巴西专利BR112016013134B1 threaded joint for steel tubes

专利PDF首页>>巴西专利

专利附录

专利说明

权利要求

类似技术

同族专利

引用文献

法律状态

优先权

专利摘要:
THREADED JOINT FOR STEEL PIPES The load flanks (15) on the male threaded portion (11) of the pin (10) and the load flanks (24) on the female threaded portion (21) of the housing (20) have a flank angle (theta) less than 0 degrees. The female threaded portion (21) is divided into, in order from close to the sealing surface (26), an incomplete thread section (21b) and a complete thread section (21a). In the female threaded portion (21), along the entire area that includes the two threaded sections (21a, 21b), roots (23) collectively define a single tapered periphery. The incomplete thread section (21b) is at least three times the thread pitch and has a thread height less than the thread height of the complete thread section (21a). In an assembled state, the shoulder surfaces (17, 27) are in contact with each other, the sealing surfaces (16, 26) are in contact with each other, and, in the incomplete thread section (21b), free spaces are provided between the roots (13) of the male threaded portion (11) and the ridges (22) of the female threaded portion (21). Consequently, the sealing performance against external pressure is maintained and the sealing performance against internal pressure is (...).
公开号:BR112016013134B1
申请号:R112016013134-7
申请日:2015-01-09
公开日:2020-11-24
发明作者:Keita INOSE；Fumio Ota；Shin Ugai；Masaaki Sugino
申请人:Vallourec Oil And Gas France；Nippon Steel Corporation；
IPC主号:

专利说明:

[0001] [0001] The present invention relates to a threaded joint for use in connecting steel pipes. BACKGROUND OF THE INVENTION
[0002] [0002] In oil wells, natural gas wells and the like (hereinafter also collectively referred to as “oil wells”), tubular products for oil producing countries for casings, pipes or similar, which are steel tubes and are sequentially connected each other by threaded joints, are used. In general, threaded joints for steel pipes for such use are classified into two types: coupling type joints and integral type joints.
[0003] [0003] A coupling-type threaded joint consists of a pair of tubular products that must be connected together, of which one is a steel tube and the other is a coupling. In that case, the steel tube is provided with a male threaded portion formed on the outer periphery at each end thereof, and the coupling is provided with a female threaded portion formed on the inner periphery at each end thereof. The male threaded portion of the steel tube is threaded into the female threaded portion of the coupling, thereby forming a joint and connecting them. A threaded joint of the integral type consists of a pair of steel tubes as tubular products that must be connected together, without using a separate coupling. In that case, each steel tube is provided with a male threaded portion formed at the outer periphery at one end thereof and a female threaded portion formed at the inner periphery at the other end thereof. The male threaded portion of one of the steel tubes is threaded into the female threaded portion of the other of the steel tubes, thereby forming a joint and connecting them.
[0004] [0004] In general, the joint portion at the tubular end on which a male threaded portion is formed is termed as a pin due to the fact that it includes an element that is inserted into a female threaded portion. On the other hand, the joint portion at the tubular end on which a female threaded portion is formed is referred to as a box due to the fact that it includes an element that receives a male threaded portion. Both a pin and a box have a tubular shape due to the fact that they are composed of end portions of tubular products.
[0005] [0005] Figure 1 is a sectional view of a threaded joint for steel tubes, showing an example of its general configuration. The threaded joint shown in Figure 1 is a coupling-type threaded joint and is constructed of a pin 10 and a housing 20.
[0006] [0006] The pin 10 includes, in the order of a free end of the pin towards the tubular body, a shoulder surface 17, a sealing surface 16 and a male threaded portion 11. The sealing surface 16 is a tapered surface. To be exact, the sealing surface 16 is a surface consisting of the peripheral surface of a truncated cone that has a diameter that decreases towards the end, or a surface consisting of a combination of the peripheral surface of the truncated cone and the peripheral surface of a solid of revolution that can be obtained by rotating a curved line such as an arc around the pipe CL axis. The shoulder surface 17 is an annular surface that extends radially and substantially perpendicular to the pipe axis CL. To be exact, it is a slightly inclined surface with the outer circumferential side being closer to the end of pin 10.
[0007] [0007] Box 20 includes, in the order of the box body towards one end of the box, a shoulder surface 27, a sealing surface 26 and a female threaded portion 21. The shoulder surface 27, the sealing surface 26 and the female threaded portion 21 are located to correspond to the shoulder surface 17, the sealing surface 16 and the male threaded portion 11 of the pin 10. The male threaded portion 11 of the pin 10 and the female threaded portion 21 of the housing 20 are tapered threaded portions with trapezoidal threads that combine.
[0008] [0008] The male threaded portion 11 and the female threaded portion 21 are screwable with each other and, in a compound state, they combine in close contact and have an interference fit. The sealing surfaces 16, 26 are brought into contact with each other by screwing pin 10 and, in a composite state, they combine in close contact to have an interference fit, thus forming a seal between them with metal contact with metal. The shoulder surfaces 17, 27 are brought into contact and pressed against each other by screwing pin 10 into the box 20 and serve as plugs to restrict the screwing of pin 10. Furthermore, in a composite state, the shoulder surfaces 17, 27 serve to give the male threaded portion 11 of the pin 10 a load in a direction opposite (backwards) to the screwing direction (forward), that is, called axial thread tightness force.
[0009] [0009] With a threaded joint that has this configuration, satisfactory sealing performance is guaranteed due to the sealing provided by the combined and intimate contact between the sealing surfaces 16, 26.
[0010] [0010] In recent years, oil well environments have become increasingly deep underground or ultra-deep aquatic environments and, consequently, have become harsh environments with high temperatures, high pressures and high corrosivity. For such harsh environments, heavy-walled steel tubes are the most used. A threaded joint to connect such steel tubes is required to have high joint strength such as resistance to tension forces, resistance to compressive forces and the like, and additionally, provide excellent sealing performance against internal pressure and external pressure.
[0011] [0011] One method to enhance the sealing performance of a threaded joint is to generate high contact pressure between the sealing surfaces. Conventionally, in order to increase the contact pressure between the sealing surfaces, the technique of increasing the interference fit between the sealing surfaces is used. Additionally, in order to prevent the combined and intimate contact of the threads causing a decrease in contact pressure between the sealing surfaces, the technique of relieving the combined and intimate contact of the threads exclusively in regions close to the sealing surfaces is used (see , for example, Patent Document No. US 2062407 (Patent Literature 1), Patent Application Publication No. JP H02-80886 (Patent Literature 2), Patent Application Publication No. JP S62-196488 (Patent Literature 3) and Patent Application Publication No. JP H10-89555 (Patent Literature 4)).
[0012] [0012] Figure 2 is a sectional view of a conventional threaded joint for steel tubes disclosed in Patent Literature 1 and 2, showing a configuration of regions close to their sealing surfaces. In the conventional threaded joint shown in Figure 2, in a composite state, the male threaded portion 11 of pin 10 and the female threaded portion 21 of box 20 combine in close contact, and the load flanks 15 of the male threaded portion 11 are in contact. contact with the load flanks 24 of the female threaded portion 21 and receive axial hermetic strength while the roots 13 of the male threaded portion 11 are in contact with the ridges 22 of the female threaded portion 21. However, in regions close to the surfaces of seal 16, 26 in the threaded portions, clearances are provided between the roots 13 of the male threaded portion 11 and the ridges 22 of the female threaded portion 21, so that the combined and intimate contact of the threads is relieved therefrom.
[0013] [0013] The loading flank 15 of the male threaded portion 11 as referred to in this document is the flank, of the projecting and towing flanks that make up each thread, which is on the opposite side of the penetration flank 14, which is in a projecting position. when screwing the male threaded portion 11 into the female threaded portion 21. The loading flank 24 of the female threaded portion 21 is the flank, of the projecting and towing flanks that make up each thread, which returns to the loading flank 15 of the male threaded portion 11.
[0014] [0014] In the threaded joint shown in Figure 2, the combined and intimate contact of the threads is relieved in regions close to the sealing surfaces 16, 26 in the threaded portions and, therefore, when the internal pressure is applied, the region close to the surface of seal 16 on the threaded portion of pin 10 is expanded radially outwardly to cause the diameter to widen, in which the contact pressure between the seal surfaces 16, 26 is amplified.
[0015] [0015] It should be noted that, in the conventional threaded joint shown in Figure 2, the flank angle θ of the load flanks 15 and the load flanks 24 is greater than 0 degree. The flank angle θ refers to the angle formed by a flank in relation to a plane perpendicular to the pipe CL axis. In this document, when referring to the flank angle of load flanks, clockwise angles are designated as positive angles and, in contrast, when referring to the flank angle of penetration flanks, counterclockwise angles are designated as positive angles. When the load flank angle θ is greater than 0 degrees, the application of internal pressure causes the reaction force on the load flanks 15 of the pin 10 that act in one direction to contract the pin 10 radially into the load flank. 24 of box 20. As a result, the expansion radially out of pin 10 is not caused sufficiently and therefore the amplification of the contact pressure between the sealing surfaces 16, 26 cannot be achieved satisfactorily when the internal pressure is applied.
[0016] [0016] Figure 3 is a sectional view of a conventional threaded joint for steel tubes disclosed in Patent Literature 3, which shows a configuration of regions close to their sealing surfaces. Also in the conventional threaded joint shown in Figure 3, in regions close to the sealing surfaces 16, 26 in the threaded portions, clearances are provided between the roots 13 of the male threaded portion 11 and the ridges 22 of the female threaded portion 21, so that the combined and intimate contact of the threads is still relieved. Its load flanks 15, 24 have a flank angle θ of less than 0 degrees.
[0017] [0017] In the threaded joint shown in Figure 3, due to the load flank angle θ that is less than 0 degrees, the application of internal pressure does not cause a reaction force on the load flanks 15 of the pin 10 acting in one direction to contract pin 10 radially inward. As a result, the expansion radially outward from the pin 10 is sufficiently caused and therefore the amplification of contact pressure between the sealing surfaces 16, 26 can be achieved when internal pressure is applied.
[0018] [0018] In the threaded joint shown in Figure 3, it should be noted that, in regions close to the sealing surfaces 16, 26 in the threaded portions, the height of ridges 12 in the male threaded portion 11 of the pin 10 decreases towards the end of the pin 10 with a sharp tapered angle, so that the thread height is markedly decreased towards the end. Because of this, the rigidity of pin 10 is reduced. This causes a decrease in the deformation resistance of pin 10 against external pressure, which results in reduced contact pressure between the sealing surfaces 16, 26 when external pressure is applied. In addition, the low thread height of the male threaded portion 11 in the region near the end of the pin 10 results in a reduced thread combination in the insertion time of the pin 10 in the box 20, and this causes increased eccentricity of the pin 10. Thus, in the beginning of the screwing of pin 10 in box 20, the threaded edge regions of the male threaded portion 11 of pin 10 contact the female threaded portion 21 of box 20 in a localized manner. In the regions where such local contact occurs, the contact pressure is increased and therefore friction is more likely to occur.
[0019] [0019] Additionally, the threaded joint shown in Figure 3 is configured so that the roots 23 of the female threaded portion 21 of box 20 have different tapered angles. This configuration requires a complex manufacturing process, which leads to a longer manufacturing time and shorter tool life, and therefore an additional problem of increased manufacturing costs appears.
[0020] [0020] The threaded joints shown in Figures 2 and 3 are both configured to relieve the combined and intimate contact of the threads in regions close to the sealing surfaces in the threaded portions, providing gaps between the roots of the male threaded portion and the crests of the thread. female threaded portion. As another technique to relieve the combined and intimate contact of the threads in regions close to the sealing surfaces, Patent Literature 4 discloses a technique of providing a circumferential groove between the female threaded portion of the box and the sealing surface thereof.
[0021] [0021] However, in the threaded joint disclosed in Patent Literature 4, the thread combination is reduced in regions close to the sealing surfaces due to the circumferential groove provided in the box. Because of this, when external pressure is applied, the pin's radial contraction occurs easily, resulting in a decrease in sealing performance against external pressure. LIST OF QUOTES PATENT LITERATURE
[0022] [0022] Patent Literature 1: US patent No. 2062407
[0023] [0023] Patent Literature 2: Patent Application Publication No. H02-80886
[0024] [0024] Patent Literature 3: Publication of Patent Application No.: S62-196488
[0025] [0025] Patent Literature 4: Publication of Patent Application No.: H10-89555 SUMMARY OF THE INVENTION TECHNICAL PROBLEM
[0026] [0026] As described above, conventional threaded joints were built only in view of the contact pressure between the sealing surfaces in a composite state. That is, the change in contact pressure due to the application of internal and external pressures is not sufficiently considered.
[0027] [0027] An objective of the present invention is to provide a threaded joint for steel tubes that have the following characteristics:
[0028] [0028] Improved sealing performance against internal pressure with sealing performance against external pressure being maintained. SOLUTION TO THE PROBLEM
[0029] [0029] A threaded joint for steel tubes, according to an embodiment of the present invention, includes a tubular pin and a tubular box, the pin and the box being constituted by bolting the pin to the box.
[0030] [0030] The pin includes, in the order of one end of the pin, a shoulder surface; a sealing surface; and a male threaded portion, the male threaded portion being a tapered threaded portion with trapezoidal threads.
[0031] [0031] The box includes a shoulder surface corresponding to the shoulder surface of the pin; a sealing surface corresponding to the sealing surface of the pin; and a female threaded portion corresponding to the male threaded portion of the pin, the female threaded portion being a tapered threaded portion with trapezoidal threads.
[0032] [0032] The male threaded portion includes: ridges, roots, penetration flanks and load flanks, the penetration flanks being in a projecting position in the screwing of the male threaded portion in the female threaded portion, the loading flanks being located opposite the penetration flanks.
[0033] [0033] The female threaded portion includes roots facing the ridges of the male threaded portion, ridges facing the roots of the male threaded portion, penetration flanks facing the penetration flanks of the male threaded portion, and load flanks facing the loading flanks of the portion male threaded.
[0034] [0034] The load flanks of the male threaded portion and the load flanks of the female threaded portion have a flank angle that is less than 0 degree.
[0035] [0035] The female threaded portion consists of in the order of close to the box sealing surface, an incomplete thread section and a complete thread section.
[0036] [0036] In the female threaded portion, for an entire area of the same that includes the incomplete thread section and the complete thread section, the roots collectively defining a single tapered periphery,
[0037] [0037] The incomplete thread section has a length along the geometric axis of the tube, the length being at least three times a thread pitch of the female threaded portion, and the incomplete thread section has a thread height less than than a thread height of the complete thread section.
[0038] [0038] In the threaded joint that has such a configuration, in a compound state: the shoulder surfaces are in contact with each other, and the sealing surfaces are in contact with each other; in the complete thread section, the roots of the male threaded portion are in contact with the ridges of the female threaded portion, and the load flanks of the male threaded portion are in contact with the load flanks of the female threaded portion; and in the incomplete thread section, clearances are provided between the roots of the male threaded portion and the ridges of the female threaded portion, and the load flanks of the male threaded portion are in contact with the load flanks of the female threaded portion.
[0039] [0039] In the threaded joint above, the length of the incomplete thread section along the pipe axis is preferably, at most, eight times the thread pitch of the female threaded portion.
[0040] [0040] In the threaded joint above, the incomplete thread section can have one of the following configurations: a configuration in which the ridges, starting from a delimitation between the complete thread section and the incomplete thread section, collectively define a cylindrical periphery that it is parallel to the geometric axis of the tube; and a configuration in which the ridges, starting from the delimitation, collectively define a tapered periphery inclined in relation to the geometric axis of the tube.
[0041] [0041] Alternatively, in the threaded joint above, the incomplete thread section can have a configuration in which the ridges, starting from a delimitation between the complete thread section and the incomplete thread section, collectively define a tapered periphery that is parallel to a tapered periphery collectively defined by the ridges in the complete thread section.
[0042] [0042] In addition, the threaded joint above can be configured so that, in the male threaded portion, for an entire area of the same corresponding to the incomplete thread section and the complete thread section, the ridges collectively define a single tapered periphery.
[0043] [0043] In addition, the threaded joint above can be configured so that:
[0044] [0044] the pin includes a nozzle portion disposed between the sealing surface and the shoulder surface,
[0045] [0045] the box includes a recessed portion corresponding to the tip portion of the pin, and
[0046] [0046] in a compound state, the tip portion of the pin is not in contact with the recessed portion of the box.
[0047] [0047] Additionally, the threaded joint above can be configured so that:
[0048] [0048] the box includes a circumferential groove arranged between the incomplete thread section and the sealing surface, the circumferential groove having a length along the geometric axis of the tube, the length of which is at most three times the thread pitch of the female threaded portion; and
[0049] [0049] the male threaded portion of the pin extends to a location corresponding to the circumferential groove.
[0050] [0050] Additionally, the threaded joint above can be configured so that:
[0051] [0051] the pin includes a sealing surface for external pressure, the sealing surface for external pressure being arranged in at least one of an end region of the male threaded portion and an intermediate region thereof, and
[0052] [0052] the box includes a sealing surface for external pressure corresponding to the sealing surface for external pressure of the pin. ADVANTAGE EFFECTS OF THE INVENTION
[0053] [0053] A threaded joint for steel tubes of the present invention has the following significant advantages:
[0054] [0054] The ability to exhibit improved sealing performance against internal pressure while sealing performance against external pressure is maintained. BRIEF DESCRIPTION OF THE DRAWINGS
[0055] [0055] Figure 1 is a sectional view of a threaded joint for steel tubes, which shows an example of its general configuration.
[0056] [0056] Figure 2 is a sectional view of a conventional threaded joint for steel tubes disclosed in Patent Literature 1 and 2, showing a configuration of regions close to their sealing surfaces.
[0057] [0057] Figure 3 is a sectional view of a conventional threaded joint for steel tubes revealed in Patent Literature 3, which shows a configuration of regions close to their sealing surfaces.
[0058] [0058] Figure 4 is a cross-sectional view of a threaded joint for steel tubes according to an embodiment of the present invention, showing a configuration of regions close to their sealing surfaces.
[0059] [0059] Figure 5 is a sectional view of the threaded joint for steel tubes according to an embodiment of the present invention, showing an exemplary configuration of the female threaded portion of the box.
[0060] [0060] Figure 6 is a sectional view of the threaded joint for steel tubes according to an embodiment of the present invention, showing another exemplary configuration of the female threaded portion of the box.
[0061] [0061] Figure 7 is a sectional view of the threaded joint for steel tubes according to an embodiment of the present invention, showing yet another exemplary configuration of the female threaded portion of the box.
[0062] [0062] Figure 8 is a sectional view of the threaded joint for steel tubes according to a modality of the present invention, showing a variant configuration of the regions close to the sealing surfaces.
[0063] [0063] Figure 9 is a sectional view of the threaded joint for steel tubes according to one embodiment of the present invention, showing another variant configuration of the regions close to the sealing surfaces.
[0064] [0064] Figure 10 is a sectional view of a variation of the threaded joint for steel tubes, according to an embodiment of the present invention.
[0065] [0065] Figure 11 is a sectional view of another variation of the threaded joint for steel tubes, according to an embodiment of the present invention.
[0066] [0066] Figure 12 is a graph showing test results from the Examples. DESCRIPTION OF THE MODALITIES
[0067] [0067] The present inventors conceived the idea that the contact pressure between the sealing surfaces can be increased by taking advantage of the expansion radially out of the pin due to the internal pressure and, based on this idea, they conducted finite element analysis conducted for various combination modes and to make the contact of threads in the regions close to the sealing surfaces more intimate and evaluated the sealing performances against internal pressure and external pressure. As a result, it has been found that it is advantageous that, of the male threaded portion of the pin and the female threaded portion of the box that are combined, the female threaded portion of the box is exclusively configured to have a lower thread height in the region close to the surface of seal to relieve the combined and intimate contact of the threads. Hereinafter, the preferred embodiments of the threaded joint for steel tubes according to the present invention will be described.
[0068] [0068] Figure 4 is a sectional view of a threaded joint for steel tubes in accordance with an embodiment of the present invention, showing a configuration of regions close to their sealing surfaces. The threaded joint of the present embodiment has a configuration based on those of the threaded joints shown in Figures 1 to 3, while having a flank angle θ of less than 0 degrees on the load flanks 15 on the male threaded portion 11 and on the load flanks 24 in the female threaded portion 21. That is, the tapered threads of the threaded joint of the present embodiment are tapered trapezoidal threads that have loading flanks that are angled to form a hook shape.
[0069] [0069] The female threaded portion 21 of box 20 is divided into, in the order of close to the sealing surface 26, an incomplete thread section 21b and a complete thread section 21a. The incomplete thread section 21b has a length along the pipe axis CL which is at least three times the thread pitch of the female threaded portion 21. In the incomplete threaded section 21b, the female threaded portion 21 has a threaded height less than the thread height of the complete thread section 21a. The roots 23 in the incomplete thread section 21b, together with the roots 23 in the complete thread section 21a, collectively define a single tapered periphery. That is, the roots 23 in the female threaded portion 21, in the two thread sections 21a, 21b, collectively define a single tapered periphery.
[0070] [0070] In a composite state, the shoulder surfaces 17, 27 are in contact with each other, and the sealing surfaces 16, 26 are in contact with each other. In both the full thread section 21a and the incomplete thread section 21b, the load flanks 15 of the male threaded portion 11 are in contact with the load flanks 24 of the female threaded portion 21. It should be noted that while in the section of full thread 21a, the roots 13 of the male threaded portion 11 are in contact with the ridges 22 of the female threaded portion 21, in the incomplete thread section 21b, which is closest to the sealing surfaces 16, 26, clearances are provided between the roots 13 of the male threaded portion 11 and the ridges 22 of the female threaded portion 21, so that the combined and intimate contact of the threads is relieved therefrom.
[0071] [0071] In the threaded joint according to this modality, the flank angle θ of the load flanks is less than 0 degrees and, therefore, the application of internal pressure does not cause a reaction force on the load flanks 15 of pin 10 that acts in one direction to contract pin 10 radially inward. As a result, the expansion radially outward from the pin 10 is sufficiently caused and therefore the amplification of the contact pressure between the sealing surfaces 16, 26 can be achieved when internal pressure is applied.
[0072] [0072] Regarding the male threaded portion 11 of the pin 10, its configuration in the area corresponding to the incomplete thread section 21b of the box 20 is similar to that in the area corresponding to the complete thread section 21a of the same. That is, the ridges 12 in the male threaded portion 11, over the entire area thereof corresponding to the entire area of the female threaded portion 21 which includes the incomplete thread section 21b and the complete thread section 21a, collectively define a single tapered periphery. As a result, in the area of incomplete thread section 21b, the rigidity of pin 10 is guaranteed and the combination of threads is sufficiently obtained. This results in increasing the deformation resistance of pin 10 against radial contraction due to the application of external pressure, thus making it possible to maintain the sealing performance against external pressure. In addition, since sufficient thread height is ensured in the male threaded portion 11 of pin 10, even in the incomplete thread section area 21b, the stable thread combination is achieved during the insertion of pin 10 in box 20, so that friction is less likely to occur.
[0073] [0073] The length of the incomplete thread section 21b of box 20 is at least three times the thread pitch of the female threaded portion 21. The reason for this is as follows. If the length of the incomplete thread section 21b is less than three times the thread pitch, the area in which the expansion radially out of pin 10 due to internal pressure can act will be less. In this way, it will be impossible to make sufficient expansion radially outward to amplify the contact pressure between the sealing surfaces 16, 26.
[0074] [0074] However, the greater the length of the incomplete thread section 21b, the more the stiffness of the box 20 is reduced so that deformation of the box 20 is more likely to occur. In this way, the contact pressure between the sealing surfaces 16, 26 under combined loading is reduced. In addition, the substantial total matching area on the threads is reduced. This leads to the risk of the occurrence of the phenomenon in which pin 10 inadvertently disengages from box 20 (jumping). Consequently, the length of the incomplete thread section 21b is preferably no more than eight times the thread pitch. The length is most preferably not more than six times the thread pitch and, even more preferably, not more than five times the thread pitch.
[0075] [0075] Additionally, in the threaded joint of the present embodiment, as described above, the flank angle θ of the load flanks 15 in the male threaded portion 11 and the load flanks 24 in the female threaded portion 21 is less than 0 degrees in order to ensure that the expansion radially out of pin 10 due to internal pressure is not interfered with. The flank angle θ, in view of the thread cutting facility, is preferably -15 degrees or greater and, more preferably, -10 degrees or greater although the lower limit is therefore not particularly specified.
[0076] [0076] For the configuration of the female threaded portion 21 (complete thread section 21a and incomplete thread section 21b) to be provided for box 20, any of the following configurations (1) to (3) can be used.
[0077] [0077] (1) Figure 5 is a sectional view of the threaded joint for steel tubes according to an embodiment of the present invention, showing an exemplary configuration of the female threaded portion of the box. In the female threaded portion 21 shown in Figure 5, the ridges 22 in the incomplete thread section 21b, starting from the boundary between the complete thread section 21a and the incomplete thread section 21b, collectively define a cylindrical periphery that is parallel to the geometric axis of CL tube. Such a configuration of the female threaded portion 21 can be easily obtained by appropriately specifying the shape of the prepared hole which is cut in the box 20 in advance before the thread cutting.
[0078] [0078] Specifically, as a prepared hole for the complete thread section 21a, a tapered prepared hole that corresponds to the ridges 22 of the complete thread section 21a is cut. Then, like a prepared hole for the incomplete thread section 21b, a prepared hole that has a cylindrical periphery parallel to the CL pipe axis is cut, starting from the delimitation between the thread sections 21a and 21b. The thread cutting can be carried out in the prepared holes formed in such a way that the thread taper angle and the thread pitch are kept constant throughout the entire area of the complete thread section 21a to the incomplete thread section 21b.
[0079] [0079] (2) Figure 6 is a sectional view of the threaded joint for steel tubes according to an embodiment of the present invention, showing another exemplary configuration of the female threaded portion of the box. In the female threaded portion 21 shown in Figure 6, the ridges 22 in the incomplete thread section 21b, starting from the boundary between the complete thread section 21a and the incomplete thread section 21b, collectively define a tapered periphery inclined in relation to the geometric axis of CL tube. This configuration of the female threaded portion 21 can be achieved as follows. Like a prepared hole for the full thread section 21a, a tapered prepared hole corresponding to the ridges 22 of the complete thread section 21a is cut. Then, like a prepared hole for the incomplete thread section 21b, a tapered prepared hole that has a diameter that increases towards the tubular body is cut, starting from the delimitation between the thread sections 21a and 21b. The thread cutting can be carried out in the prepared holes formed in such a way that the thread taper angle and the thread pitch are kept constant throughout the entire area of the complete thread section 21a to the incomplete thread section 21b.
[0080] [0080] (3) Figure 7 is a sectional view of the threaded joint for steel tubes according to an embodiment of the present invention, showing yet another exemplary configuration of the female threaded portion of the box. In the female threaded portion 21 shown in Figure 7, the ridges 22 in the incomplete thread section 21b, starting from the boundary between the complete thread section 21a and the incomplete thread section 21b, collectively define a tapered periphery that is parallel to the thread tapering collectively defined by the ridges in the full thread section 21a. This configuration of the female threaded portion 21 can be achieved as follows. Like a prepared hole for the full thread section 21a, a tapered prepared hole corresponding to the ridges 22 of the complete thread section 21a is cut. Then, like a prepared hole for the incomplete thread section 21b, a tapered prepared hole that has a peripheral parallel to the tapered periphery that corresponds to the ridges 22 of the complete thread section 21a is cut in a staggered position radially outwards, starting from the boundary between thread sections 21a and 21b. The thread cutting can be carried out in the prepared holes formed in such a way that the thread taper angle and the thread pitch are kept constant throughout the entire area of the complete thread section 21a to the incomplete thread section 21b.
[0081] [0081] The above configurations (1) and (2) are advantageous in that a step is not formed in the threads in the delimitation between the complete thread section 21a and the incomplete thread section 21b. In the meantime, the configuration (3) above is advantageous in that, although a step is formed in the threads in the delimitation between the complete thread section 21a and the incomplete thread section 21b, the gaps between the roots 13 of the male threaded portion 11 and the ridges 22 of the female threaded portion 21 are constant throughout the incomplete thread section 21b and, therefore, the clearance adjustment is facilitated.
[0082] [0082] In the incomplete thread section 21b, the gaps between the roots 13 of the male threaded portion 11 and the ridges 22 of the female threaded portion 21 are configured so that the expansion radially outward from the pin 10 due to the internal pressure is not interfered with , depending on the thread taper angle and the thread position along the CL pipe axis. The clearances can be of a height generally equal to or greater than the difference in thread heights (about 0.1 to 0.2 mm, in general) between the male threaded portion 11 of pin 10 and the female threaded portion 21 of the box 20.
[0083] [0083] The present invention is not limited to the modalities described above, and various modifications can be made without departing from the spirit and scope of the present invention. As shown in Figure 8, for example, the pin 10 may include, between the sealing surface 16 and the shoulder surface 17, a nozzle portion 18 that extends towards the end of the pin, and the box 20 may include a recessed portion 28 corresponding to the nozzle portion 18 of the pin 10. In this case, in a composite state, the nozzle portion 18 of the pin 10 is not in contact with the recessed portion 28 of the box 20. In a threaded joint that has this configuration, pin 10 exhibits improved rigidity due to the nozzle portion 18 provided therein. As a result, the sealing performance against external pressure is significantly improved.
[0084] [0084] Additionally, as shown in Figure 9, the box 20 may include a circumferential groove 29 disposed between the incomplete thread section 21b and the sealing surface 26, and the male threaded portion 11 of the pin 10 can extend to a location corresponding to the circumferential groove 29. When an excessive amount of lubricating chemical (lubricant) has been applied to the threaded portions, the circumferential groove 29 allows the lubricating chemical to accumulate in it, thereby inhibiting an abnormal increase in chemical pressure of lubrication, which results in the advantageous effect of preventing the decrease in contact pressure between the sealing surfaces 16, 26. In this case, the length of the circumferential groove 29 along the pipe axis CL is a maximum of three times the thread pitch of the female threaded portion 21. The reason for this is as follows.
[0085] [0085] In addition to the incomplete thread section 21b as described above, the greater the length of the circumferential groove 29, the more the area in which the expansion radially out of pin 10 due to the internal pressure can act is increased and consequently the pressure of contact between the sealing surfaces 16, 26 is amplified. However, when the length of the circumferential groove 29 is very large, the total matching area on the threads is reduced and, as a result, the sealing performance against external pressure tends to decrease. Since the length of the circumferential groove 29 is no more than three times the thread pitch, almost no adverse effect is produced on the sealing performance against external pressure.
[0086] [0086] The threaded joint of the present embodiment is configured to have the sealing surfaces 16, 26 only in the end regions of the threaded portions on the side free of the pin. Optionally, in addition to the sealing surfaces 16, 26, seals for external pressure can be provided in the other end regions of the threaded portions on the opposite end side or in the intermediate regions thereof so that the sealing performance against external pressure can be guaranteed .
[0087] [0087] Specifically, as shown in Figure 10, pin 10 can include a sealing surface 16A for external pressure disposed at the opposite end region of the male threaded portion 11, and box 20 can include a sealing surface 26A for external pressure corresponding to the sealing surface 16A for external pressure. Alternatively, as shown in Figure 11, pin 10 can include a sealing surface 16B for external pressure arranged in an intermediate region of the male threaded portion 11, and the housing 20 can include a sealing surface 26B for external pressure corresponding to the surface of 16B seal for external pressure. Alternatively, the sealing surfaces 16A, 26A for external pressure in the opposite end regions shown in Figure 10 can be provided in combination with the sealing surfaces 16B, 26B for external pressure in the intermediate regions shown in Figure 11. On the threaded joint that has such sealing surfaces 16A, 26A, 16B, and 26B for external pressure, it may occur that, for some reason, external pressure passes through the sealing surfaces 16A, 26A, 16B and 26B and reaches the sealing surface 16, 26 for pressure internal. However, even in such a case, the sealing surface 16, 26 for internal pressure alternatively provides sealing performance against external pressure.
[0088] [0088] The threaded joint of the present modality can be used either as a threaded joint of the integral type or as a threaded joint of the coupling type. EXAMPLES
[0089] [0089] To verify the advantages of the present invention, numerical simulation and analysis were performed using the elastoplastic finite element method. [TEST CONDITIONS]
[0090] [0090] In the FEM analysis, models of threaded joints of the coupling type, with varying lengths of threaded portions, were prepared. The common conditions were as follows.
[0091] [0091] - Steel Tube Size: 203.2 to 15.875 mm (8 to 5/8 inches), 29.02 kg (64 pounds / foot) (outer diameter of 219.1 mm and wall thickness of 19.05 mm ).
[0092] [0092] - Coupling outer diameter: 235.8 mm.
[0093] [0093] - Steel tube grid (pin) and coupling (box): API standard (American Petroleum Institute) Q125 (carbon steel that has a yield stress of 862 MPa (125 ksi)).
[0094] [0094] - Thread form: 1/18 taper, 1.575 [mm] thread height, 5.08 [mm] thread pitch, -3 degree load flank angle, penetration flank angle 10 degrees and 0.15 [mm] penetration flank clearance.
[0095] [0095] In the FEM analysis, the material properties were as follows: isotropic hardening elastoplastic, an elastic modulus of 210 [GPa] and a nominal yield strength, expressed as 0.2% stress-proof, of 862 MPa (125 ksi). Hermeticity was performed to the point where the shoulder surfaces of the pin and the box were brought into contact with each other, and additionally to a point of 1.0 / 100 turns.
[0096] [0096] The varied dimensional conditions are shown in Table 1, below.
[0097] [0097] Comments) the symbol "*" indicates that the value is outside the range specified by the present invention.
[0098] [0098] Values in sealing performance and total thread combination area sections are values relative to n valores values. 1, which are assumed to be 1.
[0099] [0099] Test Models No. 1 to 5 were prepared based on the threaded joint as shown in Figure 8 and had no circumferential groove in the box. Among them, Test models No. 1 to 3 are comparative examples in which the length of the incomplete thread section of the box does not satisfy the range specified by the present invention (at least three times the thread pitch). Test models Nos. 4 and 5 are inventive examples in which the length of the incomplete thread section satisfies the range specified by the present invention.
[0100] [00100] Test Models Nos. 6 to 12 were prepared based on the threaded joint as shown in Figure 9 and had a circumferential groove in the box. Among them, Test Models No. 6 and 7 are comparative examples in which the length of the incomplete thread section of the box does not satisfy the range specified by the present invention. Test Models Nos. 8 to 12 are inventive examples in which the length of the incomplete thread section satisfies the range specified by the present invention. [EVALUATION METHOD]
[0101] [00101] In the analysis of FEM, the load sequence that simulated that, in the ISO 13679 series a test was applied to the models in a compound state. To assess the sealing performance of the sealing surfaces, the minimum values of average contact pressures on the sealing surfaces, in the internal pressure cycle (in the first and second quadrants) and in the external pressure cycle (the third and fourth quadrants) in the load sequence, were compared. (It is observed that the higher the minimum value of average contact pressure, the better the sealing performance of the sealing surfaces.) The evaluations were made as follows: since the sealing performance against internal pressure and the performance of sealing against external pressure of test model N⍛ 1 were each represented by value 1, evaluations of the remaining models were made by determining values related to test values N⍛ 1. As an evaluation criterion, the required sealing performance against internal pressure was 1.2 or more, and the sealing performance required against external pressure was 0.85 or more.
[0102] [00102] Additionally, the total combination areas on the threads were calculated to evaluate the resistance to the jump by comparing the total combination areas. The evaluations were made as follows: since the total combination area of the test model N⍛ 1 was represented by the value 1, evaluations of the remaining models were made by determining values related to the test value N⍛ 1. As a criterion of assessment, the total combination area required was at least 0.55, and preferably at least 0.7.
[0103] [00103] Models that met the evaluation criteria for the sealing performance of the sealing surfaces and had a total combination area of 0.55 or more were evaluated as satisfactory (indicated by the symbol "◯") and, among them, those with a total combination area of 0.7 or more are rated as excellent (indicated by the “Ⓞ“ symbol). Models that did not meet the criterion for both the sealing performance of the sealing surfaces and for the total combination area were assessed as weak (indicated by the symbol “△”). [TEST RESULTS]
[0104] [00104] The test results are shown in table 1 above and in figure 12 below.
[0105] [00105] Test models Nos 2, 3 and 6, which are comparative examples, had a smaller incomplete thread section and therefore sufficient expansion radially out of the pin was not caused. Thus, there was no improvement in their sealing performance against internal pressure.
[0106] [00106] Test models Nos. 4 and 5, which are inventive examples, exhibited a 20% or more increase in sealing performance against internal pressure due to the fact that sufficient expansion radially out of the pin was caused, and also, its sealing performance against external pressure has been maintained at a high level.
[0107] [00107] Test model No. 7, which is a comparative example, exhibited improved sealing performance against internal pressure. However, it underwent increased radial contraction of the pin when external pressure was applied due to the fact that its circumferential groove had an excessively long length and, therefore, there was no combination of threads in regions close to the sealing surfaces. As a result, its sealing performance against external pressure has decreased by as much as 25%.
[0108] [00108] Test models Nos. 8 to 12, which are inventive examples, exhibited improved sealing performance against internal pressure, and additionally produced the effect of inhibiting an abnormal increase in the pressure of lubricating chemical due to circumferential grooves .
[0109] [00109] All Test Models Nos. 4, 5 and 8 to 12, which are inventive examples, had, in their boxes, an incomplete thread section that has a length in the range of three times the thread pitch for six times the thread pitch, and consequently they had a total combining area on the threads of 0.55 or more. Thus, they are expected to exhibit high resistance to jump. Among them, the test models Nas 4, 5, 8 and 9 were the most suitable due to the fact that they had a larger total combination area due to the length of the incomplete thread sections in the box that is within the range of three times the thread pitch to five times the thread pitch.
[0110] [00110] The results described above demonstrated that a threaded joint for steel tubes according to the present invention exhibits excellent sealing performance against internal pressure as well as external pressure. INDUSTRIAL APPLICABILITY
[0111] [00111] A threaded joint according to the present invention has the capacity to be used effectively in connection of heavy-walled steel tubes that are used as oil well tubes in harsh environments. LIST OF NUMERICAL REFERENCES 10: pin, 11: male threaded portion, 12: male threaded portion crest, 13: male threaded portion root, 14: penetration flank of male threaded portion, 15: male threaded portion loading flank, 16: pin sealing surface, 16A, 16B: pin sealing surfaces for external pressure, 17: pin shoulder surface, 18: beak portion, 20: box, 21: female threaded portion, 22: crest of female threaded portion, 23: root of female threaded portion, 24: loading flange of female threaded portion, 25: penetration flank of female threaded portion, 21a: complete threaded section, 21b: incomplete threaded section, 26: box sealing surface, 26A, 26B: housing sealing surfaces for external pressure, 27: box shoulder surface, 28: recessed portion, 29: circumferential groove, θ: flank angle of load flanks, CL: pipe axis.

权利要求:
Claims (8)
[0001]
Threaded joint for steel tubes FEATURED by the fact that it comprises a tubular pin (10) and a tubular box (20), in which the pin (10) and the box (20) are formed by screwing the pin (10) into the box (20), the pin (10) comprising: in the order of an end of the pin, a shoulder surface (17); a sealing surface (16); and a male threaded portion (11), the male threaded portion (11) being a tapered threaded portion with trapezoidal threads, the box (20) comprising: a shoulder surface (27) corresponding to the shoulder surface (17) of the pin (10); a sealing surface (26) corresponding to the sealing surface (16) of the pin (10); and a female threaded portion (21) corresponding to the male threaded portion (11) of the pin (10), the female threaded portion (21) being a tapered threaded portion with trapezoidal threads, the male threaded portion (11) including: ridges (12); roots (13); penetration flanks (14); and load flanks (15), the penetration flanks (14) being in a projecting position in the screwing of the male threaded portion (11) in the female threaded portion (21), with the load flanks (15) being located as opposed to the penetration flanks (14), the female threaded portion (21) includes: roots (23) facing the ridges (12) of the male threaded portion (11); ridges (22) facing the roots (13) of the male threaded portion (11); penetration flanks (25) facing the penetration flanks (14) of the male threaded portion (11); and load flanks (24) facing the load flanks (15) of the male threaded portion (11), the load flanks (15) of the male threaded portion (11) and the load flanks (24) of the female threaded portion (21) have a flank angle that is less than 0 degrees, the female threaded portion (21) being composed of: in the order of near the sealing surface (26) of the box (20), an incomplete thread section (21b); and a complete thread section (21a), on what: in the female threaded portion (21), over an entire area of the same that includes the incomplete thread section (21b) and the complete thread section (21a), the roots (23) collectively define a single tapered periphery, the incomplete thread section (21b) has a length along the pipe geometric axis (CL), the length being at least three times a thread pitch of the female threaded portion (21), and the incomplete thread section ( 21b) has a thread height less than the thread height of the complete thread section (21a), and in a compound state: the shoulder surfaces (17, 27) are in contact with each other, and the sealing surfaces (16, 26) are in contact with each other; in the full thread section (21a), the roots (13) of the male threaded portion (11) are in contact with the ridges (22) of the female threaded portion (21), and the loading flanks (15) of the male threaded portion (11) are in contact with the load flanks (24) of the female threaded portion (21); and in the incomplete thread section (21b), clearances are provided between the roots (13) of the male threaded portion (11) and the ridges (22) of the female threaded portion (21), and the load flanks (15) of the portion male threaded (11) are in contact with the load flanks (24) of the female threaded portion (21).
[0002]
Threaded joint for steel tubes, according to claim 1, CHARACTERIZED by the fact that: the length of the incomplete thread section (21b) along the pipe axis (PL) is at most eight times the thread pitch of the female threaded portion (21).
[0003]
Threaded joint for steel tubes, according to claim 1 or 2, CHARACTERIZED by the fact that: the incomplete thread section (21b) has one of the following configurations: a configuration in which the ridges (22), starting from a delimitation between the complete thread section (21a) and the incomplete thread section (21b), collectively define a cylindrical periphery that is parallel to the pipe geometric axis (PL); and a configuration in which the ridges (22), starting from the delimitation, collectively define a tapered periphery inclined in relation to the geometric axis of the tube (PL).
[0004]
Threaded joint for steel tubes, according to claim 1 or 2, CHARACTERIZED by the fact that: the incomplete thread section (21b) has a configuration in which the ridges (22), starting from a delimitation between the complete thread section (21a) and the incomplete thread section (21b), collectively define a tapered periphery that is parallel to a tapered periphery collectively defined by the ridges (22) in the complete thread section (21a).
[0005]
Threaded joint for steel tubes according to any one of claims 1 to 4, CHARACTERIZED by the fact that: in the male threaded portion (11), over an entire area corresponding to the incomplete thread section (21b) and the complete thread section (21a) of the female threaded portion (21), the ridges (12) collectively define a single periphery funneled.
[0006]
Threaded joint for steel tubes according to any one of claims 1 to 5, CHARACTERIZED by the fact that: the pin (10) includes a nozzle portion (18) disposed between the sealing surface (16) and the shoulder surface (17), the box (20) includes a recessed portion (28) corresponding to the nozzle portion (18) of the pin (10), and in a composite state, the nozzle portion (18) of the pin (10) is not in contact with the recessed portion (28) of the housing (20).
[0007]
Threaded joint for steel tubes according to any one of claims 1 to 6, CHARACTERIZED by the fact that: the box (20) includes a circumferential groove (29) disposed between the incomplete thread section (21b) and the sealing surface (21), the circumferential groove (29) having a length along the pipe geometric axis ( PL), the length of which is at most three times the thread pitch of the female threaded portion (21); and the male threaded portion (11) of the pin (10) extends to a location corresponding to the circumferential groove (29).
[0008]
Threaded joint for steel tubes, according to any one of claims 1 to 7, CHARACTERIZED by the fact that: the pin (10) includes a sealing surface (16A, 16B) for external pressure, the sealing surface (16A, 16B) for external pressure being arranged in at least one of an end region of the male threaded portion (11 ) and an intermediate region thereof, and the housing (20) includes a sealing surface (26A, 26B) for external pressure corresponding to the sealing surface (16A, 16B) for external pressure of the pin (10).

类似技术:

公开号 | 公开日 | 专利标题

BR112016013134B1|2020-11-24|threaded joint for steel tubes

BR112016026808B1|2021-08-17|THREADED JOINT FOR STEEL PIPES

BR112017005668B1|2021-07-06|THREADED JOINT FOR STEEL PIPE

JP6512586B2|2019-05-15|Steel pipe screw joint

WO2015083382A1|2015-06-11|Threaded joint for steel pipes

WO2018211873A1|2018-11-22|Threaded coupling for steel piping

BR112016028401B1|2021-05-18|threaded joint for steel pipes

CA3015307C|2020-02-18|Threaded joint for steel pipes

US10883319B2|2021-01-05|Threaded connection for steel pipe

US10774958B2|2020-09-15|Threaded joint for steel pipe

BR112020006152A2|2020-10-06|threaded connection for steel pipe

BR112018013662B1|2021-11-16|THREADED JOINT FOR STEEL TUBE

WO2021145162A1|2021-07-22|Threaded coupling for pipe

BR112018016593B1|2021-10-26|THREADED JOINT FOR OIL WELL PIPING

同族专利:

公开号 | 公开日

CN105899864A|2016-08-24|

WO2015105054A1|2015-07-16|

RU2631590C1|2017-09-25|

CN105899864B|2017-07-25|

EP3093543B1|2018-07-04|

EP3093543A4|2017-08-30|

JPWO2015105054A1|2017-03-23|

CA2934937C|2018-06-05|

EP3093543A1|2016-11-16|

MX2016008917A|2017-02-06|

US10473241B2|2019-11-12|

US20160305585A1|2016-10-20|

CA2934937A1|2015-07-16|

JP6139708B2|2017-05-31|

引用文献:

公开号 | 申请日 | 公开日 | 申请人 | 专利标题

US2062407A|1935-02-19|1936-12-01|Spang Chalfant & Company Inc|Joint|

US4795200A|1986-12-04|1989-01-03|Hydril Company|Lengthened tubular pin member nose for improving sealing integrity and bearing forces|

US4944538A|1989-03-08|1990-07-31|Baroid Technology, Inc.|Threaded pipe joint having improved seal ring entrapment|

US5687999A|1995-10-03|1997-11-18|Vallourec Oil & Gas|Threaded joint for tubes|

JP3405086B2|1996-09-17|2003-05-12|住友金属工業株式会社|Threaded fittings for oil country tubular goods|

US6158785A|1998-08-06|2000-12-12|Hydril Company|Multi-start wedge thread for tubular connection|

FR2833335B1|2001-12-07|2007-05-18|Vallourec Mannesmann Oil & Gas|UPPER TUBULAR THREADING CONTAINING AT LEAST ONE THREADED ELEMENT WITH END LIP|

ES2349166T5|2003-06-06|2018-12-28|Nippon Steel & Sumitomo Metal Corporation|Threaded joint for steel pipes|

US20050093250A1|2003-11-05|2005-05-05|Santi Nestor J.|High-strength sealed connection for expandable tubulars|

JP2007205361A|2004-08-27|2007-08-16|Sumitomo Metal Ind Ltd|Steel pipe screwed joint|

PL2002165T3|2006-03-31|2017-12-29|Nippon Steel & Sumitomo Metal Corporation|Tubular threaded joint|

CN101883944B|2007-10-03|2012-07-25|住友金属工业株式会社|Screw-threaded joint for steel pipe|

CN202417340U|2011-12-29|2012-09-05|住友金属工业株式会社|Threading connector for oil well pipe|EP1153476B1|1999-02-05|2003-01-08|Texas Instruments Denmark A/S|A circuit for compensating noise and errors from an output stage of a digital amplifier|

EP3366968B1|2015-10-21|2020-12-02|Nippon Steel Corporation|Threaded fitting for steel pipes|

MX2019001385A|2016-09-16|2019-06-03|Nippon Steel & Sumitomo Metal Corp|Threaded joint.|

EP3514431B1|2016-09-16|2020-04-15|Nippon Steel Corporation|Threaded joint|

US11154936B2|2016-09-29|2021-10-26|Kyocera Corporation|Cutting tool and method of manufacturing machined product using them|

MX2019006393A|2017-01-18|2019-08-01|Nippon Steel Corp|Threaded joint for steel pipes.|

US11015746B2|2017-01-18|2021-05-25|Nippon Steel Corporation|Threaded connection|

US11035502B2|2017-06-07|2021-06-15|Marubeni-Itochu Tubulars America Inc.|Compression resistant threaded connection|

DE202017105378U1|2017-09-06|2018-12-07|Neoperl Gmbh|aerator|

RU183769U1|2018-06-05|2018-10-02|Общество С Ограниченной Ответственностью "Тмк-Премиум Сервис"|THREADED COUPLING CONNECTION|

CN110374522A|2019-06-28|2019-10-25|中国石油天然气集团有限公司|A kind of shale gas exploitation nipple|

法律状态:
2019-10-08| B25D| Requested change of name of applicant approved|Owner name: VALLOUREC OIL AND GAS FRANCE (FR) ; NIPPON STEEL C |

2020-05-05| B06U| Preliminary requirement: requests with searches performed by other patent offices: suspension of the patent application procedure|

2020-09-08| B09A| Decision: intention to grant|

2020-11-24| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 09/01/2015, OBSERVADAS AS CONDICOES LEGAIS. |

优先权:

申请号 | 申请日 | 专利标题

JP2014002614|2014-01-09|

JP2014-002614|2014-01-09|

PCT/JP2015/000076|WO2015105054A1|2014-01-09|2015-01-09|Threaded joint for steel pipe|

[返回顶部]