CN112145859A - pressure test plug - Google Patents

Abstract

The invention provides a pressure test plug, which includes a plug main body and a first sealing ring; the outer periphery of the front end of the plug main body is provided with an external thread to form a connection section for screw connection with an external interface; the plug main body is provided with an external thread. The first air chamber and the second air chamber; the first sealing ring is sleeved on the outer periphery of the connecting section and seals the opening of the second air chamber. When the pressure of the gas supply system is detected, the gas in the external interface pushes the first sealing ring to deform, so as to seal the external interface. After the pressure detection is completed, the gas pressure in the external interface is released, so that the gas pressure on the first sealing ring is removed, and the pressure of the first sealing ring on the external interface is reduced, so as to facilitate the removal of the pressure test plug. The pressure of the external interface itself is used to deform the first sealing ring under the action of the gas pressure inside the external interface to seal the external interface. The first sealing ring will not generate impurities to block the external interface, which can effectively avoid the impact on the external interface.

Description

pressure test plug

technical field

The invention relates to the technical field of sealing tooling, in particular to a pressure test plug.

Background technique

In the field of liquefied natural gas supply, during the production process of the gas supply system, it is necessary to carry out the sealing and pressure testing of the tank and the corresponding pipeline to ensure the airtightness of the gas supply system and enable it to be used normally. Therefore, in the production process of the air supply system, it is necessary to use the corresponding plug tooling to block each interface, and then pressurize the air supply system to supply air to test the airtightness of the air supply system.

In the prior art, the plug tooling is generally connected in the interface through a threaded connection. In order to block and seal the interface, a sealing material such as raw material tape or sealant is wrapped around the thread of the plug tooling to ensure sealing, but or Sealants and other sealing materials are prone to produce impurities during use, which can block valves and other components and affect the quality of the interface.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a pressure test plug, which can effectively avoid affecting the interface.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

According to one aspect of the present invention, the present invention provides a pressure test plug, which is characterized in that it includes a plug main body and a first sealing ring; the outer periphery of the front end of the plug main body is provided with an external thread to form a connection section, which is used for The plug body is provided with a first air chamber and a second air chamber; the first air chamber is open at the front end of the connecting section and can communicate with the internal space of the external interface The front end of the second air chamber is open, and the second air chamber is communicated with the first air chamber; the first sealing ring has elasticity; the first sealing ring is sleeved on the outer circumference of the connecting section, and is sealed The opening of the second air chamber; the gas in the external interface can pass through the first air chamber and the second air chamber to squeeze the first sealing ring at the opening of the second air chamber, so that the first sealing ring is A sealing ring is elastically deformed to seal the external interface.

In some embodiments, the plug main body further includes a limiting segment connected to the rear end of the connecting segment and an annular housing sleeved on the outer periphery of the limiting segment, the annular housing and the limiting segment The second air chamber is formed by enclosing between them.

In some embodiments, the limiting section extends radially outward from the connecting section at the connection with the connecting section, and forms a first step; the first step is radially connected to the annular The casing has an opening spaced to form the second air chamber; the first sealing ring abuts against the first step and the annular casing in the axial direction.

In some embodiments, the annular housing is sleeved on the outer circumference of the limiting segment, so that the limiting segment can rotate relative to the annular housing; the annular housing faces away from the first seal One end of the ring is sealed with the limiting section.

In some embodiments, a second sealing ring is disposed between the limiting section and the annular casing, the second sealing ring has elasticity; the second sealing ring is sleeved in the second air chamber on the outer circumference of the limiting section and abutting against the annular casing, the second sealing ring is in interference fit with the limiting section and the annular casing.

In some embodiments, an annular groove that opens radially outward is defined on the limiting segment, and the second sealing ring is clamped and limited in the annular groove.

In some embodiments, the pressure test plug further includes a sealing gasket, and the sealing gasket is elastic; the sealing gasket is clamped and sleeved in the annular groove; the sealing gasket abuts against the annular shell The inner wall of the body and an interference fit with the annular housing.

In some embodiments, one side of the sealing gasket is abutted against one axial side of the second sealing ring, and the other side is abutted against the side wall of the annular groove.

In some embodiments, the outer peripheral wall of the end of the limiting segment facing away from the connecting segment is provided with anti-slip tooth patterns.

In some embodiments, the limiting section is provided with an air hole that communicates with the first air chamber and the second air chamber.

As can be seen from the above technical solutions, the present invention at least has the following advantages and positive effects:

In the present invention, the outer periphery of the front end of the main body of the plug is provided with an external thread to form a connection section, which is used for screw connection with the external interface; the main body of the plug is provided with a first air chamber and a second air chamber; the first sealing ring is sleeved on the connection the outer circumference of the segment, and seal the opening of the second air chamber; the gas in the external interface can pass through the first air chamber and the second air chamber and squeeze the first sealing ring at the opening of the second air chamber, so that the first seal The ring deforms elastically to seal the external interface. When the pressure of the air supply system is detected, the gas in the external interface is transported to the second air chamber through the first air chamber, thereby pushing the first sealing ring to deform, so that the first sealing ring is tightly pressed against the port of the external interface to ensure Sealing of external interfaces. After the pressure detection of the gas supply system is completed, the gas pressure in the external interface is released, so that the gas pressure on the first sealing ring is removed, and the pressure of the first sealing ring on the external interface is reduced, so as to facilitate the removal of the pressure test plug . Using the pressure of the external interface itself, the first sealing ring is deformed under the action of the gas pressure inside the external interface to seal the external interface. The first sealing ring will not generate impurities to block the external interface, and will not affect the external interface. It can effectively to avoid affecting the external interface.

Description of drawings

FIG. 1 is a schematic structural diagram of an embodiment of a pressure test plug of the present invention.

FIG. 2 is a schematic cross-sectional structure diagram of an embodiment of the pressure test plug of the present invention.

3 is a schematic structural diagram of a plug main body of an embodiment of the pressure test plug of the present invention, wherein the annular housing is not shown.

FIG. 4 is a schematic structural diagram of the annular housing of the embodiment of the pressure test plug of the present invention.

The reference numerals are explained as follows:

100, plug main body; 110, connecting section; 120, limit section; 121, first step; 122, second step; 130, annular housing; 140, first air chamber; 150, second air chamber; 160 , air hole; 170, ring groove; 200, first sealing ring; 300, second sealing ring; 400, gasket.

Detailed ways

Exemplary embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and drawings therein are essentially used for illustration rather than limitation this invention.

In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " rear, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc., or The positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation on this application. In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined as "first", "second" may expressly or implicitly include one or more of said features. In the description of the present application, "plurality" means two or more, unless otherwise expressly and specifically defined.

FIG. 1 is a schematic structural diagram of an embodiment of a pressure test plug of the present invention. FIG. 2 is a schematic cross-sectional structure diagram of an embodiment of the pressure test plug of the present invention.

Referring to FIG. 1 and FIG. 2, this embodiment provides a pressure test plug, which is used to seal the interface of the pressure equipment or the gas supply system, so that the pressure equipment or the gas supply system can be filled with gas to test the pressure equipment or the gas supply system. The tightness of the air supply system.

The pressure test plug includes a plug body 100 , a first sealing ring 200 and a second sealing ring 300 . The front end of the plug main body 100 is provided with an external thread, which can be threadedly connected to the external interface. After the plug main body 100 is threadedly connected to the external interface, the first sealing ring 200 can be elastically deformed under the action of the pneumatic pressure of the external interface, and Seal the external interface.

3 is a schematic structural diagram of a plug main body of an embodiment of the pressure test plug of the present invention, wherein the annular housing is not shown.

Referring to FIGS. 2 and 3 , in this embodiment, the plug main body 100 includes a connecting section 110 located at the front end of the plug main body 100 and provided with external threads on the outer periphery, a limiting section 120 connected to the rear end of the connecting section 110 , and a limiting section 120 sleeved on the limiting section 110 . The annular housing 130 on the outer periphery of the bit segment 120 .

The plug main body 100 is provided with a first air chamber 140 and a second air chamber 150 that communicate with each other. In this embodiment, the connecting section 110 and the limiting section 120 are hollow inside to form the first air chamber 140 . The first air chamber 140 is opened at the front end of the connecting section 110 and can be communicated with the internal space of the external interface, so as to be used in the pressure equipment. Or when the air supply system is inflated and pressurized, the gas can enter the second air chamber 150 through the first air chamber 140 .

In this embodiment, the peripheral wall of the first air chamber 140 is cylindrical, and its axis coincides with the axis of the connecting section 110 , so as to facilitate processing and at the same time ensure the stress balance in the circumferential direction of the connecting section 110 .

A second air chamber 150 with an open front end is enclosed between the limiting section 120 of the plug main body 100 and the annular housing 130 .

An air hole 160 is formed on the limiting section 120 of the plug main body 100 to communicate with the first air chamber 140 and the second air chamber 150 . In the actual design process, the size of the air hole 160 is adjustable, so that the gas pressure in the second air chamber 150 can be controlled.

Referring to FIG. 3 again, in this embodiment, the outer circumference of the connecting segment 110 is a tapered thread, and the inner circumference of the corresponding external interface is provided with a corresponding tapered thread, so as to facilitate the alignment connection between the connecting segment 110 and the external interface, and to preliminarily seal the outside interface.

In some embodiments, the outer perimeter of the connecting segment 110 does not have a taper. The threads on the outer circumference of the connecting section 110 are straight threads.

The limiting section 120 extends radially outward from the connecting section 110 at the connection with the connecting section 110 to form a first step 121 , and the first sealing ring 200 is sleeved on the outer circumference of the connecting section 110 and abuts in the axial direction on the first step 121, so that the axial backward movement of the first sealing ring 200 is restricted.

In this embodiment, the limiting section 120 is provided with an annular groove 170 that opens radially outward, for limiting the second sealing ring 300 .

In this embodiment, the outer circumference of the limiting section 120 is still provided with a second step 122 . After the annular casing 130 is sleeved on the limiting section 120 , the side wall of the second step 122 can limit the axial backward movement of the annular casing 130 .

The second step 122 extends radially outward beyond the annular groove 170 . The bottom surface of the second step 122 is a conical surface or a cylindrical surface, so that the annular housing 130 can move from the connecting section 110 toward the limiting section 120 in the axial direction, and is sleeved on the outer periphery of the limiting section 120 .

The outer peripheral wall of the end of the limiting segment 120 facing away from the connecting segment 110 is provided with anti-skid tooth patterns (not shown in the figure). The design of the anti-slip tooth pattern enables the plug body 100 to be directly rotated by hand, so as to realize the quick connection and disassembly of the pressure test plug and the external interface. No tools are required to turn by hand, the connection and disassembly are convenient, and the operation is simple.

FIG. 4 is a schematic structural diagram of the annular housing of the embodiment of the pressure test plug of the present invention.

Referring to FIG. 2 and FIG. 4 , in this embodiment, the annular casing 130 is a structure with open ends at both ends and a hollow inside, so as to be sleeved on the outer circumference of the limiting section 120 . The annular housing 130 includes a first segment and a second segment connected to the front end of the first segment in the axial direction.

The inner peripheral wall of the first section of the annular housing 130 is a cylindrical structure to be adapted to the second step 122 of the limiting section 120 . Peripheral limit.

The inner peripheral wall of the second segment of the annular housing 130 extends radially inwardly beyond the inner peripheral wall of the first segment. There is an interval between the inner peripheral wall of the second segment of the annular housing 130 and the corresponding position of the limiting segment 120 , so that the second air chamber 150 is formed between the end of the second segment of the annular housing 130 and the limiting segment 120 . Open your mouth.

The annular casing 130 protrudes forward to the connecting section 110 in the axial direction, and a gap is formed in the inner side of the front end of the annular casing 130 .

One end of the annular housing 130 facing away from the first sealing ring 200 is in sealing connection with the limiting section 120 . The annular housing 130 is sleeved on the outer circumference of the limiting segment 120 , so that the limiting segment 120 can rotate relative to the annular housing 130 .

The inner peripheral wall of the end of the annular housing 130 facing away from the first sealing ring 200 is sleeved and overlapped on the bottom wall of the second step 122 . There is a certain gap between the side walls of the step 122, so that the rearward movement of the annular housing 130 in the axial direction can be restricted by the side walls of the second step 122, and due to the existence of the gap, the annular housing 130 and the limiting section When the 120 moves relatively, the frictional force between the annular housing 130 and the limiting segment 120 is reduced, so as to facilitate the rotation of the limiting segment.

In some embodiments, an axial thrust bearing is provided between the end of the annular housing 130 at the end facing away from the first sealing ring 200 and the side wall of the second step 122 .

The shape of the inner peripheral wall of the annular housing and the shape between the limiting section 120 and the connecting section 110 facilitate the rapid assembly of the pressure test plug, and the assembly is simple.

Referring to FIG. 2 again, the first sealing ring 200 is sleeved on the outer periphery of the connecting section 110 of the plug main body 100 and seals the opening of the second air chamber 150 . The first sealing ring 200 has elasticity so as to be able to elastically deform under the action of pressure.

In this embodiment, the first sealing ring 200 blocks the opening of the second air chamber 150 and at least partially extends forward of the annular housing 130 , so that after the connecting section 110 is connected to the external interface, the first sealing ring 200 can communicate with the outside The end of the interface is connected to seal the end of the external interface.

After the plug body 100 is connected to the external port, after the gas supply system is inflated and pressurized, the gas in the external port can pass through the first air chamber 140 and the second air chamber 150 and squeeze at the opening of the second air chamber 150 . The first sealing ring 200 is pressed, and the obtained first sealing ring 200 is elastically deformed to seal the external interface.

The first sealing ring 200 is located at one end of the connecting section 110 facing the limiting section 120 and abuts against the first step 121 and the annular housing 130 in the axial direction to seal the opening of the second air chamber 150 .

The first sealing ring 200 abuts against the first step 121 , so that the axial backward movement of the first sealing ring 200 is restricted, so as to ensure that the first sealing ring 200 is not thick when the connecting section 110 is connected and fixed to the external interface A rearward movement in the axial direction occurs, ensuring that the first sealing ring is blocked at the end of the external interface.

In this embodiment, a portion of the first sealing ring 200 is located in a gap in the inner circumference of the front end of the annular housing 130 . The first sealing ring 200 is clamped between the annular casing 130 and the connecting section 110 in the radial direction, so that both the axial side and the radial outer side of the first sealing ring 200 are fitted to the annular casing 130 , so as to It has a better sealing effect on the second air chamber 150 , and can effectively prevent the gas in the second air chamber 150 from rushing out between the first sealing ring 200 and the annular housing 130 .

In this embodiment, the notch of the annular casing 130 is rectangular, and in some embodiments, the peripheral wall of the notch of the annular casing 130 is arc-shaped.

In this embodiment, the cross section of the first sealing ring 200 is circular, partially blocked in the opening of the second air chamber 150 , and partially extending out of the opening of the second air chamber 150 to seal the external interface.

In some embodiments, the cross-section of the first sealing ring 200 can be of other structures, for example, the cross-section of the second sealing ring is rectangular, or the cross-section of the second sealing ring can be divided into two parts, the two parts are of different structures, and one part is made of In order to block the opening of the second air chamber 150 , the other part extends out of the second air chamber 150 for sealing the external interface.

In some embodiments, a corresponding step or gap is provided on the inner side of the end of the external interface, so that the first sealing ring 200 fits with the corresponding step or gap, so that the first sealing ring 200 can seal the external interface.

At the same time, during the process of connecting the plug body 100 to the external interface, the first step 123 and the external interface can also be squeezed to some extent elastically deform the first sealing ring 200 to seal the external interface.

Referring to FIG. 2 again, the second sealing ring 300 is disposed between the limiting section 120 and the annular housing 130 , and is located at the end of the annular housing 130 away from the first sealing ring 200 , and seals the annular housing 130 and the limiting section 120 .

The second sealing ring 300 has elasticity. The second sealing ring 300 is sleeved on the outer circumference of the limiting section 120 in the second air chamber 150 and abuts against the annular housing 130 . The second sealing ring 300 and the limiting section 120 and The annular housing 130 is an interference fit, thereby sealing one end of the annular housing 130 .

Through the sealing of the second sealing ring 300, when the limiting segment 120 rotates relative to the annular housing 130, the sealing is always maintained.

In this embodiment, the sealing ring 300 is clamped and limited in the annular groove 170 to prevent the sealing ring 300 from moving under the gas pressure of the second air chamber 150 or the force of the annular housing 130 .

Referring to FIG. 2 again, in this embodiment, the pressure test plug further includes a sealing gasket 400, and the sealing gasket 400 is an annular structure. The sealing gasket 400 is clamped and sleeved in the annular groove 170 ; the sealing gasket 400 abuts against the inner wall of the annular casing 130 and has an interference fit with the annular casing 130 . The cooperation of the sealing gasket 400 and the second sealing ring 300 forms two seals on the end of the annular housing 130 that is away from the first sealing ring 200 , thereby increasing the sealing effect.

In this embodiment, one sealing gasket 400 and one second sealing ring 300 are provided. In some embodiments, the sealing gasket 400 and the second sealing ring 300 may be provided in multiples, or may be individually provided in multiples to increase the sealing effect.

In this embodiment, one side of the sealing gasket 400 is attached to one axial side of the second sealing ring 300 , and the other side is contacted to the side wall of the annular groove 170 . The second sealing ring 300 and the sealing gasket 400 are fixed and positioned by the ring groove 170, so as to avoid the movement of the second sealing ring 300 and the sealing gasket 400, and the sealing is more effective, and at the same time, the sliding blockage of the second sealing ring 300 and the sealing gasket 400 can be avoided. Air holes 160 .

The sealing gasket 400 abuts on the side wall of the annular groove 170 , which can effectively prevent the sealing gasket 400 from tipping in the axial direction, so that the deformation direction of the sealing gasket 400 is in the radial direction, so as to ensure the connection between the sealing gasket 400 and the annular housing 130 tightness to ensure the sealing effect.

The second sealing ring 300 and the sealing gasket 400 are placed in the same annular groove 170 , so that the second sealing ring 300 and the sealing gasket 400 can be pressed against each other and elastically deformed, so that the inner wall of the annular housing 130 can be more tightly fitted , to enhance the sealing effect.

In this embodiment, the outer periphery of the front end of the plug main body 100 is provided with external threads to form a connection section 110 for screw connection with the external interface; the plug main body 100 is provided with a first air chamber 140 and a second air chamber 150; A sealing ring 200 is sleeved on the outer periphery of the connecting section 110 and seals the opening of the second air chamber 150; The first sealing ring 200 is squeezed at the opening, so that the first sealing ring 200 is elastically deformed, so as to seal the external interface. When the pressure of the air supply system is detected, the gas in the external interface is transported to the second air chamber 150 through the first air chamber 140, thereby pushing the first sealing ring 200 to deform, so that the first sealing ring 200 is tightly pressed against the outer interface. port to ensure a seal against the external interface.

After the pressure detection of the gas supply system is completed, the gas pressure in the external interface is released, so that the gas pressure on the first sealing ring 200 is removed, and the pressure of the first sealing ring 200 on the external interface is reduced, so as to facilitate the pressure test plug move out. Using the pressure of the external interface itself, the first sealing ring 200 is deformed under the action of the gas pressure inside the external interface to seal the external interface. The first sealing ring 200 will not generate impurities to block the external interface and will not affect the external interface. It can effectively avoid the impact on the external interface.

The annular housing 130 is sleeved on the outer circumference of the limiting segment 120 , so that the limiting segment 120 can rotate relative to the annular housing 130 , thereby driving the connecting segment 110 to rotate relative to the annular housing 130 . After the airtightness detection of the air supply system is completed, when the limiting segment 120 is twisted to drive the connecting segment 110 to rotate, since the front end of the annular housing 130 may contact the end of the external interface, the limiting segment 120 can rotate relative to the annular housing 130 . The rotation of the limiting segment 120 does not need to overcome the friction force between the annular housing 130 and the external interface, and the rotation of the limiting segment 120 is easier and labor-saving.

In another embodiment of the pressure test plug:

The pressure test plug includes a plug body 100 and a first sealing ring 200 . The plug main body 100 includes a connecting section 110 located at the front end of the plug main body 100 and provided with external threads on the periphery, a limiting section 120 connected to the rear end of the connecting section 110 , and an annular housing 130 disposed on the outer periphery of the limiting section 120 .

One end of the annular housing 130 facing away from the connecting segment 110 is connected to the limiting segment 120 , and the annular housing 130 and the limiting segment 120 are integrally formed or fixed as a whole.

The annular casing 130 is sleeved on the outer periphery of the limiting section 120 .

The plug main body 100 is provided with a first air chamber 140 and a second air chamber 150 that communicate with each other. In this embodiment, the connecting section 110 and the limiting section 120 are hollow inside to form the first air chamber 140 . The first air chamber 140 is opened at the front end of the connecting section 110 and can be communicated with the internal space of the external interface, so as to be used in the pressure equipment. Or when the air supply system is inflated and pressurized, the gas can enter the second air chamber 150 through the first air chamber 140 .

A second air chamber 150 with an open front end is enclosed between the limiting section 120 of the plug main body 100 and the annular housing 130 .

The first sealing ring 200 is sleeved on the outer periphery of the connecting section 110 of the plug main body 100 and seals the opening of the second air chamber 150 . The structure and position of the first sealing ring 200 refer to the position and structure of the above-mentioned embodiment, and are not repeated here.

While the present invention has been described with reference to several exemplary embodiments, it is to be understood that the terminology used is of description and illustration, and not of limitation. Since the invention can be embodied in many forms without departing from the spirit or spirit of the invention, it is to be understood that the above-described embodiments are not limited to any of the foregoing details, but are to be construed broadly within the spirit and scope defined by the appended claims Therefore, all changes and modifications that come within the scope of the claims or their equivalents should be covered by the appended claims.

Claims (10)

1. A pressure testing plug is characterized by comprising:

the plug comprises a plug main body, a plug body and a plug body, wherein the periphery of the front end of the plug main body is provided with an external thread to form a connecting section for being in threaded connection with an external interface; the plug main body is provided with a first air chamber and a second air chamber; the first air chamber is opened at the front end of the connecting section and can be communicated with the inner space of the external interface; the front end of the second air chamber is opened, and the second air chamber is communicated with the first air chamber;

a first seal ring having elasticity; the first sealing ring is sleeved on the periphery of the connecting section and seals the opening of the second air chamber; the gas in the external interface can press the first sealing ring at the opening of the second air chamber through the first air chamber and the second air chamber, so that the first sealing ring is elastically deformed to seal the external interface.

2. The pressure test plug according to claim 1, wherein the plug body further comprises a limiting section connected to the rear end of the connecting section and an annular shell sleeved on the periphery of the limiting section, and the annular shell and the limiting section enclose to form the second air chamber.

3. The pressure test plug as claimed in claim 2, wherein the limiting section radially outwardly extends beyond the connecting section at the connection with the connecting section to form a first step; the first step has a space in the radial direction from the annular housing to form an opening of the second air chamber; the first seal ring is abutted against the first step and the annular shell along the axial direction.

4. The pressure test plug as claimed in claim 2, wherein the annular casing is sleeved on the periphery of the limiting section, so that the limiting section can rotate relative to the annular casing; one end of the annular shell, which is far away from the first sealing ring, is connected with the limiting section in a sealing manner.

5. The pressure test plug as claimed in claim 4, wherein a second sealing ring is arranged between the limiting section and the annular shell, and the second sealing ring has elasticity; the second sealing ring is sleeved on the periphery of the limiting section in the second air chamber and is abutted against the annular shell, and the second sealing ring is in interference fit with the limiting section and the annular shell.

6. The pressure test plug as claimed in claim 5, wherein the limiting section is provided with a ring groove which is opened radially outwards, and the second sealing ring is clamped and limited in the ring groove.

7. The pressure testing plug of claim 6, further comprising a sealing gasket, wherein the sealing gasket has elasticity; the sealing gasket is clamped and sleeved in the annular groove; the sealing gasket is abutted against the inner wall of the annular shell and is in interference fit with the annular shell.

8. The pressure testing plug according to claim 7, wherein one surface of the sealing gasket is attached to one axial side of the second sealing ring, and the other surface of the sealing gasket abuts against the side wall of the annular groove.

9. The pressure test plug according to claim 2, wherein the outer peripheral wall of the end of the limiting section, which is away from the connecting section, is provided with anti-slip insections.

10. The pressure test plug according to claim 2, wherein the limiting section is provided with an air hole for communicating the first air chamber and the second air chamber.

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