Metal seal ring extraction tool and method

Abstract

The application belongs to the technical field of nuclear reactor maintenance of nuclear power plant, and particularly relates to a metal sealing ring taking-out tool and method, which comprises a handle, handle supports, a base, a protection seat and an execution knife; wherein the handle is connected to the upper ends of the two handle supports, the lower ends of the two handle supports are connected with the base, a groove is opened on the left side of the base, the upper part of the execution knife is connected with the top of the base, the side part of the execution knife penetrates through the groove on the left side of the base, the lower part of the base is connected and fixed with the protection seat, and the blade on the side part of the execution knife penetrates through the opening on the left side of the protection seat. The metal sealing ring taking-out tool has the key equipment protection function, reduces the damage risk of the key equipment in the whole nickel sealing ring taking-out process, is simple to operate, greatly reduces the skill level requirement of the operation personnel for the operation, can effectively shorten the operation time in the high radiation dose place, and effectively reduces the radiation dose of the operation personnel.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nuclear reactor maintenance of nuclear power plant, and particularly relates to a metal sealing ring taking-out tool and method. BACKGROUND

[0002] The first and second phase projects of a certain nuclear power plant have four nuclear power units. Compared with other pressurized water reactor nuclear power units in China, the flange sealing structure of the reactor pressure vessel of the unit has great difference. There are 54 bolt holes arranged outside the main sealing surface of the nuclear reactor pressure vessel, and 54 light holes arranged on the top cover flange. The main sealing surface of the pressure vessel is provided with two annular sealing grooves with "V" type cross section and a circumference of about 12 meters. The annular metal sealing ring with a diameter of 5 mm is installed in the sealing grooves and is made of nickel. The pressure vessel flange sealing member is composed of 54 main bolts, 54 main nuts, 54 sets of concave-convex spherical gaskets and two nickel sealing rings. The main bolts are stretched by the integral main bolt stretcher to compress the nickel sealing ring. The nickel sealing ring is plastically deformed in the "V" type sealing groove to fill the gap between the upper and lower flange sealing surfaces, thereby achieving good sealing.

[0003] The nuclear power unit usually takes 12 months or 18 months as a fuel cycle. After each fuel cycle, the top cover of the reactor pressure vessel must be opened for nuclear fuel replacement. Since the used nickel sealing ring has been plastically deformed, the protruding sealing surface height is only about 0-0.5 mm. Therefore, the pressure vessel must be replaced with a new nickel sealing ring, i.e. the old nickel sealing ring is taken out and a new sealing ring is installed. The existing technical solution for taking out the old nickel sealing ring is as follows: a flat screwdriver is used to take out the nickel sealing ring from the "V" type sealing groove in the state that the top cover of the pressure vessel is lifted, and a bevelled forceps is used to cut the sealing ring to achieve the taking-out of the old nickel sealing ring.

[0004] The existing technical solution has the following problems: the nickel sealing ring is tightly connected with the "V" type sealing groove after being compressed for a long time, and it is difficult to separate the two by using a flat screwdriver. It takes 10-30 minutes to take out each sealing ring, and the work efficiency is low. The protruding sealing surface height of the old sealing ring is only about 0-0.5 mm, and the stress area is small during the separation of the nickel sealing ring and the "V" type sealing groove. If the flat screwdriver is not used properly, the key part of the equipment, i.e. the sealing surface, can be damaged. For the case that metal adhesion occurs between the nickel sealing ring and the sealing surface material, the nickel sealing ring cannot be taken out from the sealing groove. The working environment of the nickel sealing ring taking-out operation is a high radioactive pollution area with high environmental radiation dose rate and long operation time, and the radiation dose received by the operator is large. The operator needs to wear a radiation protection suit and multiple gloves for operation, and the skill requirement for the operator is high.

[0005] Therefore, it is necessary to provide a metal sealing ring taking-out tool and method to solve the problems in the prior art. SUMMARY

[0006] The application aims to provide a metal seal ring taking-out tool and method to solve the problems of low work efficiency, high environmental radiation dose rate, long operation time and large radiation dose received by the operator in the prior art.

[0007] The technical scheme for achieving the application is as follows:

[0008] A metal seal ring taking-out tool, comprising a handle, two handle supports, a base body, a protection seat and an execution knife.

[0009] The handle is connected to the upper ends of the two handle supports, the lower ends of the two handle supports are connected to the base body, a groove is formed in the left side of the base body, the upper part of the execution knife is connected to the top of the base body, the side part of the execution knife passes through the groove in the left side of the base body, the lower part of the base body is connected to the protection seat, and the blade of the side part of the execution knife passes through the opening in the left side of the protection seat.

[0010] The handle is a round pipe and is welded to the two handle supports.

[0011] The two handle supports are sheet metal parts, and the lower ends of the handle supports are connected to the base body through support fastening bolts.

[0012] The protection seat is a half-shell structure, and the bottom surface of the protection seat is in contact with the sealing surface of the seal ring.

[0013] The front end of the protection seat is an L-shaped opening, which is the outlet of the blade of the execution knife.

[0014] The base body and the execution knife are connected through positioning fastening bolts.

[0015] The upper part of the execution knife is connected to a front adjusting bolt and a rear adjusting bolt, the front adjusting bolt and the rear adjusting bolt are respectively located on the two sides of the positioning fastening bolt, and the height and the pitch of the execution knife are adjusted by adjusting the front adjusting bolt and the rear adjusting bolt.

[0016] The base body and the protection seat are connected through protection seat fastening bolts, and are supplemented with sealing glue.

[0017] The protection seat fastening bolts are countersunk head bolts.

[0018] A taking-out method of the metal seal ring taking-out tool, comprising the following steps:

[0019] Step 1: loosen the front adjusting bolt, the positioning fastening bolt and the rear adjusting bolt, so that the lower end plane of the execution knife is higher than the lower plane of the protection seat.

[0020] Step two, the hand-held metal seal ring removal tool is placed on a flat surface or a sealing surface, and the lower end of the execution knife is adjusted to a suitable height higher than the lower plane of the protection seat by adjusting the front adjusting bolt, the positioning fastening bolt and the rear adjusting bolt;

[0021] Step three, the metal seal ring removal tool is taken to the outer edge of the gasket to be removed, the execution knife blade is contacted with the gasket, one hand holds the handle, and the other hand uses a rubber hammer to knock the execution knife, so that the execution knife generates an impact force on the gasket to shake the gasket loose.

[0022] The beneficial technical effect of the present application is that:

[0023] (1) The metal seal ring removal tool in the present application has high work efficiency, and it only takes about 5 minutes to remove each seal ring, which improves the work efficiency by 2-6 times on average and shortens the key path time of overhaul;

[0024] (2) The metal seal ring removal tool in the present application can remove the nickel seal ring with metal adhesion;

[0025] (3) The metal seal ring removal tool in the present application has a key equipment protection function, which reduces the risk of damage to the key equipment in the entire nickel seal ring removal process;

[0026] (4) The removal tool in the present application is easy to operate, which greatly reduces the skill level requirement of the operation personnel for the operation;

[0027] (5) The removal tool in the present application can effectively shorten the operation time in a high radiation dose place and effectively reduce the radiation dose of the operation personnel. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A metal seal ring removal tool structure schematic diagram provided by the present application;

[0029] Figure 2 A metal seal ring removal tool top view provided by the present application;

[0030] Figure 3 A metal seal ring removal tool A-A sectional view provided by the present application;

[0031] In the figure: 1-handle; 2-handle support; 3-base body; 4-support fastening bolt; 5-protection seat; 6-execution knife; 7-front adjusting bolt; 8-positioning fastening bolt; 9-rear adjusting bolt; 10-protection seat fastening bolt. DETAILED DESCRIPTION

[0032] In order to make the skilled in the art better understand the present application, the following will be combined with the drawings of the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the following described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments described in the present application, all other embodiments obtained by the skilled in the art without creative labor are within the scope of protection of the present application.

[0033] As shown in Figure 1 , Figure 2 and Figure 3 , the metal seal ring extraction tool provided by the present application comprises a handle 1, a handle support 2, a base 3, a support fastening bolt 4, a protection seat 5, an execution knife 6, a front adjusting bolt 7, a positioning fastening bolt 8, a rear adjusting bolt 9, and a protection seat fastening bolt 10.

[0034] The handle 1 is welded at the upper ends of the two handle supports 2, the lower ends of the two handle supports 2 are bolted to the base 3 through the support fastening bolt 4, the base 3 is bolted to the execution knife 6 through the positioning fastening bolt 8, the front adjusting bolt 7 and the rear adjusting bolt 9 are threadedly connected to the execution knife 6, the height of the execution knife 6 is adjusted up and down and the pitch of the execution knife 6 is adjusted forward and backward by adjusting the rear adjusting bolt 7 and the front adjusting bolt 9, the base 3 is bolted to the protection seat 5 through the protection seat fastening bolt 10, and sealing glue is used as an auxiliary.

[0035] The handle 1 is a circular tube, which mainly serves as a hand-holding position of the metal seal ring extraction tool and is welded to the two handle supports 2.

[0036] The handle support 2 is a sheet metal part, the upper end of which is welded to the handle 1, and the lower end of which is bolted to the base 3 through the eight support fastening bolts 4.

[0037] The protection seat 5 is a half-shell structure, the bottom surface of which is in contact with the sealing surface of the seal ring to be extracted and simultaneously serves as a reference surface for adjusting the height of the execution knife 6.

[0038] The bottom surface of the protection seat 5 is connected to the two protection seat fastening bolts 10, and sealing glue is used as an auxiliary to prevent loosening. The protection seat fastening bolt 10 is a countersunk bolt, so that after being fastened, the protection seat fastening bolt 10 does not protrude from the protection seat 5, thereby protecting the sealing surface.

[0039] The front end of the protection seat 5 is an L-shaped opening, which mainly serves as an outlet for the blade of the execution knife 6.

[0040] The present application also provides a metal seal ring extraction method of the metal seal ring extraction tool, which comprises the following steps:

[0041] Step one, loosen the front adjusting bolt 7, the positioning fastening bolt 8 and the rear adjusting bolt 9, so that the lower end plane of the execution knife 6 is higher than the lower plane of the protection seat 5;

[0042] Step two, the hand-held metal seal ring extraction tool is placed on a flat surface or a sealing surface, and the lower end of the execution knife 6 is adjusted to a suitable height above the lower surface of the protection seat by adjusting the adjusting bolt 7, the positioning fastening bolt 8 and the rear adjusting bolt 9;

[0043] Step three, the tool is taken to the outer edge of the pad ring to be extracted, the execution knife 6 is contacted with the pad ring, one hand holds the handle 1 and stabilizes the tool downward to ensure that the lower surface of the protection seat 5 is tightly attached to the sealing surface, and the other hand uses a rubber hammer to strike the execution knife 6, so that the execution knife 6 generates an impact force on the pad ring to shake the pad ring loose.

[0044] The metal seal ring extraction tool in the application has high working efficiency, and it only takes 5 minutes to extract each seal ring, the average working efficiency is improved by 2 to 6 times, and the key path time of overhaul is shortened by at least 20 minutes; the working time in a high-dose place can be effectively shortened, and the collective dose of the workers is reduced by at least 1 mSv.

[0045] The application has been described in detail above in combination with the drawings and examples, but the application is not limited to the above examples, and various changes can be made within the knowledge possessed by those skilled in the art without departing from the purpose of the application. The contents not described in detail in the application can adopt the prior art.

Claims

1. A metal sealing ring removal tool, characterized by: The tool comprises a handle (1), a handle support (2), a base (3), a protective seat (5) and an execution knife (6); The handle (1) is connected to the upper ends of the two handle supports (2), the lower ends of the two handle supports (2) are connected to the base (3), a groove is provided on the left side of the base (3), the upper part of the execution knife (6) is connected to the top of the base (3), the side of the execution knife (6) passes through the groove on the left side of the base (3), the lower part of the base (3) is connected and fixed to the protective seat (5), and the blade of the side of the execution knife (6) passes through the opening on the left side of the protective seat (5); The handle (1) is a round tube and is welded to the two handle supports (2); The two handle supports (2) are sheet metal parts, and the lower ends of the handle supports (2) are connected to the base (3) via support fastening bolts (4); The protection seat (5) is a semi-shell structure, and the bottom surface of the protection seat (5) contacts the sealing surface of the sealing ring; The front end of the protection seat (5) is an L-shaped opening, which is the outlet of the blade of the execution knife (6); The base (3) and the execution knife (6) are connected via positioning and fastening bolts (8); The upper portion of the execution knife (6) is connected to a front adjusting bolt (7) and a rear adjusting bolt (9), which are respectively located on both sides of the positioning fastening bolt (8). The upper and lower heights and the front and rear pitch of the execution knife (6) can be adjusted by adjusting the front adjusting bolt (7) and the rear adjusting bolt (9); The base (3) and the protective seat (5) are connected by protective seat fastening bolts (10) supplemented with sealant; The protection seat fastening bolt (10) is a countersunk bolt.

2. The method for removing a metal sealing ring according to claim 1, wherein: The method comprises the following steps: Step 1: Loosen the front adjusting bolt (7), the positioning fastening bolt (8) and the rear adjusting bolt (9) so that the lower end plane of the execution knife (6) is higher than the lower plane of the protection seat (5); Step 2: Take out the tool by holding the metal sealing ring and place it on a flat surface or sealing surface. Adjust the front adjusting bolt (7), the positioning fastening bolt (8) and the rear adjusting bolt (9) so that the lower end plane of the execution knife (6) is higher than the lower plane of the protective seat at a suitable height. Step 3: Take the metal sealing ring removal tool to the outer edge of the gasket to be removed, so that the blade of the execution knife contacts the gasket, hold the handle (1) with one hand, and use a rubber hammer with the other hand to hit the execution knife (6), so that the execution knife (6) generates impact force on the gasket and shakes the gasket loose.

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