Pipeline flange type pressure test plug

Abstract

The utility model discloses a flange type pressure test plug for a pipeline. The flange type pressure test plug comprises a connecting rod, a plurality of studs, a blind hub, a pressing ring, a sealing ring and an end cover, the end cover is sleeved with the pressing ring and the sealing ring in a concentric mode, the connecting rod and the studs penetrate through the blind hub to be connected with the end cover, a first through hole is formed in the center of the connecting rod and penetrates from one end of the connecting rod to the other end of the connecting rod, a second through hole is formed in the center of the end cover, and the second through hole is communicated with the blind hub. And the second through hole penetrates from one end of the end cover to the other end of the end cover, so that the first through hole is communicated with the second through hole after the connecting rod is connected with the end cover. The novel pressure test plug is high in reusability and convenient to install in place.

Description

Technical Field

[0001] The present invention relates to a pressure test plug, in particular to a pipeline flange type pressure test plug. Background Art

[0002] Pipeline pressure test is a work to inspect the strength of pipeline welds and the tightness of intermediate flange connections of pipelines after pipeline installation is completed. The pressure test level is usually defined as four pressure levels: low-pressure pipeline 0.1≤P≤1.6MPa; medium-pressure pipeline 1.6<P≤10MPa; medium-high pressure pipeline 11<P≤49MPa; high-pressure pipeline 50≤P≤100MPa; ultra-high pressure P>101MPa.

[0003] Traditional inspection methods generally adopt the form of blind flange (FF, RF, API, ASE, HUB) + gasket (graphite gasket, RTJ-Ring, conforming gasket). The blind flange and the pipeline flange are sealed by gasket extrusion, and high-strength bolts are used to connect the flanges. In order to ensure the tightness between the flanges, the flange bolts need to be tightened evenly (torqued) using a torque wrench according to the flange management requirements to achieve the sealing effect. This traditional method is applicable from low pressure to ultra-high pressure, but there are the following problems: The gasket uses extrusion hard sealing, which is easy to damage and has a low reuse rate; The test requires blind flanges of the same standard as the project, sealing gaskets and bolts of the same grade, and the direct test cost is high; The test steps are cumbersome (installing and removing flanges, torquing), the auxiliary working hours of the crane are long, the torque time is long, etc., and the construction time is long due to the cumbersome process; There are potential hazards of leakage and flange connection parts falling off. The flange sealing surface is easily damaged due to frequent use, the gasket has a low number of cycles of reuse and a high leakage risk, the bolts are fatigued due to repeated use, and the NPT connection parts are frequently disassembled, all of which will cause leakage or falling off during the test process, posing safety hazards.

[0004] WO2017031233A1 discloses a pressure test plug, the structure of which is as Figure 8 shown. The pressure test plug has a plurality of circumferentially spaced metal tooth rows 138 and a set of circumferentially spaced holders 128, and has a rear plate 136 and a front plate 122. The rear plate 136 and the front plate 122 can slide longitudinally along the shaft 112. Nuts 116 and 118 are provided at both ends of the shaft, and there is a central hole 114 on the shaft 112. It may also include, for example, an O-ring 130, a hardened washer 132, a compression tube 134, etc. Figure 8 It shows a pressure test plug 110 inserted into the open end of a straight pipe section 164, and Figure 8The test plug 110 is shown tightened (i.e., in a compressed state) with the retainer 128 secured and advanced into secure clamping engagement with the inner surface of the straight pipe section 164. Of course, further tightening of the test plug 110 will cause the sealing element 124 of the test plug 110 to be compressed and expanded into sealing engagement with the inner wall. The sealing gasket 162 prevents any extrusion of the sealing element 124 into the gap between the cam element 126 and the shaft 112. The shaft 112 extends concentrically within the open passage 160 of the tapered element 126 and the cylindrical inner surface wall of the tube 164, and the metal teeth row 138 is securely engaged with the inner wall of the tube 164. The pressure test plug of WO2017031233A1 has the following problems: it adopts a technical solution of metal teeth engaging with the inner wall of the pipe to stop retreat. The pressure that the engaging part can withstand is relatively low, so this pressure test plug is only suitable for low-pressure or medium-pressure testing; on the other hand, the metal teeth will exert a large tension on the inner wall of the pipe during the engaging process, which will damage the inner wall of the pipe, especially for pipes with protective coating on the inner wall, this pressure test plug is not suitable; moreover, during repeated use, the metal teeth are easily squeezed and deformed, resulting in the pressure test plug being unable to effectively engage with the inner wall of the pipe and falling off. Utility Model Content

[0005] In view of the defects of the prior art, the present invention provides a pipeline flange type pressure test plug.

[0006] A pipeline flange type pressure test plug, comprising a connecting rod, a plurality of studs, a blind hub, a pressure ring, a sealing ring and an end cover; the pressure ring and the sealing ring are concentrically sleeved on the end cover, the connecting rod and the plurality of studs are connected to the end cover through the blind hub, a first through hole is provided at the center of the connecting rod, the first through hole runs through from one end of the connecting rod to the other end, a second through hole is formed at the center of the end cover, the second through hole runs through from one end of the end cover to the other end, so that after the connecting rod is connected to the end cover, the first through hole is connected to the second through hole; the sealing ring is located between the pressure ring and the end cover, the blind hub is outside the pipeline, the pressure ring, the sealing ring and the end cover can be inserted into the pipeline, and the sealing ring is expanded and closed by tightening the nut at one end of the stud; the sealing ring is a rubber or polyester sealing ring.

[0007] Optionally, the inside of the pipe is communicated with the outside of the pipe through the first through hole and the second through hole; the pressure ring and the end cover are rigid; a lifting ear is also provided on the blind hub; the blind hub is planar, and its maximum diameter is greater than or equal to the diameter of the pipe flange; the blind hub has a protruding flange and a boss, the diameter of the flange is greater than the diameter of the boss, and the diameter of the flange is greater than or equal to the diameter of the pipe flange; the multiple studs are evenly distributed around the connecting rod; a retaining ring is provided between the pressure ring and the sealing ring or between the sealing ring and the end cover; a groove matching the end cover is provided on the side of the blind hub facing the end cover; the end cover has a column, a supporting ring is formed at one end of the column, and the pressure ring and the sealing ring are sleeved on the column.

[0008] This new type of pressure test plug has high reusability, is easy to install and remove, has a short operation time, a high safety factor, is convenient, has a "0" chance of leakage, and has no risk of falling off, which greatly reduces costs. It has a wide range of applications, is not limited by pressure levels, has "0" damage to the formal flange sealing surface, "0" damage to the inner wall material of the pipeline, and "0" risk of safe falling off. The structure in which multiple studs are connected to the end cover makes the force on the end cover and the sealing ring more uniform. At the same time, more pressure can be applied to the sealing ring through multiple studs, and the sealing ring has a greater deformation, thereby exerting greater pressure on the inner wall of the pipeline, so that the pressure test plug can withstand greater pressure during the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a three-dimensional diagram of the pressure test plug;

[0010] Figure 2 This is the exploded view of the pressure test plug;

[0011] Figure 3A A first stereoscopic view of a boss-shaped blind hub;

[0012] Figure 3B A second stereoscopic view of a boss-shaped blind hub;

[0013] Figure 4A A first stereogram of a planar blind hub;

[0014] Figure 4B A second stereogram of a planar blind hub;

[0015] Figure 5 is a three-dimensional diagram of the end cap;

[0016] Figure 6 is a cross-sectional view of the pressure test plug;

[0017] Fig. 7A This is a schematic diagram of the installation structure of the test system;

[0018] Figure 7B is a cross-sectional diagram of the test system;

[0019] Figure 8 It is a schematic diagram of the structure of the pilot plug in the prior art. DETAILED DESCRIPTION

[0020] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings, so that the above-mentioned and other purposes, features and advantages of the present invention will be clearer. The same reference numerals in all the drawings indicate the same parts. The drawings are not deliberately drawn to scale, and the focus is on illustrating the main purpose of the present invention.

[0021] The terms and words used in the following description and claims are not limited to the written meanings, but are only used by the novel person so that the novel can be clearly and consistently understood. Therefore, it is obvious to those skilled in the art that the following description of various embodiments of the novel is provided for the purpose of illustration only, and not for the purpose of limiting the novel as defined by the attached claims and their equivalents.

[0022] like Figure 1 As shown, the new pressure test plug is suitable for pressure testing of pipelines with flanges at the ends, and comprises a connecting rod 1, multiple studs 2, a blind hub 3, a pressure ring 4, a sealing ring 5 and an end cover 6. The pressure ring 4 and the sealing ring 5 are concentrically sleeved on the end cover 6, and the connecting rod 1 and the multiple studs 2 pass through the blind hub 3 and are connected to the end cover 6. The blind hub 3 is outside the pipeline, and the pressure ring 4, the sealing ring 5 and the end cover 6 can be inserted into the pipeline. The pressure ring 4 and the sealing ring 5 can slide freely along the end cover 6. A lifting lug 7 can also be provided on the blind hub 3, and the lifting lug 7 is convenient for lifting the pressure test plug.

[0023] See also Figure 2 The center of the connecting rod 1 is provided with a first through hole 1.1, which runs from one end of the connecting rod 1 to the other end. The center of the end cap 6 forms a second through hole 6.3, which runs from one end of the end cap 6 to the other end. Thus, after the connecting rod 1 is connected to the end cap 6, the first through hole 1.1 is connected to the second through hole 6.3, and the test liquid or gas can enter the interior of the pipeline through the first through hole 1.1 and the second through hole 6.3. The connecting rod 1 and the end cap 6 can be connected in any way, such as interference fit, threaded connection, etc. Figure 2 As shown, an external thread 1.2 can be formed at one end of the connecting rod, and an internal thread can be formed in the second through hole 6.3, so that one end of the connecting rod 1 can be screwed into the second through hole 6.3 through the thread, thereby achieving the connection between the connecting rod 1 and the end cover 6.

[0024] A retaining ring 8 can also be arranged between the pressure ring 4 and the sealing ring 5. The retaining ring 8 can prevent the sealing ring from being squeezed into the pressure ring 4 when a force is applied. Of course, the retaining ring 8 can also be arranged between the sealing ring 5 and the end cover 6, or retaining rings can be arranged between the sealing ring 5 and the end cover 6, and between the pressure ring 4 and the sealing ring 5 at the same time.

[0025] See also Figure 3A and Figure 3B A third through hole 3.3 is provided at the center of the blind hub 3, and the connecting rod 1 can pass through the third through hole 3.3 and can move freely in the third through hole 3.3. A plurality of fourth through holes 3.4 are formed on the blind hub 3 around the third through hole 3.3, and the stud 2 can pass through the fourth through hole 3.4 and can move freely in the fourth through hole 3.4, and the number of the fourth through holes 3.4 is equal to the number of the studs 2.

[0026] The blind hub 3 can be in a planar shape or a boss shape, and the maximum diameter of the blind hub 3 is greater than or equal to the diameter of the pipeline flange. Figure 3A and Figure 3B As shown, the blind hub 3 has a protruding flange 3.2 and a boss 3.1, the diameter of the flange 3.2 is larger than the diameter of the boss 3.1, and the diameter of the flange 3.2 is larger than or equal to the diameter of the pipeline flange, so that the blind hub 3 is outside the pipeline, providing support for the pressure test plug. Furthermore, a groove 3.5 matching the end cover 6 can be opened on the side of the blind hub 3 facing the end cover 6, so that a part of the end cover 6 is deeply inserted into the groove 3.5, so that the installation of the end cover 6 can be more stable. Figure 4A and Figure 4B It is a structural schematic diagram of a planar blind hub. The blind hub is planar, for example, it can be disc-shaped. A plurality of mounting holes 3.6 are provided on the circumferential edge of the blind hub. Correspondingly, holes corresponding to the mounting holes 3.6 are also provided on the flange at the end of the pipeline. In this way, the pressure test plug can be engaged with the pipeline by passing bolts through the mounting holes 3.6 and the flange.

[0027] Figure 5 The figure is a schematic diagram of the structure of the end cover 6. The end cover 6 has a column 6.2, one end of the column 6.2 forms a supporting ring 6.1, and the pressure ring 4 and the sealing ring 5 are sleeved on the column 6.2, and the pressure ring 4 and the sealing ring 5 can slide freely along the column 6.2. A second through hole 6.3 is opened in the center of the end cover 6, and a plurality of blind holes 6.4 are arranged around the second through hole 6.3. The blind holes 6.4 are arranged on the column 6.2, and the blind holes 6.4 correspond to the fourth through holes 3.4, so that the stud 2 can pass through the fourth through hole 3.4 and penetrate into the blind hole 6.4 to achieve the connection between the stud 2 and the end cover 6. For example, an internal thread can be arranged in the blind hole 6.4, and the stud 2 is screwed into the blind hole 6.4, so as to achieve the connection between the stud 2 and the end cover 6. The supporting ring 6.1 is used to provide support for the pressure ring 4 and the sealing ring 5 to prevent them from sliding off the column 6.2.

[0028] Figure 6 The state diagram after the pressure test plug is inserted into the pipe 9 is shown. The end of the pipe 9 has a flange 9.1. The blind hub 3 can be fixed to the flange 9.1, for example, by a snap or a screw. Figure 6 A boss-shaped blind hub is used, which can be fixed by snap-fitting. A pressure ring 4, a sealing ring 5, and an end cover 6 are located in a pipe 9, and a connecting rod 1 passes through the blind hub 3 and is connected to the end cover 6. One end of a plurality of studs 2 is fixedly connected to the end cover 6, and the other end extends out of the blind hub 3. After the blind hub 3 and the flange 9.1 are fixed, the nut 2.1 at the outer end of the stud 2 can be tightened by a wrench. As the nut 2.1 is rotated and tightened, the stud 2 will gradually extend out of the pipe 9. Due to the fixed connection between the blind hub 3 and the flange 9.1, the end cover 6 will move toward the outside of the pipe 9 driven by the stud 2. Since the blind hub 3 is fixed and locked, the pressure ring 4 will abut the inner side of the blind hub 3, and the sealing ring 5 located between the end cover 6 and the pressure ring 4 will be pressurized. The pressure ring 4 and the end cover 6 are rigid structures and will not deform. The sealing ring 5 can be a rubber or polyester sealing ring, which can undergo elastic deformation. In this way, as the nut 2.1 is tightened, the pressure ring 4 and the end cover 6 will apply pressure to the sealing ring 5. Under the action of pressure, the sealing ring 5 will expand and deform. As the sealing ring 5 expands, the sealing ring 5 will abut against the inner wall of the pipe 9, thereby achieving sealing of the pipe 9 through the sealing ring 5.

[0029] The new pressure test plug can be used for testing such as air pressure, water pressure, oil pressure, etc. Take the water pressure test as an example, please refer to Fig. 7A and Figure 7B , both ends of the pipeline 9 are sealed and pressure tested by pressure test plugs. Of course, a pressure test plug can also be set at only one end of the pipeline 9 and the other end can be sealed by, for example, a blind flange. The first through hole 1.1 is connected to the water pump through a connector and a valve. During the test, a flat blind hub pressure test plug is used on the left side of the pipeline 9, and the pressure test plug is fixed to the flange 9.1 of the pipeline 9 by a screw 9; a boss-shaped blind hub pressure test plug is used on the right side of the pipeline 9, and the pressure test plug is fixed to the flange 9.1 of the pipeline 9 by a buckle 11; tighten the nut 2.1 to expand the sealing ring 5 in the pressure test plug, and the pipeline 9 is sealed by the sealing ring 5, and then the water pump is started, and the test water flows into the pipeline 9 through the first through hole 1.1 and the second through hole 6.3. The current pressure value in the pipeline 9 can be read by the pressure gauge. When the set value is reached, the welding condition, sealing condition, and pressure resistance value of the pipeline 9 can be tested.

[0030] This new type uses a blind hub and a flange to connect them together, and seals the pipeline by inserting a sealing plug into the pipeline. This changes the traditional practice of adding a blind plate and a gasket during the pressure test. It does not require torque or pressure test gaskets, saving the cost of pressure test gaskets and the labor cost of bolt torque. The construction steps are flexible and simple (installation and removal) and time-saving. There is no leakage risk. The sealing ring uses a soft sealing material and can be frequently and repeatedly used (no leakage risk). The sealing ring does not damage the inner wall of the pipeline and is suitable for anti-corrosion pipelines with protective coatings on the inner wall. The blind hub and the flange are fixed with screws or buckles, so that the entire pressure test plug can withstand greater pressure and is suitable for high pressure or ultra-high pressure testing. The structure of multiple studs connected to the end cover makes the force on the end cover and the sealing ring more uniform. At the same time, more pressure can be applied to the sealing ring through multiple studs, and the sealing ring has a greater deformation, so that the pressure on the inner wall of the pipeline is also greater, so that the pressure that the pressure test plug can withstand during the test is greater.

[0031] This new type of pressure test plug has high reusability, is easy to install and remove, has a short operation time, a high safety factor, is convenient, has a "0" chance of leakage, has no risk of falling off, and significantly reduces costs. It has a wide range of applications, is not limited by pressure levels, has "0" damage to the formal flange sealing surface, and "0" safety risks.

[0032] Although the technology has been illustrated and described with respect to one or more embodiments, changes and / or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. In particular, with respect to the various functions performed by the above-described components or structures (assemblies, devices, circuits, systems, etc.), the terms used to describe such components (including references to "means") are intended to correspond to any component or structure (e.g., functionally equivalent) that performs the specified function of the described component, even if not structurally equivalent to the disclosed structure that performs the function in the example embodiments described herein, unless otherwise specified. In addition, although a particular feature may have been disclosed with respect to one of several embodiments, such a feature may be combined with one or more other features in other embodiments as may be desired and advantageous for any given or particular application. In addition, to the extent that the terms "comprising," "including," "having," "having," "containing," or variations thereof are used in the detailed description or claims, such terms are intended to be inclusive in a manner similar to the term "comprising."

[0033] Many specific details are described in the above description to facilitate a full understanding of the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited by the specific implementation disclosed above. At the same time, any person familiar with the technical field can make many possible changes and modifications to the present technical solution using the methods and technical contents disclosed above without departing from the scope of the present technical solution, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the present technical solution still falls within the scope of protection of the present technical solution.

Claims

1. A pipeline flange type pressure test plug, characterized in that: It comprises a connecting rod, a plurality of studs, a blind hub, a pressure ring, a sealing ring and an end cover; the pressure ring and the sealing ring are concentrically sleeved on the end cover, the connecting rod and the plurality of studs are connected to the end cover through the blind hub, a first through hole is arranged at the center of the connecting rod, the first through hole runs through from one end of the connecting rod to the other end, a second through hole is formed at the center of the end cover, the second through hole runs through from one end of the end cover to the other end, so that after the connecting rod is connected to the end cover, the first through hole is connected to the second through hole; the sealing ring is located between the pressure ring and the end cover, the blind hub is outside the pipe, the pressure ring, the sealing ring and the end cover can be inserted into the pipe, and the sealing ring is expanded and closed by tightening the nut at one end of the stud; the sealing ring is a rubber or polyester sealing ring.

2. The pipeline flange type pressure test plug according to claim 1, characterized in that: The inside of the pipeline is communicated with the outside of the pipeline through the first through hole and the second through hole.

3. The pipeline flange type pressure test plug according to claim 1, characterized in that: The pressure ring and the end cover are rigid.

4. The pipeline flange type pressure test plug according to claim 1, characterized in that: The blind hub is also provided with a lifting lug.

5. The pipeline flange type pressure test plug according to claim 1, characterized in that: The blind hub is planar, and its maximum diameter is greater than or equal to the diameter of the pipeline flange.

6. The pipeline flange type pressure test plug according to claim 1, characterized in that: The blind hub has a protruding flange and a boss, the diameter of the flange is larger than the diameter of the boss, and the diameter of the flange is larger than or equal to the diameter of the pipe flange.

7. The pipeline flange type pressure test plug according to claim 1, characterized in that: The plurality of studs are evenly distributed around the connecting rod.

8. The pipeline flange type pressure test plug according to claim 1, characterized in that: A retaining ring is arranged between the pressure ring and the sealing ring or between the sealing ring and the end cover.

9. The pipeline flange type pressure test plug according to claim 1, characterized in that: A groove matched with the end cover is provided on one side of the blind hub facing the end cover.

10. The pipeline flange type pressure test plug according to claim 1, characterized in that: The end cover has a column, a supporting ring is formed at one end of the column, and the pressure ring and the sealing ring are sleeved on the column.

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