, pipes of corrosion-resistant steels and alloys are used instead pipes made of quality steels, e.g., Steel 20 or similar, than the material cost, as compared to that of MPT pipes, is app. 30 times greater, and, consequently, the cost of laying such a pipeline will be increased greatly.

(127) The cost-effectiveness of replacement of metal pipes by metal-polymeric reinforced pipes is most evident on the basis of expenses and operation periods of networks until the next major repair or replacement.

(128) Also, when comparing a weight of one linear meter of pipes made of iron alloys and that of MPT pipes, difference will appear in pipe transportation and mounting expenses also, since metal pipes are 2.5 times heavier than MPT pipes and, correspondingly, require other equipment and labor.

(129) From the point of quality of the pipe internal surface, it should be noted that the surface of a metal-polymeric MPT pipe along the inner diameter is formed by the mandrel polished surface within an extrusion head, which is reflected in roughness of the inner surface of a finished pipeRa 0.25-Rz 1.25. A metal pipe has roughness of its internal surface that is regulated by the respective standard and defined within the limits of Ra 6.3-Ra 50. Due to this, hydrodynamic losses in a pipeline made of a metal will be significantly greater than those in a pipeline made of a metal-polymeric MPT pipe.

EXAMPLE 18

(130) A pipeline, which fragment is shown in FIG. 6, was constructed from the metal-polymeric reinforced pipes 19 produced in accordance with the claimed invention with the use of the connecting elements 32. The pipeline was constructed with due regard to the requirements established for transportation of a well product while producing oil and gas. For these purposes polymeric pipes made of polyethylene, glass-reinforced plastic, or of a metal (iron alloys), or of composite materials. Transported agents are: oil, gases, combustible gases, technological liquids. Operating pressure in a pipeline is up to 40 atm, operating temperature is from 10 to 80 C.

(131) One specific feature of using pipeline transport in the oil and gas industry is that well products exert very strong chemical action on a pipeline. Due to this, in the result of corrosion process, metal pipes have a comparatively short service life until their replacement. In these conditions polymeric pipelines are much more efficient.

(132) A pipeline constructed from metal-polymeric reinforced pipes may be operated at a hydrogen sulfide concentration higher than 16%, which enables to use them instead of pipes made of special steels and aluminum when constructing pipelines in sites with high content of sulfides.

(133) Common polymeric pipes may not be used in these conditions due to their low strength. Composite pipes (glass-reinforced plastic) have low axial strength in points of connection and do not ensure sufficient reliability of the pipeline operation.

EXAMPLE 19

(134) A pipeline, which fragment is shown in FIG. 6, was constructed from the metal-polymeric reinforced pipes 19 produced in accordance with the claimed invention with the use of the connecting elements 32. The pipeline was constructed with due regard to the requirements applied to pipelines for underground and heap leaching of non-ferrous and rare-earth metals in hydrometallurgy.

(135) A combination of strength in the axial and radial directions and chemical stability allow to consider a metal-polymeric reinforced pipe as the most reliable among polymeric pipes used in hydrometallurgy for leaching of ores. In hydrometallurgy it is possible to use metal-polymeric reinforced pipes, in particular, as a casing column when developing deposits, as a pipe string for conservation of mines, as a pipeline for transportation of metal salt solutions. The structure of the claimed pipeline made of metal-polymeric reinforced pipes withstands an earthquake with magnitude of 9. Only pipelines made of highly alloyed stainless steel are the only equivalent, pipes for which are 30 times more expensive than metal-polymeric reinforced pipes.

EXAMPLE 20

(136) A pipeline, which fragment is shown in FIG. 6, was constructed from the metal-polymeric reinforced pipes 19 produced in accordance with the claimed invention with the use of the connecting elements 32. The pipeline was constructed with due regard to the requirements applied to pipelines for pneumatic transport of cement and abrasive materials.

(137) At present, pipelines made of steel or composite pipes are usually used for pneumatic transport of cement and abrasive materials.

(138) As compared with a pipeline made of metal-polymeric reinforced pipes, a disadvantage of a pipeline made of metal pipes is a great specific weight of metal pipes and their poor wear resistance. Wear resistance of metal-polymeric reinforced pipes is 4-10 times greater than that of steel pipes. From the economic point it is manifested in a short term of operation of a metal pipeline.

(139) Polymeric non-reinforced pipelines do not have rigidity sufficient for the above-said purpose; therefore, structures made of polymeric non-reinforced pipes intended for pneumatic transport of cement and abrasive mixtures are to be further strengthened with girders and supports, which complicates the construction of such an object and increases its cost.

EXAMPLE 21

(140) A pipeline, which fragment is shown in FIG. 6, was constructed from the metal-polymeric reinforced pipes 19 produced in accordance with the claimed invention with the use of the connecting elements 32. The pipeline was constructed with due regard to the requirements applied to pipelines used in the chemical industry, in particular, for transportation of concentrated acids and alkalis.

(141) The chemical industry sets higher requirements to pipeline transport, which relate, first of all, to chemical (corrosion) stability of the material a pipe is made of, strength and tightness of connections in a pipeline.

(142) Common steel pipes and pipelines made of them do not suit for transportation of concentrated acids and alkalis. In such conditions only corrosion-resistant alloys, stable to corrosive media, may be applied. Also, special coatings are necessary that are applied to surfaces of metal pipes for keeping them intact.

(143) The cost of materials for producing pipes from stainless steels and alloys as well as the construction costs of such pipelines will be significantly higher than the cost of materials for producing metal-polymeric reinforced pipes and expenses for constructing a pipeline from them. The construction of a pipeline from metal-polymeric reinforced pipes (MPT) for transportation of chemical agents does not differ, as to technical work, from the construction of a pipeline from MPT for water supply or oil product transportation, since a pipeline made of MPT is leakproof and does not require any additional measures for maintaining tightness. The chemical stability of the MPT polymer is sufficient for transportation of corrosive agents without compromising the pipe wall integrity. No special coatings are required for the internal and external surface of such a pipeline. Pipe connections made with the use of the connecting elements 32, connecting sleeves 40 and 48, flange connections 45 and other structures described in this specification ensure reliable tightness necessary in this application.

EXAMPLE 22

(144) This Example described the application of the metal-polymeric reinforced pipes 19 produced in accordance of the claimed invention and intended for use in corrosive environment in contact with sea water, e.g., for creating sea infrastructure as well as for cost protection for constructing ports and docks. The claimed metal-polymeric reinforced pipes also may find application for constructing pipelines for transportation of salt water for desalination, for constructing pipelines in saline soils, for laying any pipelines in the marine environment as well as for constructing platforms for producing oil and gas.

(145) High strength of metal-polymeric reinforced pipes and possibility of filling their internal space with concrete enables to use MPT pipes as supports for various facilities in the conditions of external corrosive environment. The welded metal framework, which provides the claimed pipe with high-strength characteristics, is protected by a polymer all around, therefore, during contact with salt water no oxidation processes on the metal framework occur both inside a pipe and on the outside, due to which the pipe strength remains an invariable parameter.

(146) The requirements to strength and stability of pipes and pipelines made of them that are used in the marine environment are similar to those for pipes for the chemical industry.

(147) As compared to polyethylene pipes, metal-polymeric reinforced pipes have a number of advantages that are more manifested with an increasing pipe diameter and include a lower cost of materials for production, a lower weight and a lesser wall thickness with higher values of strength indices in the axial and radial directions.

EXAMPLE 23

(148) This Example illustrates the application of the metal-polymeric reinforced pipes 19 as supports and piles used for construction of buildings and structures.

(149) In the process of constructing various buildings and structures it is necessary to stabilize the soil under the foundation for the purpose of preventing soil layers from possibly displacing relative to each other, which can lead to destruction of the foundation and the whole structure. Common piles for these purposes are produced from reinforced concrete. However, in a number of construction cases it is possible to use metal-polymeric reinforced pipes instead of piles or supports made of reinforced concrete.

(150) In a number of cases this is based on circumstances that are manifested in advantages of metal-polymeric reinforced pipes over concrete piles. For example, if there exists a possibility of washing soils with underground waters, then the service life of common reinforced concrete piles is shortened, which may result in their destruction and, consequently, in violation of the structure foundation stability. Furthermore, metal reinforcement of piles is subject to corrosion and fails while being in the soil wet environment, thus losing its capacity of maintaining the pile integrity. Contrary to this, high strength characteristics of the welded framework used in the claimed pipe are ensured by a polymer covering the framework all around. Therefore, during contact with underground waters no oxidation processes on the metal framework occur, due to which the pipe strength does not change with the course of time.

(151) The main applications of metal-polymeric reinforced pipes are shown in Table 12.

(152) TABLE-US-00001 TABLE 1 Physical-mechanical properties of pipes produced by the claimed method. Ultimate Pipe Axial tensile breaking Weight of outer load, in pressure, one linear diameter, tons-force (kN), in MPa meter, in mm at least (kg-force/cm.sup.2) in kg 1. 95 11 (110) 19.0 (190) 6.7 2. 115 14 (140) 15.0 (150) 8.3 3. 125 15 (150) 14.2 (142) 9.1 4. 140 16 (160) 13.0 (130) 10.1 5. 160 20 (200) 11.5 (115) 11.8 6. 180 22 (220) 10.4 (104) 13.6 7. 200 24 (240) 9.0 (90) 15.2 8. 225 28 (280) 8.0 (80) 17.2

(153) TABLE-US-00002 TABLE 2 Properties of pipe produced by the claimed method, when metal framework therefor includes metal reinforcement of round section and polyethylene matrix. Axial tensile Ultimate Outer load, in tons- Wire breaking Operation Weight of diameter, in force, at diameter, in pressure, in temperature, one linear mm least mm MPa C. meter, in kg 1. 125 15 3 14.2 50-+95 9.1 2. 180 22 3 10.4 50-+95 13.6 3. 200 24.2 3 9 50-+95 15.2

(154) TABLE-US-00003 TABLE 3 Properties of pipe produced by the claimed method, when metal framework therefor includes metal reinforcement of square section and polyethylene matrix. Dimension of side of Ultimate Outer Axial tensile wire section breaking Operation Weight of diameter, in load, in tons- square, in pressure, in temperature, one linear mm force mm MPa C. meter, in kg 1. 125 18.2 2.7 15.1 50-+95 9.1 2. 180 25.6 2.7 11.3 50-+95 13.6

(155) TABLE-US-00004 TABLE 4 Properties of pipe produced by the claimed method with the use of metal reinforcement of trapezoid section as longitudinal elements and metal reinforcement of round section with diameter of 3 mm as transverse elements of the reinforcing framework and polyethylene matrix. Ultimate Outer Axial tensile Dimension breaking Operation Weight of diameter, in load, in tons- of trapezoid pressure, in temperature, one linear mm force base, in mm MPa C. meter, in kg 1. 160 23.2 3 14.6 50-+95 11.7 2. 225 31 3 9.3 50-+95 17.2

(156) TABLE-US-00005 TABLE 5 Properties of pipe produced by the claimed method with the use of fluoroplastic-4 as the polymer matrix. Axial tensile Ultimate Outer load, breaking Operation Weight of one diameter, in tons- pressure, in temperature, linear meter, in mm force MPa C. in kg 1. 115 14.6 7.0 (190) 150-+260 11.6

(157) TABLE-US-00006 TABLE 6 Properties of pipe produced by the claimed method with the use of polyesterketone of PEKK grade as the polymer matrix. Axial tensile Ultimate Outer load, breaking Operation Weight of one diameter, in tons- pressure, in temperature, linear meter, in mm force MPa C. in kg 1. 160 20.4 14.0 90-+260 15.1

(158) TABLE-US-00007 TABLE 7 Properties of pipe produced by the claimed method with the use of polyestersulfon of PES grade as the polymer matrix. Axial tensile Ultimate Outer load, breaking Operation Weight of one diameter, in tons- pressure, in temperature, linear meter, in mm force MPa C. in kg 1. 140 16.0 16.0 100-+200 14.2

(159) TABLE-US-00008 TABLE 8 Properties of pipe produced by the claimed method with the use of polyurethane of TPU grade as the polymer matrix. Axial tensile Ultimate Outer load, breaking Operation Weight of one diameter, in tons- pressure, in temperature, linear meter, in mm force MPa C. in kg 1. 115 15.0 14.1 70-+170 10.0

(160) TABLE-US-00009 TABLE 9 Properties of pipe produced by the claimed method with the use of thermoplastic vulcanized elastomers as the polymer matrix. Axial tensile Ultimate Outer load, breaking Operation Weight of one diameter, in tons- pressure, in temperature, linear meter, in mm force MPa C. in kg 1. 200 24.0 9.4 60-+130 15.2

(161) TABLE-US-00010 TABLE 10 Properties of pipe produced by the claimed method with the use of PVC-S (suspension polyvinylchloride) as the polymer matrix. Axial tensile Ultimate Outer load, breaking Operation Weight of one diameter, in tons- pressure, in temperature, linear meter, in mm force MPa C. in kg 1. 115 13.8 14.4 10-+70 10

(162) TABLE-US-00011 TABLE 11 Properties of pipe produced by the claimed method with the use of polyamides PA-6 and PA-12 as the polymer matrix. Axial tensile Ultimate Outer load, breaking Operation Weight of one diameter, in tons- pressure, in temperature, linear meter, in mm force MPa C. in kg 1. 225 32.0 10.2 60-+115 18.6

(163) TABLE-US-00012 TABLE 12 Main applications of metal-polymeric reinforced pipes. Operating Product Laying pressure Ambient Pipeline to be arrange- (max), temper- purpose transported ment in MPa ature, C. 1. Gas Gas Buried, 4.0 45-+60 distribution surface networks 2. Oil Gasoline, fuel Buried, 4.0 45-+60 product oil, kerosene surface pipelines 3. Industrial Air, water, gas, Buried, 4.0 45-+60 pipelines acids, alkalis surface 4. Industrial Dry suspended Buried, 4.0 45-+60 pipelines matter, dust, surface bulk products, pulp 5. Field Produced Buried, 4.0 45-+60 pipelines water, oil, gas surface 6. Water supply Drinking and Buried, 4.0 45-+60 pipelines process water, surface sewage 7. Casing Underground Wells 4.0 45-+60 pipes leaching with the use of acids