Sealing gasket taking-out device for liquid rocket engine valve test

Abstract

The invention discloses a sealing gasket taking-out device for a liquid rocket engine valve test. The sealing gasket taking-out device comprises a replaceable head, an extension rod, a limiting piece and a riveting pin. One end of the replaceable head is a duckbilled tip, and the other end is screwed with the extension rod; a radial through groove is formed in the position, close to the duckbilled tip, of the replaceable head, and the limiting piece is installed in the radial through groove and fixed through the riveting pin. By means of the sealing gasket taking-out device for the liquid rocket engine valve test, the problem that a soft metal sealing gasket cannot be taken out of a flange groove after a valve low-temperature and high-pressure test is conducted is solved.

Description

Technical Field

[0001] The invention belongs to the field of cryogenic technology, and in particular relates to a sealing gasket removal device for liquid rocket engine valve testing. Background Art

[0002] With the rapid development of aerospace, petrochemical and other fields, the application of cryogenic and high-pressure valves is becoming more and more widespread, requiring cryogenic valve tests to fully cover the actual working conditions of the products. Therefore, there are more and more demands for cryogenic and high-pressure valve tests. The tongue and groove flange structure is widely used in the connection between liquid rocket engine valves and pipelines. During the cryogenic test stage, the tested valve and the test system use soft metal as sealing gaskets, which need to be removed after the test.

[0003] In order to ensure that the system does not leak during the low-temperature and high-pressure test, a large tightening torque needs to be applied to the bolts when the product flange is connected to the system flange, so that the soft metal sealing gasket is deformed under pressure and embedded in the flange groove and cannot be removed. Especially after the low-temperature test, the soft metal sealing gasket and the flange groove surface are frosted and frozen, and cannot be removed, becoming redundant. The soft metal sealing gasket embedded in the flange groove can only be removed by mechanical processing such as valve integral turning, resulting in problems such as too long production test cycle, increased risk of redundant materials, and increased labor intensity. The use of tools such as manual hooks will cause risks such as scratches on the flange groove sealing surface, resulting in product scrapping. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and to provide a sealing gasket removal device for liquid rocket engine valve testing, aiming to solve the problem that the soft metal sealing gasket cannot be removed from the flange groove after the valve low temperature and high pressure test.

[0005] In order to solve the above technical problems, the present invention discloses a sealing gasket removal device for liquid rocket engine valve testing, comprising: a replaceable head, an extension rod, a limit plate and a riveting pin;

[0006] One end of the replaceable head is a duckbill tip, and the other end is screwed to the extension rod;

[0007] The replaceable head is provided with a radial through groove near the duckbill tip, and the limiting piece is installed in the radial through groove and fixed by a riveting pin.

[0008] In the above-mentioned sealing gasket removal device for liquid rocket engine valve testing, the replaceable head is made of stainless steel material with a hardness greater than HRC38.

[0009] In the above-mentioned sealing gasket removal device for liquid rocket engine valve testing, the head width of the duckbill tip is smaller than the width of the flange groove, and the duckbill tip gradually becomes thicker and thicker from the head to the back.

[0010] In the above-mentioned sealing gasket removal device for liquid rocket engine valve testing, the length of the replaceable head is greater than the outer diameter of the soft metal sealing gasket, and is used to withstand the fulcrum force during the lifting operation.

[0011] In the above-mentioned sealing gasket removal device for liquid rocket engine valve testing, the extension rod is a solid metal rod, and the end connected to the replaceable head is a threaded structure; the surface of the extension rod is processed with a flat surface to prevent the device from rotating when placed.

[0012] In the above-mentioned sealing gasket removal device for liquid rocket engine valve testing, the limit plate is made of a non-metallic material that will not scratch the flange groove sealing surface.

[0013] In the above-mentioned sealing gasket removal device for liquid rocket engine valve testing, the distance from the edge of the limit plate to the edge of the duckbill tip is less than 0.5 mm of the flange groove depth, so as to control the depth of the duckbill tip penetrating into the soft metal sealing gasket and prevent the flange groove sealing surface from being pierced by the duckbill tip.

[0014] In the above-mentioned sealing gasket removal device for liquid rocket engine valve testing, a fixing hole A is provided on the replaceable head, and a fixing hole B is provided on the limiting plate; the rivet pin passes through the fixing hole A and the fixing hole B to fix the limiting plate in the radial through groove of the replaceable head.

[0015] The present invention has the following advantages:

[0016] (1) The present invention discloses a sealing gasket removal device for testing a liquid rocket engine valve, which can remove a soft metal sealing gasket from a flange groove after a low-temperature and high-pressure test of the valve without scratching the flange groove sealing surface.

[0017] (2) The present invention discloses a sealing gasket removal device for liquid rocket engine valve testing, which can be customized to produce a series of detachable heads of different sizes according to the size of the flange groove to adapt to flange grooves of different sizes.

[0018] (3) The present invention discloses a sealing gasket removal device for testing a liquid rocket engine valve. The duckbill-shaped pointed head adopts a combination of a flat surface and a rounded surface design, which improves the strength of the replaceable head while ensuring the cutting of the soft metal sealing gasket.

[0019] (4) The present invention discloses a sealing gasket removal device for liquid rocket engine valve testing. The duckbill-shaped pointed head is thickened in the direction of lifting the soft metal sealing gasket, further improving the strength of the replaceable head.

[0020] (5) The present invention discloses a sealing gasket removal device for liquid rocket engine valve testing. Through the design of a limit plate, the duckbill tip can be visualized when piercing the soft metal sealing gasket, thereby controlling the penetration depth and preventing damage to the flange groove sealing surface.

[0021] (6) The present invention discloses a sealing gasket removal device for testing a liquid rocket engine valve. The limit plate is made of a non-metallic material that will not scratch the flange groove sealing surface. During the lifting operation, the limit plate can be deformed according to the tilt angle to prevent the flange groove sealing surface from being scratched.

[0022] (7) The present invention discloses a sealing gasket removal device for testing a liquid rocket engine valve. The distance from the edge of the limit plate to the edge of the duckbill tip is less than the depth of the flange groove. The depth of the duckbill tip penetrating into the soft metal sealing gasket can be controlled to prevent the flange groove sealing surface from being pierced by the duckbill tip.

[0023] (8) The present invention discloses a sealing gasket removal device for testing a liquid rocket engine valve. The extension rod adopts an oblate design, that is, the surface of the extension rod is processed with a flat surface to prevent the device from rotating when placed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a sealing gasket removal device for liquid rocket engine valve testing according to an embodiment of the present invention;

[0025] Figure 2 It is a schematic diagram of the structure of a replaceable head in an embodiment of the present invention;

[0026] Figure 3 is a schematic structural diagram of a limiting piece in an embodiment of the present invention;

[0027] Figure 4 It is a schematic diagram of a method for removing a soft metal sealing gasket in an embodiment of the present invention;

[0028] Figure 5 It is a schematic diagram of another method of removing the soft metal sealing gasket in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] Reference Figures 1 to 3In this embodiment, the sealing gasket removal device for liquid rocket engine valve test includes: a replaceable head 1, an extension rod 2, a stopper 3 and a rivet pin 4. Among them, one end of the replaceable head 1 is a duckbill tip 11, and the other end is screwed to the extension rod 2; the replaceable head 1 is provided with a radial through groove 12 near the duckbill tip 11, and the stopper 3 is installed in the radial through groove 12 and fixed by the rivet pin 4.

[0031] In this embodiment, a fixing hole A13 is provided on the replaceable head 1, and a fixing hole B31 is provided on the limiting plate 3; the rivet pin 4 passes through the fixing hole A13 and the fixing hole B31 to fix the limiting plate 3 in the radial through groove 12 of the replaceable head 1.

[0032] In this embodiment, the length of the replaceable head 1 is greater than the outer diameter of the soft metal sealing gasket, and is used to withstand the fulcrum force during the lifting operation. The replaceable head 1 is made of stainless steel with a hardness greater than HRC38. Furthermore, the head width of the duckbill tip 11 is less than the width of the flange groove, and the duckbill tip 11 gradually thickens and thickens from the head to the back. Furthermore, the duckbill tip 11 adopts a combination of a plane and a chamfered design, which improves the head strength while ensuring the cutting of the soft metal sealing gasket.

[0033] In this embodiment, the extension rod 2 is a solid metal rod, and one end connected to the replaceable head 1 is a threaded structure; a flat surface 21 is processed on the surface of the extension rod 2 to prevent the device from rotating when placed.

[0034] In this embodiment, the stopper 3 is made of a non-metallic material that will not scratch the flange groove sealing surface. The distance from the edge of the stopper 3 to the edge of the duckbill tip 11 is less than 0.5 mm of the flange groove depth, so as to control the depth of the duckbill tip 11 penetrating into the soft metal sealing gasket and prevent the flange groove sealing surface from being pierced by the duckbill tip 11. Furthermore, the thickness of the stopper 3 is not more than 2 mm, and it can be deformed during the lifting operation, thereby eliminating the interference between the stopper and the flange end face.

[0035] In this embodiment, the replaceable head 1 is a series part, and the replaceable head 1 of different specifications and sizes (mainly referring to the head width of the duckbill tip) can be processed and customized according to the size of the flange groove. The limit plate 3 is also a series part, which can be replaced after being disassembled by riveting pins and can be customized according to the width of the flange groove.

[0036] In this embodiment, based on the above-mentioned liquid rocket engine valve test sealing gasket removal device, a liquid rocket engine valve test sealing gasket removal method is also disclosed, which has successfully removed soft metal sealing gaskets that have swollen and frozen in the flange groove without damaging the sealing surface of the low-temperature valve flange groove. The removal method includes:

[0037] S1, based on the flange groove width, select a replaceable head that is smaller than but closest to the flange groove width.

[0038] S2, according to the flange groove depth, select a limit plate of corresponding length, and install the selected limit plate in the radial groove of the replaceable head selected in S1 through a riveting pin to control the depth of the duckbill tip of the replaceable head penetrating into the soft metal sealing gasket.

[0039] S3, screwing the replaceable head after the limit plate is installed to the extension rod to obtain a complete removal device.

[0040] S4, when removing the gasket, first vertically insert the removal device into the soft metal sealing gasket until the edge of the limit plate contacts the flange end face, control the insertion depth to prevent the removal device from damaging the flange groove, and then use a cylindrical structure of non-metallic material as a fulcrum to lift the soft metal sealing gasket off by lifting, and use this method to lift out the soft metal sealing gasket.

[0041] Based on the above embodiments, two specific examples are given below for illustration.

[0042] Example 1

[0043] In this example, a removal device suitable for flange grooves with a width of 3.0 to 5.0 mm and a depth of 3.7 mm is provided. The width of the duckbill tip of the replaceable head of the removal device is about 0.3 mm less than the width of the flange groove, and the thickness of the duckbill tip is about 1 mm; the duckbill tip is narrowed at two places and the intersection edges are processed with a 1 mm radius arc chamfer. The two narrowing and chamfering together constitute a plane and chamfering combination design, which ensures strength while facilitating the duckbill tip to penetrate the soft metal sealing gasket. Further, the limit plate is an isosceles trapezoid as a whole, and a rectangle is removed from the bottom edge along the height direction, and the length of the short side of the rectangle is slightly greater than the width of the duckbill tip; a small hole is opened above the trapezoid for connection with the rivet pin; the distance between the bottom edge of the limit plate and the duckbill tip is the maximum depth of penetration into the soft metal sealing gasket. By replacing limit plates of different specifications, the depth of the duckbill tip penetrating the soft metal sealing gasket in the flange groove can be controlled.

[0044] like Figure 4As shown, for the soft metal sealing gasket that has swollen to death in the flange groove, when removing the gasket, first place the long side of the duckbill tip of the replaceable head along the radial direction of the soft metal sealing gasket, then place the duckbill tip on the soft metal sealing gasket to be removed, and make the removal device as a whole perpendicular to the end face of the soft metal sealing gasket; use a hammer or other tool to lightly hammer the tail of the extension rod to slowly penetrate the soft metal sealing gasket with the duckbill tip of the replaceable head, and observe the distance between the lower edge of the limit plate and the end face of the flange groove at any time during the penetration process. When the lower edge of the limit plate contacts the end face of the flange groove, stop knocking immediately. Keep the duckbill tip of the replaceable head penetrated into the soft metal sealing gasket, and slowly tilt the removal device, with the tilting direction tangent to the circumference of the soft metal sealing gasket. When the angle between the removal device and the end face of the flange groove is less than about 45°, place a hard non-metallic round rod with the same diameter as the removal device at the angle, and make contact with the replaceable head and the end face of the flange groove as a fulcrum. While pushing the removal device in along the axial direction, use the hard non-metallic round rod as a fulcrum to slowly pry the soft metal sealing gasket until the soft metal sealing gasket breaks and is pried out of the flange groove. Use the above method to pry the soft metal sealing gasket multiple times along the tangent direction of the soft metal sealing gasket, each time making the duckbill tip of the replaceable head contact the bottom of the soft metal sealing gasket, but not contact the end face of the flange groove, until the soft metal sealing gasket is completely removed from the flange groove.

[0045] Example 2

[0046] In this example, when the width of the soft metal gasket is greater than the head width of the duckbill tip, Figure 5As shown, when removing the gasket, first place the long side of the duckbill tip of the replaceable head along the radial direction of the soft metal sealing gasket, and then place the duckbill tip on the soft metal sealing gasket to be removed. At this time, tilt the removal device so that the angle formed by the axis of the removal device and the end face of the flange groove is about 30°. Use a hammer or other tool to lightly hammer the tail of the extension rod so that the duckbill tip is tilted and slowly penetrates the soft metal sealing gasket. Observe the penetration distance at any time during the knocking process. Stop knocking when the duckbill tip penetrates the soft metal sealing gasket by about 1.5 times the thickness of the soft metal sealing gasket. Place a hard non-metallic round rod with the same diameter as the removal device at the angle, and contact it with the replaceable head and the end face of the flange groove as a fulcrum. While pushing the removal device in along the axis direction, use the hard non-metallic round rod as a fulcrum to slowly pry the soft metal sealing gasket until the soft metal sealing gasket is deformed and pried out of the flange groove. Then, from the prying position, along the radial direction of the soft metal sealing gasket, use the hard non-metallic round rod as a fulcrum, and pry it multiple times using the above method, each time making the duckbill tip contact the radial position of the soft metal sealing gasket pried out, but not touching the flange groove end face, until the soft metal sealing gasket is completely removed from the flange groove. This method is only suitable for emergency situations. There is no removal device that matches the size of the soft metal sealing gasket. It must be removed by experienced and skilled personnel.

[0047] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0048] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A sealing gasket removal device for liquid rocket engine valve testing, characterized in that: include: A replaceable head (1), an extension rod (2), a stopper (3) and a riveting pin (4); One end of the replaceable head (1) is a duckbill-shaped pointed head (11), and the other end is screwed to the extension rod (2); The replaceable head (1) is provided with a radial through groove (12) near the duckbill tip (11), and the limiting piece (3) is installed in the radial through groove (12) and fixed by a riveting pin (4).

2. The sealing gasket removal device for liquid rocket engine valve testing according to claim 1, characterized in that: The replaceable head (1) is made of stainless steel material with a hardness greater than HRC38.

3. The sealing gasket removal device for liquid rocket engine valve testing according to claim 1, characterized in that: The width of the head of the duckbill tip (11) is smaller than the width of the flange groove, and the duckbill tip (11) gradually becomes thicker and thicker from the head to the back.

4. The sealing gasket removal device for liquid rocket engine valve testing according to claim 1, characterized in that: The length of the replaceable head (1) is greater than the outer diameter of the soft metal sealing gasket and is used to bear the fulcrum force during the lifting operation.

5. The sealing gasket removal device for liquid rocket engine valve testing according to claim 1, characterized in that: The extension rod (2) is a solid metal rod, and one end connected to the replaceable head (1) is a threaded structure; the surface of the extension rod (2) is processed with a plane (21) to prevent the device from rotating when placed.

6. The sealing gasket removal device for liquid rocket engine valve testing according to claim 1, characterized in that: The limiting piece (3) is made of a non-metal material that will not scratch the flange groove sealing surface.

7. The sealing gasket removal device for liquid rocket engine valve testing according to claim 1, characterized in that: The distance from the edge of the limiting piece (3) to the edge of the duckbill tip (11) is less than 0.5 mm of the flange groove depth, so as to control the depth of the duckbill tip (11) piercing into the soft metal sealing gasket and prevent the flange groove sealing surface from being pierced by the duckbill tip (11).

8. The sealing gasket removal device for liquid rocket engine valve testing according to claim 1, characterized in that: The replaceable head (1) is provided with a fixing hole A (13), and the limiting plate (3) is provided with a fixing hole B (31); the rivet pin (4) passes through the fixing hole A (13) and the fixing hole B (31) to fix the limiting plate (3) in the radial through groove (12) of the replaceable head (1).

Images