Inner wall protection device for welding outer wall of thin-walled tube

Abstract

The invention relates to a thin-walled tube outer wall welding inner wall protection device which is characterized in that one end of a spring (2) is connected with a top sealing ball (1), the other end of the spring (2) is connected with a lower sealing ball (4), and the spring can be bent within a certain range; a cavity is formed in the lower sealing ball (4), a plurality of exhaust holes (3) are formed in the side, connected with the spring (2), of the lower sealing ball (4), and protective gas enters gaps (7) between the main pump motor cooling water pipe (6) and the top sealing ball (1) and between the main pump motor cooling water pipe (6) and the lower sealing ball (4) through the exhaust holes (3). According to the device, a good inert gas protection environment is provided for the inner wall of the pipeline in the welding process, and the fillet weld of the cooling water pipe and the main pump motor shell of the shielding type nuclear main pump motor is completed.

Description

Technical field:

[0001] The invention relates to a thin-wall pipe outer wall welding inner wall protection device. Background technology:

[0002] Reactor coolant pump is a critical equipment in the nuclear island of nuclear power plant, and its integrity has a great impact on the safe operation of the primary circuit. The cooling water pipe of the external cooling jacket of the nuclear main pump motor stator needs to pass through the main pump motor housing, and the cooling water pipe and the main pump motor housing are sealed and welded by fillet welds. During welding, due to the thin wall of the cooling water pipe, the inner wall of the pipe is severely oxidized and cannot meet the design requirements. Summary of the invention:

[0003] The purpose of the present invention is to provide a thin-walled tube outer wall welding inner wall protection device, so as to achieve the gas protection effect of the inner wall when welding the shielded nuclear main pump motor cooling water pipe, and effectively prevent the excessive oxidation of the inner wall of the pipeline. The technical scheme of the present invention is: a thin-walled tube outer wall welding inner wall protection device, one end of the spring (2) is connected to the top sealing ball (1), the other end of the spring (2) is connected to the lower sealing ball (4), and the spring can be bent within a certain range; the lower sealing ball (4) is hollow inside, and the lower sealing ball (4) and the spring (2) are connected with a plurality of exhaust holes (3), and the protective gas enters the main pump motor cooling water pipe (6) and the gap (7) between the top sealing ball (1) and the lower sealing ball (4) through the exhaust holes (3); the ventilation pipe (5) can be bent within a certain range, one end of the ventilation pipe (5) is connected to the lower sealing ball (4), and the other end of the ventilation pipe (5) is connected to the protective gas source.

[0004] The top sealing ball (1) is made of red copper, the spring (2) is made of alloy material, the bottom sealing ball (4) is made of red copper, and the ventilation pipe (5) is a stainless steel metal bellows.

[0005] The top sealing ball (1) is solid inside.

[0006] The top sealing ball (1) is hollow inside.

[0007] The working principle of the present invention is as follows: Figure 2As shown, the device of the present invention is inserted into the main pump motor cooling water pipe (6) from the top sealing ball (1) side, and the spring (2) and the lower sealing ball (4) enter the main pump motor cooling water pipe (6). The spring (2) and the vent pipe (5) can be bent according to the bending angle of the main pump motor cooling water pipe (6). By adjusting the insertion depth of the device, the weld (8) is located between the top sealing ball (1) and the lower sealing ball (4). Then, protective gas is introduced into the air inlet (10) of the vent pipe (5). The protective gas is discharged from the exhaust hole (3) through the vent pipe (5) and the lower sealing ball (4). An inert gas protective atmosphere is formed in the gap (7) between the top sealing ball (1) and the lower sealing ball (4) in the pipeline, and the weld (8) between the main pump motor cooling water pipe (6) and the main pump motor housing (9) can be completed.

[0008] Technical effects of the present invention:

[0009] The present invention is a thin-walled pipe outer wall welding inner wall protection device. By adopting a bendable design, the gas protection effect of the inner wall during the welding of the straight and curved cooling water pipes of the shielded nuclear main pump motor is achieved, which effectively prevents excessive oxidation of the inner wall of the pipeline and greatly simplifies the difficulty of operation. That is, it can cooperate with motorized argon arc welding equipment to weld large welds, and can also cooperate with manual tungsten inert gas arc welding to complete smaller welds and weld repair. It has the advantages of simple operation and high weld qualification rate. The weld passes the weld quality inspection and meets the relevant technical requirements. Practice has proved that the achievement has high practical value in engineering.

[0010] The present invention provides a good inert gas protection environment for the inner wall of the pipeline during the welding process by inventing a new device, completes the corner weld between the shielded nuclear main pump motor cooling water pipe and the main pump motor casing, meets the design requirements, and the achievement has high application value in engineering. Description of the drawings:

[0011] Figure 1 Schematic diagram of inner wall protection device for outer wall welding of thin-walled tube

[0012] Figure 2 Schematic diagram of the use of the inner wall protection device for the outer wall welding of thin-walled pipes Specific implementation method:

[0013] A cooling and protection device for pipeline welding, which adopts a bendable design to achieve a gas protection effect on the inner wall when welding the shielded nuclear main pump motor cooling water pipe and the main pump motor housing, effectively preventing excessive oxidation of the inner wall of the pipeline and greatly simplifying the operation difficulty. It can be used in conjunction with motorized argon arc welding equipment to weld large welds, and can also be used in conjunction with manual tungsten inert gas welding to complete smaller welds and weld repair. It has the advantages of simple operation and high weld qualification rate.

[0014] Its specific implementation method:

[0015] like Figure 1 As shown, a thin-walled tube outer wall welding inner wall protection device, one end of the spring 2 is connected to the top sealing ball 1, and the other end of the spring 2 is connected to the lower sealing ball 4, and the spring can be bent within a certain range; the lower sealing ball 4 has a cavity inside, and the lower sealing ball 4 is connected to the spring 2 with a plurality of exhaust holes 3, such as Figure 2 As shown, the protective gas enters the gap 7 between the main pump motor cooling water pipe 6 and the top sealing ball 1 and the lower sealing ball 4 through the exhaust hole 3. The ventilation pipe 5 can be bent to a certain extent. One end of the ventilation pipe 5 is connected to the lower sealing ball 4, and the other end of the ventilation pipe 5 is connected to the protective gas source.

[0016] The top sealing ball 1 is made of red copper, the spring 2 is made of alloy material, the lower sealing ball 4 is made of red copper, and the vent pipe 5 is a stainless steel metal bellows.

[0017] The top sealing ball 1 is solid inside.

[0018] The top sealing ball 1 is hollow inside.

[0019] The device has the advantages of simple structure, convenient operation, easy installation and disassembly, excellent protection effect, and saving the amount of protective gas.

Claims

1. A thin-walled tube outer wall welding inner wall protection device, characterized by: One end of the spring (2) is connected to the top sealing ball (1), and the other end of the spring (2) is connected to the lower sealing ball (4). The spring can be bent within a certain range. The lower sealing ball (4) has a cavity inside. The lower sealing ball (4) is connected to the spring (2) on a side with a plurality of exhaust holes (3). The protective gas enters the main pump motor cooling water pipe (6) and the gap (7) between the top sealing ball (1) and the lower sealing ball (4) through the exhaust holes (3). The ventilation pipe (5) can be bent within a certain range. One end of the ventilation pipe (5) is connected to the lower sealing ball (4), and the other end of the ventilation pipe (5) is connected to a protective gas source.

2. A thin-walled tube outer wall welding inner wall protection device according to claim 1, characterized in that: The top sealing ball (1) is made of red copper, the spring (2) is made of alloy material, the bottom sealing ball (4) is made of red copper, and the ventilation pipe (5) is a stainless steel metal bellows.

3. A thin-walled tube outer wall welding inner wall protection device according to claim 1, characterized in that: The top sealing ball (1) is solid inside.

4. A thin-walled tube outer wall welding inner wall protection device, characterized by: The top sealing ball (1) is hollow inside.

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