Steel pipes lined by injection-moulded concrete or mortar and methods of their fabrication

FIELD: metallurgy.

SUBSTANCE: lined steel pipe intended for transfer of fluid comprises circular lining of concrete or mortar that makes pipe ID and metal shell enveloping said lining. Lining stays in direct contact with metal shell wall inner surface. Note here that said lining is prestressed by metal shell at initial state prior to putting said pipe in operation for transfer of fluid. After putting said pipe in operation for transfer of fluid lining prestressing at final state is in fact ruled out.

EFFECT: higher stiffness and corrosion resistance.

33 cl, 4 dwg

 

The present invention relates to a steel pipe lined with concrete or mortar, and more specifically to a steel pipe coated die-cast concrete or mortar, which are manufactured by methods that allow the simultaneous curing and creating pre-stressing of the pipe, thus increasing the permissible rated voltage of steel, while maintaining production efficiency and reducing production costs.

Regular lined with concrete, steel pipe, such as a large diameter pipe that is currently suitable for the maximum operating voltage of steel of approximately 21000 pounds per square inch. The reason for limiting the permissible rated voltage for this tube is limited allowable strain in the lining of concrete or mortar. More tension steel will cause cracking of the lining of concrete or mortar under pressure and the formation of destructive cracks, adversely affecting the performance of the lining and causing the chance of damage to the cladding or otherwise away from the inner surface of the steel pipe.

The use of coatings from concrete or mortar with such steel pipe known for use in the water industry, because it is has proven the best properties protect steel pipes from internal corrosion for a long period of time, for example, more than 50 years. Alternatively, the concrete lining can be used a polymer coating, such as cladding based on epoxy resin and the like, with steel pipes, which can be adapted for higher strain to failure. However, no currently available polymer cladding cannot guarantee or imply service for 50 years in the water supply system without some form of periodic service, in the typical case, with approximately 15-year intervals. Impractical decommissioning of such coated steel water pipes, for example, when they are used as a water supply line and the like, for sandblasting and re-lining every 15 years for maintenance.

The second limitation of the steel-lined concrete water pipes are engineering considerations and the need to have a ratio of diameter to thickness of approximately 240 and, preferably, less than about 220. This means that the pipe diameter of 100 inches shall have a minimum wall thickness of pipe, comprising approximately 0,417 inch (ratio of diameter to thickness=240; height=100/240=0,417). The result of this requirement of the design is that the tube that can be performed with a smaller wall thickness due to internal is nego pressure, requires greater thickness due to the stress associated with handling, transportation and installation. In this example, with a diameter of 100 inches and a wall thickness of 0,417 inch pipe characteristics Pressure=(2*thickness*voltage)/diameter=2*0,417*21000/100=175 pounds per square inch or less have yet to have a wall thickness of pipe, based on the ratio of diameter to thickness=240. The demand relationship of diameter to thickness is based on the practicality of loading, transportation and installation of the pipe. In unstable soil, the pipe is also subject to destruction or excessive sagging, if not will be strengthened by increased thickness of the cladding, wall thickness steel pipe, attached stiffeners or expensive making more sustainable materials base.

Conventional cylindrical pipe with pre-tense concrete provides concrete inner tube or core, which is provided in a state of high compression ratio by means of wire, which is wound around the inner pipe. Compressive loads that act on the pipe when used, are pre-stressed steel wire using high permissible rated voltage, thus also serving to reduce the amount of steel that is used to provide the required size LF the party. Concrete core creates resistance creates pre-tension wire and assists in keeping the load of the soil in buried condition. Core prestressed concrete also contributes to supporting the pipe during transportation and installation.

However, one of the problems with a cylindrical pipe with a pre-tense concrete is the difficulty of protection creates a high pre-tension wire from corrosive environments, when the pipe is put into operation, and the potential susceptibility of such wire to hydrogen embrittlement when used excessive levels of cathodic protection. The ability to easily implement cathodic protection creates the initial tension of the wire is further complicated by the low dielectric strength of typical concrete lining, which is placed on top of creating the initial tension of the wire to protect it from corrosion. Insulation resistance can be improved by applying appropriate polymer coating, such as that supplied by Ameron International under the name Amercoat 1972B. Although the use of such polymeric cladding facilitates cathodic protection of steel creates the initial tension of the wire, it causes additional costs from the point of view of the production of the different operations and raw material costs.

Because the underground water supply complex of pipes and surface or underground transit systems in a typical large cities has increased over the years, another problem was the result of "cathodic interference or parasitic underground currents caused by the adjacent steel pipelines under cathodic protection from the point of view of external corrosion, caused by the systems of power transmission DC. Large water pipes, installed many years ago, now meet with new pipes, which are laid nearby. These new pipes can have cathodic protection and stray stray currents induced from cathodic protection, can cause corrosion currents in a cylindrical pipe with a pre-tense concrete. In the possible existence of such parasitic earth currents many urban water supply companies now prefer or ordinary steel pipe with a dielectric coating for external corrosion protection, or reinforced steel cylinder concrete pipe, when the external load is high. Although this is an effective approach to control corrosion of the pipe, it is expensive.

One approach known in the art for the manufacture of pre-stressed steel pipes, involved the use of a multi-stage process personalinformation/casting concrete core, the steel pipe slipped on easily over a preformed concrete core and then inflating high pressure liquid cement in the annular gap between the preformed concrete core and the steel pipe to provide compression of the concrete core. However, with this method of creating a pipe, there are two main problems. The first problem relates to the difficulty of properly sealing all concrete core relative to the steel pipe during the operation of grouting under pressure. The second problem is how to make and maintain the pressure of the liquid cement during curing grout, especially if a small leak of liquid cement is in the sealing between the steel tube and the concrete core, while the cement slurry hardens. If you use a high-pressure pump for cementation, the potential leakage of liquid cement during curing should be filled pump for cementation. This would mean that the pump for grouting must be active during the curing operation to compensate for leakage, which leaves the possibility of solidification of the grout in the pump and destruction of the pump and receiving tubes having insufficient levels of the HB pre-tension.

Thus, it is necessary to get the design of the pipe and method of its manufacture, which is capable of achieving the desired level of properties such as the rigidity of the pipe and the internal corrosion resistance, which corresponds to the typical minimum of 50 years of service provided by the conventional cylindrical pipe with pre-tense concrete or lined with concrete steel pipe. It is also necessary that such a construction of the pipe was able to provide the desired degree of protection against external corrosion and cathodic interference. It is also necessary that such a construction of the pipe was manufactured economically and from the point of view of the perspective of raw materials, and from the point of view of the amount of time and labour expended on its production.

Faced with pressure die casting steel pipe according to the present invention contain an annular lining of concrete or mortar, forming the inner diameter of the pipe, and a metal sheath surrounding the cladding. The cladding is in direct contact with the inner wall of the metal shell and the lining is in a state of compression of the metal shell. The ratio of the wall thickness of the cladding and the metal shell is in the range from about 5:1 to 80:1 and preferably from about 10:1 to 50:1. In a typical embodiment, the OS is the hope of the invention the wall thickness of the metal shell is in the range of from about 0.06 to 0.75 inches, and wall thickness of the cladding is in the range from about 1.5 to 10 inches. The wall thickness of the cladding can be 10-50 times greater than the thickness of the metal shell, depending on the specific version of the run pipe and the final application. If necessary, the tube may also contain a coating of dielectric material located along the outer surface of the metal shell.

The pipe is formed using a molding site, which is specially adapted to accommodate the necessary volume of structure of concrete or mortar and exposure to power compression, calculated for the application of the necessary pre-stressing force to the metal shell. In a typical embodiment of the invention these tubes form by means of a flow amount of the composition of the concrete or mortar in the mold is formed between the metal shell along the outer diameter and the movable core along the inner diameter. The molded part is subjected to a pressure force for the expansion of the metal shell. In a typical embodiment of the invention the pressure supplied in the form of fluid under pressure, such as water, and fluid under pressure is introduced into contact with the surface of the molded composition. As soon as the desired degree of cure dost is Gota, the pressure force is removed, causing the application to the metal shell of the necessary compression forces to the lining of concrete or mortar.

In a typical embodiment of the invention forming the node contains a cylindrical metal shell which forms the metal outer part of the pipe supporting element, which in the working position is connected with the bottom part of the metal shell, and the top element, which in the working position is connected with the upper part of the metal shell. The inner form element located concentrically inside of the metal shell. Between the metal shell and the inner form element formed annular chamber for concrete or cement mortar for placing an amount of the composition of the concrete or mortar. In a typical embodiment of the invention the inner form element is able to be reduced in diameter to retrieve the coated molding of the pipe from the mold after forming. The site also contains a means for supplying a liquid medium to increase the pressure, such as water, in the form and on the surface of the concrete composition or solution for expanding the composition of the metal shell.

Faced with pressure die casting steel pipe according to the present invention, possess the necessary level of pipe stiffness and internal corrosion with what honostly, which corresponds to a typical minimum 50-year service life, ensure the normal cylindrical pipe with pre-tense concrete or lined with concrete steel pipe. In addition, these pipes according to the present invention capable of providing the necessary degree of protection against external corrosion and cathodic interference. In addition, pipes, according to the present invention, can be formed with a reduced thickness of the metal shell or wall steel pipe, thus resulting in the desired savings in the costs of raw materials.

These and other features and advantages of the present invention will be appreciated when they are better understood when reading the following detailed description with reference to the accompanying drawings, on which:

figure 1 is a perspective view side view typical choices faced by molding steel pipes made in accordance with the principles of the invention;

figure 2 is a side view in cross section of a typical variant of the process used for manufacturing the coated molding steel pipe, shown in figure 1;

figure 3 is a side view in cross section of another typical variant of the process used for manufacturing the coated molding steel pipe, shown in figure 1; and

4 is a side view in cross section on the natives typical variant of the process, used for the manufacture of coated molding steel pipe, shown in figure 1.

Faced with pressure die casting steel pipes and methods for their manufacture, in accordance with the principles of the invention contain a lining of concrete or cement mortar, which is surrounded by a metal shell or steel pipe, that is, except for the use of the stretch or creating the initial tension of the wire as in the conventional cylindrical pipe with pre-tense concrete described above. The ratio of the thickness of the lining to the shell thickness can and will vary depending on the specific requirements of the technical project and/or operational performance, which requires a specific end use, as described in more detail below.

An indication of such structures steel pipes coated by injection molding, is that they are made according to one or more different methods of injection molding, which include forming coatings from concrete or cement in place during the process of pre-stressing the surrounding metal shell and the resulting design of the pipe, thus eliminating many stages, for example, comprising separately forming a pre-molded lining of concrete or cement the aqueous solution, that combined with a metal outer shell pipe for further processing, which causes the voltage. Used in this description, the term "location" refers to the fact that the composition of the concrete or cement mortar (which is used for the manufacture of coatings from concrete or cement mortar) is formed and hardened simultaneously with impact pressure to create for the surrounding metal of the outer shell or steel pipe stress state.

A sign of a coated molding of steel pipes according to the present invention, is that they are constructed in such a way that it creates the initial tension of the metal shell by means of a lining of concrete or cement in such a way that the voltage of steel can be increased by internal fluid pressure without the risk of harmful cracking of the cladding. In addition, the presence of compacted lining of concrete or cement mortar also promotes resistance to stress during transportation, installation, and from exposure to soil at the time of commissioning. Faced with pressure die casting steel pipe according to the present invention can also be covered with many dielectric coatings, thus providing a desirable level of external protection against corrosion. It is tranae problem cathodic interference from neighboring pipelines and transit systems, and the steel used in this type of pipe may have a much lower yield strength than creating pre-tension wire, and therefore can be much less susceptible to hydrogen embrittlement under cathodic protection.

Figure 1 shows a coated molding of the steel pipe 10, made in accordance with the principles of the present invention, generally containing a cylindrical metal or steel shell, casing, pipe or casing 12 which surrounds the inner cladding 14, formed from the required composition of the concrete or mortar. The inner cladding 14 is located concentrically within the inner diameter of the shell 12 and in a typical embodiment of the invention is in direct contact with the shell, i.e. no intermediate material of another type, which is placed between the lining and the shell.

Faced with pressure die casting steel pipe 10 includes a bell shaped end 16 that is attached to one axial end 16 of the pipe 10, and a smooth end 20 that is attached to the opposite end 21 of the tube 10. The smooth end 20 has a shape, outer diameter and size for insertion into the bell-shaped end 16 of the other tube and includes one or more annular grooves 22, passing along its circumference, which are configured to Kil the value of one or more annular sealing elements or gaskets (shown in figure 2), accordingly, to provide the necessary hermetic seal between adjacent pipe ends. Bell-shaped and smooth the ends 16 and 20 can be configured the same or similarly used with conventional steel pipe and attached to the ends of the metal casing suitable welding method. Sealing elements can be formed from an elastomeric material. Other connection methods used for conventional steel pipe, such as methods using bell-shaped and smooth ends or other differently configured end pipes with plain ends, butt welded, or pipes with plain ends, welded overlapping, equally suitable for coated molding of steel pipes, as will be clear to experts in the field of design of steel pipes.

Although a typical embodiment of a coated molding of the steel pipe, shown in figure 1, depicted with a specific type of all, it should be understood that the coated molding steel pipe according to the present invention, may be configured with other types of ends as required for final application. For example, faced with pressure die casting steel pipe may have a connecting ring (in the form of bell-shaped and smooth konzo is, as shown), or it can be butt welded in place, or she may have pressed the bell for moving the landing corresponding to the outside diameter steel pipe for welding a lap joint in place, or she may have pressed the bell, including the seal groove for sealing relative to the outside diameter of steel pipe, or it can be rolled and spigot groove (covered by the bell, rolled right into the wall of the pipe, which is inserted into the inflator socket (stamped in the pipe wall). It should be understood that the coated molding steel pipes made in accordance with the principles of the present invention may contain all such options.

Another sign of a coated molding of the steel pipe is that the cladding 14 of the concrete or cement is shown in the desired state of compression before placing the finished pipe on purpose, for example, before the pipe is transported and buried at some depth in the soil by the action of the metal shell 12, impacting directly on the lining. In a typical embodiment of the invention the metal shell 12 is subjected to a strain in the required extent during the casting process, i.e. casting and solidification of the cladding 14 so that oblicovka which after curing is in a state of compression to meet the required performance pipe, for example, to meet specific end version of the application.

The thickness of the shell and lining for a coated molding of steel pipes can and will vary depending on the specific design/performance and/or final application. A common feature of the coated molding of steel pipes is that the thickness of the steel shell is much smaller than the thickness of conventional steel pipe (i.e. not containing a compressed concrete lining). The combination of thinner steel shell with thicker lining in a state of compression allows the use of the relationship of diameter to thickness, which is impossible with conventional steel pipe, which would have too much flexibility to resist loads during loading and installation at these higher relationship of diameter to thickness. More thin steel shell can now be designed using a higher rated voltage without harmful cracking of the lining of concrete or cement in operating pressure. The use of the steel shell, as opposed to using compression or pre-bend the wire in a cylindrical pipe with a pre-tense concrete, creates necessary for facing the compression state with much the more durable construction, which can be made more resistant to external corrosion and which provides reception of the nature of the failure, which is more predictable than with a compression or creating pre-tension wire.

For example, when tightening or creating pre-tension wire used in conventional cylindrical pipe with pre-tense concrete fails due to external corrosion, the result can be a sudden loss of compressive stress on the concrete lining, which can cause sudden failure of the pipe. In addition, repair of the damaged stretch of wire is difficult to implement when the pipe is in the ground. Faced with pressure die casting steel pipe according to the present invention, has the character of a waiver, reminiscent of the nature of the failure of the steel tube that is characterized by a gradual leak through the steel shell, which does not lead to sudden loss of compression lining of concrete or cement mortar, and the fact that the pipe can be easily repaired on the spot with the help of external weld metal overlay, etc.

Faced with pressure die casting steel pipes made in accordance with the principles of the present invention contain a lining of concrete or cement or core and okrujayuschuyu shell or steel pipe. The relative thickness of the lining and the shell can vary depending on the engineering design criteria, the nature of the materials used, and the desired performance. In a typical embodiment of the invention the ratio of the thickness of the lining to the wall thickness of the metal shell may be in the range from about 5:1 to 80:1 and preferably in the range from about 10:1 to 50:1. Typical range of strength for facing will be approximately 3,000 to 10,000 pounds per square inch with a range of pre-stress in the cladding constituting from about 500 psig to 6000 pounds per square inch, when the internal pressure is reduced to zero, and the voltage of the outer steel tube is partially transferred to the core of concrete or cement mortar. Permissible rated voltage in a steel shell can range from about 25,000 to 72000 pounds per square inch depending on the preset nominal pressure and yield strength of steel used for the outer steel shell.

In General, it is necessary that the cladding or the core had a thickness of approximately 10-50 times greater than the thickness of the metal shell. For example, a cylindrical metal shell may initially be subjected to a voltage of approximately 4200 pounds per square inch pressure. This is two times more than the current rated voltage for steel pipes, resulting in wall steel pipe having about two times smaller wall thickness than the existing pipe. Because steel is a large part of the cost of pipe materials, reducing the wall thickness of the steel component at two times faced by molding steel pipe represents a significant savings in raw material costs.

The decreasing diameter of the cladding, the core or inner tube after discharge pressure in the casting during the formation of the coated molding steel pipe will depend on the thickness and modulus of the core, the thickness of the metal shell or the steel pipe and the voltage of steel under pressure casting. Between the steel cylinder and the core has a balance of forces (that is, they represent the two springs opposing each other). The variation of deformation of the core should be equal to the change in strain of the steel pipe. To meet these criteria, you can display the number of equations. Such equation is given below concerning the example of the coated molding steel pipe having a diameter of 84 inches.

Faced with pressure die casting steel pipe with a diameter of 84 inches class 150/p>

The production process includes the effect of pressure on the outer steel pipe and the mold during casting and curing of concrete lining. The effect of pressure on the mold creates the voltage of the outer steel tube during the casting process.

When the pressure is supported during the operation of casting, reset, external steel pipe will sit on a concrete lining. She will continue to sit until the force of the concrete lining does not become equal to the force exerted by a steel pipe. Can be derived the following equations.

Faced with pressure die casting steel pipe according to the present invention, can be produced using many different methods of casting under pressure. These methods may include horizontal or vertical injection molding depending on the specific system pressure die casting. Figure 1 shows the use of the technology vertical injection molding and related node, the composition of concrete or cement mortar on liveout in a vertically oriented mold for forming a cladding on the place with the simultaneous application of power voltage to the surrounding metal sheath or steel pipe. As soon as the power voltage is correct, the metal shell introduces completely hardened facing the obtained coated molding steel pipe in the desired state of compression. In a typical embodiment, this invention illustrative technique involves the influence of pressure on the cast structure of concrete or mortar to create the necessary tension of the metal shell using hydrostatic means, for example, by introducing a volume or mass of fluid under pressure, such as water, in contact with the surface of structure of concrete or mortar.

Figure 2 shows a typical node 30, is suitable for a coated molding of the steel pipe in accordance with the above principles. In this typical embodiment of the invention a cylindrical metal shell 32 is formed with the ends 34 and 36 attached to the respective ends of the shell as described above. The wall thickness of the metal shell may be within the above ranges. In a typical embodiment of the invention, a metallic shell or steel pipe may be machined with a cylindrical drum with welded onto the ends 34 and 36. In a typical embodiment of the invention, a metallic shell formed of steel X60.

C is indicesa metallic shell 32 is provided on the support ring 38, which is located at the base of the node 30. The support ring 38 includes generally circular casing 39, which may include one or more grooves 40, passing through the circle along the outer surface of the wall of the support ring and located adjacent to the internal surface of the end 36 of the shell. The support ring is formed from a structurally rigid material such as metallic material, and in the preferred embodiment of the invention, the preferred material is steel.

One or more grooves 40 are of a size and shape for positioning one or more respective sealing elements 42, and one or more sealing elements 42 are of a size and shape to interact with and form a seal relative to the inner diameter of the end 36 of the metal shell. In a preferred embodiment of the invention the support ring comprises a pair of grooves 40, which are spaced axially from each other at the required distance along the outer surface, and contains located in the corresponding sealing elements 42 in the form of circular rings. Round sealing ring 42, preferably formed from an elastomeric material such as rubber and the like, capable of providing sealing relative to the end of the metal shell.

TNA is a great ring 38 includes an upper surface 44, which forms the closed bottom end of the annular cavity or chamber 46 to pouring concrete or cement mortar. The support ring 38 also includes a groove 48, which passes around the circumference along the inner diameter of the ring 38. The groove 48 is located and has a size and shape to be placed in him sealing element 50 to interact with and form a seal with the adjacent outer surface of the wall pulled together the inner element 52 forms.

The support ring 38 also includes a section that protrudes radially inward from the casing 39 from the inner diameter of the supporting ring, and it is connected with a generally cylindrical discharge tube 54, for example the lower end of the discharge pipe 54 is thus mounted on the support ring. As shown in figure 2, pulled together the inner element 52 forms is located concentrically around the outer diameter of the discharge pipe 54. Pulled together the inner form element and the discharge pipe formed from a structurally rigid material such as metallic material, and in the preferred embodiment of the invention pulled together the inner form element and the discharge pipe is formed from steel.

Pulled together the inner element 52 forms can be formed from a single sheet of material which is rolled into a cylindrical shape or mo is et to be formed from many panels or sheets, which are welded or otherwise connected for forming a cylindrical shape. In a typical embodiment of the invention pulled together the inner form element made in the form of a cylindrical sheet having two ends, which pass longitudinally along the inner form element. The ends are configured so that they can be moved inward towards each other, for example, wound around each other to reduce the diameter of the inner form element and thus call for the retraction of the inner form element to facilitate easy removal of the formed coated molding steel pipe.

In a typical embodiment of the invention the ends pulled together the inner form element are connected to each other by a mechanism that operates to maintain a fixed diameter of the inner form element during the operation of molding and which can be manipulated to move the ends of the inner form element to each other, thus pulling together form element to facilitate easy removal of the form element from the molded core with concrete or cement mortar. The inner form element is also configured to minimize leakage of the composition of the concrete or mortar during casting and the formation of a coated molding of the steel pipe. In preferably the m variant embodiment of the invention between contractible inner ends of the form element is a flap, which can remotely operate to reduce the diameter of the inner form element at an appropriate stage of the work, thus allowing you to remove the inner element in the form of a coated molding of the steel pipe after its formation.

The lower reinforcing ring 56 is located along the surface of the inner diameter of the pulled together the inner element 52 forms adjacent to the support ring 38 and promotes the necessary sealing engagement between the lower section pulled together the inner form element and the support ring. The lower reinforcing ring 56 may be formed from a structurally rigid material and may contain one or more elements, which individually or jointly form a ring base, located concentrically within the lower end section of the tightening of the inner form element. In a typical embodiment of the invention the lower reinforcing ring is made of steel and welded to the lower part of the inner form element.

Closer to the top of the node 30 is circular upper ring 58 adjacent to the upper end of the metallic shell 32. In a typical embodiment of the invention, the upper ring has a cylindrical outer section 60, which is located concentrically around the end 34 IU aricescu shell 32. The outer section 60 has an inner diameter that is the same size and shape adapted to accommodate the end 34 within the lower region of the inner diameter. Sealing elements 62 are located within one or more corresponding grooves 64, located on a circle around the end 34 to provide a seal between the upper ring 58 and the metal shell 32. Sealing elements 62 may be annular elements, which are made of elastomeric material such as rubber, etc.

Although the alternative embodiment of the invention shown in figure 2, illustrates the use of sealing elements in the upper and lower parts of the site, located in the grooves, which are respectively located on the end of the shell and core ring, it should be understood that the specific mechanism seals used for forming the necessary seal at the top and bottom of the camera 46 for concrete or cement, may differ from those described and shown, and that such changes should be considered as included in the scope of the present invention.

The inner diameter of the outer section of the upper ring also includes a Central area that has a size and configuration adapted to receive it environment under pressure and needed additional volume of concrete or C is the elemental solution above covered by the socket end 34. Additional volume provided by the top ring, useful to compensate for the volume increase that occurs within the chamber 46 during pressure increase, when the outer steel pipe or casing 32 is enlarged in diameter under pressure. Typical volume change during the increase of pressure leads to the loss of approximately 6-7 inches of vertical height for concrete lining thickness of 4 inches. The top ring configured to facilitate the adaptation to such change of scope.

In a typical embodiment of the invention the environment to increase the pressure is water, and the Central area of the upper ring has a size with a height vertically, and adapted to change the volume of concrete or cement, which occurs when the pressure increases, and with a diameter that is smaller than the diameter of the lower region of the upper ring. Such sizing of the inner diameter of the outer section of the upper ring helps limit the extent to which the end 34 is inserted into it during Assembly for casting concrete composition or solution in the node 30 and into the chamber 46 and subsequently to the impact of pressure on the cast structure of concrete or mortar.

The outer section 60 of the upper ring includes an upper area of the inner diameter, which has a size and shape to accommodate the upper element or erotichnoe cover 66, which is located on top of the node 30. In a typical embodiment of the invention the upper area of the inner diameter has a diameter size that is smaller than the Central area, to control the axial accommodate the upper element 66, for example, so that it was not included in the Central district.

The upper ring 58 also includes an upper section 68. In a typical embodiment of the invention this top section is welded to the upper ring 58 by means of the centering wedges (not shown). The inner section 68 is located radially inside with respect to the outer section 60 and radially on the outside at a distance from the discharge pipe in position adjacent to the top end pulled together the inner element 52 forms. The upper section 68 includes a pair of protruding downward protrusions or rings 70, which are located and have dimensions adapted to accommodate between them the upper end pulled together the inner element 52 forms.

In a typical embodiment of the invention pulled together the inner element 52 forms is fixed corresponds to the location of the anchor ring 38, and at least one of the projections 70 of the upper ring acts to limit radial movement outward pulled together the inner form element. In a typical embodiment of the invention, the protrusions 70 and ve is knee ring 60 is made in the form of a single node. In addition, the other of the tabs, which is not in contact with pulled together the inner form element is located adjacent to the outer surface of the upper section of the discharge pipe to facilitate the location of the upper end of the inner element 52 forms concentrically with the end 34 of the metallic shell 32.

The upper reinforcing ring 72 is located along the surface of the inner diameter of the pulled together the inner element 52 forms adjacent to the inner section 68 of the upper ring and promotes podromanijo pulled together element 52 forms to the ledge 70. The upper reinforcing ring 72 is formed from a structurally rigid material and may contain one or more elements, which individually or jointly form a ring base, located concentrically within the upper end of the section pulled together the inner form element. In a typical embodiment of the invention the upper reinforcing ring 72 is made of steel and welded to the end pulled together the inner element 52 forms.

The top element or tight cover 66 includes an annular element located radially between the outer section 60 of the upper ring along the outer diameter and the upper section 74, which is attached to the upper end of the discharge pipe 54 along the inner diameter. Top with the Ktsia 74 receives lateral pressure from the upper element 66, produced by internal pressure during operation, the pressure increase.

Tight cover 66 includes the surface of the wall of the outer diameter, which is situated adjacent to the upper region of the inner diameter of the outer section 60 of the upper ring and includes a groove 76, passing along its circumference. The annular sealing element 78 is located within the groove and may be formed from an elastomeric material to provide the necessary seal with respect to the outer section of the upper ring. In an alternative embodiment, the upper region of the internal diameter of the upper ring can be configured with a groove to accommodate the sealing element.

Tight cover 66 also includes a wall surface of the inner diameter, which is situated adjacent to the outer surface of the upper section 74 of the discharge tube and which is configured to provide sealing relative to it. In a typical embodiment of the invention the upper section of the discharge pipe includes a groove 80 located around the circumference along its outer surface, which has a size to accommodate an annular seal element 82 and the sealing element may be formed from an elastomeric material, such as described above for other sealing elements used in e is th node 30.

On top of the sealed cover 66 is locking element 84, configured for fixed fixing the location of the sealed cover 66 on the upper ring 58 for closing and locking the molding of the site in place. In a typical embodiment of the invention the locking element 84 is made in the form of a spring locking ring and the like, which has a size with the edge of the inner diameter, which is able to match the slot 86 located along the outer diameter of the upper section 74 of the injection pipe. The locking element is engaged with the groove 86 to counteract the pressure on the upper element 66 during the operation of molding.

The discharge pipe 54 is a generally cylindrical element that extends from the upper section 74 down to the support ring 38 and which may include one or more ribs 88. One or more ribs act to stabilize the discharge pipe from collapse due to external pressure exerted by the mold during the operation of molding, and can be carried out between diametrically opposite portions of the pipe and/or to a centrally located mounting sleeve and the like (not shown), also to stabilize the situation and to minimize radial movement or deflection of the discharge pipe during the process of forming faced with casting is by making a steel pipe.

The discharge pipe 54 includes input 90 passing through the pipe wall to provide the fluid to increase the pressure, for example, water in the node. The entrance includes a sealed connection end 92 to facilitate its attachment to the usual device of the fluid to increase the pressure, such as a water pipe. In a preferred embodiment of the invention the input 90 is located near the lower part of the discharge pipe 54 and configured to receive water under pressure from the respective device to increase the pressure, for example, from the output end of the pump or similar means.

The above-described node 30 operates in the following manner for the formation of a coated molding of the steel pipe. Before placing a sealed cover 66 and the locking element 84 on the upper part of the site, the desired amount of the composition of the concrete or mortar is cast or otherwise fed into the chamber 46 formed between the metal shell 32 and pulled together the inner element 52 forms.

In a typical embodiment of the invention the composition of the concrete or cement mortar contains a mixture having the following characteristics. One desirable feature is that the concrete or cement mortar should be sambiranensis so that it acts like a liquid. It is necessary to generate the, the concrete or cement mortar will transmit the pressure applied to its surface, from the top of the pipe to the bottom of the pipe and radially outward to expand steel pipe. The second characteristic is that the concrete or cement mortar can be extensible. The use of expandable mixture helps to minimize and/or eliminate unwanted volume loss from creep and shrinkage when drying to help preserve the necessary voltage of the pipe wall during the operation.

In a preferred variant of the invention, the pre-tension concrete core will be very small or it will be eliminated when the internal pressure reaches working pressure. The maximum strain of the strain in the concrete core will be limited to ensure that the concrete core is in contact with the inner diameter of the metal shell, or there is only a very small annular gap between the concrete core and the inner diameter of the metal shell. Such contact or close proximity will help to ensure that the concrete core creates high-alkaline environment necessary for the protection of steel from corrosion for a period of approximately 50 years. In a preferred embodiment of the invention the steel is carried and load pressure without the use of any available voltage steel for loads from soil or reactions at the core of the cement mortar or concrete. The core and support the adjacent backfill will provide the rigidity necessary to hold external loads from the weight of the soil, weight of the pipe and the weight of water. In a typical embodiment of the invention the composition of the concrete or cement mortar leveling with limited shrinkage and non-reinforced, for example, does not contain reinforcing elements of the reinforcing steel or other metal.

The amount of structure of concrete or mortar that is used for manufacturing a coated molding of steel pipes, thus may vary depending on such factors as the length of the coated molding of the steel pipe and the desired thickness of the concrete lining. The composition of the concrete or cement is fed into the chamber 46 until the upper surface of the casting will not reach the top edge of the end 34. In a typical embodiment of the invention the composition of the concrete or cement is served in a form so that its surface is held at a certain distance in the upper ring 58. As indicated above, the top ring 58 acts to provide an additional volume of concrete or cement required for movement down to the level surface of concrete or cement within the form when the pressure increases due to the outward expansion of the steel shell. In typical is ariante the invention, the volume of concrete or cement mortar, located above the end 34 sufficient to compensate for the change in height vertically during pressure increase so that the final level of the concrete is located exactly on the top edge of the end 34. The equations presented above, provide an example calculation of the reduction in the height of the concrete during the process of injection molding.

When the composition of the concrete cast into the chamber 46 and has not yet hardened, sealed the lid 66 and the locking element 84 establish into place on top of the site. Then in the molding site, water is supplied through the inlet 90 to the water at the required working pressure. The water passes into the site, filling the annular water chamber 94 formed between the discharge pipe 54 and pulled together the inner element 52 forms. Water also takes place in the upper part of the site, filling the upper chamber 96 of the site, which is located above the surface of the concrete composition or solution and which is limited in General, within the Central district of the upper ring. Water within the site has the same pressure inside the chambers 94 and 96, thus acting for the application of the necessary pre-stressing force to the composition of concrete or cement, at the same time maintaining the radial position of the pulled together core within the site, for example, equal pressure affect both sides pulled together the inner form element, acting for the storage of its radial position within the node.

The pressure of the water within the site is maintained at a constant level within a reasonable period of time during the casting and solidification of the composition of the concrete or cement mortar. The use of water as medium pressure increase allows you to submit, as necessary, make-up water in the process, increase the pressure to compensate for any leakage which may occur at various o-rings, without the risk of calling the event of a pump failure, that is, the water will not harden in the injection pump, as would occur if the pressure was maintained injection pump for liquid cement or concrete. The exact amount of time during which the composition of the concrete or cement mortar is under pressure, will vary depending on the specific design of the pipe and/or operational performance, the type of concrete mix, as well as the specific end application.

Faced with pressure die casting steel pipes and methods for their manufacture according to the principles of the present invention may become clearer when referring to the next example.

EXAMPLE

Faced with pressure die casting steel pipe formed with the site, shown in figure 2, and having a metal shell with a diameter of approximately 92 inches, manufacturing is go through the submission of concrete composition, containing approximately 750 pounds of cement (Type I/II), 1490 pounds of coarse aggregate, 1400 pounds of sand, 319 pounds of water, 60 FL oz strong water-absorbing additives (Glenium 7700), 10 liquid ounces of viscosity modifier (VMA 538) and containing a small amount of air voids (2,5%), while the total weight of the composition was approximately 3959 pounds. If necessary, part (15-20 wt.%) cement component specified in the above composition may be replaced by an expanding tool, such as Komponent from CTS Cement Manufacturing Corp, to compensate for the shrinkage during drying and creep. This composition was fed into a mold chamber for concrete or cement mortar. Pulled together the inner form element is set so that the internal diameter of the resulting hardened concrete lining was approximately 84 inches. The metal shell was made in the form of a steel shell having a wall thickness of approximately 0.16 inches. The desired wall thickness of concrete lining for this coated molding steel pipe was approximately 4 inches. After the concrete composition was fed into the molding chamber, forming a node has been filed with water so that it covers the surface of the concrete composition. The water pressure in the node has been promoted to a pressure which produced tension in the steel constituting the p is blithedale 90% of the specified minimum yield strength. In this case, the steel was an X60 with a minimum yield strength of 60,000 pounds per square inch, and thus the internal pressure required to create 54000 pounds per square inch, approximately 188 pounds per square inch. It should be noted in this example that the ratio of diameter to thickness is 92/0,16=575 that is outside the normal practice for the design of water supply pipe and is only possible due to the thicker concrete facing, is able to withstand external loads from the ground. The water pressure was maintained at this level for about 24 hours, causing tension in the steel pipe approximately 54000 pounds per square inch and causing its expansion. After 24 hours curing high temperature, for example, from 140 to 160°F, pulled together the inner form element has been moved into its tightened position, and the pressure of the water within the site were dropped, causing a shortening of the steel pipe on the concrete core, subjecting it to compression. The obtained coated molding steel pipe was removed from the site, and the coated molding steel pipe was left to continue curing under conditions of ambient pressure. Immediately after the initial curing of high temperature concrete core ablezova the Noah molding steel pipe was under compression for approximately 1659 pounds per square inch. Cm. the set of equations presented above, which give an example of a calculation.

A sign describes the manufacture of coated molding of steel pipes is the use of water as medium pressure instead of using the concrete or grout as the environment to increase the pressure. The disadvantage of using the composition of the concrete or grout as the environment pressure is the possible damage to the unit increase of pressure such as a pump and the like, as by the inherent abrasive nature of concrete composition, and because changes in the rheological characteristics, which are known to occur during the time when the composition hardens, making the problem of maintaining the required constant pressure force even more serious.

The use of water as medium pressure to increase the pressure of structure of concrete or cement eliminates these problems and allows you to apply constant pressure to the composition of the concrete so that it is easy to implement using conventional pumping equipment, and thus that it is not affected by the curing of the concrete composition. In addition, because the composition of the concrete leveling, it will largely act as water and to transmit the pressure applied to the surface of the composition in the form of metal about Locke. It passed the pressure causes the metal shell to increase in diameter as it would be under normal hydrospatial pressure. If during the process of pressure increase occurs any minor leak on any of the sealing surfaces, the device increase the water pressure, for example, the pumping device can easily compensate for the loss to maintain the stretched condition of the metal shell. Because the composition of concrete or cement may harden under water, water header pressure allows the composition to harden, also maintaining the desired pressure with the help of make-up water, even if there is any leakage of cement mortar or concrete.

When the core of concrete or cement mortar subjected to the necessary pressure for the required duration of time, the pressure is eliminated by the release of water from the site, causing the reduction of the metal shell on the hardened concrete lining or core, thereby creating a pre-tension of the core by the application thereto of pressure. Once this occurs, the inner diameter of the cladding of concrete or cement mortar is also reduced, causing compression pulled together on the core, so the mouth is area need to use the inner core, which is tightened to ensure retrieval of already formed coated molding steel pipe. In a preferred embodiment of the invention, when faced with pressure die casting steel pipe was under pressure, within a reasonable period of time, pulled together the inner form element first edge to relieve the pressure within the node, thus, to prevent damage to the inner form element power compression core and facilitate or simplify the process of pulling or otherwise reduce the diameter of the inner form element.

In a typical embodiment of the invention forming the node is configured in such a way that the water pressure inside the chambers 94 and 96 are equally, such as a camera configured so that the chambers 94 and 96 are communicated in fluid with each other. In a typical embodiment of the invention shown in Fig. 2, the water under pressure will pass from the chamber 94 into the chamber 96 through the tabs or centering ring 70 due to the lack of seals. If necessary, may be applied to the grooves and/or holes to gain the necessary passage of water between the chambers 94 and 96.

When the inner form element is compressed and the pressure dropped, the sealing cap 66 is removed and the rest of the site for casting/above the Oia pressure assort. Faced with pressure die casting steel pipe may be removed from the support ring 38. Remote faced with pressure die casting steel pipe can be transported to a desired location for further curing of the lining of concrete or cement mortar under ambient pressure and hydration environment, for example, where it may be exposed to water, as needed, to facilitate further curing. In a typical embodiment of the invention the composition of the concrete can be cast vertically and subjected to the pressure force, which constitutes approximately 188 pounds per square inch, for about 24 hours, after which the pressure drop, and the coated molding steel pipe removed for further cured under ambient pressure for about twenty eight days. In a typical embodiment of the invention the coated molding steel pipe can be cured by steam within the first 24 hours while maintaining the pressure in the casting in the form. 24 hours of steam curing the coated molding steel pipe can be equivalent to a 7-day curing at ambient conditions, which is usually 80% of the strength at 28 days. Curing PA is ω elevated temperature accelerates the rate of curing, allowing faster to retrieve faced with pressure die casting steel pipe from the site of injection molding, thus increasing productivity for manufacturing next-lined pressure die casting steel pipe.

Figure 3 shows another typical node 200, suitable for the manufacture of coated molding steel pipe in accordance with the above principles, which is somewhat similar to that described above and shown in figure 2 in that it is used pulled together the inner form element and water as medium pressure for molding and forming a coated molding of the steel pipe. In General, the site uses a cylindrical metal shell 202 containing the ends 204 and 206 and forming the outer surface of the resulting coated molding steel pipe. The node 200 includes an annular support ring 208, which is located in the lower part of the site and which is in compressed contact with the inner end surface 206. The support ring may be configured generally similar to the support ring described above and used in the site shown in figure 2.

In General, a cylindrical discharge tube 210 is located concentrically inside of the metal shell 202 and passes longitudinally upward from the support ring 208 to the top to the ICU discharge pipe 212, which is in contact with the node 213 of the upper cover located in the upper section of the node 200. The discharge pipe is generally configured the same as described above for the site shown in figure 2, and includes input 214 for water passing through part of the wall for receiving water to increase the pressure in the node.

Pulled together internal element 216 form is located in the radial direction between the metal shell 202 and the discharge tube 210. Pulled together the inner form element configured similar to that described above for the node shown in figure 2, and is used to form together with the metal shell mold chamber or cavity 218 for receiving and casting of structure of concrete or mortar. Upper and lower reinforcing rings or belts 220 and 222 are pulled together to hold the inner form element in the desired radial position.

To the node 213 of the upper cover attached to the top ring 224 located on top of the end 204 of the metal shell, and an annular sealing element 226 may be used for forming the necessary seal between the end and the top ring. The top ring 224 includes an inner diameter, which together with an outer diameter pulled together the inner form element forms therein a mold cavity 228. The top ring 224 includes, IU the greater extent, one projection or ring 230, passing down and the corresponding outer surface of the pulled together internal element 216 forms, to limit its radial movement during injection molding.

To the upper end of the discharge tube 210 is attached to the upper ring section 212. On top of the upper annular section 212 of the discharge tube 210 is the node 213 of the upper cover. The node 213 of the upper cover includes a loading tube 232 which passes through hole, which passes through the upper circular ring 236 and the lower o-ring 231 node 213 of the upper cover, for the supply of concrete composition or solution in a mold cavity 218 and 228 before the pressure increase. Boot pipe 232 may include a waterproof connector end to be attached to a suitable feeder concrete or cement, such as tubing and the like In a typical embodiment of the invention the boot tube 232 has a diameter of approximately 4 inches to facilitate injection or casting through her composition of the concrete or mortar. In a typical embodiment of the invention, the node 213 of the upper cover and the upper ring 224 combined welded element in the region of the lower circular ring 231.

The node 213 of the upper cover made of top round ring 236 and the lower circular ring 231 which are related to each other and attached to each other by corner plates. The node 213 of the upper cover is in tight contact with the annular seal 234 and 226. Node top cover is held in place by means of the locking element 238, such as a springy retaining ring, etc. In a typical embodiment of the invention the locking element 238 is springy retaining ring, which is located in the locked position engages in a groove located along the adjacent surfaces of the end rings 212 attached to the discharge tube 210.

The materials used to form all of the items listed above for the node 200 may be the same as used for the formation of similar items listed above for the node 30 shown in figure 2.

Configured this way, the node 200 operates in the following manner for the formation of a coated molding of the steel pipe. Compared with the node, shown in figure 2, the site shown in figure 3, allows you to set and lock the position of the node 213 of the top cover prior to the filing of structure of concrete or mortar in the node. The desired amount of the composition of the concrete or mortar is then applied, for example, is poured or injected into the node through the boot of the pipe, filling the chamber 218 and at least part of the chamber 228.

As shown in figure 3 and as described above for the node shown in figure 2, the load composition betaneli cement is necessary distance above the end 204 to account for the lower level of the concrete surface when the pressure increases due to the outward expansion of the metal shell. In a typical embodiment of the invention, the node 200 may include other pipe, which is charged to approximately 180 degrees from the boot of the pipe and which can be used as a control pipe to determine that the desired level of the surface of the concrete is reached. If necessary, in the control pipe can be placed float, etc. to ensure accurate determination of the level of loading.

When the composition of the concrete or cement is filed, the loading tube is closed, and the node through the inlet 214 to supply water at the required pressure. Water under pressure fills the annular gap between the discharge pipe 210 and pulled together internal element 216 form and then passes over the upper edges pulled together the inner form element and enters the mold cavity 228, where it acts to increase the pressure of structure of concrete or cement mortar. The water pressure acts for the application of the necessary pressure voltage to the composition of concrete or cement mortar, which passes it to the metal shell just as described above for the site shown in figure 2.

Figure 4 shows another typical node 100, suitable for the manufacture of coated molding steel pipe in accordance with the above principles. Unlike typical nodes, p is shown in figure 2 and 3, using pulled together internal form, in an embodiment of the node, shown in figure 4, is used murine item, such as aperture, fiberglass pipe, etc. that can be used for forming the inner diameter of concrete lining during casting and injection molding and can be removed from the concrete facing, when faced with pressure die casting steel pipe formed by resetting the initial pressure of the expansion chamber 152.

In the node 100 uses the metallic shell 102 and the ends 104 and 106, which are attached to respective opposite upper and lower ends of the shell. The shell and the ends can be the same as described above and shown in figure 2 and 3. The annular support ring 108 is located at the base node 100 and includes a groove 110, passing through the circle along the outer diameter and having a size and shape for the location therein of the sealing element 112 to form a seal relative to the inner surface of the end 106. The support ring also includes a section 114 of the internal diameter, which is configured to accommodate the lower end of the discharge pipe.

The support ring 108 also includes a mechanism for entering into contact and form a seal with murine element 116. In a typical embodiment, realized is I of the invention the mechanism is made in the form of o-rings 118, which is configured for landing inside of the groove 120, located along the upper surface of the ring and which may with branches attached to the ring threaded fastening means 122. A sealing ring configured to contact the target part murine element, attaching his seal to the support ring. Sealing element 124 may be used, if necessary, to provide the necessary seal between murine element and the support ring.

Closer to the top of the site 100 top ring 126 includes an outer section 128, which is in front end parts 104, and one or more annular sealing elements 130 are located within the respective grooves 132, located on a circle around the tip 104, to provide a seal with respect to the outer section 128. The top ring 126 includes an upper section 134, which is located against the upper section 136, which is connected to the discharge pipe 138. The discharge pipe extends longitudinally between the support ring and the upper section and located concentrically within murine element 116. The upper section 136 includes a groove 140 having located therein an annular sealing element 142, which provides the necessary seal relative to the inner section 134 of the upper ring.

Stanoch the first element 116 is attached to the upper section suitable fastening mechanism 144 depending on the type of material, selected for use as murine item. When murine element is made form rubber diaphragms, the fastening mechanism used for its attachment to the upper section may be contractible band like tool. It should be understood that the specific type and/or configuration of the mounting hardware used to attach murine element 116 to the upper section and the support ring, can and will vary depending on the type of material and/or structure that is used for its formation. For example, when murine element 116 is made in the form of a hard but elastic material, such as fiberglass pipe and the like, the fastening mechanisms may differ from those described above. However, their function in General is to facilitate the insertion of the ends of murine item corresponding to the upper section and the annular element and also implementation of this in such a way as to minimize and/or eliminate any undesirable leakage of material from both sides of the murine element.

In a typical embodiment of the invention the upper sealing cover 148 is welded to the upper ring 128 for sealing molding site. In this typical embodiment of the invention the upper sealing cover 148 includes a loading tube (as shown in the node, shown in figure 3), which passes through the cover 148 to supply the desired amount of the composition of the concrete or mortar in the node.

The node 100, shown in figure 4, is used to form a coated molding of the steel pipe as follows. When the desired amount of the composition of the concrete or mortar filled, pumped or otherwise filed into the mold cavity or chamber 146 to the required level within the water chamber 150 (as described above, to compensate for the lowering of the surface of concrete at elevated pressure), and the spring load of concrete or cement mortar hermetically closed, water is fed under pressure to the node 100 in such a way that it covers the surface of the molded composition of concrete or mortar and fill the water chamber 150 that is located inside the upper ring 128.

In one embodiment, the host 100 murine element 116 is a passive element, such as a rubber diaphragm and the like, and the site contains an annular chamber or cavity 152, which is filled with the right amount of liquid, such as water. When the water pressure in the molding chamber 150 is increased to the required level, the water pressure in the annular cavity 152 is increased by the passive reaction directly on the discharge pipe. In this embodiment of the invention no real power does not make for the most murine El is into, as the fluid in the diaphragm, i.e. the water is incompressible.

In another embodiment, the host 100 murine element 116 is an active element, such as fiberglass pipe, which is located concentrically around the discharge pipe. In this embodiment of the invention prior to casting the concrete core, the pressure in the annular chamber or cavity 152, existing between the discharge pipe and tube increased liquid, such as water, and the tube expands under pressure. Fluid under pressure within the cavity 152 hermetically sealed, and the water is fed under pressure into the molding chamber 150, as described above, for the implementation of injection molding lining of cement mortar or concrete.

The water pressure used for injection molding of the composition of concrete or cement in this embodiment of the invention, as well as the duration of the process of injection molding can be the same as described above for the nodes shown in figure 2 and 3. In this process, the molding pressure of the water exerts pressure to the composition of concrete or cement mortar, and this pressure is transmitted to the metal shell, causing the voltage of the shell and extending outward to the desired value.

After a predetermined period of time, the water pressure within formula the Noah camera 150 fold, causing the occurrence of the metal shell in the contract with the hardened lining of concrete or cement mortar, introducing it in a compressed state and causing the reduction of the inner diameter of the cladding of concrete or cement mortar. The fluid in the annular chamber 152 of both embodiments of the invention mentioned above, and then release it, causing a contraction of the diaphragm in one embodiment of the invention and fiberglass pipes in another embodiment of the invention and the separation from the inner diameter of the hardened coating of concrete or cement mortar, thus allowing to extract the formed coated molding steel pipe from the node. The node then dismantled, and the resulting coated molding steel pipe can be removed as described above for embodiments of a node, shown in figure 2 and 3.

In General, faced with pressure die casting steel pipe having the above-described construction, cast under pressure with nodes and according to the methods specified above for the period of one day or 24 hours, allowing the composition of the concrete or cement mortar to seize and initially harden. The structures of concrete or cement used to form the coated molding steel t the UB, according to the present invention can include the required amount of additive or extender means to achieve increased and/or a constant pre-tension when faced with pressure die casting steel pipe continues to harden in the course of molding and after him. The use of expanding additives may also compensate for shrinkage during curing and drying that occurs during curing of the core concrete or cement mortar, and creep of concrete or cement, caused by compression, attached to concrete covering the steel cylinder. The expanding use of supplements can help maintain maximum pre-tension in the concrete core and a metallic shell relative to the voltage under pressure in a metal shell during the process of molding and curing.

In a typical embodiment of the invention may not be possible or necessary molding pressure above approximately 90% of the specified minimum yield strength. The pressure relief during the process of molding lowers tension steel lined pressure die casting steel pipe to a value substantially below 90% of the specified minimum yield strength. At this point, the presence of R is schiraldi supplements in concrete or cement mortar is capable of applying a tension to the steel for the compensation of losses resulting from creep and compression without overvoltage steel. It is desirable to extend the additives used for this purpose, had the delay time from the initial curing of the concrete, allowing the concrete enough to grab on to counter the pre-tension steel, and then later (after the pressure dropped, and the pipe is removed from the molding node) extensible concrete adds pre-tension steel, not entering the steel in the state outside of the calculated yield. Creep and shrinkage during drying also happen after the pipe is removed from the mold for injection molding, and thus these two opposing effects offset each other after the pipe is cast under pressure.

Appropriate extender additives useful for this purpose include available under the product name Komponent from CTS Cement Manufacturing Corp. to compensate for the shrinkage during drying and creep. In a typical embodiment of the invention extends the additive may be up to about 15 or 20 wt.% cement component used in the composition of the concrete. It should be understood that any possible use of supplements and extends the amount of any such supplements can and will vary depending on many factors such as materials used for forming the pipe, criteria for technical design and operational parameters, and to the final version of the application.

In a typical embodiment of the invention, the pressure during molding is set at 90% of the specified minimum yield stress during curing. The initial pre-tension concrete core is reduced shrinkage during the hardening of concrete, shrinkage during drying of the concrete plus the creep of concrete lining and the steel pipe. These losses are such that the full rated voltage, the potential for steel cylinder, cannot be achieved without removal of the entire preliminary voltage applied to the concrete lining, and the creation of a strain of concrete lining, or create the possibility of harmful annular gap between the concrete lining and the steel pipe during operation. It should be noted that a small annular gap or tension in the concrete are acceptable and it is proven concrete and steel pipe, such as pipe AWWA C300, but excessive deformation in the steel casing shall be excluded. Concrete lining can be sealed in a steel pipe to prevent the formation of the annular gap, thereby creating a voltage of concrete lining during operation. All of these options are possible and may be desirable for specific applications.

In a preferred embodiment of the invention, the lining of concrete or cement mortar is away at a very small pre-stress from the steel cylinder at operating pressures, or steel cylinder is extended on a very limited amount above the free core diameter of concrete or cement mortar with operating pressures. This allows you to use all permissible rated voltage in a steel pipe to resist the internal pressure, while facing and support backfill can be used to resist loads from the soil at the depth plus the weight of the pipe and the weight of water. The amount of widening of the additive required to achieve a preferred variant of the invention, will depend upon the pressure in the casting, the coefficients of creep, shrinkage coefficients and the necessary operating voltage in a steel pipe. Full pipe design provides recoverable shrinkage when drying. Approximately 70% shrinkage when drying are reversible when the pipe is filled with water, and the concrete lining may re-absorb lost during the drying of the water. This re-swelling of concrete can be used as part of the total pre-stressing of concrete lining, including all losses and increment associated with the initial injection molding, shrinkage during drying and curing, expansion of concrete extending from supplements plus creep in steel and concrete lining under the length of the nutrient load.

A sign of a coated molding of steel pipes, made as described above, is that they contain a lining of concrete or cement mortar, which is able to provide a degree of corrosion resistance, which corresponds to the currently provided by a cylindrical tube with a pre-tense concrete steel cylinder pipe with reinforced concrete and plain steel pipe with concrete lining, for example, of the order of 50 years. In addition, faced with such pressure die casting steel pipe contains a metal shell, which introduces a concrete lining in a compressed state and which makes it so that the tube is more rigid and not subject to sudden failure compared to a cylindrical pipe with a pre-tense concrete, for example, due to corrosion and destruction of the tension wire. In addition, the metal shell can easily be covered with an appropriate plastic material and the like, which is able to provide the necessary degree of dielectric protection/resistance from the undesirable effects of a corrosive environment or cathodic interference. In addition, the metal shell can be easily repaired using welded plates and the like, if identified corroded section, without neo is needed to withdraw the pipe from the operation and/or without having to remove the pipe from its recessed position.

In addition, faced with pressure die casting steel pipes, made as described above, can be formed in a single step injection molding, and concrete lining form, and strength pre-stressing is attached to a metal shell, which is valid for introducing concrete into a compressed condition, thereby eliminating the many steps, which saves time and labor costs. In addition, the coated molding of the steel tube are made using water as creating pressure environment, as described above, exclude the possibility of failure of the pump during the process of creating pressure, which could lead to the rejection of the site, loss of material, labor costs and reduced production efficiency.

In addition, faced with pressure die casting steel pipes made in accordance with the principles of the invention provide pipe construction, which is very stable during transportation and installation. Ordinary steel pipe with concrete lining is so flexible that the required spacer mount or wooden or metal supports inside the pipe to prevent excessive bending of the pipe and the crushing and/or breaking the coating. A thicker lining with compression, attached to the lining from steel, connected the Oh with panelled molding steel pipe, makes the tube very durable during transportation and depth without fasteners, which provides a further reduction in costs compared to conventional steel pipe with concrete lining. The above equations give the approximate comparison of hardness standard steel tubes and covered with molding steel pipe.

Other modifications and changes structures lined by molding steel pipes and methods, and components for its production, according to the principles of the present invention will be obvious to a person skilled in the art. Thus, it should be understood that in the framework of the attached claims, the invention can be practiced otherwise than specifically described.

1. Faced with pressure die casting steel pipe, which is put into operation for transporting a liquid medium containing:
an annular lining of concrete or cement mortar, forming the inner diameter of the pipe; and
metal sheath surrounding the cladding,
in which the cladding is in direct contact with the inner wall of the metal shell, and the cladding is pre-tensioned by means of the metal shell in the initial state before entering the pipe in operation for transporting liquid is Reda, moreover, the initial tension of the lining in the final state is essentially eliminated when it is put into operation for transporting a liquid medium.

2. The pipe according to claim 1, in which the ratio of the wall thickness of the cladding and the metal shell is in the range from about 5:1 to 80:1.

3. The pipe according to claim 1, in which the ratio of the wall thickness of the cladding and the metal shell is in the range from about 10:1 to 50:1.

4. The pipe according to claim 1, in which the wall thickness of the metal shell is in the range of from about 0.06 to 0.75 inches, and wall thickness of the cladding is in the range from about 1.5 to 10 inches.

5. The pipe according to claim 1, also containing a coating of dielectric material located along the outer surface of the metal shell.

6. The pipe according to claim 1, in which the concrete lining is formed with an uncured composition of concrete or cement and the metal shell are subjected to pressure by direct contact between the uncured composition of concrete or cement mortar and liquid medium under pressure for the introduction of the lining in the compression state, when facing solidified and the pressure dropped.

7. The pipe according to claim 1, in which the wall thickness of the metal shell is from about 0.06 to 0.75 inches, the thickness of the wall facing approximately 10-50 RA is greater than the thickness of the wall of the shell.

8. Faced with pressure die casting steel pipe, containing:
an annular lining of concrete or cement mortar, forming the inner diameter of the pipe; and
metal sheath surrounding the casing and having a wall thickness of from about 0.06 to 0.75 inches,
in which the cladding has a thickness that is approximately 10-50 times greater than the wall thickness of the shell and the lining is in direct contact with the inner wall of the metal shell, at the same time facing hardens in place against the metal shell by direct contact with a liquid medium under pressure for the introduction of a hardened lining in the compression state of the metal shell.

9. The pipe of claim 8, in which, when the pipe is in original condition and has not been commissioned for transporting a liquid medium, the cladding is pre-tensioned state, and when the pipe is in the final state and put into operation for transporting a liquid medium, the initial tension on facing severely limited.

10. A method of manufacturing a coated molding steel pipe containing phases in which carry out:
the supply amount of the composition of the concrete or mortar in shape, formed between the metal shell along the outer is first diameter and a movable core along the inner diameter;
the impact force of pressure on the composition for the expansion of the metal shell, and the pressure force provided by the fluid under pressure in direct contact with the surface of the composition;
the pressure relief after the composition of the concrete or mortar degree of curing for forming coatings from concrete or cement mortar, and the stage discharge pressure causes the application of compression forces the metal shell to the lining; and
remove mobile core to the inner diameter of the cladding.

11. The method according to claim 10, in which fluid under pressure is water.

12. The method according to claim 10, in which the movable core is made in the form of an elastomeric element.

13. The method according to claim 10, in which the movable core is made in the form of pulled together a solid element.

14. The method according to claim 10, in which the movable core is made in the form of a cylindrical rigid structure that can grow to form the cladding and to contract for the removal of the core after casting under pressure.

15. The method according to claim 10, in which the movable core is made of a steel pipe of high strength.

16. The method according to claim 10, in which the movable core is selected from the group of materials consisting of fiber reinforced plastic pipes, plastic pipes and their combinations.

17. The method according to claim 10, in which the composition of the be who she or cement includes expanding additive, which metal shell contributes to the application of compressive force to the lining.

18. The method according to claim 10, in which the form contains an annular chamber which is oriented vertically.

19. Faced with pressure die casting steel pipe made according to the method according to claim 10, in which the lining of concrete or cement mortar is in direct contact with the inner wall of the metal shell.

20. Faced with pressure die casting steel pipe made according to the method according to claim 10, in which the lining of concrete or cement mortar has a wall thickness that is approximately 10-50 times greater than the wall thickness of the steel shell.

21. The method according to claim 10, in which, when the pipe is in original condition and has not been commissioned for transporting a liquid medium, the cladding is pre-tensioned state, and when the pipe is in the final state and put into operation for transporting a liquid medium, the initial tension on facing severely limited.

22. Site for injection molding for the manufacture of coated steel pipes containing:
a cylindrical metal shell forming the outer part of the pipe;
supporting element is in the operating position connected with the bottom part of the metal shell;
the inner form element located concentrically inside of the metal shell;
an annular chamber located between the metal shell and the inner form element for placing an amount of the composition of the concrete or mortar; and
means for supplying a liquid medium to increase the pressure in the form and in direct contact with the surface of the concrete composition or solution for expanding the composition of the metal shell,
in which the diameter of the inner form element can be reduced when the composition reaches a given degree of cure.

23. Site for injection molding according to article 22, in which the liquid medium to increase the pressure is water.

24. Site for injection molding according to article 22, also containing the discharge pipe, which is arranged concentrically inside the inner form element.

25. Site for injection molding according to article 22, in which the liquid medium to increase the pressure is inside the annular chamber for fluid, located between the injection pipe and the inner form element.

26. The site for casting under pressure A.25, in which the pressure of a liquid medium to increase the pressure is approximately the same on the surface of structure of concrete or mortar and inside the annular chamber for the liquid.

28. Site for injection molding according to article 22, in which the upper element includes an upper ring over the end of the metallic shell.

29. The site for casting under pressure p, in which the surface composition of concrete or cement in front of the pressure increase is above the end of the metallic shell and is located inside the upper ring.

30. Site for injection molding according to article 22, in which the annular chamber is oriented vertically.

31. Site for injection molding according to article 22, in which the inner form element is a solid cylindrical element having opposite longitudinal edges, which can move to reduce the diameter of the element.

32. Site for injection molding according to article 22, in which the inner form element is a rubber element.

33. Site for injection molding according to article 22, in which the inner form element is a solid cylindrical element, which can expand and contract by a sufficient margin to ensure the formation of the cladding and separation from him about what licowki.



 

Same patents:

FIELD: construction.

SUBSTANCE: pipe is installed vertically onto a base with a stand and guides, so that the lower part of the pipe is enveloped with a circular form with a concrete pipeline connected to it, the concrete mortar is supplied into the form, besides, the pipe comprises a circular space formed between external surface of the pipe and shell arranged concentrically around the pipe, an upper plug and a lower plug, which limit the circular space with holes for supply of the concrete mortar. The device of concrete application onto the pipe in vertical position, including a stand with guides fixed on the base and a circular form with connected concrete pipeline, which envelops the pipe. At the same time the circular form comprises inner, outer, lower and upper walls and has at least one cavity with the connected concrete mortar, and holes in the upper wall, and facilities to press the circular form to the lower plug are installed on the base.

EFFECT: higher speed of concrete application onto the pipe with availability of the shell that protects the concrete against impact of environment at it.

5 cl, 8 dwg

FIELD: construction.

SUBSTANCE: combined pipe comprises a central pipe, a shell, a circular space with centring skids, formed between the pipe and the shell, plugs with holes, covering the circular space, at that at least one of plugs has several holes, a disk gate to close holes in the plug by its rotation after the circular space has been filled with the concrete mortar. The device of concrete application onto a pipe arranged horizontally or in an inclined manner, comprises a circular form that embraces the pipe and is made of internal, external and two side walls, one of which, facing the plug with the disk gate, has holes; the walls form at least one cavity, having a nozzle for connection of a concrete pipeline, at the same time the device has facilities to press the circular form to the plug, which are made of a bush with a flange fixed at the pipe end and jacks installed on the flange, and facilities of the disk gate rotation.

EFFECT: increased efficiency of combined pipe circular space concrete filling process and reduced pressure of concrete mortar injection.

4 cl, 6 dwg

FIELD: construction.

SUBSTANCE: composite pipe comprises asbestos-concrete pipe or concrete basic pipe and outer coating made of composite-fiber material whose fibers are oriented in peripheral and axial directions. The ring fibers are preliminary stretched. The outer coating embraces the outer cylindrical surface and faces of the basic pipe, completely or in part, or fills the ring grooves formed from both ends of the basic pipe. The method comprises pressing the basic pipe before winding, winding the outer coating made of composite-fiber material on the basic asbestos-concrete or concrete pipe, stretching the ring layers during winding, and solidifying the composite material.

EFFECT: enhanced strength.

3 cl, 1 dwg

Combined pipe // 2232333
The invention relates to the construction industry, namely to the backbone and technological pipelines for heating and hot water, and gas and oil pipelines

The invention relates to the field of construction of engineering networks, in particular sewer pipes and collectors

Pipe (options) // 2161748
The invention relates to the construction and used for the construction of pipelines for the transportation of liquid and gaseous aggressive media at high pressures, vacuum, extreme temperature fluctuations, used in chemical and oil and gas industries

The pipeline // 2084743
The invention relates to pipelines, namely the pipes through which the gas is delivered to consumers

The invention relates to the design and device for manufacturing a cylindrical dispersion-reinforced tubular products used in pressure and non-pressure pipelines for transportation of various liquids, not aggressive to concrete, as mine timbering elements, as well as load-bearing columns in the industrial and civil buildings, etc

The line element // 2046241
The invention relates to the construction and mechanical engineering, in particular to a supporting devices pipelines

FIELD: engines and pumps.

SUBSTANCE: set of invention relates to oil-and-gas industry. Steel tubing comprises outer thread made at its ends for interconnection with the help of couplings. Steel tubing inner surface has coating of silicate enamel with circular section of silicate enamel melt saturated with iron oxides. Above said section an intermediate circular silicate enamel layer section is arranged having gas inclusions filled with oxides of carbon and hydrogen. Besides, upper circular coating section is made with flame-polished surface of silicate enamel. Thermal factor of linear expansion of coatings of silicate enamel makes 0.6-0.97 of that of steel whereof steel tubing is made. Besides, this invention covers the design of flow string.

EFFECT: higher reliability.

2 cl

Tubular material // 2415328

FIELD: machine building.

SUBSTANCE: tubular material has external border and internal border in its cross section. The external border of tubular material in cross section has a shape of ellipse (conic section). The internal border of cross section corresponds to circumference. Also, centre of circumference is in the centre of ellipse of the external border of cross section. Ratio of bigger axis of ellipse to smaller axis of ellipse at the external border (ellipse) is from 1.5 to 5.

EFFECT: increased service life of tubular material.

1 dwg

FIELD: metallurgy.

SUBSTANCE: steel consists in wt %: C: from 0.12 to 0.27, Si: from 0.05 to 0.40 and Mn: from 0.8 to 2.0, the rest is Fe and impurities of Ca, P and S. Contents of Ca are 0.001 % or less, P 0.02 or less and S: 0.01 or less. Steel additionally contains at least one element chosen from Cr: 1 % or less, Mo: 1 % or less, Ti: 0.04% or less, Nb: 0.04 % or less and V: 0.1 % or less. Maximal diametre of non-metallic inclusions present in at least in zone running from internal surface of steel tube to depth of 20 mcm is 20 mcm or less.

EFFECT: disclosed steel tube is not subjected to fatigue destruction and possesses increased fatigue life and high reliability due to high strength and high limit of internal pressure.

2 cl, 2 tbl, 1 ex

FIELD: machine building.

SUBSTANCE: pipe contains protective bushings out of corrosion resistant metal concentrically arranged on ends of pipe; bushings are made with bell mouth. Internal parts of protective bushings are located inside ends of the shell and hold them down to pipe surface; while external parts with removed shell are located in zones of welding thermal effect. Thrust rings attached to the protective bushings are arranged in circular gaps between the pipe and protective bushings tightly to the ends of the shell.

EFFECT: reduced material expenditures, simplified process of fabrication and raised efficiency of pipe.

4 cl, 4 dwg

FIELD: machine building.

SUBSTANCE: pipe with internal plastic shell consists of concentric arranged external bushings out of carbon steel and internal bushings out of corrosion resistant steel inserted inside calibrated ends of pipe. The external bushings are arranged inside ends of the shell and the pipe, while the internal ones close end sections of the pipe with a remote shell, partially are introduced inside the ends of the shell and hold them down to pipe surface. The pipe is equipped with assembly bushings out of carbon steel placed in the internal bushings so, as to overlap zones of bushing ends holding down; the assembly bushings have circular lugs on internal ends resting against ends of the internal bushings.

EFFECT: raised reliability of pipe.

8 cl, 4 dwg

FIELD: metallurgy.

SUBSTANCE: invention elates to metallurgy field, particularly to alloyed steel, provided for manufacturing of tubing and casing, and also downhole equipment, operating in hostile environment, containing hydrogen sulfide and carbonic acid. Steel contains carbon, silicon, manganese, chrome, molybdenum, vanadium, niobium, aluminium, rare-earth metals, iron and unavoidable admixtures, at following correlation of components, wt %: carbon not more than 0.16, silicon 0.30 - 0.50, manganese 0.50 - 0.70, chrome from more than 3.0 - 6.0, molybdenum 0.40 - 1.00, vanadium 0.04 - 0.10, niobium 0.04 - 0.10, aluminium 0,02 - 0.05, rare-earth metals 0.005 - 0.015, iron and unavoidable admixtures are the rest. In the capacity of unavoidable admixtures steel contains not more than 0.01 wt % of sulfur and not more than 0.01 wt % of phosphorus.

EFFECT: there are increased mechanical properties and stability to carbon dioxide corrosion, sulfide corrosive action under tension and biological corrosion.

2 cl, 4 tbl

FIELD: oil industry.

SUBSTANCE: invention refers to oil producing industry and particularly to casing pipes and tubing strings meant for being operated in corrosive media containing hydrogen sulfide and carbon dioxide. The pipe is made from chrome-molybdenum steel containing the following, wt %: carbon 0.1-0.35, chrome 1.0-6.0, molybdenum 0.4-1.0, and is subject to normalisation and double tempering. Steel has ultimate resistance σu of not less than 690 MPa, yield point σy of not less than 570 MPa, relative elongation δ of not less than 20% and impact strength KCV at the temperature of -50°C of not less than 70J/cm2.

EFFECT: providing high strength of pipes in combination with cold resistance and resistance to sulfide stress corrosion cracking and to carbon dioxide corrosion.

1 tbl

FIELD: technological processes.

SUBSTANCE: invention is related to the field of pipes production. Pipe comprises the following components - basic body (8) from cast iron, which limits external surface (10) of basic body and internal surface (12) of basic body, and internal coat (14) applied on internal surface (12) of basic body. Internal coat (14) comprises thermoplastic material based on polyolefines or polyamide. Invention is also related to method for manufacturing of pipe and tool for processing of internal surface.

EFFECT: lower cost of pipes production.

12 cl, 5 dwg

FIELD: construction, pipeline.

SUBSTANCE: invention is related to construction of pipeline transport and may be used in installation of pipelines on water basin bottoms and in swampy area. Pipe assembled with shell and plugs is laid on location plate, concrete pipeline is connected to holes in plugs, and ballast material is supplied in the form of moving concrete mixture by pump into annular space until is filled, then concrete pipeline is disconnected from openings.

EFFECT: expansion of technical facilities arsenal.

5 cl, 4 dwg

FIELD: mechanic.

SUBSTANCE: the invention relates to the machine building industry and can be used in oil and gas industry, during construction of pipelines for transportation of oil products, process liquids, and chemically aggressive fluids. The technical result of the invention is increase in reliability, decrease in cost and metal consumption of metallopolymeric tubing, increase in their fabricability and efficiency. In a metallopolymeric tube, the metallic tube ends are protected with fixers placed to the internal surface of the metal tube, designed as metal bushes with ledges and a cylindrical seating part, the diameter of the outside surface of seating part of the fixers is equal to the internal diameter of the outer metal tube, the diameter of the inside surface of fixers is equal to the internal diameter of the polymeric tube, the outside surface of the ledges has a conic shape, with a conicity angle equal to the angle of the tapered thread of the metallic tube, the bigger diameter of conic ledges surface is equal of outside diameter of the mating edge of the tapered thread of metallic tube; as the polymer tube, a thin-wall fiberglass tube with smooth internal surface is used, the outside diameter of which is 1÷1.5 mm smaller than the inside diameter of the metallic tube, and its length is smaller than the length of the metallic tube by the double length of the seating surface of the fixer; the thin-wall inside fiberglass tube from thrusts the internal ends of the fixers at both sides with its ends. In the method of metallic tube production, a thin-wall tube of fiberglass is used as the polymer tube, on the ends of which, plugs with holes are installed by screwing them on the threaded ends of the tube to the end so that the plug tightly enters the inside surface of the fiberglass tube on the distance 7÷10 mm, thus centering the fiberglass tube relative to the metallic tube and protecting the inside surface sections of the metallic tube against concrete solution ingress, from its edge to the length of the putting fixer; the concrete solution is fed from the hole in one of the plugs up to the uniform outflow of the concrete solution from the free hole of the plug on the opposite end of the metallic tube, after the consolidation of the concrete solution, the plugs are removed and fixers are glued in.

EFFECT: increased reliability and efficiency, decreased costs and material consumption of well tubing.

2 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to construction and specifically to methods of making slabs. The method of all-purpose making slabs involves mixing magnesia binder, organic filler, mineral filler and aqueous magnesium chloride solution, moulding articles, hardening and drying. The magnesia filler consists of two or more components, one of which is solid wastes from production of magnesia binder-based slabs and the second component is pearlite. Before adding to the mixture, all dry components are mixed to a homogeneous state, wherein components in the overall mixture are in the following ratio, wt %: magnesia binder 10-40, aqueous magnesium chloride solution with density of 1.1-1.3 g/cm3 40-70, organic filler 4-15, mineral filler 2-20.

EFFECT: invention improved environmental safety of slabs.

11 cl

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