CN112916990B - Replacement method of nuclear grade branch pipe seat - Google Patents
Replacement method of nuclear grade branch pipe seat Download PDFInfo
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- CN112916990B CN112916990B CN202110105284.0A CN202110105284A CN112916990B CN 112916990 B CN112916990 B CN 112916990B CN 202110105284 A CN202110105284 A CN 202110105284A CN 112916990 B CN112916990 B CN 112916990B
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- branch pipe
- pipe seat
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/235—Preliminary treatment
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/16—Arc welding or cutting making use of shielding gas
Abstract
The invention discloses a method for replacing a nuclear grade branch pipe seat, which comprises the following steps: s1, according to the branch pipe seat to be replaced, drilling and finishing the hole position of the original branch pipe seat on the main pipe to form a new communicating hole; s2, aligning the butt joint end of the branch pipe seat on the communication hole of the main pipe, wherein the butt joint end of the branch pipe seat is provided with a groove with an angle larger than 25 degrees; s3, welding in the groove by adopting full argon welding to form a welding seam and connecting the branch pipe seat to the main pipe; the branch pipe seat is communicated with the main pipe through the communicating hole. According to the replacement method of the nuclear-grade branch pipe seat, the groove, the welding mode and the like of the branch pipe seat are improved, so that a new branch pipe seat replacement method is formed, the construction difficulty is reduced, the welding quality is improved, and the cost is reduced.
Description
Technical Field
The invention relates to the technical field of nuclear power equipment, in particular to a method for replacing a nuclear grade branch pipe seat.
Background
The branch pipe seat is a reinforced pipe fitting for connecting a main pipe and a branch pipe or other parts such as an instrument sleeve and the like in a pipeline system, is widely used in important systems such as a primary loop and an auxiliary system thereof of a nuclear power plant, a secondary loop important system and the like, and is a part of a system pressure boundary. The branch pipe seats used in the important systems of the nuclear power station are various in types and large in quantity, most of the branch pipe seats are nonstandard parts, and the branch pipe seats can be classified differently according to angles such as structural types, materials, installation processes and installation angles. Generally speaking, each branch pipe seat is provided with two welding seams, wherein one welding seam connects the branch pipe seat and the main pipe and is a branch pipe seat welding seam; and the other way is used for connecting the branch pipe seat with other parts such as a branch pipe or an instrument sleeve and the like and is a branch pipe welding line. Among these two welding seams, the branch pipe seat welding seam structure is comparatively complicated, and the key feature has: (1) the side of the welding seam mother pipe is in a penetrating line shape, and the penetrating line shape is more complex as some branch pipe seats and the mother pipe are in a non-vertical state; (2) the wall thickness of the welding seam is uneven, the side of the main pipe is thick, and the side of the branch pipe seat is thin.
In the nuclear power station construction stage, the branch pipe seat welding line is prefabricated in a workshop by a prefabrication factory, and the branch pipe seat welding line is generally installed and welded by adopting the processes of welding before drilling and argon-electric welding (GTAW + SMAW), so that the advantages of convenience and high efficiency are achieved. There are also a few thin-walled pipes that use "drill before weld" and "all argon welding" (GTAW) processes. The branch pipe welding lines are generally welded on site, the welding line type is simple, the construction difficulty is not large, most of the welding lines are socket welding lines or sealing welding lines, and few welding lines are butt welding lines.
In the in-service stage of the nuclear power station, the problems to be faced by the welding seam of the branch pipe seat are inconsistent with the engineering installation period and are much more complex, and the technology adopted in the engineering installation period has certain reference but cannot be directly used. In the same foreign countries, no related report of a complete set of branch pipe seat welding seam maintenance technology exists, and a WSI (Wireless sensor interface) company of a nuclear power welding maintenance professional company in America proposes a surfacing repair scheme, but the processing process of the scheme needs to invest a large amount of manpower and material resources, and the scheme has the advantages of small application range, high cost and no popularization value.
Disclosure of Invention
The invention aims to provide a replacement method of a nuclear grade branch pipe seat, which reduces the construction difficulty and improves the welding quality.
The technical scheme adopted by the invention for solving the technical problem is as follows: a method for replacing a nuclear grade branch pipe seat is provided, which comprises the following steps:
s1, according to a branch pipe seat to be replaced, drilling and finishing the hole position where the original branch pipe seat is located on the main pipe to form a new communicating hole;
s2, aligning the butt joint end of the branch pipe seat on the communication hole of the main pipe, wherein the butt joint end of the branch pipe seat is provided with a groove with an angle larger than 25 degrees;
s3, welding in the groove by adopting full argon welding to form a welding seam and connecting the branch pipe seat to the main pipe; the branch pipe seat is communicated with the main pipe through the communicating hole.
Preferably, the step S1 further includes polishing the original weld residue on the mother pipe by using a conical polishing rod.
Preferably, in step S2, the angle of the bevel is 45 °.
Preferably, step S2 further comprises: penetrating a centering rod into the branch pipe seat and the main pipe, and centering the branch pipe seat and the main pipe; a plurality of fixing blocks are arranged at intervals along the circumferential direction of the groove, and the fixing blocks are fixed on the branch pipe seat and the main pipe in a spot welding manner;
and step S3, sequentially grinding the fixed blocks in the welding process in the groove.
Preferably, the centering rod, the branch pipe seat and the mother pipe are made of the same material.
Preferably, the centering rod comprises a centering rod body used for penetrating into the branch pipe seat and the female pipe, and a positioning part arranged on the end part of the centering rod body and abutted against the end part of the branch pipe seat far away from the female pipe.
Preferably, in step S3, before welding, an argon gas protection device is installed in the branch pipe seat;
the argon protection device comprises a cylinder body with two closed ends, wherein a first end of the cylinder body is provided with a vent hole, and the opposite second end of the cylinder body is provided with an air inlet interface for connecting argon; penetrating a first end of the cylinder into the branch pipe seat, enabling a second end of the cylinder to be outside the branch pipe seat, and connecting argon through the air inlet interface;
and during welding, the argon entering the cylinder is discharged through the vent hole, and the welding position is protected by the argon.
Preferably, the method further comprises the following steps before the step S1:
s0, removing the original branch pipe seat on the main pipe by cutting the welding line.
Preferably, in step S0, before the weld joint is cut, the foreign matter prevention assembly is inserted into the original branch pipe seat and enters the main pipe, and the inner side of the weld joint is blocked.
Preferably, when the inner hole of the original branch pipe seat is an equal-diameter hole, the foreign matter prevention assembly comprises a main rod and a limiting part arranged on the end part of the main rod, and an annular groove is formed in the main rod;
before cutting a welding seam, inserting the main rod into the original branch pipe seat and entering the main pipe, and enabling the groove to correspond to the inner side of the welding seam; the limiting part is abutted against the original branch pipe seat to position the main rod.
Preferably, when the inner hole of the original branch pipe seat is provided with a necking section, the foreign matter prevention assembly comprises a main rod, a limiting part arranged on the end part of the main rod and a rubber ring sleeved on the main rod;
before a welding seam is cut, the main rod is inserted into the original branch pipe seat and enters the main pipe, the rubber ring corresponds to the necking section, and the necking section is filled; the limiting part is abutted against the original branch pipe seat to position the main rod.
The invention has the beneficial effects that: by improving the groove of the branch pipe seat, the welding mode and the like, a new branch pipe seat replacing method is formed, the construction difficulty is reduced, the welding quality is improved, and the cost is reduced.
The method is simple and feasible, and can be used for carrying out large-scale processing and identification of the welding seam defects of the branch pipe seat through standardized large-scale copying.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
FIG. 1 is a view showing a construction of an embodiment of a foreign object prevention assembly according to the present invention;
FIG. 2 is a view showing a construction of use of another embodiment of the foreign matter prevention assembly according to the present invention;
FIG. 3 is a schematic structural diagram of the present invention for polishing the original weld residue on the mother pipe by a polishing rod;
FIG. 4 is a schematic view of the alignment of the stem on the parent tube according to the present invention;
FIG. 5 is a schematic view of the welded structure of the branch pipe seat and the main pipe in the present invention;
FIG. 6 is a schematic diagram of the test structure of the through rod of the present invention.
Detailed Description
For a more clear understanding of the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
As shown in FIGS. 1-6, a method for replacing a nuclear branch vessel according to an embodiment of the present invention comprises the steps of:
s0, removing the original branch pipe seat 11 on the main pipe 10 through cutting and welding.
Before cutting the welding seam, prevent that the foreign matter subassembly inserts in former branch pipe seat 11 and get into female pipe 10, carry out the shutoff with the welding seam inboard, prevent that foreign matters such as piece in the cutting process from getting into female pipe 10.
As shown in fig. 1, when the inner hole of the original branch pipe seat 11 is an equal-diameter hole, the foreign object preventing component comprises a main rod 101 and a limiting part 102 arranged on the end part of the main rod 101, and an annular groove 103 is arranged on the main rod 101. Before cutting a welding seam, inserting the main rod 101 into the original branch pipe seat 11 and into the main pipe 10, and enabling the groove 103 to correspond to the inner side of the welding seam; the stopper 102 abuts on the end of the primary pipe base 11 away from the primary pipe 10 to position the primary rod 101.
As shown in fig. 2, when the inner hole of the original branch pipe seat 11 has a constricted section, the foreign object prevention assembly includes a main rod 201, a limiting portion 202 disposed on an end portion of the main rod 201, and a rubber ring 203 sleeved on the main rod 201. Before cutting a welding seam, inserting the main rod 201 into the original branch pipe seat 11 and entering the main pipe 10, and filling the necking section by making the rubber ring 203 correspond to the necking section; the limiting portion 202 abuts on the end portion of the original branch pipe seat 11 far away from the main pipe 10, and positions the main rod 201.
After the cutting and the removal of the original branch pipe seat 11 are completed, the foreign body prevention assembly can be taken out.
S1, according to the branch pipe seat 30 to be replaced, hole drilling and finishing processing are carried out on the hole position where the original branch pipe seat is located on the main pipe 10, and a new communicating hole is formed.
In addition, as shown in fig. 3, a conical grinding rod 20 is further used to grind the original weld residues on the mother pipe 10. The conical polishing rod 20 is used for polishing, the polishing is mainly performed through the small end of the size, the large end of the size is larger than the aperture on the female pipe 10, and the large end of the size cannot fall into the female pipe 10.
S2, aligning the butt joint end of the branch pipe seat 30 on the communication hole of the main pipe 10, wherein the butt joint end of the branch pipe seat 30 is provided with a groove 31 with an angle larger than 25 degrees.
As shown in fig. 4, the angle of the groove 31 is preferably 45 °, which not only can obtain a proper swing range of the welding wire and the welding rod during the welding process, but also can facilitate observation of the state of the molten pool during the welding process, is beneficial to control of the welding process and the welding formation, and can effectively eliminate the welding quality defects such as poor formation of the welding seam, air holes, slag inclusion, non-fusion and the like.
Referring to fig. 4, step S2 further includes: a centering rod 40 penetrates into the branch pipe seat 30 and the main pipe 10 to center the two; and a plurality of fixing blocks 41 are arranged at intervals along the circumferential direction of the groove 31, and the fixing blocks 41 are fixed on the branch pipe seat 30 and the main pipe 10 in a spot welding mode.
The centering rod 40 includes a centering rod body, a positioning portion provided on an end portion of the centering rod body. The centering rod body is inserted into the branch pipe seat 30 and the mother pipe 10, and the positioning part is abutted on the end part of the branch pipe seat 30 far away from the mother pipe 10. The positioning part is integrally formed on the centering rod body.
The centering rod 40, the branch tube seat 30 and the main tube 10 are made of the same material, such as brass.
In addition, because the problem that the branch pipe seat and the branch pipe cannot be aligned normally due to the shrinkage of the welding seam after welding is solved, in order to compensate the welding shrinkage, the branch pipe seat 30 is lengthened, so that the length of the branch pipe seat is larger than that of a conventional branch pipe seat, and the lengthening amount can be determined according to actual conditions.
S3, welding in the groove 31 by adopting full argon welding to form a welding seam 32 and connecting the branch pipe seat 30 to the main pipe 10; the branch pipe holder 30 communicates with the mother pipe 10 through a communication hole, as shown in fig. 4 to 5.
Referring to fig. 4 and 5, the centering rod 40 is removed before welding. In the welding process in the groove 31, the fixing blocks 41 are sequentially ground. After welding, the inside of the groove 31 is filled with a weld 32, and the branch pipe seat 30 is connected to the mother pipe 10.
If necessary, the outer surface of the weld 32 is also ground to smooth the surface to form a transitional joint surface between the branch tube socket 30 and the parent tube 10.
In addition, an argon shield is also installed into the manifold base 30 prior to welding.
Specifically, the argon protection device comprises a cylinder body with two closed ends, a vent hole is formed in the first end of the cylinder body, and an air inlet interface for connecting argon is formed in the opposite second end of the cylinder body. During installation, the first end of the cylinder body penetrates into the branch pipe seat 30, the second end of the cylinder body is arranged outside the branch pipe seat 30, and argon is connected through the air inlet interface.
When welding, the argon gas entering the cylinder body is discharged through the vent hole, and the welding position is protected by the argon gas.
For the manifold base 30, the inward projection of the weld 32 primarily affects the flow area. Therefore, after the welding is completed, the measurement of the inward projection of the welding seam of the branch pipe seat 30 is also included. The measurement method is as follows:
referring to fig. 6, the measurement is performed using a T-shaped through-rod 50, which is designed to prevent the through-rod from falling into the pipe during the measurement. Three through rods 50 with different diameters are used for each branch pipe seat 30, the outer diameters of the through rods are respectively 2mm, 2.5mm and 3mm smaller than the diameter of a branch pipe seat hole, the through rods are respectively marked as an A through rod, a B through rod and a C through rod, and the through rods 50 are respectively inserted into the branch pipe seats 30 according to the outer diameters from large to small. And the C-shaped through rod still cannot be inserted into the hole, which indicates that the inward projection of the welding seam is greater than the standard. At this time, the welding seam root needs to be processed, and at last, at least the C through rod can smoothly pass through the C through rod.
The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent structures or equivalent processes performed by the present invention or directly or indirectly applied to other related technical fields are included in the scope of the present invention.
Claims (9)
1. A method for replacing a nuclear branch pipe seat is characterized by comprising the following steps:
s1, according to the branch pipe seat to be replaced, drilling and finishing the hole position where the original branch pipe seat is located on the main pipe to form a new communicating hole, wherein the length of the branch pipe seat to be replaced is longer than that of the original branch pipe seat;
s2, aligning the butt joint end of the branch pipe seat on the communication hole of the mother pipe, wherein the butt joint end of the branch pipe seat is provided with a groove with an angle larger than 25 degrees, a centering rod penetrates into the branch pipe seat and the mother pipe to center the branch pipe seat and the mother pipe, and the centering rod comprises a centering rod body penetrating into the branch pipe seat and the mother pipe and a positioning part arranged on the end part of the centering rod body and abutted against the end part of the branch pipe seat far away from the mother pipe; a plurality of fixing blocks are arranged at intervals along the circumferential direction of the groove, and the fixing blocks are fixed on the branch pipe seat and the main pipe in a spot welding manner;
s3, welding in the groove by adopting full argon welding to form a welding line and connect the branch pipe seat to the main pipe, and sequentially grinding the fixed blocks in the welding process in the groove; the branch pipe seat is communicated with the main pipe through the communicating hole; and after the welding is finished, measuring the inward projection of the welding seam of the branch pipe seat.
2. The method for replacing a nuclear grade branch pipe seat according to claim 1, wherein the step S1 further comprises polishing the original weld seam residue on the mother pipe by using a conical polishing rod.
3. The method of replacing a nuclear grade nozzle according to claim 1, wherein the angle of the bevel is 45 ° in step S2.
4. The method of replacing a nuclear grade nozzle of claim 1, wherein the centering rod is made of the same material as the nozzle and the mother tube.
5. The method for replacing a nuclear grade branch pipe seat according to claim 1, wherein in step S3, an argon gas protection device is installed in the branch pipe seat before welding;
the argon protection device comprises a cylinder body with two closed ends, wherein a first end of the cylinder body is provided with a vent hole, and the opposite second end of the cylinder body is provided with an air inlet interface for connecting argon; penetrating a first end of the cylinder into the branch pipe seat, enabling a second end of the cylinder to be outside the branch pipe seat, and connecting argon through the air inlet interface;
and during welding, the argon entering the cylinder is discharged through the vent hole, and the welding position is protected by the argon.
6. The method for replacing a nuclear grade nozzle according to any one of claims 1 to 5, further comprising the following steps before step S1:
s0, removing the original branch pipe seat on the main pipe by cutting the welding line.
7. The method of replacing a nuclear grade branch pipe seat according to claim 6, wherein in step S0, before the weld is cut, the foreign matter prevention assembly is inserted into the original branch pipe seat and enters the main pipe, and the inner side of the weld is sealed.
8. The method for replacing a nuclear-grade branch pipe seat according to claim 7, wherein when the inner hole of the original branch pipe seat is an equal-diameter hole, the foreign-matter-preventing component comprises a main rod and a limiting part arranged on the end part of the main rod, and an annular groove is arranged on the main rod;
before cutting a welding seam, inserting the main rod into the original branch pipe seat and entering the main pipe, and enabling the groove to correspond to the inner side of the welding seam; the limiting part is abutted against the original branch pipe seat to position the main rod.
9. The method for replacing a nuclear-grade branch pipe seat according to claim 7, wherein when the inner hole of the original branch pipe seat has a neck section, the foreign matter prevention assembly comprises a main rod, a limiting part arranged on the end part of the main rod, and a rubber ring sleeved on the main rod;
before a welding seam is cut, the main rod is inserted into the original branch pipe seat and enters the main pipe, the rubber ring corresponds to the necking section, and the necking section is filled; the limiting part is abutted against the original branch pipe seat to position the main rod.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110105284.0A CN112916990B (en) | 2021-01-26 | 2021-01-26 | Replacement method of nuclear grade branch pipe seat |
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| CN202110105284.0A CN112916990B (en) | 2021-01-26 | 2021-01-26 | Replacement method of nuclear grade branch pipe seat |
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| CN112916990A CN112916990A (en) | 2021-06-08 |
| CN112916990B true CN112916990B (en) | 2023-01-17 |
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| CN113231720B (en) * | 2021-06-18 | 2022-09-13 | 深圳中广核工程设计有限公司 | Internal and external combined surfacing maintenance method for BOSS head weld joint |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN207316330U (en) * | 2017-10-16 | 2018-05-04 | 中国核动力研究设计院 | A kind of new tube socket replaced suitable for PWR nuclear power plant maintenance |
| CN208528638U (en) * | 2018-06-08 | 2019-02-22 | 中广核核电运营有限公司 | A kind of anti-foreign matter device |
| CN110142532A (en) * | 2019-05-10 | 2019-08-20 | 中广核核电运营有限公司 | A kind of branch holder welding argon-filling device |
| CN210115608U (en) * | 2019-04-30 | 2020-02-28 | 中广核核电运营有限公司 | Device for adjusting welding pressure abnormity of branch pipe seat |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56148490A (en) * | 1980-04-22 | 1981-11-17 | Mitsubishi Heavy Ind Ltd | Circular butt welding of tube using gas shielded welding |
| US5310982A (en) * | 1993-04-26 | 1994-05-10 | Hobart Brothers Company | T-joint welding fixture |
| JP2012066277A (en) * | 2010-09-24 | 2012-04-05 | Hitachi-Ge Nuclear Energy Ltd | Heat treatment method for branch pipe welded portion, and branch pipe seat structure |
| CN104858517A (en) * | 2015-04-29 | 2015-08-26 | 西北有色金属研究院 | Repairing method of palladium alloy tube assembly for hydrogen purification device |
| CN106041411B (en) * | 2016-08-23 | 2018-01-05 | 郑州荣奇热电能源有限公司 | A kind of high temperature superheater imports and exports header restorative procedure |
| CN109570691A (en) * | 2018-12-28 | 2019-04-05 | 江苏华滋海洋工程有限公司 | A kind of mixing welding procedure of low-temperature storage tank part through welding connector |
| CN209671843U (en) * | 2019-02-13 | 2019-11-22 | 廊坊华宇天创能源设备有限公司 | A kind of heat supply pipeline field joint heat preservation combined type outer protection tube |
| CN110170813A (en) * | 2019-06-24 | 2019-08-27 | 大连中远海运川崎船舶工程有限公司 | Auxiliary fixture is used in a kind of pipeline branch tube and main pipe assembly |
| CN211728067U (en) * | 2019-12-26 | 2020-10-23 | 江阴市节流装置厂有限公司 | Screw hole centering clamp for pipeline welding flange |
-
2021
- 2021-01-26 CN CN202110105284.0A patent/CN112916990B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN207316330U (en) * | 2017-10-16 | 2018-05-04 | 中国核动力研究设计院 | A kind of new tube socket replaced suitable for PWR nuclear power plant maintenance |
| CN208528638U (en) * | 2018-06-08 | 2019-02-22 | 中广核核电运营有限公司 | A kind of anti-foreign matter device |
| CN210115608U (en) * | 2019-04-30 | 2020-02-28 | 中广核核电运营有限公司 | Device for adjusting welding pressure abnormity of branch pipe seat |
| CN110142532A (en) * | 2019-05-10 | 2019-08-20 | 中广核核电运营有限公司 | A kind of branch holder welding argon-filling device |
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