Threaded pipe connection
FIELD: machine building.
SUBSTANCE: pipe connection has seat element with internal thread designed for assembled conjugation with rod element having external thread. Dimensions of conjugated threads facilitate radial tightness in assembly, while a thread pitch of the rod element is shorter, than a thread pitch of the seat element at value sufficient for compensation of axial elongation of thread of the rod element and axial compression of thread of the seat element occurring during assembly of the said elements as result of radial tightness between conjugated threads, facilitating in essence equality of steps of conjugated threads in assembles state. There are disclosed versions of pipe threaded connection.
EFFECT: increased reliability of connection.
27 cl, 8 dwg
The technical FIELD
The subject of this invention is a high-strength threaded pipe connection, with exceptional sealing properties and intended to be used essentially in all industries.
The LEVEL of TECHNOLOGY
Threaded pipe connections, which connect the joints of pipes and which provide a seal between them to prevent leakage fluid from the pipe, has been used for centuries in step threading made as close as possible to step the internal threads. Most of the threads currently in use in pipe joints are tapered, so the pressure on the border between threads increases with each added twist to such a degree of tension, which is considered sufficient to prevent loosening and leakage of fluid from the pipe. If the pressure at the boundary is too low, it will lead to a weakening of the thread and leakage, if it is too high, this may cause a plastic deformation of the truss element, i.e. the end with an external thread, or female element, i.e. the end with internal thread, so that the suitability of a thread may be in question. With increasing pipe sizes and pressure of the fluid gradually changed material is s pipe, since bamboo and turning to wood, copper, iron, steel, and sometimes to high-strength, high-temperature alloys with the need to preserve the strength and integrity, which in turn requires an increase in radial threaded tension and pressure at the boundary between adjacent turns of the thread. In the framework of this proposal:
- angle thread profile is measured in a plane coinciding with the axis of the pipe, the gap between the working party thread and a plane perpendicular to the axis of the pipe,
- rod element is a tubular element with an external thread,
- the female element is a tubular element with a mating internal thread intended for connection with the core element,
- one thread corresponds to one revolution of the thread
- step corresponds to the axial length of the thread as you move forward in one revolution,
negative side surface of the thread corresponds to the side that faces to a greater extent in the direction of the hollow profile,
positive side thread surface corresponds to the side that is facing more towards the top of the profile,
thread hook type is a thread with a negative angle profile
- the expression "the invention" means the subject of this is awci.
Historically, the threaded rod element was carried out with the same taper and step, and that coupled with her thread female element, while in U.S. patent No. 4974882 name watts was not informed that the external thread can run on a cone with a smaller slope than in the case of an internal thread, to ensure arise at the time of Assembly, the maximum radial interference fit between the mating threads at the end of the threaded connection of small diameter, which facilitates the Assembly of the rod and the nesting of the elements, enhances the strength of the threaded connection and contributes to its density.
In U.S. patent No. 6976711 name Sivley reported change step in your profile and/or the step of the rear profile of the paired thread rod and nesting of elements, so that the steps in the workflow thread profile and steps back thread profile is equal to the average step at a selected distance from the end of the threads, and the steps in the workflow thread profile and the rear thread profile differ from each other by at least some portion of the length of the thread", but in the mentioned patent is not informed about the change step, the outer thread concerning a pitch of the internal thread and no mention of any inconsistency step, which arises due to Poisson's ratio in the Assembly of outer and inner threads. Whereas in the Iman patents No. 04-1039, - 1040 (Invitroge v. Clontech Lab), patent No. 6976711 does not apply to prior art, since it does not mention about the problem or its solutions. According to the applicant, and according to the information available to it, does not currently have any information about the implementation of corrective operations, providing intimate contact between mating threads or compensating the inconsistency of their steps, caused by radial tension.
To demonstrate some of the problems solved by this invention, figure 1 shows the first type of damage is often encountered in the prior art, for example in a round pipe threads 8 threads per inch standard API specification 5B, when the Assembly of the breeding element 57 and the rod element 50 causes compression of the specified core element in the radial direction, causing the elongation in the axial direction, and also extends the socket element in the radial direction, causing the shortening in the axial direction, the difference in lengths presses the rear side 52 of the threaded rod member to the back side 53 of the female thread element with the angle of 30°, resulting radial component of the axial force moves the end surface 54 of the truss element inside and removes it from contact with the adjacent inner is her thread 55, that weakens the connection, as in this case, the contact is fewer turns of thread, opposing axial loads, and, furthermore, it opens a spiral channel 56 from leaking between the mating threads.
Figure 2 shows a second type of damage is normal threads, such as round pipe threads 8 threads per inch standard API specification 5B, after exposure to the external pressure of the fluid acting on the perimeter of the socket element 61 and increases the annular compressive stress on the end surface 62 of the truss element due to the threaded tension arising from the Assembly. The interaction of forces causes the plastic deformation of the end of the rod element and the weakening of the contact between the internal thread 63 female element and related external thread 64 of the truss element, resulting after a reset, the external pressure remains open both axial and helical channel 67 leaks, preventing mates and tight contact of the threads under the action of the internal pressure of the fluid after still elastic socket element returns to its original diameter, and the truss element is deformed at its end surface, not because of the ring strain compression ratio has the highest value near the specified behavior of the displacement. Damage to the first and second type most likely to occur in compounds in which the thickness of the core element around its end surface is smaller than the thickness of the adjacent wall of the socket element.
Figure 6 illustrates the primary contact between the regular threads, such as round pipe threads 8 threads per inch standard API specification 5B, when the institution in the angular position, which provides the smallest angle 68 pressure for a thread of this type, formed between the axis of the pipe 25 and the vector 46 of force passing through the point 93 of mutual contact, and the lowest possible pressure angle equal to the angle 81 of inclination of the rear profile. These threads are back working surface 70 of the outer thread, the top 74 and the rear working surface 71 of the internal thread, angled 81. Figure 7 illustrates the primary contact between the outer and inner threads at their institution in the angular position, which provides a very wide angle of 79 pressure, which can lead to damage of the third type, in which the top 74 of the profile of the truss element is in contact with the top 77 of the rear profile of the breeding element and which occurs due to a too large angle 79 pressure, creating too much tension shear between paired rear profiles at point 82 mutual touch is directed and, the specified vector 76 forces. The rear surface of the truss element are surface 74 formed between the rear of the working surface 70 of the specified element and the top 74 of the outer thread. The rear surface of the female element are surface 75 formed between the rear surface 71 of the specified element and the top 77 of the internal thread. The surface 74, 75 may be arcuate, conical, or other shape provides maximum prevention of damage of sharp corners when you move that would have occurred in another form surfaces, are well known in the art. This refers to the trapezoidal thread API standard and other types of threads, having a cylindrical top with recesses between the side surface and the top. After the establishment of the truss element in the female element is usually performed his turn on the part of the turnover in the direction opposite to the screwing, in an attempt to reach the angular position corresponding to the minimum pressure angle for the design of the carving depicted in Fig.6. Depending on the angular position between the rod and socket elements in the establishment of the pressure angle may vary from a minimum angle equal to the angle 81 of the slope profile, up to an angle of almost 90°indicated in Fig.7. number 79 position. Increasing the pressure angle increases the specific the voltage collapse between the threads at the point 82 mutual touch, which increases the torque required for turning the rod element at the first element in overcoming the frictional forces resulting from the weight of the exciting tube. When increasing the pressure angle increases the force vector, and depending on the weight of the exciting pipe friction force can become so large that thread tear, davinciaudio skewed and/or blocked, which prevents the proper assembling the rod and socket elements. The smaller the tip radius and the faster the rotation is carried out in the reverse direction, the higher the probability that the inertia of the pipe during reverse rotation will cause the truss element will be the corner of a critical point before the force of gravity will cause it to lowering one coil to achieve the most advantageous position, but after the passage of the optimum position depicted in Fig.6, again there is a threat of damage to the third type within a distance of less than one orbit.
Used for many years a coupling joint with compressed ends, as a rule, possess a strength that constitutes 65% of the strength of the pipe, and in some cases up to 75% on the strength of the pipe body when executed on a certain thick-walled pipes. They can't show higher values, because the threaded connection is robotic not across the wall of the socket element, and ends in objetos part, executed on the same cone that thread, and this reduces the critical area of the cervix female element to a value of not more than 75% of the cross-sectional area of the pipe wall if the position of the threads is strictly regulated both in axial and in radial direction relative to objetos wall. However, such a strict positioning of the threads cannot be maintained during the application thread in the manufacturing process, so the resulting efficiency is known crimp connections, generally limited by the strength values that make up less than 75% of the strength of the pipe.
In the report of the American petroleum Institute (API) reported that 90-95% of the problems in the deep wells caused by a leaking pipe threads, and protocols ANI records exist on a large number of experiments, by which attempts were made to find out the cause of the leaking pipe threads during operation. For a long time in ANI mistakenly believed that all pipe threads API specification 5B, covered with sealing grease API 5A2, ensure integrity, as evidenced by the fact that the tolerances and dimensions of the threads 5V, and used sealing lubrication API 5A2 essentially has not changed since then, as they were approved in 1939, and prior to issuance of the 1995 U.S. patent No. 5427418, which was the proposed solution to this problem. At the moment the applicant is not found in the prior art sources, wherever it was reported that when the Assembly is mated threads of equal axial length of the step, damage-prone first, second and third types, and also pointed out the solutions to these problems, resulting in the identification of the essence of the problems and proposed solutions identified in this application are advanced to the prior art.
Description of the INVENTION
The present invention describes a method of preventing damage of the first, second and third type, and describes the new tube design, which essentially ahead of the prior art. When assembling threaded pipe connection rod element is screwed into the female element, this increases the radial interference fit between the mating threads, which reduces the diameter of the truss element and increases the diameter of the socket element, and in accordance with Poisson's ratio of the change in diameter causes a lengthening of the rod element and the shortening of the breeding element in the axial direction, leading to inconsistencies between the inner and outer threads, which initially have equal spacing. The degree of inconsistency depends on the thread diameter, thread pitch, radial tension and adjusted the rate of the Poisson for the pipe material.
Damage of the first type can be eliminated by performing an outer thread with a pitch smaller than the pitch of the inside thread, to ensure the elongation in the axial direction of the rod element and compression in the axial direction of the nesting element during Assembly, so that the final Assembly step of the outer thread was essentially equal step related internal thread to ensure better compliance profiles of these threads, which increases the structural strength of the connection and sealing of threads for lighter fluid and fluid under higher pressure. To achieve the above improvements either the outer or inner thread can be executed with a constant pitch, and the other thread made adjustable step, the step of threading will be lower step of the internal thread. At a given value of the Diametric interference fit between mating threads per unit of diameter adjustment per unit axial length is equal to the specific diametrically the tension multiplied by the Poisson's ratio. For example, if you want to collect with tightness 0.75 mm (0,030 inch) pipe threads, having a nominal diameter of 25 cm (10 inches) and Poisson's ratio of 0.28, specific diametrical tension will be equal 0,030”/10”=of 0.003 inch (0.075 mm) per inch is iameter, and the adjustable length between the mating rod and socket elements will be equal 0,0030”×0.28 in=0,00084 inch (0.02 mm) per inch of axial length. In this case, if the thread is made with a nominal pitch of 6 mm (1/4”), the adjustment step is equal 0,00084/4=0,00021” (0,0005 mm), and all the adjustment can only be applied to one of the paired threads or split between threads, for example can be extended step internal thread on 0,00007” (0,002 mm), and the step of threading to shorten to 0,00014” (0,004 mm). The invention can be performed with varying degrees of accuracy depending on the operational requirements of the threads, and price restrictions.
In the case of a significant difference in the specific radial tension along the axis of the mating threads, which occurs between the inner and outer threads executed at the same cones, and/or when the outer thread has a more gentle taper than the internal thread may be the preferred variable pitch adjustment, depending on the requirements for precision landing between mating threads for specific cases of use. The fit is perfect, if step changes with each turn of the thread, but if you do not require very high precision, the step may vary stepwise or in a few turns of thread, which roughly corresponds to the ideal change in W is ha on stage.
In addition, the proposed connection provides the ability to prevent damage of the second type. Preferably use threads hook type with additional adjustment step in the interval between the end of the rod element and its middle which is added to the above described adjustment of step with the provision in the assembled state of axial tension in this part of the truss element or for simple closure of paired threads, or for clamping provided in combination with the effect of radial pressure on the border, which may occur between the mating threads. It is well known that a negative angle of inclination of the working thread profile hook type prevents "bounce" outer thread of the internal thread in the case of exposure to high drive forces generated in the connection, but so far no reports that the step threading shorter compared to the step related internal thread, as described above, can provide a bond of paired threads of a hook type regardless of the radial tension of the thread. This creates a tensile force in a truss member between its front surface and the middle part to ensure increase in both radial and axial pressure on the page between mating threads. Bulletin S (4.2) ANI reported that "internal pressure leak resistance is equal to the pressure on the border, but only the pressure at the boundary created by a circumferential compression rod element, and not reported any other way to create or maintain pressure on the border. Adjust the length of the step between the inner and outer threads required in specific cases of operation to ensure the establishment of such a load at a negative angle of inclination of the working profile, which is sufficient to maintain a tight connection rod elements and associated internal threads without using radial threaded preload can be calculated for various angles of the profile and diameter of the thread for any combination of rated pressure of internal and external fluid and/or mechanical loads, but the principles that are reported in this document remain unchanged. Calculations and tests show that for the operation of suitable working thread profiles made parallel to the rear profile, however, it should be understood that other combinations of angles of inclination of the thread profiles is also within the scope of this invention. The calculation by the finite element method (FEA) showed that during operation of the proposed connection with compacted all his strength composition is yet at least 95% of the strength of the pipe, and pressure test proved that thread will keep the integrity in the event of impact pressure, withstand design when the wall thickness of the connection.
The pressure at the boundary between the inner and outer threads, caused by the radial tension of the thread during Assembly, as a rule, is the largest in the middle of the linked threads, which usually is the thickest connection of the walls of the rod and socket elements; therefore, when using this particular tension rod element coils, located in the middle, preferably do not have specified additional adjustment step to provide maximum axial stress in the middle part of the rod and socket elements when they are assembled, in consequence of which thread exactly mate and fix the truss element preventing relative axial movement together with a female element, while maintaining tension in a thin part of the truss element and preventing the loosening of a threaded fit. Thus, the turns of the truss element, located between its front surface and the middle part are connected with adjacent turns of the female element in the tension acting on negative working profile thread hook type, whereas in other on the managing threads are detected using paired coils, located in the middle under the greatest pressure on the border, which keeps a tight threaded connection, even if a truss element near its end becomes plastically deformed under conditions of regional compression, for example under the action of pressure of the external fluid medium, since the paired coils threading remain in close contact in case of further pressure of the internal fluid. Specified additional adjustment step can be performed for all coils, coils, located only between the front surface and the Central part of the core element, or only some of the coils closest to the end surface of the rod element, in case are assumed to be small workloads. Ideally, but not necessarily, the pitch adjustment of the thread preferably is a maximum at the end surface of the rod element and decreases towards his neck, so that at the time of Assembly, all paired coils, essentially, have equal spacing, while the coils of the core element between its front surface and the middle part are tensioned. For some cases of operation it is desirable that the coils of the truss element, located between the middle part and neck were a little constrained with toronyi work profiles to ensure sealing when the counter-pressure of the external fluid medium and/or corrosion. However, you can use other methods of adjusting the thread pitch without deviating from the essence of the present invention. After Assembly of the pressure fluid and the operating load can cause additional compression and/or stretching of the United thread, but the original ratio steps in the assembled state remains constant, because the rod and socket elements are expanded and compressed together and to the same extent. Therefore such compounds can be used in columns expandable pipes, because, when the inner and outer threads together expand or contract diametrically tension remains constant, and therefore the set difference of the axial step constant.
The radial width of the pipe wall, required to run a cylindrical thread, is less than the radial width of the pipe wall, required to run a conical thread of the same depth, so application of the present invention, for example, in thin-walled tubes may maintaining the sealing contact of the mated threads with a radial screw tightness or without him, which is sufficient to maintain a tight threaded fit, and also to hold the threads in the desired assembled position, provides a seal when the counter mechanical effort.
In practical use the ke this invention can be applied to threads of different shapes, having a positive or negative angle thread profile, but preferably the rear profile with a small positive angle, and business profiles with a small negative angle, however, the invention can also be applied in the case of threads not hook type, for example all threads 8 threads per inch according to API specification 5B, to ensure prevention of damage to the first, second and third types. For the implementation of this invention can be applied to various forms of threads of a hook type and thread in the form of a wedge, but if you need higher performance, preferably the use of open threads in the form of a wedge, made in accordance with U.S. patent No. 6578880 and No. 6682101. Now I understand how to create and maintain intimate contact between mating pipe threads with a radial threaded preload or without it and therefore, to obtain reliable threaded pipe connections, designed for any industrial or household maintenance, improve safety, reduce costs and better protect the environment in case of leakage of hazardous fluid and a sudden and complete failure of the mechanical connector, which often occur when using conventional threaded pipe connections.
Another feature of this and the finding, which can be used in combination with other described features to enhance the efficiency of the connection without using the double box joints or disembarking pipe ends, is to create a compressed nesting element, the critical area of the cervix which is the selection of up to 100% of the cross-sectional area of the pipe body, and an associated threaded connection takes place essentially from the outer diameter of the truss element to the inner surface of the crimping. According to the applicant, and on the available information, threaded pipe connections, such as pipe connections with trapezoidal thread API for a long time used the rise of the thread on the neck of the truss element, but the rise of the thread inside the crimped socket element was not reported. The proposed compressed socket element contains the upper conical portion which tapers inward in a direction from the end surface of the specified element down to the bottom of the conical part, is made along the length of the cone having a smaller slope and passing inwards towards the pipe body. Alternatively compressed socket element may contain an intermediate part located axially between the upper and lower conical parts having in this case a cylindrical shape and is and is performed on a more gentle taper, than the upper and lower parts. And in that and in other case to accommodate the paired rod element, such as element 11, is shown in figure 3, the coils of the nesting element is made in the upper part with the rise within the inner diameter of the crimping next part, whether lower or intermediate portion. Thus, in the absence of the need of the landing tube, providing a thicker wall socket element in comparison with the wall thickness of the pipe, a critical cross-sectional area wall socket element reaching the choice up to the value of the cross-sectional area of the pipe and providing compounds which can be as strong as the pipe body. Preferably the internal diameter of the crimped socket element at sbeg his thread is made large enough to provide sufficient radial width around the inner diameter of the pipe to position the end surface 14 of the truss element, the width of which is sufficient to support the turns of the truss element and the resistance forces applied during installation. In the case of applications that require pipe connection having a strength less than 100% of the strength of the pipe, the proposed connection can be made with the durability factor of 75% to 100% of the strength of the pipe body, EPA is the what's on the inside of the pipe with a smooth end strength values of the nesting element can be below 65%.
An additional feature of the present invention ensures the proper place and screwing the external and internal threads with a minimum expenditure of time and effort without damaging the threads, which is achieved by limiting the pressure angle that occurs between paired rear profiles of connected threads, to values which are less than 80°, as shown in Fig, but preferably the pressure angle is not more than 60°, the minimum pressure angle equal to any used angle of the rear profile. The pressure angle is an acute angle between the pipe axis and the line of action of the forces drawn through the point of mutual contact of the threads perpendicular to the line of contact between the turns of the external and internal screw threads in the regulations of the institution. The line of action of forces determines the current position and direction of force of resistance is transferred between the paired rear side surfaces and usually occur under the weight of exciting pipe.
BRIEF DESCRIPTION of DRAWINGS
Figure 1 depicts a partial cut thread specifications API standard 5B, showing the warp threads, due to the Assembly.
Figure 2 depicts a partial section of the connection specification 5 In the standard API, shown is the overall separation of the thread during operation.
Figure 3 depicts a partial section of the preferred option execution core and the nesting of elements in accordance with the invention.
Figure 4 depicts a partial section of the crimping at the first element in accordance with the invention.
Figure 5 depicts a partial section of an alternative implementation of the crimping at the first element in accordance with the invention.
6 depicts a partial section view showing a small pressure angle between paired back working surfaces of the thread.
7 depicts a partial section, showing a large pressure angle between paired back working surfaces of the thread.
Fig depicts a partial section view showing the pressure angle in accordance with this invention.
Embodiments of the INVENTIONS
The preferred embodiment of the present invention is shown in figure 3, which shows the nesting element 1 having an internal thread 2 with a constant step 3, the end surface 4, the middle part 5, the neck 6, a positive rear side surface 7 of the thread, negative working the side surface 8 of the thread, cylindrical top 9 and the cavity 10 of the profile of the specified thread. The female element is assembled with the core element 11, which is made on the tube 28 and having an external thread 12, is made with a variable axial Sha is ω 13, the end surface 14, the channel 21, the middle portion 15, a neck 16, a positive rear side surface 17 of the thread, negative working side surface 18 of the thread, cylindrical top 19 and the cavity 20 of the profile of the specified thread. The step of threading the end surface is made shorter than the step related internal thread, and increases with each round in the direction from the end surface of the female element to his neck, so when you increase threaded preload during Assembly the length of the truss element is increased, and the length of the nesting element is reduced in accordance with Poisson's ratio up until in winchendon state, all paired lengths of the steps will not be essentially equal.
If there is a need to increase or better maintaining pressure on the border of threads about the core element, then the Assembly of the two elements to truss element can be applied axial tension in the area between its end and the middle part by the additional step reduction of the outer thread of the specified length. The thick connection of the walls of the rod and socket elements are usually located in the middle of the United threads, and the thick walls, in turn, create the greatest pressure on the border between the mating threads, so the angle of sadnes the thread profile is preferably small enough in the case of threads, located in the middle part, to strong fastening rod element and prevent its axial movement relative to the female element by ensuring a tight connection that can withstand the pressure of the fluid and prevent loosening of the thread. Adjust the length of the step between the inner and outer threads required to create such a load at a negative angle of inclination of the working profile, which is sufficient to maintain a tight connection turns of the truss element and associated coils of the breeding element without the aid of radial threaded preload can be calculated for various combinations of angles of the profile and diameter of the thread, but the principles that are reported in this document remain unchanged. The value of the initial load under axial tension in the truss member between its front surface and the middle part ensures the preservation of the close contact of paired coils in the elastic or plastic stretching or compression under the action of pressure of the external fluid medium. This invention allows to reduce circumferential compression in the beam element about its end surface in comparison with compression observed without the use of the invention for maintaining a tight connection that can withstand fluctuations in the high pressure the Oia and/or high temperature internal or external fluid within the allowable values, which occur simultaneously or sequentially. When you select the corresponding positive angle of inclination of the rear thread profile, you must consider at least the operating load, pipe size and wall thickness, pipe material and the tightness of the thread. To apply this invention in practice requires the use of relatively large negative angles worker thread profile to preserve the connection threads with any combination of allowable internal pressure and the external fluid and mechanical loads. Calculations and tests show that satisfactory are working profiles having a negative angle of 7° and is made parallel to the rear side surfaces having a positive angle of 7°, however, it should be understood that other combinations of angles of the thread profile is also within the scope of this invention.
In a preferred embodiment, the compressed socket element shown in figure 4, contains the pipe 44, the upper part 32 of the crimping at the first element 27 having an end face 38, the inner conical surface 36 and the outer conical surface 37, and the lower part 43 of the crimp having an inner conical surface 34. Obitaemyy end 38 machined with providing education end on which ernesti 39 female element, and the outer diameter of the specified element machined to obtain a diameter of 40, the size of which is large enough to perform it tapered coils 29 of the internal thread and provides sufficient operational strength of the end wall of the nesting element. The coils of the socket element extending from its end surface 39 to rise 45, going from the inner surface 34 within portion 43 after butt diameter 41, so that the critical area 26 formed between the specified sbeg 45 and the outer surface 48 of the part 43 may have the same size as the area 30 of the cross-section of the pipe body. Now it is clear that the turns of the internal thread can be machined in the area of the crimp to ensure that critical areas of the rod and socket elements having to select the same size as the cross-sectional area of the pipe required to perform panopreter connection with objitem nesting element. The ability of the lower part 43 to contain the pressure of the fluid may be a bit smaller in comparison with the same capacity of the pipe body, because after crimping in the outer direction relative to the initial size of pipe specified part has a lower "ratio of wall thickness to outside diameter compared with the pipe (however specific the strength of the part 43 is increased when it is hardening in the process of crimping, when this part becomes more uniform in thickness and, in addition, is short enough to rely on the adjacent overlying and underlying less strenuous pipe walls), and also because when computing the allowable pressure of the fluid in the pipe according to API assumes that the pipe wall is only 7/8 of the nominal pipe wall. Thus, if the inner diameter of the crimping exceeds the internal diameter of the pipe not more than 14%, then there is no need to reduce the allowable load values on the nesting element relative to the tube. Diameter 41 is made large enough to ensure that the radial width around the inner diameter 31 of the pipe, sufficient to accommodate the end surface 14 of the truss element.
Figure 5 shows an alternative configuration of the crimping at the first element, in which the intermediate part 33 of the crimp connected with the upper part 32 at the location of the inner butt diameter 46 and the bottom 43 with the provision of sbeg internal thread 29 made in the element 27, to the point 42 on the inner surface 35 of the intermediate part, with the critical area 26 in this place and is cylindrical or has a flatter cone compared to parts 32, 43. Using the part 33 and the upper and lower the Yaya parts may have the same taper, as an internal thread, while the axial length of the intermediate portion is sufficient to allow threading again in case of damage of the element with the specified thread. Although described thread suitable for creating a tight connection that will withstand high pressure gas to the proposed compounds can be added lip seal on the pipe end with an external thread, made in accordance with U.S. patent No. 2766829 the author of this invention and is often called sealed with a metal contact, if required by the technical specifications of the user.
On Fig depicts the form of thread, made in accordance with this invention which is a modification of the standard thread and designed to prevent the possibility of formation of the critical pressure angle, shown in Fig.7. On Fig shows the rear side surface 70 of the outer thread at its entry into primary contact with the rear side surface 71 of the internal thread at the point 22 of mutual contact when the rod element in the female element, and in accordance with the invention, a portion 84 of the top of the General profile of the outer thread and the part 83 of the top of the General profile of the internal thread removed with the formation respectively of the peaks 90 and 91 to provide constraints in the La 92 pressure, formed between the pipe axis and the vector 24 forces, to the value not more than 60°, which is preferred, although this value may reach up to 80° for lightweight threads or decrease the value of the angle of inclination of the rear side surface of the thread. The surface 74, 75 are depicted as curved surfaces, but may have another shape, for example conical, or to be made in the combinations, for example in the form of arcuate surfaces extending from the rear side surface of the thread, touch the conical surfaces, which are adjacent with vertices 90, 91. The value of the obtuse angle 94 formed between the top 90 of the outer profile of the thread and the common tangent line 23, and an obtuse angle 95 formed between the top of the 91 profile of the internal thread and the specified tangent 23, are sufficient for effective responses to mechanical damage at the connection surfaces. The value of the obtuse angle 96 formed between the cavity 98 of the outer profile of the thread and the line 85, held tangent to the radius 86 of the cavity through the place of its connection with the specified cavity 98 is sufficient to provide for the reduction of stress concentration at the troughs of the outer profile of the thread to acceptable values in similar configurations, the hollow profile of the internal thread. In the absence of you is t meet the minimum clearances between peaks and troughs, necessary, for example, for maintaining a tight connection that can withstand very high pressure, depression can be made tangentially to the radius at the point 99 with the provision of the gap 97 between the top of the 91 profile of the internal thread and the next cavity 89 of the outer profile of the thread. Now it is clear how to limit the angle of pressure to ensure the prevention of excessive shear stresses arising between the threads when the pivotal element in the female element, as well as providing quick and easy insertion without damage and reduce stress concentration in the cavity.
All embodiments of the present invention can be used in wells in the oil and gas industries and used in pipes, casing, guide tubes, caissons, pipelines, drainage pipes, tension elements support platforms and/or superstructures as pipe connection provides a seal that can withstand the pressure of dry gas, because it can be attributed to the tubing, the clerk as to isolate the fluid, and to withstand mechanical loads. Threaded pipe connections, which are currently used in oil refineries, manufacturing plants, power plants, trubor the waters and the like, limited to a small size and a low pressure fluid, as they are prone to loosening, leakage and rupture, while the proposed connection does not have these disadvantages and therefore can be used virtually anywhere where tubes are used.
1. Pipe connection having a female element (1) with internal thread (2) step (3)designed for interfacing Assembly with the core element (11)having an external thread (12) with a step (13), and the sizes of paired threads provide radial tension in the assembled state, and the thread pitch of the truss element is shorter than the thread pitch of the breeding element by an amount sufficient to compensate for the axial elongation of the thread rod element and axial compression thread female element, which occur during the Assembly of these elements in the radial interference fit between mating threads and due to Poisson's ratio, ensuring substantive equality steps of paired threads in the assembled state.
2. Pipe connection having a female element (1) with internal thread (2)made in increments of (3) and the working-side surface (8), which is designed for interfacing Assembly with the core element (11)having an external thread (12) with a step (13), the end surface (14), the middle part (15) and working Bo the new surface (18) of the thread, while the thread pitch of the specified core element, located between the middle part and the end surface, shorter step related internal thread socket element, so that when assembling the step difference is sufficient to create such axial tensile loads in the truss member between its front surface and the middle part, which is sufficient to create a pre-load on the working side surfaces of the internal thread socket element relative to the associated working side surfaces of the outer threads of the truss element with the creation of sealing contact, can withstand the operational loads.
3. Pipe connection having a female element (27)is performed by crimping the pipe (44) and having an end surface (39), and the crimping zone contains the upper part (32), which narrows in the inner direction of the specified end surface in the direction of the pipe and has a conical internal thread (29)intended for mated connection with an external thread (12) on truss member (11)having an end surface (14), while the crimping zone contains the lower part (43), which narrows in the inner direction of the specified upper part to the pipe, and a threaded female element tapers in the inner the m direction from the end surface of the specified socket element to run away (45) thread on the inner surface (34) of the said lower part of ensuring the formation of a critical area (26), located radially between the specified sbeg and the outer surface (48) of the lower part, with the inner connecting diameter (41) is located at the junction of these upper and lower parts, and its size provides radial width around the pipe channel, sufficient to position the end surface (14) of the truss element, the width of which is sufficient to perform threading and withstand operational loads, while the taper of the specified lower part is less than the taper of the specified upper part, so that the United inner and outer thread can be essentially from the outer diameter of the truss element to the inner surface of the specified lower part below the expansion of the diameter of ensuring, thus, the strength of the crimp connection by selecting from 75 to 100% of the strength of the pipe.
4. Threaded pipe connection having a rear side surface (70) of the outer threads of the truss element with a surface (74)located between the said lateral surface (70) and the top (90) the profile of the outer thread, and the rear side surface (71) of the internal thread socket element with the surface (75)located between the said lateral surface (71) and the top (91) profile of the internal thread, and the primary contact between the outer and internally the threads occurs at the Assembly point (22) of the mutual contact between these surfaces (74, 75), the tangent line (23) passes through the specified point of mutual contact, and the vector (24) power passes through the point of contact is perpendicular to the line (23), pressure angle (92) is measured between the axis (25) of the pipe and the force vector, and the rear side surface is carried out by providing the pressure angle of not more than 75°, when the rod element is wound in the socket element.
5. Pipe connection according to claim 3, in which compressed the female element has an intermediate portion (33) of the crimping located between the upper and lower parts having an inner surface (35) and is made with less taper than the upper or lower portions to allow passage connected paired female thread and core elements from the outer diameter of the core element to run away (42) threads on the inner surface (35) of the intermediate part in ensuring the strength of the crimp connection by selecting from 75 to 100% of the strength of the pipe.
6. Pipe connection according to claims 1, 2 or 4, in which all the threads of the nesting element is made with equal step, and at least some of the threads of the truss element is made with a shorter step than the associated coils of a carving nested element.
7. Pipe connection according to claim 6, in which the thread pitch of the truss element increases is raised in the direction from the end surface of the rod element to his neck (16).
8. Pipe connection according to claims 1, 2 or 4, in which all the threads of the truss element is made with equal step, and at least some of the threads of the nesting element is made with a longer step than that associated the threads of the truss element.
9. Pipe connection of claim 8 in which the step of at least some of the threads of the socket element increases in the direction from the end surface of the female element to his neck.
10. Pipe connection according to claims 1, 2 or 4, in which threads are cylindrical.
11. Pipe connection according to claims 1, 2 or 4, in which the female thread of the element is made on the cone and the threaded rod item made on a more gentle taper than the specified thread female element.
12. Pipe connection according to claims 1, 2 or 4, in which the thread has a negative angle of inclination of the working profile, the value of which is sufficient to maintain a tight connection of paired threads that can withstand permissible operating load.
13. Pipe connection according to claims 1, 2 or 4, in which the thread has a positive slope work profiles, the magnitude of which is sufficient for the application of vector radial forces from the axial tensile loads, sufficient to maintain a pressure seal at the interface as axially in the, and in the radial direction between the mating threads, ensuring adherence to the permissible operating load.
14. The connection 13, in which the coupled threads in the assembled state has a diametrical interference fit, which provides a pressure at the interface between the mating threads, sufficient to hold the mated threads in tight contact, can withstand all loads that are within acceptable limits for this connection.
15. Pipe connection according to claim 2, in which the axial tensile load is fixed in the middle part using the paired rear side surfaces of the thread and fixed in the direction of the end surface of the rod element using paired work side surfaces of the thread to a degree sufficient to prevent relative axial movement between the rod and socket elements.
16. Pipe connection according to claims 1, 2 or 4, in which the threads are tapered.
17. Pipe connection according to claims 1, 2 or 4, in which the threads have a negative rear side surface.
18. Pipe connection according to claims 1, 2 or 4, in which the threads have a positive rear side surface.
19. Pipe connection according to claims 1, 2 or 4, in which the threads have a negative working side surfaces.
20. Pipe connection is giving according to claims 1, 2 or 4, in which the threads have a positive working side surfaces.
21. Pipe connection according to claims 1, 2 or 4, in which the working side surfaces of the threads are made perpendicular to the pipe axis.
22. Pipe connection according to claims 1, 2 or 4, in which the rear side surfaces of the threads are made perpendicular to the pipe axis.
23. Pipe connection according to claims 1, 2 or 4, in which the threads have a negative working side surface and a negative rear side surface.
24. The compound according to claims 1, 2 or 4, which has an upper compressed part (32), which conically tapers in the inner direction of the tube and has an internal tapered thread (29), and the crimping zone, with the lower part (43), which conically tapers from the top in the inner direction of the pipe and has an inner surface (34), the inner connecting diameter (41)located at the junction of these upper and lower parts and having a size large enough to position the end surface (14) of the truss element around the inner diameter (31) pipe, and the width of the specified end surface is sufficient to withstand operational loads, while the taper of the lower portion is less than the taper of the upper part, so that the female thread element can interact with mating threaded rod e is ementa essentially from the outer diameter of the truss element to the inner surface of the lower part and, therefore, to ensure the strength of the crimp connection by selecting from 75 to 100% of the strength of the pipe.
25. Pipe connection point 24, further comprising the intermediate portion (33) of the crimping performed in the axial direction between the specified upper and lower parts and having an inner surface (35), the taper which is less than the taper of the upper or lower parts, so that the female thread element can interact with mating threaded rod element sufficiently to ensure the strength of the crimped connection can be chosen from 75 to 100% of the strength of the pipe.
26. Pipe connection point 24, further comprising the intermediate portion (33) of the crimping performed in the axial direction between the specified upper and lower parts and which is cylindrical, so that the female thread element can interact with mating threaded rod element sufficiently to ensure the strength of the crimped connection can be chosen from 75 to 100% of the strength of the pipe.
27. Pipe connection having a pivot element (11), is made on the pipe (28) and having a neck (16), nut (12) with a step (13), the end surface (14), the rear side surface (70) of the thread surface (74)formed between the said lateral surface (70) and the top (90) thread profile of the truss element, and the decree of the hydrated core element configured to mate with a female element (27), performed by crimping the pipe (44) ensuring narrowing of the upper part (32) crimping inward toward the pipe and having a conical thread (29) from step (3), the back side surface (71) and the surface (75)formed between the said lateral surface (71) and the top (91) profile of the internal thread, optionally containing intermediate portion (33) of the crimping chamber connected with the upper part of the inner connecting diameter (46), and the lower part (43) of the crimping chamber connected with the lower end of the specified intermediate part, and rear side surfaces of the socket and rod elements are designed so that the location of the truss element within the female element in position institution pressure angle of 75°with the axial thread pitch of the truss element is shorter than the axial thread pitch socket element by an amount sufficient to compensate for the axial elongation of the thread rod element and axial compression thread female element, which occur during the Assembly of these elements due to Poisson's ratio, ensuring substantive equality axial steps of paired threads in the assembled state, and the thread pitch of the truss element, located between the middle part and the end surface, for some additional value shorter than the thread pitch socket e is ementa before Assembly to ensure the establishment in the Assembly of the axial tension in the truss member between its front surface and the middle part, which is sufficient to connect the negative working side surfaces in the axial and in the radial direction with the creation of sealing contact, can withstand operational loads, the size of the inner connecting pipe diameter ensures the passage of the United threads of the rod and socket elements essentially from the outer diameter of the truss element with accuracy to the inner surface of the intermediate part of the lower inner connecting diameter, ensuring, thus, the strength of the connection by selecting from 75 to 100% of the strength of the pipe.
FIELD: machine building.
SUBSTANCE: here is disclosed method for connection of multi-layer metal-polymer pipes. Pipes are connected by welding through a connecting device having not less, than two connecting elements with seats for end sections of pipes. Welding is performed along external, internal and end surfaces of the end section of the pipe enveloped with internal surfaces of the seat of the connecting device. Also, the end section of the pipe and seat of the connection device are preliminary simultaneously heated. Successively, preliminary heated sections of the pipe and the connection device are matched. To avoid destruction of polymer layers and exposure of an internal metal layer and for removal of adhesion layers of the pipe applied on the metal layer the end section of pipe is heated to softening temperature of material of external and internal layers of the pipe at pipe and the connecting device matching. The seat of the connecting device is made in form of a circular slot coaxial with an internal orifice of the connecting element of the connecting device. The circular slot has a cylinder wall from the side of external surface of a connected pipe and a conic wall truncated along plane of the end of the connecting element from the side of internal surface of the connected pipe. The seat is preliminary heated to melting temperature of material of the connecting device. The end section of the pipe and seat are preliminary heated by means of a welding device equipped with a control unit and a heater whereon there are arranged a tool of the pipe and a tool of fitting. Temperature of the heater and tool of fitting directly contacting surface of the heater equal to temperature of connecting device material melting is set with the control unit and is maintained at a constant level within ranges of preset error. Securing the tool of the pipe on the heater through a transit bush facilitates limit of end section of the pipe heating to temperature not exceeding softening temperature of material of external and internal layers of the pipe. The tool of the pipe can travel along axis of the transit bush for adjustment of heating temperature at external conditions change.
EFFECT: upgraded quality and reliability of connection of multi-layer metal-polymer pipes.
FIELD: machine building.
SUBSTANCE: according to present method components of analysed group of threaded connections are determined by analysis of model. Further, the first group of threaded connections in an analysed group is subjected to physical tests. There is performed modelling analysis of the first and second groups of threaded connections. Physical tests are not carried out for the second group. After modelling results of a physical test and modelling analysis are compared to obtain a factor of working characteristic for the first group. Further, the factor of the working characteristic is applied for the second group and limits of functionality are determined on base of this factor of the working characteristic.
EFFECT: increased reliability of threaded connections.
18 cl, 5 dwg
FIELD: machine building.
SUBSTANCE: device consists of metal case in form of cylinder with internal cylinder groove restricted with internal circular lug, and also having cylinder lug on external surface. Two stepped cylinder of dielectric material and a sealing padding are set between the pipe and the groove of the case. A metal ring, a C-shaped ring made of material harder, than material of the pipe and a movable bush are arranged between the pipe and the cylinder of dielectric material. Uniform around circumference transfer of the end cover, of the stepped cylinder positioned before it and the pipe, and of the movable bush occurs in axial direction at tightening bolts which enter orifices in the cylinder lug of the case and the end cover. With its internal conic surface the movable bush weighs upon external surface of the C-like ring, compresses it, forces pointed radial lugs of the C-like ring into a body of the pipe and fixes the pipe in the insulating device for pipe assembly. It also compresses the insulating padding.
EFFECT: insulating padding, three cylinders and insertion of dielectric material form reliable electro-insulating circuit.
FIELD: machine building.
SUBSTANCE: connection consists of first and second expanded tubular elements each containing multitude of bent sheets. Each sheet has concave and convex surfaces and a place of connection whereat one of multitude of bent sheets is attached to another from multitude of bent sheets, and multitude of connecting elements each positioned on at least one of multitude of bent sheets. The first and the second expandable elements can be expanded and compressed. Multitude of connecting elements of the first tubular element interacts with multitude of connecting elements of the second tubular element.
EFFECT: increased strength and pressure tightness of connection.
33 cl, 28 dwg
FIELD: machine building.
SUBSTANCE: electro-insulated connection of pipelines consists of metal branches with ring bosses whereon there is formed fastener in form of bush out of composite material, of protective ring out of dielectric material installed between ends of branches and of packing collar out of elastomer material enveloping end sections of branches. Circular recesses are made on the end sections of the branches on their end surfaces; behind the cross section of the recesses to the side of the opposite branch there are made circular projecting sections. The protective ring has a narrow section installed between the circular projecting sections and a convex section put on the circular projecting sections. The packing collar envelopes the protective ring with its internal surface; while with its external surface it contacts surface of a cavity formed with the fastener and ends of the branches. Adjacent surfaces of the projecting sections of the branches ends and the packing collar are glued.
EFFECT: increased reliability of pressure tightness of connection under low and high loads.
2 cl, 2 dwg
FIELD: machine building.
SUBSTANCE: connection of main and lateral pipelines in heat systems consists of T-joint on main pipeline and of L-shaped tubular insertion. The side branch of the T-joint is perpendicular to the lateral pipeline. According to the first version the L-shaped insertion connects the side branch of the T-joint with the lateral pipeline. The distinguished feature of the claimed design of the first version is connection of the L-shaped insertion with the side branch of the T-joint by means of a hinge wherein axis of rotation coincides with axis of the branch. According to another version the lateral pipeline has a L-shaped tubular element wherein one axis is parallel to axis of the side branch of the T-joint, while a "П"-shaped tubular insertion is installed between the branch of the T-joint and the L-shaped element of the lateral pipeline. The tubular insertion is connected to them by means of pivot connections with axes of rotation coinciding with axes of the side branch and L-shaped element.
EFFECT: increased reliability of pipelines connection.
2 cl, 5 dwg
FIELD: machine building.
SUBSTANCE: coupling is made with grooves. In the middle part of the coupling there is located an arrester for centring connected pipes. Grooves are cut on ends of connected pipes on external side; before connection the grooves are preliminary filled with glue composition; ends of the pipes are successively press fitted into the coupling.
EFFECT: raised reliability of pipes connection, preservation of internal coating of pipes.
FIELD: machine building.
SUBSTANCE: dielectric pads are arranged between adjacent ends of two branches made out of pipeline material and between branches and connecting them external coupling. The branches are permanently connected with the coupling by means of joint radial expansion of the branches and coupling thus forming circular lugs on external surface of the branches and coupling with height exceeding thickness of the dielectric pads between the branches and the coupling. Internal surface of the branches is lined with a polymer coating ends of which are fastened and sealed by means of radial deformation of metal binding tips in them. The circular ends on external surface of the coupling and branches are formed at a certain distance from the ends of the coupling, while end sections of the coupling are reduced by means of radial squeezing and forming internal lugs in the branches.
EFFECT: raised reliability of insertion at high pressure in pipeline.
4 cl, 1 dwg
FIELD: machine building.
SUBSTANCE: dielectric pads are arranged between adjacent ends of two branches made out of pipeline material and between branches and external coupling connecting them. The branches are permanently connected by a coupling by means of joint expansion of branches and coupling, thus forming circular lugs on external surfaces of the branches and coupling with height exceeding thickness of the dielectric pads between the branches and the coupling. Internal surface of the branches is lined with polymer coating, ends of which are secured and sealed. Also the dielectric pads between the branches and coupling are compound. In zones of external biases of at least of one of the lugs and within the range of each branch there are positioned dielectric pads out of material of low creep, while on the rest of sections there are used the dielectric pads out of plastic or elastic material.
EFFECT: raised reliability of insertion at high pressure in pipeline.
5 cl, 1 dwg
FIELD: machine building.
SUBSTANCE: between nozzles and external coupling that connects them there are dielectric gaskets installed of hot melt polymer, having adhesion to materials of coupling and nozzles, nondetachable joint of nozzles is arranged with coupling by means of joint radial expansion of nozzles and coupling to form circular ledges on external surfaces of nozzles and coupling with height that exceeds thickness of dielectric gaskets between nozzles and coupling. Radial pressing of end sections of coupling is done to form internal ledges in nozzles, central part of coupling is heated up to temperature of hot melt polymer melting start with maintenance of temperature of end sections of coupling below temperature of polymer melt, and internal surface of nozzles is lined with polymer shell, ends of which are fixed and sealed by means of radial deformation of metal jamming tips in them.
EFFECT: increased reliability of current-isolating insert at high pressure in pipeline.
5 cl, 1 dwg
FIELD: pipeline engineering.
SUBSTANCE: joint comprises two metallic branch pipes and ring made of dielectric material and interposed between the faces of branch pipes. The branch pipes have bells which are interconnected through insert by permanent dielectric adhesive joint from the inside and through metallic coupling by permanent dielectric locking adhesive joint on the outside.
EFFECT: enhanced reliability and prolonged service life.
4 cl, 1 dwg
FIELD: electrical engineering.
SUBSTANCE: proposed device has case for abutting against body to be brought in contact and at least one contact member set in wiring position between case and body to be brought in contact so as to establish electrical connection with current-conducting part of this body. At least one laminated contact member is made of alloy that has in its composition at least 94.5% of copper (Cu), 2 - 4% of nickel (Ni), 0.5 - 1% of silicon (Si), and 0.05 - 0.25% of magnesium.
EFFECT: reduced pressure on contacted body.
21 cl, 7 dwg
FIELD: pipeline transport.
SUBSTANCE: pipe comprises fiberglass layer with electroconducting binder. The electroconducting binder is applied only on the outer side of the reinforced fiberglass layer.
EFFECT: enhanced reliability.
FIELD: the invention refers to the field of the pipeline transport and may be used for electric disconnection of pipelines and/or their sections particularly at protecting them from corrosion.
SUBSTANCE: dielectric insertions are placed between adjacent butt-ends of two sockets fulfilled out of the material of the pipeline and between the sockets and the exterior muff connecting them. The interior surface of the sockets in the zone of location of the muff is provided with ring lugs with the height exceeding the thickness of the dielectric insertions between the sockets and the muff and radial distribution of sockets is carried out as a minimum until elimination of gaps between the sockets and the muff along the entire length of their coupling. The ring lug on the interior surface of the sockets are made by way of fixing of packing rings inside the sockets. As dielectric insertions between the sockets and the muff an exterior plastic covering of the sockets may be used. In case of transporting along the pipeline of electrically conducting fluid the inner surface of current insulating insertion is provided with dielectric covering.
EFFECT: reduces labor-intensiveness of manufacturing.
4 cl, 3 dwg
SUBSTANCE: insulating coupling comprises thickened branch pipes which are cut in the pipeline over their outer diameters. The inner side of the branch pipes is provided with thin-walled sealing members arranged with a spaced relation to each other. The insulating coupling is mounted in the split coupling. The spaces between the split coupling and branch pipes receive the reinforced dielectric material.
EFFECT: enhanced reliability.
2 cl, 2 dwg
FIELD: pipeline engineering.
SUBSTANCE: electrically insulating fitting comprises two metallic branch pipes and dielectric member which are interconnected through the threaded joint whose inter-thread space is filled with the glue composition. The flexible member is interposed between the face of the dielectric member and face surfaces of branch pipes for permitting control of the load in the thread to provide optimal gluing pressure.
EFFECT: enhanced reliability.
FIELD: pipe joints.
SUBSTANCE: joint comprises male member provided with thread turns that define the pitch of the load-bearing side, pitch of the stabilizing side, and nominal pitch. The female member has thread turns that engage the thread turns on the male member. The turns of the thread on the female member define the pitch of the load-bearing side, pitch of stabilizing side, and nominal pitch. At least one of the pitches of the load-bearing side and pitches of the stabilizing side on, at least, the female member or on the male member changes controllably from the specified distance from the end of the thread turns. The pitch of loading and pitch of stabilizing are different at least over a part of the thread length.
EFFECT: enhanced reliability.
44 cl, 26 dwg
FIELD: rocket-space engineering.
SUBSTANCE: nondetachable joint comprises end member made of bushing with shank at its one end and face ring groove at its other end and tubular member made of composition material glued in the groove of the end member. The end member is provided with axial slots from the side of the face ring groove to define pairs of tabs each of which has inner and outer tabs. The pairs of inner and outer tabs are tightened to corresponding surfaces of the tubular member by means the radial fastening members. The bend rigidity in the cross-sections of the inner and outer tabs may be the same. The tubular member may be provided with ends strengthened in radial direction.
EFFECT: enhanced reliability.
2 cl, 3 dwg
FIELD: mechanical engineering.
SUBSTANCE: joint comprises joining member made of a material with the shape memory effect. The end of one of the parts is provided with ring provided with a groove. The end of the other part is provided with the second ring having a projection. The projection is coated with a material with the shape memory effect. The thickness of the coating depends on the deformation to be recovered.
EFFECT: enhanced reliability.
1 cl, 1 dwg
FIELD: engines and pumps.
SUBSTANCE: elongated column assemble contains hollow pumping booms and jointing elements with an axle jointed together between the driving head arranged of the petroleum well surface and rotary pump arranged in the hole bottom. Every boom has, at least, one end with inner thread to mate the jointing element outer thread, e.g. a nipple. To optimise the strain distributions across the structural elements, the threads with various profiles are used, e.g. an asymmetric truncated cone and varying taper thread profiles. The collars to transmit torque have maximum possible mean diameter and cross-section to rule out accumulation of reactive torque in the column. A modified nipple has, preferably, a seal on its free end to reduce the risks of corrosion. A modified boom can have a number of orifices on each its end to increase flow of medium to forced out.
EFFECT: higher shear resistance, lower concentration of strains and lower accumulation of reactive torque.
34 cl, 35 dwg, 1 tbl