A gas protection device for butt welds of stainless steel pipes in nuclear power plants

Abstract

This utility model discloses a gas protection device for butt welds of stainless steel pipes in nuclear power plants. The device includes a housing with a centrally located bore. The housing comprises an upper housing and a lower housing, hinged at one end and detachably fixed at the other. Arc-shaped grooves are provided inside both the upper and lower housings, with relay pipes positioned on both sides of each groove. These relay pipes are connected by a gas supply pipe, which connects to an externally connected air inlet on the housing. Multiple exhaust holes are evenly distributed along the circumference of each relay pipe. This utility model solves the problems of uneven gas distribution, complex assembly and disassembly, and poor sealing in traditional devices through a modular housing, layered gas channels, a high-temperature resistant ceramic coating, and precise hole positioning design.

Description

Technical Field

[0001] This utility model relates to the field of nuclear power equipment welding technology, and in particular to a gas protection device for butt welds of stainless steel pipes in nuclear power plants. It is especially suitable for high-precision welding scenarios in nuclear power plants. Through modular structural design and layered gas channel optimization, it improves the uniform coverage of inert gas on the weld area and avoids oxidation pollution. Background Technology

[0002] In existing nuclear power plant stainless steel pipe butt welding, fixed gas protection devices are commonly used, but they have the following drawbacks:

[0003] 1. Uneven gas distribution: Traditional equipment relies on single-point gas supply, and the gas coverage in the weld area is less than 70%, which easily leads to local oxidation defects;

[0004] 2. Low disassembly and assembly efficiency: The fixed structure requires special tools for disassembly, and each disassembly and assembly takes more than 5 minutes, making it difficult to adapt to the confined space of nuclear power plant pipelines.

[0005] 3. Insufficient sealing: Sealing materials are prone to aging under high temperature conditions, resulting in a gas leakage rate of up to 15%, which affects the welding quality.

[0006] Therefore, there is an urgent need for a special protective device that can be quickly disassembled and assembled, has uniform gas distribution, and is resistant to high temperatures. Utility Model Content

[0007] To solve the above-mentioned technical problems, this utility model designs a gas protection device for the butt weld of stainless steel pipes in nuclear power plants. Through modular shell, layered gas channels and precise hole position design, it solves the problems of uneven gas distribution, complicated disassembly and assembly and poor sealing of traditional devices.

[0008] The present invention adopts the following technical solution:

[0009] A gas protection device for butt welds of stainless steel pipes in nuclear power plants includes a shell with a central bore. The shell comprises an upper shell and a lower shell, hinged at one end and detachably fixed at the other. Arc-shaped grooves are provided inside both the upper and lower shells, with relay pipes positioned on either side of each groove. The relay pipes are connected by a gas supply pipe, which connects to an externally connected gas inlet on the shell. Multiple exhaust holes are evenly distributed along the circumference of each relay pipe. The device consists of a separable upper and lower shell, precisely aligned using a positioning pin and quickly locked with a latch, reducing assembly and disassembly time to within 5 seconds. Thirteen φ1±0.05mm exhaust holes are evenly spaced along the circumference of the relay pipes in the upper shell, with adjacent exhaust holes spaced 13°±0.5° apart, ensuring an inert gas coverage rate of over 98%.

[0010] Preferably, the upper and lower housings are provided with filter screens in the arc-shaped grooves, which filter the gas discharged from the exhaust holes.

[0011] Preferably, the inner walls of the upper and lower housings are coated with a high-temperature resistant ceramic coating. This coating can withstand temperatures up to 800°C and extends the service life to 12 years.

[0012] Preferably, the upper and lower housings are hinged at one end by a pin.

[0013] Preferably, the other ends of the upper and lower housings are engaged by a locking mechanism.

[0014] Preferably, the lower housing is fixed to the base by bolts.

[0015] Preferably, the upper housing has a connection hole for connecting instruments.

[0016] The beneficial effects of this utility model are: (1) Gas uniformity: Through precise hole design, the oxidation defects in the weld area are reduced by 80%, and the first-time welding qualification rate reaches 99.8%; (2) Operation efficiency: The modular shell can be disassembled and assembled within 5 seconds, and the maintenance efficiency is improved by 60%; (3) Durability: The high-temperature resistant ceramic coating design extends the service life to 12 years, which is suitable for the harsh environment of nuclear power plants. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the internal structure of the upper shell of this utility model;

[0019] Figure 3 This is a schematic diagram of the internal structure of the lower shell of this utility model;

[0020] Figure 4 This is a schematic diagram of the structure of the upper shell of this utility model;

[0021] Figure 5 yes Figure 4 A left view;

[0022] Figure 6 This is a schematic diagram of the gas flow path inside the upper shell of this utility model;

[0023] Figure 7 yes Figure 6 The left view;

[0024] In the diagram: 1. Upper housing, 2. Lower housing, 3. Air supply pipe, 4. Filter screen, 5. Lock, 6. Pin, 7. Bolt, 8. Relay pipe, 9. Exhaust port, 10. Air inlet port. Detailed Implementation

[0025] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0026] Example: Figures 1-7 As shown, a gas protection device for the butt weld of stainless steel pipes in nuclear power plants includes a shell with a central hole. The shell comprises an upper shell 1 and a lower shell 2, hinged at one end and detachably fixed at the other. Arc-shaped grooves are provided inside the upper and lower shells, with relay pipes 8 arranged on both sides of the grooves. The relay pipes are connected by a gas supply pipe 3, which connects to an externally connected air inlet 10 on the shell. Multiple exhaust holes 9 are evenly distributed along the circumference of the relay pipes. The device consists of a separable upper and lower shell, precisely aligned using a positioning pin and quickly locked with a latch, reducing assembly and disassembly time to within 5 seconds. Thirteen φ1±0.05mm exhaust holes are evenly spaced along the circumference of the relay pipes in the upper shell, with adjacent exhaust holes spaced 13°±0.5° apart, ensuring an inert gas coverage rate of over 98%.

[0027] The upper and lower shells are equipped with arc-shaped grooves containing filter screens 4, which filter the gas discharged from the exhaust port.

[0028] The inner walls of both the upper and lower shells are coated with a high-temperature resistant ceramic coating. This allows them to withstand temperatures up to 800℃ and extends their service life to 12 years.

[0029] The upper and lower housings are hinged at one end by a pin 6. The other ends of the upper and lower housings are engaged by a latch 5. The lower housing is fixed to the base by bolts 7. The upper housing has connection holes for connecting instruments.

[0030] In use, the pipe to be welded is placed in the central bore of the housing. The upper and lower housings are quickly locked together using a latch. Inert gas (purity ≥99.999%) is introduced through the air inlet, and after being diverted through a relay pipe, it is evenly distributed through the exhaust port to cover the weld area. After welding is completed, the latch is unlocked, the outer shell is separated, and the weld slag is cleaned. No auxiliary tools are required throughout the entire process.

[0031] The embodiments described above are merely preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A gas protection device for butt welding of a nuclear power stainless steel pipe, comprising a housing, a pipe hole is arranged in the center of the housing, characterized in that, The housing includes an upper housing and a lower housing. The upper housing and the lower housing are hinged at one end and detachably fixed at the other end. Arc-shaped grooves are provided inside the upper housing and the lower housing respectively. Relay pipes are provided on both sides of the arc-shaped grooves. The relay pipes are connected to each other through an air supply pipe. The air supply pipes are connected to the air inlet on the housing and connected to the outside. Multiple exhaust holes are evenly distributed along the circumference of the relay pipes.

2. The gas protection device for butt welds of stainless steel pipes in nuclear power plants according to claim 1, characterized in that, The upper and lower housings are equipped with filter screens in the arc-shaped grooves, which filter the gas discharged from the exhaust holes.

3. The gas protection device for butt welds of stainless steel pipes in nuclear power plants according to claim 1, characterized in that, The inner walls of the upper and lower shells are respectively coated with high-temperature resistant ceramic coatings.

4. The gas protection device for butt welds of stainless steel pipes in nuclear power plants according to claim 1, characterized in that, The upper and lower housings are hinged at one end by a pin.

5. A gas protection device for butt welds of stainless steel pipes in nuclear power plants according to claim 1, characterized in that, The other ends of the upper and lower housings are engaged by a locking mechanism.

6. A gas protection device for butt welds of stainless steel pipes in nuclear power plants according to claim 1, characterized in that, The lower housing is fixed to the base by bolts.

7. A gas protection device for butt welds of stainless steel pipes in nuclear power plants according to claim 1, characterized in that, The upper housing has connection holes for connecting instruments.

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