JP6576234B2 - Tube pressure test machine - Google Patents

Description

  The present invention relates to an external pressure load tester for applying an external pressure to a pipe material to be tested.

  For pipe materials such as steel pipes and pipe joints, a test for applying an external pressure (hereinafter referred to as “external pressure load test”) is performed. This is to ensure the external pressure resistance performance of the pipe material in the usage environment. In particular, in a seamless steel pipe used for an oil well pipe and a threaded joint connecting the steel pipes, an external pressure load test is indispensable according to ISO 13679 and API 5C5. Testing machines used for the external pressure load test are disclosed in, for example, Japanese Patent Application Laid-Open No. 54-85085 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2001-74624 (Patent Document 2).

  The external pressure load tester described in Patent Literature 1 includes a cylindrical pressure vessel (vessel) and lids attached to both ends of the pressure vessel. In the external pressure load test, an intermediate portion of the tube material is accommodated in the hollow portion of the pressure vessel, and an end portion of the tube material is protruded from a through hole provided in the lid. In this state, pressure is applied to the outer surface of the pipe material by injecting a pressurized liquid into a space formed by the pressure vessel, the lid, and the pipe material.

  Moreover, the external pressure load tester described in Patent Document 2 includes a hydraulic cylinder rod in addition to the same pressure vessel and lid as in Patent Document 1. By pushing the hydraulic cylinder rod into the outer surface of the pipe material, an external pressure load test can be performed with a bending load applied to the pipe material.

  By the way, the aforementioned oil well pipe may be used in a high temperature environment (for example, about 180 ° C. or more). Therefore, it is required to perform the external pressure load test at a temperature similar to or higher than that of the high temperature environment. Therefore, in recent external pressure load testing machines, a heating device and a heat insulating material may be installed outside the pressure vessel. By this heating device, the inner pressure vessel, the pressurized liquid, and the tube material are heated, and a high temperature environment can be simulated. The heating device is disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-109623 (Patent Document 3) and Japanese Patent Application Laid-Open No. 8-96944 (Patent Document 4).

JP 54-85085 A JP 2001-74624 A JP 2007-109623 A JP-A-8-96944

  As described above, the external pressure load tester may include a cylindrical pressure vessel and lids attached to both ends of the pressure vessel. Moreover, since an external pressure load test is performed at a high temperature, the external pressure load tester may further include a heating device.

  When the external pressure load test of the tube material is performed at a high temperature, it is necessary to lower (cool) the tube material to a temperature at which the tube material can be removed (for example, 50 ° C. or less) in advance when the tube material is removed from the tester (pressure vessel) after the test is completed. . Therefore, the test of the next pipe material (test material) cannot be started promptly. Therefore, it is desired to shorten the time (cooling time) required for cooling the pipe member in a state where the intermediate portion is accommodated in the hollow portion of the pressure vessel. That is, it is desired to shorten the cooling time of the tube material and improve the test efficiency (the number of test materials that can be tested per unit time).

  In the external pressure load test, a predetermined thermal cycle and pressure cycle may be repeatedly applied to the pipe material. In the thermal cycle, for example, after being heated to a high temperature, it is cooled to a temperature close to room temperature (for example, 65 ° C. or less). Even in the case of applying such a heat cycle, it is desired to shorten the cooling time of the pipe material in order to shorten the test time.

  Patent Documents 1 and 2 described above describe a tube external pressure load tester, but do not describe a method for cooling a high-temperature tube. Moreover, there is no description about a heating apparatus. As a method for cooling the tube material, for example, natural cooling or circulating gas or liquid in the hollow portion of the tube material can be considered. However, since the heat capacity of the pressure vessel is remarkably larger than that of the tube material as the test body, it is difficult to significantly reduce the cooling time by a method of circulating a gas or the like through the hollow portion of the tube material.

  In addition, as a cooling method for the pipe material, it is conceivable to install a cooling jacket outside the pressure vessel and to form a cooling path through which the cooling medium flows in the cooling jacket. However, in the external pressure load tester, since the heating device is installed outside the pressure vessel, it is difficult to secure a space for installing the cooling jacket. Even if a space is secured and a cooling jacket is installed outside the pressure vessel, the heating efficiency of the heating device is significantly hindered.

  An object of the present invention is to provide an external pressure load tester for pipes that can shorten the time required for cooling a high-temperature pipe and improve test efficiency.

  A tube external pressure load testing machine according to an embodiment of the present invention includes a cylindrical pressure vessel, a pair of lids, and a heating device. The pressure vessel accommodates an intermediate portion of the tube material and is injected with a pressurized liquid. The pair of lids are attached to both ends of the pressure vessel and have through holes for projecting end portions of the tube material. The heating device surrounds the outer periphery of the pressure vessel and heats the tube material. The peripheral wall of the pressure vessel has a cooling path through which a cooling medium flows.

  Preferably, the external pressure load tester further includes a plurality of bolts arranged along a circumferential direction of the pressure vessel in order to attach the lid to the pressure vessel. The centers of the plurality of bolts are located on the same circle. The cooling path extends along the axial direction of the pressure vessel and is located outside the circle.

  The distance from the portion of the cooling path closest to the center of the pressure vessel to the center of the pressure vessel is greater than the distance from the portion of the bolt farthest to the center of the pressure vessel to the center of the pressure vessel. Is preferably small.

  Said external pressure load test apparatus can also be equipped with the structure of the following (1) or (2). Thereby, the heating time of the pipe material in the external pressure load test of the pipe material can be shortened. Therefore, the test efficiency of the external pressure load test of the pipe can be further improved.

  (1) The peripheral wall of the pressure vessel has at least one heating path through which a heating medium flows. Desirably, the heating path is disposed more on the lower side than the upper side of the center in the height direction of the peripheral wall.

  The external pressure load test apparatus may further include the following configuration. The external pressure load tester includes an auxiliary heating device. The peripheral wall of the pressure vessel has at least one hole for accommodating the auxiliary heating device. Desirably, the hole for accommodating the auxiliary heating device is disposed more on the lower side than the upper side of the center in the height direction of the peripheral wall.

  (2) A plurality of the cooling paths are provided. A switching device that switches a medium to be introduced into the cooling path between the cooling medium and the heating medium is connected to at least one of the cooling paths. Preferably, the cooling path to which the switching device is connected is disposed more on the lower side than the upper side of the center in the height direction of the peripheral wall.

  Since the external pressure load testing machine for pipes according to the present invention has a cooling path on the peripheral wall of the pressure vessel, the cooling time of the pipes can be shortened while maintaining the heating efficiency of the pipes by the heating device at the same level. Thereby, test efficiency can be improved in a high-temperature external pressure load test and an external pressure load test in which a thermal cycle is repeatedly applied to the pipe material.

FIG. 1 is a schematic diagram showing a configuration example of an external pressure load testing machine for pipes according to a first embodiment, FIG. 1 (a) is a cross-sectional view along a surface along the axial direction of the testing machine, and FIG. The figure which shows a lid | cover, FIG.1 (c) is BB sectional drawing which shows a pressure vessel. FIG. 2 is a cross-sectional view showing a configuration example when the cooling path does not penetrate the peripheral wall. FIG. 3 is a schematic diagram showing a configuration example in the case where the cooling medium is repeatedly passed through the cooling channel by the return channel, and FIG. 3A is a cross-sectional view taken along a plane perpendicular to the axial direction of the testing machine. 3 (b) is a perspective view. FIG. 4 is a schematic diagram showing a configuration example of an external pressure load testing machine for pipe material according to the second embodiment, FIG. 4 (a) is a cross-sectional view along a surface along the axial direction of the testing machine, and FIG. The figure which shows a lid | cover and FIG.4 (c) is DD sectional drawing which shows a pressure vessel. FIG. 5 is a schematic diagram showing a configuration example of an external pressure load testing machine for pipe material according to the third embodiment, FIG. 5A is a cross-sectional view taken along the axial direction of the testing machine, and FIG. The figure which shows a lid | cover, FIG.5 (c) is FF sectional drawing which shows a pressure vessel. FIG. 6 is a schematic diagram showing a configuration example of an external pressure load testing machine for pipes according to the fourth embodiment. FIG. 6A is a cross-sectional view taken along a plane along the axial direction of the testing machine, and FIG. It is a figure which shows a lid | cover. FIG. 7 is a diagram showing the analysis results of Examples 1 to 3 of the present invention. FIG. 8 is a diagram showing experimental results of Comparative Example 2. FIG. 9 is a diagram showing experimental results of Example 4 of the present invention.

  Hereinafter, an external pressure load testing machine for pipes according to this embodiment will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic diagram showing a configuration example of an external pressure load testing machine for pipes according to a first embodiment, FIG. 1 (a) is a cross-sectional view along a surface along the axial direction of the testing machine, and FIG. The figure which shows a lid | cover, FIG.1 (c) is BB sectional drawing which shows a pressure vessel. FIG.1 (b) is the figure which observed the lid | cover from the AA position of Fig.1 (a). FIG. 1A shows a pipe material 31 to be tested and an external pressure load tester 10. The pipe material 31 is a threaded joint of seamless steel pipes used for oil well pipes, and the steel pipes are connected by coupling. The pipe material 31 to be tested may be a threaded joint that does not use a coupling, and is not limited to a threaded joint. For example, a pipe material other than the joint part may be used.

  The testing machine 10 includes a pressure vessel 11, a pair of lids 12, and a heating device 16. The pressure vessel 11 has a cylindrical shape, and accommodates an intermediate portion of the pipe material 31 in a hollow portion of the pressure vessel 11. The pair of lids 12 are respectively attached to both ends of the pressure vessel 11. As shown in FIG.1 (b), the cover 12 is cyclic | annular and has the through-hole 12a in the center. The end portion of the tube material 31 protrudes from the through hole 12a.

  A pressurized liquid (for example, oil or water) is injected into the pressure vessel 11. Strictly speaking, a pressurized liquid is injected into a space formed by the pressure vessel 11, the pair of lids 12, and the pipe material 31 (hereinafter also referred to as “space in the pressure vessel”). Pressure is applied to the outer surface of 31. In order to prevent the injected pressurized liquid from leaking, a seal member (not shown) is appropriately provided between the pressure vessel 11 and the lid 12 and between the tube material 31 and the lid 12 as in the prior art. And the gaps between them are sealed.

  In order to inject the pressurized liquid 14 into the space in the pressure vessel 11 at the start of the test, the test machine 10 includes a liquid injection device (not shown). The liquid injection device can be constituted by, for example, a tank, a pump, a pressure intensifier, and a liquid supply pipe. In this case, the tank stores the liquid, and the pump transfers the liquid from the tank. The pressure intensifier pressurizes the liquid supplied from the pump. The liquid supply pipe connects a tank, a pump, a pressure intensifier, and a pressure vessel in that order.

  In order to discharge the pressurized liquid 14 from the space in the pressure vessel 11 after the end of the test, the test machine 10 includes a liquid discharge pipe (not shown). The liquid discharge pipe connects the pressure vessel 11 and the tank (not shown) to return the pressurized liquid 14 in the pressure vessel 11 to the tank.

  The heating device 16 surrounds the outer periphery of the pressure vessel 11, in other words, is adjacent to the pressure vessel 11 outside the pressure vessel 11. The heating device 16 directly heats the pressure vessel 11 inside thereof, and indirectly heats the pressurized liquid 14 and the pipe material 31 in the space in the pressure vessel 11 by heat conduction from the pressure vessel 11.

  The tube external pressure load testing machine of this embodiment includes a pressure vessel 11, a pair of lids 12, and a heating device 16, and the pressure vessel 11 has cooling passages 21a to 21d through which a cooling medium flows on a peripheral wall. In the present configuration example, the cooling paths 21a to 21d of the pressure vessel 11 penetrate the peripheral wall of the pressure vessel 11 as shown in FIG. That is, the cooling paths 21a to 21d extend from one end surface (first end surface) 11a of the pressure vessel 11 to the other end surface (second end surface) 11b. In the example shown in FIG. 1, the pressure vessel 11 has four such cooling paths 21a to 21d. The four cooling paths 21 a to 21 d are arranged along the circumferential direction of the pressure vessel 11 as shown in FIG.

  In order to distribute the cooling medium through the cooling paths 21a to 21d, the test machine 10 shown in FIG. 1 includes a refrigerant supply / discharge device. The refrigerant supply / discharge device includes a tank (not shown), a pump (not shown), a refrigerant supply flow path 22, a refrigerant discharge flow path 23, a first return flow path 24a, and a second return flow path (illustrated). None). The tank stores a cooling medium, and the pump transfers the cooling medium from the tank. Moreover, the refrigerant | coolant supply flow path 22 connects the 1st end surface 11a side of a tank, a pump, and the 1st cooling path 21a in that order. The refrigerant supply flow path branches off between the pump and the first end face side of the first cooling path 21a, and is also connected to the first end face 11a side of the fourth cooling path 21d.

  The first return flow path 24a connects the second end face 11b side of the first cooling path 21a and the second end face 11b side of the second cooling path 21b. The second return flow path (not shown) connects the second end face 11b side of the fourth cooling path 21d and the second end face 11b side of the third cooling path 21c. The refrigerant discharge passage 23 connects the first end face 11a side of the second cooling passage 21b and the tank. Moreover, the refrigerant | coolant discharge flow path 23 has branched and is connected also to the 1st end surface 11a side of the 3rd cooling path 21c.

  According to such a refrigerant supply / discharge device, the cooling medium in the tank is supplied by the pump with the refrigerant supply passage 22, the first cooling passage 21a, the first return passage 24a, the second cooling passage 21b, and the refrigerant discharge passage. 23 in that order and return to the tank again. Further, since the refrigerant supply channel 22 and the refrigerant discharge channel 23 are branched, a part of the cooling medium is replaced with the first cooling channel 21a, the first return channel 24a, and the second cooling channel 21b. The cooling channel 21d, the second return channel (not shown), and the third cooling channel 21c are circulated in that order. If necessary, a cooling device (not shown, for example, a cooling tower) for cooling the cooling medium may be provided separately (for example, on the refrigerant discharge channel 23).

The tube material external pressure load tester of the present embodiment that can adopt the above-described configuration example may cool and take out the high-temperature tube material after the test is completed, for example, by the following procedures (1) to (3).
(1) After the test, the cooling medium is circulated through the cooling paths 21 a to 21 d of the pressure vessel 11 in a state where the pressurized liquid is injected into the space in the pressure vessel 11. Thereby, the high temperature pressure vessel 11 is directly cooled, and the pressurized liquid and the pipe material 31 in the space in the pressure vessel 11 are indirectly cooled with heat conduction.
(2) After the temperature of the pipe material 31 reaches a temperature at which it can be taken out, the supply of the cooling medium to the cooling paths 21 a to 21 d is stopped and the pressurized liquid is discharged from the space in the pressure vessel 11.
(3) After the discharge of the pressurized liquid, the tube material 31 is taken out.

  The pipe external pressure load testing machine according to the present embodiment includes cooling paths 21 a to 21 d on the peripheral wall of the pressure vessel 11. For this reason, by circulating the cooling medium through the cooling paths 21a to 21d, the high-temperature pipe material 31 can be efficiently cooled, and the cooling time of the high-temperature pipe material can be greatly shortened. Thereby, in a high temperature external pressure load test, the test of another pipe material (test material) can be started rapidly. In addition, in the external pressure load test in which the thermal cycle is repeatedly applied to the pipe material, the test time can be greatly reduced. As a result, the test efficiency can be improved both in the high-temperature external pressure load test and in the external pressure load test in which the thermal cycle is repeatedly applied.

  Moreover, since it has the cooling paths 21a-21d in the surrounding wall of the pressure vessel 11, the heating apparatus 16 can be installed in the outer side of the pressure vessel 11 like the past. For this reason, the cooling time of a pipe material can be shortened, maintaining the heating efficiency of the pipe material by the heating apparatus 16 at the same level.

  The cooling paths 21a to 21d are only required to be formed on the peripheral wall of the pressure vessel 11, and the arrangement of the cooling paths 21a to 21d is not particularly limited. From the viewpoint of reducing the processing cost, the cooling paths 21a to 21d preferably extend along the axial direction of the pressure vessel 11 as shown in FIG. When the cooling path extends along the axial direction of the pressure vessel 11, the configuration is not limited to the configuration that penetrates the peripheral wall as shown in FIG. 1A, and a configuration that does not penetrate the peripheral wall can also be adopted.

  FIG. 2 is a cross-sectional view showing a configuration example when the cooling path does not penetrate the peripheral wall. The cooling path 21a shown in FIG. 2 is provided on the peripheral wall of the pressure vessel 11 and extends along the axial direction, like the cooling path 21a of FIG. However, both ends of the cooling path 21a shown in FIG. 2 are closed by plugs (plugs) 11c. The pressure vessel 11 has a supply port 11d extending from one end of the cooling passage 21a to the outer peripheral surface of the peripheral wall, and a discharge port 11e extending from the other end of the cooling passage 21a to the outer peripheral surface of the peripheral wall. The supply port 11d connected to the cooling path 21a shown in FIG. 2 is connected to the refrigerant supply channel 22, and the discharge port 11e is connected to the return channel 24a.

  When the cooling path extends along the axial direction of the pressure vessel 11, the cooling rate of the pipe material varies depending on, for example, the number of cooling paths, the outer diameter of the pressure vessel, the cross-sectional area of the cooling path, the flow rate of the cooling medium, and the like. The area of the cross section of the cooling path refers to a cross sectional area in a plane perpendicular to the axial direction of the cooling path. Among them, the number of cooling paths has the largest influence on the cooling rate of the pipe material. As the number of cooling paths increases, the cooling rate of the pipe material 31 tends to increase. For this reason, from the viewpoint of ensuring the cooling rate of the pipe material, the pressure vessel 11 preferably has a plurality of cooling paths, more preferably 4 or more, and even more preferably 12 or more.

  However, even if the number of cooling paths is large, specifically, as will be clarified in the embodiments described later, the cooling effect is saturated when the number of cooling paths is about 16. For this reason, the number of cooling paths is preferably 16 or less.

  1 and 2, the case where a plurality of holes are provided in the peripheral wall of the pressure vessel 11 and all of the holes are applied to the cooling path has been described. However, the hole applied as a cooling path is not limited to the case shown in FIGS. The external pressure load testing machine 10 of the present embodiment may be provided with more holes than the number that can be applied to the cooling path in the peripheral wall of the pressure vessel 11 as the cooling path. In this case, in an actual high-temperature external pressure test, a part or all of the holes may be used as a cooling path so as to achieve appropriate test conditions and test efficiency.

  As described above, the pair of lids 12 are attached to both ends of the pressure vessel 11, respectively. Since the reaction force acts on the lid when an external pressure is applied, the attachment needs to be performed to such an extent that it can withstand the reaction force. For example, the lid 12 can be attached to the pressure vessel by fastening with a bolt 15. The testing machine 10 shown in FIG. 1 includes 18 bolts 15. The 18 bolts 15 are arranged along the circumferential direction of the pressure vessel 11, and the center of each bolt 15 is located on the same circle 12 b (hereinafter also referred to as “pitch circle”). In order to attach the lid 12 with the bolt 15, a screw hole (not shown) is provided on the end surface of the peripheral wall of the pressure vessel 11. The lid 12 is concentrically provided with a bolt hole (not shown) into which the shaft portion of the bolt 15 is inserted and a counterbore hole (not shown) for receiving the head of the bolt 15. The head of the bolt 15 is pressed against the bottom surface of the counterbored hole.

  In this way, the testing machine may include a plurality of bolts 15 arranged along the circumferential direction of the pressure vessel 11, and the bolts 15 may be located on the pitch circle 12b. In this case, it is preferable to provide cooling paths 21a to 21d extending along the axial direction outside the pitch circle 12b. In the case where a bolt is installed on the peripheral wall of the pressure vessel 11, the pressure strength of the pressure vessel 11 by the strength calculation is calculated using the dimensions inside the pitch circle 12b and the like. The outer dimensions of the pitch circle 12b do not contribute to the pressure resistance of the pressure vessel 11. For this reason, when the cooling paths 21 a to 21 d are provided inside the pitch circle 12 b, it is necessary to increase the thickness of the peripheral wall of the pressure vessel 11 in order to maintain the pressure resistance of the pressure vessel 11. On the other hand, if the cooling paths 21a to 21d are arranged outside the pitch circle 12b, the cooling paths 21a to 21d can be provided without increasing the thickness of the peripheral wall of the pressure vessel. In other words, the cooling paths 21a to 21d can be provided without impairing the pressure resistance performance of the pressure vessel 11.

  On the other hand, the cooling paths 21a to 21d have a tendency that the cooling effect decreases as the distance between the pressurized liquid in the space in the pressure vessel 11 and the pipe material increases. For this reason, from the viewpoint of securing the cooling effect of the cooling paths 21a to 21d, the distance d1 (mm, see FIG. 1C) is preferably smaller than the distance d2 (mm, see FIG. 1B). In other words, the cooling paths 21a to 21d are preferably arranged between the adjacent bolts 15 along the circumferential direction. Here, the distance d <b> 1 is a distance from a portion of the cooling paths 21 a to 21 d closest to the center of the pressure vessel 11 to the center of the pressure vessel 11. The distance d <b> 2 is a distance from a portion of the bolt 15 farthest to the center of the pressure vessel 11 to the center of the pressure vessel 11.

  From the viewpoint of improving the cooling effect of the cooling passages 21a to 21d without increasing the thickness of the peripheral wall of the pressure vessel 11, the cooling passages 21a to 21d are located outside the pitch circle 12b and as close as possible to the pitch circle 12b. It is more preferable to arrange them.

  The cooling paths 21a to 21d may be lined with a metal having excellent corrosion resistance from the viewpoint of preventing the pressure vessel 11 from being corroded. Or you may form the cooling paths 21a-21d by providing a hole in a pressure vessel and inserting the metal tube which is excellent in corrosion resistance in the hole. In this case, the metal tube may be inserted by light press-fitting in order to suppress the cooling effect from decreasing due to the gap between the pressure vessel 11 and the metal tube. Alternatively, the gap between the pressure vessel 11 and the metal tube may be filled with molten metal.

  The cooling paths 21a to 21d may be arranged asymmetrically with respect to the center of the pressure vessel 11 as shown in FIG. In this case, by arranging the cooling paths 21 a to 21 d above the pressure vessel 11, natural convection may be generated in the pressurized liquid in the space inside the pressure vessel 11, and cooling of the tube material 31 may be promoted. In short, it is preferable that many cooling paths are arranged above the lower side of the center CL in the height direction of the pressure vessel 11.

  As described above, a large number of holes that can be used as cooling paths are provided in the peripheral wall of the pressure vessel 11 of the testing machine 10, and a part of them is used to achieve appropriate test conditions and test efficiency in an actual high-temperature external pressure test. These holes or all the holes may be used as the cooling path.

  You may return the cooling medium which distribute | circulated the cooling path to a tank, without distribute | circulating to another cooling path. Further, as described above, the cooling medium that has circulated through the cooling path may be supplied and circulated to the other cooling path by the return path. The circulation path of the accordion-like cooling medium may be formed by repeatedly supplying and circulating the cooling medium to the other cooling paths through the return flow path. As described above, a cooling device for cooling the cooling medium may be separately provided as necessary.

  FIG. 3 is a schematic diagram showing a configuration example in the case where the cooling medium is repeatedly passed through the cooling channel by the return channel, and FIG. 3A is a cross-sectional view taken along a plane perpendicular to the axial direction of the testing machine. 3 (b) is a perspective view. The test machine 10 shown in FIG. 3 has the same basic configuration as the test machine 10 shown in FIG. 1, and is obtained by changing the number of cooling channels 21a to 21p and the return channels 24a to 24g. In order to facilitate understanding of the drawings, some parts of the testing machine are omitted, and FIG. 3A shows the pressure vessel 11, the pipe material 31, and the pressurized liquid 14. 3B shows the pressure vessel 11, the lid 12, the cooling passages 21a to 21h, the refrigerant supply passage 22, the refrigerant discharge passage 23, and the return passages 24a to 24g. Moreover, in FIG.3 (b), the 9th-16th cooling path is abbreviate | omitted among the 1st-16th cooling paths 21a-21p, and the refrigerant | coolant supply flow path connected with it, a refrigerant | coolant discharge flow path, and The return flow path is also omitted.

  As shown in FIG. 3A, the pressure vessel 11 of this configuration example has 16 cooling paths 21a to 21p. The refrigerant supply passage 22 supplies a cooling medium from a tank (not shown) to the first cooling passage 21a and the sixteenth cooling passage 21p. As shown in FIG. 3 (b), the cooling medium that has circulated through the first cooling path 21a is composed of a plurality of return flow paths 24a to 24g, a fifth cooling path 21e, a second cooling path 21b, a sixth cooling path 21f, The third cooling path 21c, the seventh cooling path 21g, the fourth cooling path 21d, and the eighth cooling path 21h flow in that order. On the other hand, the cooling medium flowing through the sixteenth cooling paths 21a to 21p is omitted in FIG. 3B, but the twelfth, fifteenth, eleventh, fourteenth, tenth, thirteenth and ninth cooling paths are omitted. 21i to 21o are distributed in that order. The cooling medium flowing through the eighth cooling path 21h and the ninth cooling path 21i is returned to the tank (not shown) by the refrigerant discharge path 23.

  The tubular material external pressure load testing machine of the present embodiment may further include a hollow portion cooler (not shown) in order to cool the tubular material from the hollow portion. Thereby, the cooling time of the pipe material 31 can further be shortened. As a hollow part cooler, for example, a fan that blows air to the hollow part of the pipe material, a compressor that supplies compressed air to the hollow part of the pipe material, and a refrigerant supply / discharge device for hollow part that feeds and discharges a cooling medium to the hollow part of the pipe material Can be adopted.

  In order to cool the pressurized liquid in the space in the pressure vessel 11, the external pressure load tester for the pipe material of the present embodiment may further include a pressurized liquid cooler (not shown). The pressurized liquid cooler is, for example, a heat exchanger that cools the high-temperature pressurized liquid, a pipe that takes out the pressurized liquid from the space in the pressure vessel 11 and supplies it to the heat exchanger, and has been cooled by the heat exchanger. And a pipe that returns the pressurized liquid to the space in the pressure vessel 11. For example, an oil chiller can be adopted as the heat exchanger that cools the hot pressurized liquid.

  The cooling medium is typically water. Oil or other media may be used depending on the test conditions.

  The pressure vessel 11 is not particularly limited as long as it has the above-described cooling path, and the size, material, and the like may be appropriately selected as in the conventional case.

  As described above, the lid 12 has a through hole through which the end of the tube material projects. Further, when the lid 12 is fastened and attached to the pressure vessel 11 by the bolt 15, a bolt hole or a counterbore hole is appropriately provided. A flow path is provided to supply and discharge the cooling medium to and from the cooling path of the pressure vessel 11 as necessary. There is no restriction | limiting in particular in a material, a dimension, etc., such a lid | cover 12 should just set suitably similarly to the past.

  The heating device 16 is not particularly limited as long as the pressure vessel 11 can be appropriately heated. For example, the heating device 16 includes a heater that surrounds the pressure vessel 11 and a heat insulating material (heat insulating material) that covers the heater from the outside. A heater in particular is not restrict | limited, For example, a mantle heater, a heating wire, an induction heating coil etc. are used. Alternatively, induction heating may be used. The pressure vessel 11 self-heats by induction heating, and the pressurized liquid 14 and the pipe material 31 in the pressure vessel 11 are indirectly heated by heat conduction from the pressure vessel 11. If desired, the heating device 16 may be extended to a region 17 outside the lid 12, as shown in FIG. If the heating capacity and structure are appropriate and sufficient heating and holding are possible, the heat insulating material (heat insulating material) may be omitted. In general, the temperature of the pressurized liquid 14 in the pressure vessel 11 is likely to rise faster than the lower side than the upper side, so that, for example, heating from the lower side of the pressure vessel 11 is performed on the upper side of the pressure vessel 11. You may make it stronger than the heating from the side.

  In the above-described procedures (1) to (3), the pressurized liquid is discharged after the temperature of the tube material 31 reaches a temperature at which it can be taken out. However, the external pressure load testing machine for pipes of the present embodiment is not limited to this aspect. For example, the pressurized liquid may be discharged before the cooling medium is circulated through the cooling path of the pressure vessel 11. Alternatively, the pressurized liquid may be discharged in a state in which the cooling medium is circulated through the cooling path of the pressure vessel 11 before the temperature of the pipe material 31 reaches a temperature at which it can be taken out. From the viewpoint of shortening the cooling time, the cooling medium is circulated through the cooling path of the pressure vessel 11 in the state where the pressurized liquid exists in the space in the pressure vessel 11 as in the above-described procedures (1) to (3). Is preferred.

  As described above, the test machine 10 includes a liquid injection device (not shown) for injecting the pressurized liquid 14 into the space in the pressure vessel 11 at the start of the test, and pressurizes from the space in the pressure vessel 11 after the end of the test. In order to discharge the liquid 14, a liquid discharge pipe (not shown) is provided. When the cooling medium is circulated through the cooling path of the pressure vessel 11, the cooling of the tube material 31 may be promoted by circulating the pressurized liquid using a liquid injection device and a liquid discharge pipe.

[Second Embodiment]
The external pressure load test of the pipe material in a high temperature environment is actually a heating process in which the pipe material is heated to a predetermined temperature, a test process in which the external pressure is applied to the pipe material while the pipe material is heated to a predetermined temperature, and the pipe material is cooled. It proceeds in the order of the cooling process. Accordingly, the substantial test time is determined by the sum of the heating time required for the heating process, the test time required for the test process, and the cooling time required for the cooling process. The first embodiment pays particular attention to shortening the cooling time. Hereinafter, focusing on shortening the heating time, a testing machine capable of comprehensively shortening the test time will be described.

  Referring to FIG. 1A, in the external pressure load test, when the pressure vessel 11 is heated by the heating device 16, the temperature of the pressurized liquid 14 in the pressure vessel 11 may not rise uniformly. Specifically, the temperature of the pressurized liquid 14 above the center CL in the height direction of the pressure vessel 11 is likely to rise, and the pressure liquid 14 below the center CL in the height direction of the pressure vessel 11 is easy to rise. Temperature hardly rises. This phenomenon is considered because the pressurized liquid 14 in the pressure vessel 11 is convected by heating.

  In the external pressure load test in a high temperature environment, the variation in the temperature of the pressurized liquid 14 in the pressure vessel 11 is preferably within a range of ± 15 ° C. of the specified temperature. This is to perform an accurate external pressure load test. Therefore, after the heating of the pressurized liquid 14 is started, the start of the test is awaited until the temperature of the pressurized liquid 14 reaches a predetermined temperature and the variation in the temperature of the pressurized liquid 14 is within ± 15 ° C. of the specified temperature. There must be. Hereinafter, this waiting time is also referred to as a soaking time. The external pressure load tester of the second embodiment increases the heating efficiency and further shortens the heating time of the tube material by shortening the soaking time.

  In the external pressure load tester of the second embodiment, a cooling path and a heating path are provided on the peripheral wall of the pressure vessel. Other configurations of the external pressure load tester of the second embodiment are the same as those of the external pressure load tester of the first embodiment. Below, the code | symbol of a cooling path is named generically "21".

  FIG. 4 is a schematic diagram showing a configuration example of an external pressure load testing machine for pipe material according to the second embodiment, FIG. 4 (a) is a cross-sectional view along a surface along the axial direction of the testing machine, and FIG. The figure which shows a lid | cover and FIG.4 (c) is DD sectional drawing which shows a pressure vessel. FIG. 4B is a view of the lid 42 observed from the CC position in FIG. In the external pressure load testing machine 40 of the second embodiment, the peripheral wall of the pressure vessel 41 has at least one heating path 51 through which the heating medium flows. The heating medium directly heats the pressure vessel 41 and indirectly heats the pressurized liquid 14. The heating medium is, for example, water vapor, high-temperature oil or the like.

  The heating path 51 is provided on the peripheral wall of the pressure vessel 41 and is surrounded by the heating device 16. Therefore, the heat from the heating device 16 and the heat of the heating medium flowing through the heating path 51 are effectively transmitted to the pressure vessel 41 and thus the pressurized liquid 14. Therefore, the external pressure load test apparatus 40 of the second embodiment can efficiently heat the pipe material 31. The heating path 51 is preferably provided on the peripheral wall of the pressure vessel 41 along the axial direction.

  The external pressure load testing machine 40 of the second embodiment may have a number of holes applicable as the cooling path 21 and the heating path 51 in the peripheral wall of the pressure vessel 41. That is, there may be holes 52 that are not used as the cooling path 21 and the heating path 51. In this case, in an actual high-temperature external pressure test, a part of the plurality of holes is used as the cooling path 21 so that appropriate test conditions and test efficiency are obtained, and a part of the other holes is used. Is used as the heating path 51.

  4B and 4C, all holes arranged on the upper side of the lid 42 and the pressure vessel 41 are used as the cooling path 21, and some holes arranged on the lower side are used as the heating path 51. The case where it is used is shown. In this case, holes 52 other than the hole used as the heating path 51 among the holes arranged on the lower side of the pressure vessel 41 are not used. That is, the cooling medium and the heating medium do not flow through the holes 52. Here, arrangement | positioning of the cooling path 21, the heating path 51, and the hole 52 is not limited to the case shown in FIG.4 (b) and FIG.4 (c). There may be a heating path 51 and an unused hole 52 above the pressure vessel 41. There may be a cooling path 21 below the pressure vessel 41. In short, a plurality of holes are provided in the pressure vessel 41, and the plurality of holes are selected as any one of the cooling path 21, the heating path 51, and the unused hole 52, respectively.

  FIG. 4B shows a case where a hole selected as one of the cooling path 21, the heating path 51, and the unused hole 52 is provided between all the bolts 15 of the lid 12. However, in practice, it is preferable to provide the necessary number of holes in order to reduce the number of steps. The same applies to a third embodiment and a fourth embodiment described later.

  In the external pressure load tester 40, depending on the arrangement of the heating path 51, the heating efficiency can be increased and the soaking time can be shortened. As described above, when the pressure vessel or the like is heated to a predetermined temperature only by the heating device 16, the temperature of the pressurized liquid 14 on the upper side of the center CL in the height direction of the pressure vessel 41 tends to increase, and the lower pressure is applied. The temperature of the liquid 14 tends to decrease. Therefore, in the external pressure load tester 40 of the second embodiment, it is desirable that the heating path 51 is disposed more below the upper side of the center CL in the height direction of the peripheral wall of the pressure vessel 41. Thereby, the amount of heat given to the lower side of the pressure vessel 41 is larger than the amount of heat given to the upper side. Accordingly, the pressurized liquid 14 in the pressure vessel 41 is heated uniformly. That is, the variation in the temperature of the pressurized liquid 14 in the pressure vessel 41 is suppressed.

  For example, as shown in FIG. 4, when five heating paths 51 are arranged on the lower side of the pressure vessel 41, the number of heating paths 51 arranged on the upper side of the pressure vessel 41 is desirably four or less. The heating path 51 may not be above the center CL in the height direction of the pressure vessel 41.

  In short, the external pressure load tester 40 of the second embodiment can supplementarily heat the pressurized liquid 14 in the pressure vessel 41 with a heating medium that circulates through the heating path 51. Since the heating of the pressure vessel 41 with the heating medium has high heating efficiency, the pressure vessel 41 can be efficiently heated. Furthermore, if the heating path 51 is arranged more on the lower side than the upper side of the pressure vessel 41, the temperature of the pressurized liquid 14 can be easily raised uniformly in the pressure vessel 41. Therefore, the temperature of the pressurized liquid 14 can be quickly raised, and the waiting time described above can be shortened. That is, the heating time is shortened.

[Third Embodiment]
The external pressure load tester of the third embodiment is a modification of the external pressure load tester of the second embodiment. In the external pressure load testing machine of the third embodiment, the peripheral wall of the pressure vessel is provided with a cooling path and a hole for accommodating the auxiliary heating device, and the auxiliary heating device is inserted into this hole. Other configurations of the external pressure load tester of the third embodiment are the same as those of the external pressure load tester of the first embodiment.

  FIG. 5 is a schematic diagram showing a configuration example of an external pressure load testing machine for pipe material according to the third embodiment, FIG. 5A is a cross-sectional view taken along the axial direction of the testing machine, and FIG. The figure which shows a lid | cover, FIG.5 (c) is FF sectional drawing which shows a pressure vessel. FIG.5 (b) is the figure which observed the lid | cover 62 from the EE position of Fig.5 (a). The external pressure load testing machine 60 of the third embodiment has an auxiliary heating device 63. The auxiliary heating device 63 is, for example, a rod-shaped cartridge heater. The cartridge heater is one in which a heating element is accommodated in a tubular container such as glass or metal. The auxiliary heating device 63 directly heats the pressure vessel 61 and indirectly heats the pressurized liquid 14. The peripheral wall of the pressure vessel 61 has at least one hole 64 for accommodating the auxiliary heating device 63.

  The hole 64 preferably extends along the axial direction of the pressure vessel 61 as in the above-described cooling path. The hole 64 is preferably located outside the circle 62b where the center of the bolt 15 is located. The hole 64 may penetrate the lid 62 of the pressure vessel 61 or may not penetrate. The holes 64 may be arranged more below the upper side of the center CL in the height direction of the pressure vessel 61. The hole 64 may not be above the center CL in the height direction of the pressure vessel 61. From the viewpoint of soaking, the axial lengths of the holes 64 and the auxiliary heating device 63 are preferably equal to or greater than the length between the pair of lids 62.

  As the hole 64 in which the auxiliary heating device 63 is accommodated, a hole used as the cooling path 21 may be substituted. In this case, the cooling medium does not flow through the cooling path 21 in which the auxiliary heating device 63 is accommodated. In short, a plurality of holes are provided in the peripheral wall of the pressure vessel 61, and some of the holes are used as holes 64 for accommodating the cooling path 21 and the auxiliary heating device 63.

  The heating of the pressure vessel 61 by the auxiliary heating device 63 has high heating efficiency for the same reason as the heating path 51 of the second embodiment. Therefore, the heating device 60 of the third embodiment can efficiently heat the pressure vessel 41.

  5 (b) and 5 (c), all the holes arranged on the upper side of the lid 62 and the pressure vessel 61 are used as the cooling path 21, and some holes arranged on the lower side are used as the auxiliary heating device 63. The case where it uses as the hole 64 in which is accommodated is shown. In this case, holes 65 other than the hole used as the hole 64 in which the auxiliary heating device 63 is accommodated are not used among the holes arranged on the lower side of the pressure vessel 61. That is, the cooling medium and the heating medium do not flow through the holes 65. Here, the arrangement of the cooling path 21, the hole 64 in which the auxiliary heating device 63 is accommodated, and the unused hole 65 are not limited to the case shown in FIGS. 5 (b) and 5 (c). There may be a hole 64 in which the auxiliary heating device 63 is accommodated and an unused hole 65 on the upper side of the pressure vessel 61. There may be a cooling path 21 below the pressure vessel 61. In short, the pressure vessel 61 is provided with a plurality of holes, and each of the plurality of holes is selected as one of the cooling path 21, the hole 64 in which the auxiliary heating device 63 is accommodated, and the unused hole 65.

  Similarly to the second embodiment, the external pressure load tester 60 of the third embodiment can increase the heating efficiency and shorten the soaking time depending on the arrangement of the holes 64 in which the auxiliary heating device 63 is accommodated. In order to shorten the soaking time, it is desirable that a larger number of the holes 64 be arranged below the upper side of the center CL in the height direction of the peripheral wall of the pressure vessel 61. Thereby, similarly to 2nd Embodiment, the external pressure load tester 60 of 3rd Embodiment can heat the pressurized liquid 14 in the pressure vessel 61 uniformly. Therefore, the temperature of the pressurized liquid 14 can be quickly raised and the waiting time described above can be shortened. That is, the heating time is shortened.

  The auxiliary heating device 63 described in the third embodiment can also be applied to the external pressure load testing machine 40 of the second embodiment. In this case, the external pressure load tester includes a cooling path, a heating path, and a hole in which the auxiliary heating device is accommodated. Even in this case, there may be a hole that is not used as a hole for accommodating the cooling path, the heating path, and the auxiliary heating device. In short, a plurality of holes are provided in the pressure vessel, and each of the plurality of holes is selected from a cooling path, a heating path, a hole that accommodates an auxiliary heating device, and a hole that is not used.

[Fourth Embodiment]
In the external pressure load tester of the fourth embodiment, a switching device is added to the external pressure load tester of the first embodiment. Other configurations of the external pressure load tester of the fourth embodiment are the same as those of the external pressure load tester of the first embodiment.

  FIG. 6 is a schematic diagram showing a configuration example of an external pressure load testing machine for pipes according to the fourth embodiment. FIG. 6A is a cross-sectional view taken along a plane along the axial direction of the testing machine, and FIG. It is a figure which shows a lid | cover. FIG. 6B is a diagram in which the lid 72 is observed from the GG position in FIG. In the external pressure load tester 70 of the fourth embodiment, a plurality of cooling paths 21 are provided. A switching device 81 is connected to at least one of the cooling paths 21. The switching device 81 switches the medium introduced into the cooling path 21 between a cooling medium and a heating medium. Specifically, when cooling the tube material 31, the switching device 81 introduces a cooling medium from the refrigerant supply channel 73 to the cooling channel 21. When the tube material 31 is heated, the switching device 81 introduces the heating medium from the heating medium supply channel 74 to the cooling channel 21. In short, in the external pressure load tester of the fourth embodiment, the cooling path 21 provided for cooling is used as a cooling path during cooling and is used as a heating path during heating. By sharing the cooling path 21 with the heating path, there is no need to newly provide a heating path. Therefore, the manufacturing cost of the external pressure load tester is reduced.

  Similarly to the above-described embodiment, there may be a hole 75 that is not used as a cooling path and a heating path. In short, the pressure vessel 71 is provided with a plurality of holes, and each of the plurality of holes is selected from the cooling path 21, the cooling path to which the switching device 81 is connected, and the unused hole 75.

  It is desirable that the cooling path 21 to which the switching device 81 is connected be disposed more on the lower side than the upper side of the center CL in the height direction of the peripheral wall of the pressure vessel 71. When the switching device 81 switches the medium introduced into the cooling path 21 to the heating medium, many heating paths are arranged below the upper side of the center CL in the height direction of the pressure vessel 71 during heating. As a result, as described above, the temperature of the pressurized liquid 14 is less likely to vary within the pressure vessel 71 in the tube heating process. Therefore, the above-described soaking time can be shortened and the test time can be shortened.

  The switching device 81 described in the fourth embodiment can also be applied to the external pressure load tester of the second embodiment or the third embodiment. In this case, the switching device 81 is connected to at least one of the cooling paths 21 of the external pressure load testing machine of the second embodiment or the third embodiment. Even in this case, there may be a hole that is not used as a cooling path to which the cooling path, the heating path, the auxiliary heating device, and the switching device are connected. In short, a plurality of holes are provided in the pressure vessel, and each of the plurality of holes is selected as one of a cooling path, a heating path, an auxiliary heating device, a cooling path to which a switching device is connected, and a hole that is not used.

  In order to confirm the cooling performance of the external pressure load testing machine of the present embodiment, the following heat transfer analysis was performed.

[Analysis conditions]
In Example 1 of the present invention, an analysis assuming an external pressure load test at 180 ° C. was performed using the testing machine shown in FIG. After the test was completed, a cooling medium was circulated through the cooling paths 21a to 21p of the pressure vessel 11 while the pressurized liquid was injected into the space inside the pressure vessel 11, and the tube material 31 was cooled to 50 ° C.

  The pressure vessel 11 had an outer diameter of 567 mm, a wall thickness of 110 mm, and a length of 1190 mm. The 16 cooling passages 21a to 21p all had a diameter of 12.7 mm and a distance d1 of 502 mm. The pitch circle of the bolt was 515 mm. The cooling medium was water, and the flow rate of each cooling path was changed in the range of 10 to 240 l / min. The tube 31 had an outer diameter of 311 mm.

  In Invention Example 2, the number of cooling paths is 12 and in Invention Example 3, the number of cooling paths is 8. The other analysis conditions were the same as those of Example 1 of the present invention.

  In Comparative Example 1, the pressure vessel 11 having no cooling path was used, and the compressed air was blown into the hollow portion of the pipe 31. The other analysis conditions were the same as those of Example 1 of the present invention.

[Analysis result]
FIG. 7 is a diagram illustrating an analysis result of the first embodiment. FIG. 7 shows the relationship between the flow rate (l / min) of the cooling medium in the cooling path and the cooling time (min) of the pipe material. In FIG. 7, the ◯ marks indicate the analysis results of Invention Example 1, the X marks indicate the analysis results of Invention Example 2, and the ● marks indicate the analysis results of Invention Example 3, respectively. From FIG. 7, in Examples 1-3 of this invention, the cooling time of the pipe material became 3 hours or less. On the other hand, in Comparative Example 1, the cooling time of the tube material was 9 hours or more. From these, it became clear that the cooling time of the pipe material 31 can be significantly reduced by providing a cooling path in the pressure vessel.

  As shown in FIG. 7, the cooling time decreased as the flow rate of the cooling medium increased. Further, the decrease in the cooling time due to the increase in the flow rate of the cooling medium was saturated when the flow rate of the cooling medium was about 50 l / min.

  On the other hand, the cooling time decreased as the number of cooling paths increased. Moreover, the decrease in the cooling time due to the increase in the number of cooling paths was almost saturated when the number of cooling paths was about 16. Therefore, it was confirmed that the number of suitable cooling paths was 16 or less.

  In order to confirm the heating performance of the external pressure load tester of the present embodiment, the following real machine test was performed.

[Experimental conditions]
In Example 4 of the present invention, a heating test of a pipe material was performed using the testing machine 60 shown in FIG. 5 and assuming an external pressure load test at 180 ° C. The auxiliary heating device 63 was a cartridge heater. The cartridge heater had a diameter of 16 mm and a length of 2140 mm. The capacity of the cartridge heater was 3.5 kW per one. Cartridge heaters were accommodated in the eight holes 64 of the pressure vessel 61, respectively. Specifically, two cartridge heaters were arranged above the center CL in the height direction of the peripheral wall of the pressure vessel, four at the bottom, and two at the center. During the heating test, all cartridge heaters were set to the same output. The pressurized liquid 14 was oil.

  As the pressure vessel 61, a pressure vessel having the same dimensions as those in Example 1 was used. The outer diameter of the tube was 193.675 mm (7.625 inches). During the heating test, the temperature of the pressure vessel was measured. The temperature measurement was performed at each position on the upper side P1 and the lower side P2 of the pressure vessel, and at each position on the upper side P3 and the lower side P4 in the pressure vessel (see FIG. 6C).

  In the comparative example 2, the heating test of the pipe material which assumed the external pressure load test at 180 degreeC was done using the testing machine 10 shown in the said FIG. In short, in Comparative Example 2, a testing machine without a heating path and an auxiliary heating device was used. The other experimental conditions were the same as Example 4 of the present invention.

[Experimental result]
8 and 9 are diagrams showing the test results of Example 2. FIG. Of these figures, FIG. 8 shows the experimental results of Comparative Example 2. FIG. 9 shows the experimental results of Example 4 of the present invention. The horizontal axis of FIG.8 and FIG.9 shows heating time (h), and a vertical axis | shaft shows temperature (degreeC). 8 and 9, the solid line is the position of P1 (upper pressure vessel), the broken line is the position of P2 (lower pressure vessel), the alternate long and short dash line is the position of P3 (pressurized liquid above the pressure vessel), and the two-dot chain line Indicates the measurement results at each position of P4 (pressurized liquid below the pressure vessel).

  From FIG. 8, in Comparative Example 2, the upper side of the pressure vessel reached 180 ° C. earlier than the lower side. That is, the upper side of the pressure vessel was more easily heated than the lower side. After the temperature on the upper side of the pressure vessel reached 180 ° C., the waiting time (soaking waiting time) until the temperature on the lower side of the pressure vessel reached 180 ° C. was about 1 hour. In Comparative Example 2, the tube heating time exceeded 8 hours.

  From FIG. 9, in the present invention example 4, the lower side of the pressure vessel reached 180 ° C. earlier than the upper side. That is, the lower side of the pressure vessel was more easily heated than the upper side. Also, in the pressurized liquid in the pressure vessel, as compared with Comparative Example 2 (FIG. 8), the temperature variation between the lower pressurized liquid and the upper pressurized liquid was suppressed. If the arrangement and number of auxiliary heating devices on the lower side of the pressure vessel are adjusted, the temperature on the upper side of the pressure vessel and the temperature rise on the lower side can be made equal. Therefore, the soaking waiting time is shortened. Further, in Invention Example 4, the heating time of the pipe material was suppressed within 4 hours. That is, by providing the auxiliary heating device, the tube material could be heated efficiently, so the heating time was shortened.

  The present invention can be effectively used in an external pressure load test of an oil well pipe.

10, 40, 60, 70: external pressure load tester 11, 41, 61, 71: pressure vessel,
11a: 1st end surface, 11b: 2nd end surface, 11c: Plug, 11d: Supply port,
11e: outlet, 12, 42, 62, 72: lid, 12a: through hole,
12b: Pitch circle, 14: Pressurized liquid, 15: Bolt, 16: Heating device,
21, 21a to 21p: pressure vessel cooling passage, 22: refrigerant supply passage,
23: Refrigerant discharge flow path, 24a-24g: Return flow path, 31: Pipe material,
63: auxiliary heating device, 64: hole 81: switching device

Claims (9)

An external pressure load testing machine for pipes,
The external pressure load tester is
A cylindrical pressure vessel in which an intermediate part of the tube material is accommodated and pressurized liquid is injected,
A pair of lids attached to both ends of the pressure vessel and having through holes for projecting end portions of the pipe material;
A heating device that surrounds an outer periphery of the pressure vessel and heats the pipe material,
The peripheral wall of the pressure vessel is an external pressure load tester for a pipe material having a cooling path through which a cooling medium flows. It is an external pressure load testing machine of the pipe material according to claim 1,
The external pressure load tester is
In order to attach the lid to the pressure vessel, further comprising a plurality of bolts arranged along the circumferential direction of the pressure vessel,
The centers of the plurality of bolts are located on the same circle,
The cooling path extends along the axial direction of the pressure vessel and is located outside the circle, and is an external pressure load tester for pipe materials. An external pressure load testing machine for pipes according to claim 2,
The distance from the portion of the cooling path closest to the center of the pressure vessel to the center of the pressure vessel is greater than the distance from the portion of the bolt farthest to the center of the pressure vessel to the center of the pressure vessel. A small external pressure testing machine for pipe materials. An external pressure load tester for a pipe material according to any one of claims 1 to 3,
The peripheral wall of the pressure vessel is an external pressure load tester for a pipe material having at least one heating path through which a heating medium flows. It is an external pressure load tester of the pipe material according to any one of claims 1 to 4,
The external pressure load tester includes an auxiliary heating device,
The peripheral wall of the pressure vessel is a pipe external pressure load tester having at least one hole for accommodating the auxiliary heating device. An external pressure load tester for a pipe according to any one of claims 1 to 5,
A plurality of the cooling paths are provided,
An external pressure load tester for a pipe material, to which at least one of the cooling paths is connected a switching device for switching a medium introduced into the cooling path between the cooling medium and the heating medium. An external pressure load testing machine for pipes according to claim 4,
The said heating path is a pipe | tube external pressure load testing machine arrange | positioned more below the upper side of the center of the height direction of the said surrounding wall. An external pressure load testing machine for pipes according to claim 5,
The said external heating apparatus is a pipe | tube external-pressure load testing machine arrange | positioned more below the upper side of the center of the height direction of the said surrounding wall. An external pressure load testing machine for pipes according to claim 6,
The cooling path to which the switching device is connected is an external pressure load tester for pipes, which is disposed more on the lower side than the upper side of the center in the height direction of the peripheral wall.

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