CN213839959U

CN213839959U - Sealing structure for metal flange test

Info

Publication number: CN213839959U
Application number: CN202022415713.8U
Authority: CN
Inventors: 郝玉梁; 崔俊峰; 崔振飞; 刘林
Original assignee: Shanghai Langsheng Petroleum Equipment Co ltd
Current assignee: Shanghai Langsheng Petroleum Equipment Co ltd
Priority date: 2020-10-27
Filing date: 2020-10-27
Publication date: 2021-07-30
Anticipated expiration: 2030-10-27

Abstract

The utility model provides a seal structure is used in test of metal flange, including metal flange and non-metallic seal backing ring, the inside seal groove that is provided with of metal flange, non-metallic seal backing ring interference fit is in metal flange's seal groove, non-metallic seal backing ring and the concentric setting of metal flange, wherein, non-metallic seal backing ring is including the outer lane that is located the outside and being located the inboard its of outer lane and the endocentric inner circle of outer lane, there is a thickness between outer lane and the inner circle, the surface of inner circle is equipped with the annular groove, the annular groove forms along the circumferencial direction on inner circle surface extension, and the annular groove is located the central point on the surface of inner circle and puts the department. The utility model does not need to pre-tighten the bolt to the required torque during testing, only needs manual locking to excite the initial sealing of the nonmetal sealing backing ring, and is simple and efficient; the annular groove is arranged, so that higher test pressure can be borne, and the highest test pressure reaches 103.5 MPa.

Description

Sealing structure for metal flange test

Technical Field

The utility model relates to a sealing ring technical field specifically, relates to a seal structure is used in metal flange test.

Background

The flange connection mode is a pipeline connection mode, and specifically means that flanges are designed at two butted ends of pipelines, a sealing groove is formed in the end face of each flange, a sealing ring is arranged in each groove, and the pipelines are tightly connected together by bolts or double-end studs after being butted. As shown in fig. 1, the pipelines are pipelines in a flange connection mode and are connected together through a stud 2 and a hexagon nut 3, and the pipelines can be other products in a flange connection mode. An annular sealing groove is arranged in the flange 1. As shown in fig. 2, the metal sealing gasket ring 4 is arranged in the flange sealing groove, the cross section of the metal sealing gasket ring is in an octagonal shape, and the outer ring 6 of the stud bolt is in interference fit with the sealing groove under the action of 2 hexagon nuts 3, so that effective sealing at the flange connecting interface is realized. In order to improve the sealing reliability of the flange connection and prolong the maintenance period, the metal sealing gasket ring 4 is generally made of carbon steel or stainless steel with lower hardness. The sealing mode has the advantages of long maintenance interval and reliable performance, and is widely and long-term applied to occasions of oil gas, refining, transmission and the like.

The existing metal sealing gasket ring 4 has some problems to be solved. Due to the working principle of flange connection, in order to realize sealing, the metal sealing gasket ring 4 must be in interference fit with the sealing groove. The flange parts need to be subjected to sealing pressure test before factory leaving, and in the test process, the roughness of the wall surface of the sealing groove can be damaged by using the metal sealing gasket ring 4, so that the field use performance of the product after factory leaving is influenced. Especially when the diameter of seal groove is great, above-mentioned problem appears more easily, and the field repair is wasted time and energy, and has great potential safety hazard. Meanwhile, the metal sealing gasket ring 4 needs to be replaced every time when being used for a disposable product due to the sealing working principle. The two problems seriously affect the working efficiency of the factory pressure test of the flange products, simultaneously bury hidden dangers for the later use of the products and have poor economic benefit.

In order to solve the problems, the damage of the metal sealing gasket ring to the sealing groove in the delivery pressure test process of flange products is avoided, and part of manufacturers change the material of the sealing gasket ring into nylon. Since the non-metallic gasket ring is only used for in-plant testing, there is no need to consider the service life of the nylon gasket ring, and it seems that the above problems are solved. Although the use of a non-metal sealing gasket ring such as a nylon sealing gasket ring eliminates the damage to the surface roughness of the sealing groove, the nylon sealing gasket ring is easy to generate flash in the use process, so that the nylon sealing gasket ring is equivalent to a flat gasket, cannot bear high-pressure working conditions, and is only used for product tests with working pressure not higher than 35 MPa. When the pressure is too high, leakage may occur. If the volume of the nylon gasket ring is reduced, the compression amount is reduced, and the problem of high-pressure leakage is also caused. Meanwhile, the flange using the nylon sealing gasket ring needs to pre-tighten the bolt or the stud to the required torque in the test process, so that the operation is complex and the working efficiency is low.

SUMMERY OF THE UTILITY MODEL

To the defect among the prior art, the utility model aims at providing a bear higher pressure, need not be with the metal flange test of bolt pretension to the moment of torsion of requirement seal structure.

According to an aspect of the utility model, a seal structure is used in metal flange test is provided, including metal flange and non-metal seal backing ring, the inside seal groove that is provided with of metal flange, non-metal seal backing ring interference fit in metal flange's seal groove, non-metal seal backing ring with metal flange sets up with one heart, wherein, non-metal seal backing ring is including the outer lane that is located the outside and being located the outer lane inboard its with the endocentric inner circle of outer lane, the outer lane with there is a thickness between the inner circle, the surface of inner circle is equipped with annular groove, annular groove along the circumferencial direction on inner circle surface extends and forms, just annular groove is located the central point on surface of inner circle puts the department.

Preferably, the cross section of the sealing groove of the metal flange is hexagonal, and the outer ring of the non-metal sealing gasket ring is in interference fit with the outer ring of the sealing groove of the metal flange.

Preferably, the interference of the non-metal sealing gasket ring is 0.8mm-1.2 mm.

Preferably, the non-metallic gasket ring is made of nylon, polyurethane, rubber or polytetrafluoroethylene material.

Compared with the prior art, the utility model discloses following beneficial effect has:

1. the initial interference magnitude of the nonmetal sealing backing ring of the utility model is very small, the bolt does not need to be pre-tightened to the required torque when the test structure is tested, the initial sealing of the nonmetal sealing backing ring can be excited only by manual locking, and the operation is simple and efficient;

2. the utility model discloses test structure is provided with the annular groove, and when meetting internal pressure, non-metallic seal backing ring can be under the condition of interior pressure, the laminating degree of outer lane further increase and seal groove to can bear higher test pressure, highest test pressure reaches 103.5 MPa.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic cross-sectional view of a prior art flange;

FIG. 2 is a cross-sectional view of a prior art metal gasket ring;

FIG. 3 is a cross-sectional view of a prior art nylon gasket ring prior to compression;

FIG. 4 is a cross-sectional view of a prior art nylon gasket ring after compression;

fig. 5 is a schematic cross-sectional view of a sealing structure for testing a metal flange according to an embodiment of the present invention;

in the figure: the sealing structure comprises a flange 1, a stud 2, a hexagon nut 3, a metal sealing gasket ring 4, a nylon sealing gasket ring 41, a flash 42, a nonmetal sealing gasket ring 43, an annular groove 44, a sealing groove 5, a sealing groove outer ring 6 and a nonmetal sealing gasket ring outer ring 61.

Detailed Description

The present invention will be described in detail with reference to the following embodiments. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that various changes and modifications can be made by one skilled in the art without departing from the spirit of the invention. These all belong to the protection scope of the present invention.

Fig. 1 is a schematic sectional view of a flange in the prior art, and fig. 2 is a schematic sectional view of a metal gasket ring in the prior art, in which an outer ring of the metal gasket ring 4, i.e., a lower portion of a cross section in the figure, is in interference fit with an outer ring of a seal groove 5. The metal sealing gasket ring 4 can still keep good sealing effect under the high-pressure working condition because the metal sealing ring has self-excitation performance. When the interface of the flange 1 bears the internal pressure, the internal pressure of the metal sealing gasket ring 4 is expanded outwards, so that the sealing surface of the outer ring of the technical sealing gasket ring is more reliably attached to the outer ring 6 of the sealing groove, namely the sealing performance of the metal sealing gasket ring 4 is realized by the internal pressure. In order to avoid damage of the metal sealing gasket ring to the sealing groove in the factory pressure testing process of the flange products, part of manufacturers change the material of the sealing gasket ring into nylon.

FIG. 3 is a cross-sectional view of a prior art nylon gasket ring prior to compression; FIG. 4 is a cross-sectional view of a prior art nylon gasket ring after compression. Since the strength of non-metal materials such as nylon is much lower than that of metal materials, the size of the nylon gasket ring 41 is large. During assembly, the nylon gasket ring 41 is compressed before the mating flange faces have a large gap 7 therebetween. The nylon gasket ring 41 is compressed and deformed after the mating flanges are tightened by the stud bolt 2 and the hexagon nut 3. As shown in fig. 3, gap 7 is reduced and nylon gasket ring 41 is compressed to fill seal groove 5 and some material is forced out of seal groove 5 to form flash 42. Although the use of a non-metallic gasket ring such as a nylon gasket ring eliminates damage to the surface roughness of the seal groove, the presence of the flash 42 results in the nylon gasket ring being equivalent to a flat gasket and not withstanding high pressure conditions, and is only used for product testing with a working pressure not higher than 35 MPa. When the pressure is too high, leakage may occur. If the volume of the nylon gasket ring 41 is reduced, the compression amount is reduced, and the problem of high pressure leakage is also caused. Meanwhile, the flange using the nylon sealing gasket ring needs to pre-tighten the bolt or the stud to the required torque in the test process, so that the operation is complex and the working efficiency is low.

Considering that if the interference is too large, the nylon gasket ring 41 will have flash 42, and will lose the internal pressure excitation characteristics, thereby making it impossible to use it in high pressure applications. For this reason, the embodiment of the utility model provides a design a seal structure is used in metal flange test of nonmetal sealing gasket ring, do not influence other processes of test flow, have good self-excitation performance, need not pretension the moment of torsion that requires with the bolt, only need manual locking can arouse the initial of sealed pad ring circle sealed, when meetting internal pressure, the sealing gasket ring can be under the condition of interior pressure, further divide the laminating degree of increase and seal groove 5 to can bear higher test pressure. Specifically, fig. 5 is a schematic cross-sectional view of a sealing structure for testing a metal flange according to an embodiment of the present invention. As shown in fig. 5, the sealing structure for testing a metal flange in this embodiment includes a metal flange 1 and a non-metal sealing gasket ring 43, a sealing groove 5 is provided inside the metal flange 1, the non-metal sealing gasket ring 43 is in interference fit with the sealing groove 5 of the metal flange 1, and the non-metal sealing gasket ring 43 and the metal flange 1 are concentrically arranged. The non-metal gasket ring 43 includes an outer ring located outside and an inner ring located inside the outer ring, and a certain thickness is provided between the outer ring and the inner ring. An annular groove 44 is formed in the center of the inner ring surface of the non-metal gasket ring 43, and the annular groove 44 and the non-metal gasket ring 43 are concentrically arranged. Specifically, the outer ring and the inner ring of the non-metal gasket ring 43 are concentrically arranged, and an annular groove is formed in the surface of the inner ring, the annular groove extends along the circumferential direction of the surface of the inner ring, and the annular groove is located at the center of the surface of the inner ring.

The currently common test method is the scheme shown in fig. 2 and 3, the nylon gasket ring 41 cannot bear high test pressure, and during the test overcharge, the stud 2 and the hexagon nut 3 need to be pre-tightened to a set torque by a special tool. The application occasion is limited, and the device cannot be used for high-voltage testing; the working efficiency is low, and the production cost is improved. In the above embodiment of the present invention, the inner ring surface of the non-metal gasket ring 43 is provided with the annular groove 44. Meanwhile, the initial interference magnitude of the nonmetal sealing gasket ring 43 is small, after the companion flange 1 is connected and fastened, no flash 42 appears, and small pressure can be sealed. Once the initial seal is formed, the internal pressure is filled in the inner annular groove 44, so that the non-metal gasket ring 43 is forced to expand outwards, the outer ring 61 of the non-metal gasket ring is pressed against the seal groove 5, the non-metal gasket ring 43 is tightly attached to the seal groove 5 on the end face of the flange 1, and the attachment force is increased along with the increase of the pressure, so that the flange can bear higher test pressure. Because the stud 2 and the hex nut 3 only play a role in exciting the initial seal in the non-metallic gasket ring 43, the initial installation torque does not need to be too high, and only manual locking is needed. In the above embodiment of the present invention, the non-metal gasket ring 43 is provided with the annular groove 44, so that the above two disadvantages of the nylon gasket ring 41 are overcome.

The utility model discloses in the above-mentioned embodiment, thickness between outer lane and the inner circle can be selected according to the experimental conditions, considers the degree of depth of the setting of annular groove on the one hand, and on the other hand considers setting up behind the annular groove, the sealed requirement in the concrete test procedure. In the embodiment shown in fig. 5, the sealing groove 5 is annular and has a regular hexagonal cross section and is disposed inside the metal flange 1. The outer ring of the non-metal gasket ring 43 is in interference fit with the outer ring of the sealing groove 5 of the metal flange 1. Of course, in other embodiments, the shape of the sealing groove 5 may be other shapes, as long as the sealing test can be achieved, and is not limited to the preferred regular hexagon.

The above embodiments of the present invention can be implemented according to the actual size of the metal flange 1, for example, in a specific embodiment, the diameter of the metal flange 1 is 46mm-1000 mm. Under the arrangement, the highest test pressure can reach 103.5MPa, which is far higher than that of a nylon metal gasket without an annular groove.

In the above embodiment, the shape of the non-metallic gasket ring 43 can be selected as the actual case may be. Preferably, the non-metallic gasket ring 43 has an octagonal longitudinal cross-section. As shown in fig. 5, the cross section of the seal groove 5 is a regular hexagon. The outer ring of the nonmetal sealing gasket ring 43 is in interference fit with the sealing groove 5 and is pressed on the outer ring 6 of the sealing groove. So that a better sealing can be achieved.

In the above embodiment, the shape of the annular groove 44 may be selected according to circumstances. Preferably, the annular groove 44 has a U-shaped longitudinal cross-section and is disposed inside the non-metallic gasket ring 43. As shown in fig. 5, the U-shaped cross-section further facilitates the non-metallic gasket ring 43 to fit into the sealing groove 5 after being pressed. Of course, in another preferred embodiment, the longitudinal cross-section of the annular groove 44 is C-shaped. The C-shaped cross-section further facilitates the non-metallic gasket ring 43 to adhere to the sealing groove 5 after being pressed. The specific C-shaped groove and the U-shaped groove can be properly adjusted according to the section size and the diameter of the sealing ring.

The outer ring of the non-metal gasket ring 43 is in interference fit with the outer ring of the sealing groove 5 of the metal flange 1. Specifically, the interference of the non-metal gasket ring 43 may be 0.8mm to 1.2 mm. More preferably, the interference of the non-metallic gasket ring 43 is 1 mm. The interference magnitude of the existing metal sealing ring is about 0.2mm generally; the interference of the non-metallic sealing ring without the groove shape is generally larger than 3 mm; and the utility model discloses a nonmetal seal backing ring 43, interference magnitude can be controlled about 1mm, and in the compression process, the recess can be filled to the interference surplus, avoids the appearance of extrusion overlap.

The utility model discloses in the above-mentioned embodiment, non-metallic gasket ring can select multiple non-metallic material to make, for example any one of nylon, polyurethane, high strength rubber, polytetrafluoroethylene etc. prepares, can also be other non-metallic material certainly. The non-metallic material is used in order to prevent damage to the roughness of the seal groove 5 at the time of testing.

To sum up, the utility model discloses nonmetal seal backing ring 43's initial magnitude of interference is very little, need not pretension the moment of torsion that requires with the bolt during test structure test, only needs manual locking can arouse nonmetal seal backing ring 43's initial seal, and is simple high-efficient. The utility model discloses test structure is provided with annular groove 44, and when meetting internal pressure, nonmetal sealing gasket ring 43 can be under the condition of interior pressure, the laminating degree of outer lane further increase and seal groove to can bear higher test pressure, highest test pressure reaches 103.5 MPa.

The foregoing description of the specific embodiments of the invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by those skilled in the art within the scope of the appended claims without departing from the spirit of the invention.

Claims

1. The utility model provides a seal structure for test of metal flange, its characterized in that includes metal flange and nonmetal seal backing ring, the inside seal groove that is provided with of metal flange, nonmetal seal backing ring interference fit in the seal groove of metal flange, nonmetal seal backing ring with the metal flange sets up with one heart, wherein, nonmetal seal backing ring including be located the outside the outer lane and be located the outer lane inboard its with the endocentric inner circle of outer lane, the outer lane with there is a thickness between the inner circle, the surface of inner circle is equipped with annular groove, annular groove along the circumferencial direction on inner circle surface extends and forms, just annular groove is located the central point on the surface of inner circle puts the department.

2. The sealing structure for testing the metal flange as claimed in claim 1, wherein a cross section of the sealing groove of the metal flange is hexagonal, and an outer ring of the non-metal gasket ring is in interference fit with an outer ring of the sealing groove of the metal flange.

3. The sealing structure for testing the metal flange according to claim 1, wherein a through diameter of the metal flange is 46mm to 1000 mm.

4. The sealing structure for testing the metal flange according to claim 1, wherein the longitudinal section of the non-metal gasket ring is octagonal.

5. The sealing structure for testing the metal flange according to claim 1, wherein a longitudinal section of the annular groove is U-shaped.

6. The sealing structure for testing the metal flange according to claim 1, wherein a longitudinal section of the annular groove is C-shaped.

7. The sealing structure for testing the metal flange according to claim 1, wherein an interference of the non-metal gasket ring is 0.8mm to 1.2 mm.

8. The sealing structure for testing the metal flange according to claim 7, wherein an interference of the non-metal gasket ring is 1 mm.

9. The seal structure for testing metal flanges according to claim 1, wherein the non-metallic gasket ring is made of nylon, polyurethane, rubber or polytetrafluoroethylene material.