Combined hard sealing structure of valve seat of forced sealing ball valve

Abstract

The invention relates to the technical field of ball valves, and discloses a forced sealing ball valve seat combined hard sealing structure which comprises a valve body and a ball body, a valve seat assembly is arranged between the valve body and the ball body, and the valve seat assembly is connected with a valve body bolt through a valve seat pressing ring to achieve fixation. The valve seat assembly comprises a valve seat supporting ring, a valve seat inserting piece installed in the inserting piece clamping groove, a disc spring installed between the valve seat inserting piece and the valve seat supporting ring and a limiting bolt used for limiting the valve seat inserting piece, and multi-stage sealing can be formed between the valve seat assembly and the ball body. A pressure inlet groove, a pressure inlet hole and a leak detection hole are formed in the valve seat supporting ring, the pressure inlet groove and the pressure inlet hole are communicated with the inner cavity of the valve body and the plug-in clamping groove, the valve seat plug-in can axially move through the pressure inlet hole by means of medium pressure to achieve sealing, and a leak detection channel is formed in the bottom end of the valve body and communicated with the leak detection hole of the valve seat to facilitate leak detection. According to the forced sealing ball valve, multi-stage sealing, spring pre-tightening and piston effect self-sealing are combined, and the sealing performance of the forced sealing ball valve under the complex working condition is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ball valves, in particular to a combined hard sealing structure of a forced sealing ball valve seat. BACKGROUND

[0002] The forced sealing ball valve is also called track ball valve, and due to some unique advantages of its own structure, such as no friction in the opening and closing process, small opening and closing torque, etc., it is more and more widely used in the working conditions such as oil and gas metering station, molecular sieve dehydration device, hydrogenation device, etc., which have large pressure difference, frequent opening and closing, require the valve to maintain good sealing for a long time and do not allow the valve to be frequently stopped for maintenance and replacement. Among them, some severe working conditions require the forced sealing ball valve to use metal hard sealing, and to realize positive and reverse sealing, and the sealing performance reaches zero leakage.

[0003] At present, the commonly used metal hard sealing structure of the forced sealing ball valve is to form a hard sealing by tightly combining the metal sealing surface of the ball with the metal sealing surface of the valve seat. However, neither the European and American manufacturers with deep technical accumulation nor the domestic manufacturers with rapid development can achieve the goal of zero leakage of the valve in positive and reverse directions by using a single metal hard sealing. Moreover, after long-term operation of the valve seat sealing structure in the above-mentioned severe working conditions, the metal sealing surfaces of the ball and the valve seat may be worn or even deformed, thereby affecting the sealing performance of the ball valve and causing leakage. Therefore, when the forced sealing ball valve uses a hard sealing structure, how to ensure its reliable sealing performance under complex working conditions needs to be further analyzed and researched. SUMMARY

[0004] In view of the above situation, in order to overcome the defects of the prior art, the purpose of the present application is to provide a combined hard sealing structure of a forced sealing ball valve seat, which combines multi-stage sealing, spring pre-tightening and piston effect self-sealing, so as to ensure the sealing performance of the ball valve under complex working conditions, and has an online leakage detection function.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following solutions:

[0006] A combined hard sealing structure of a forced sealing ball valve seat comprises a valve body and a ball, a valve seat assembly is arranged between the valve body and the ball, a valve seat pressing ring is arranged outside the valve seat assembly, and the valve seat pressing ring and the valve body clamp the valve seat assembly and are connected and fixed by a hexagonal head bolt.

[0007] Further, the valve seat assembly comprises a valve seat support ring, an insert clamping groove is formed outwardly on the side close to the ball of the valve seat support ring, a valve seat insert is installed in the insert clamping groove, and a disc spring is installed between the valve seat insert and the valve seat support ring, so as to provide spring pre-tightening force for the valve seat insert.

[0008] Further, the valve seat support ring is provided with a plurality of "L" shaped grooves on the side close to the ball, and when the valve seat assembly is attached to the ball, a first cavity, a second cavity and a third cavity are formed, thereby dividing the sealing surface into a plurality of sealing surfaces to form a multi-stage sealing.

[0009] Further, a plurality of limiting holes are uniformly arranged on the valve seat support ring, and a limiting slot corresponding to the limiting hole is arranged on the valve seat insert, a limiting bolt is installed in the limiting hole, and the limiting bolt is fixed with the valve seat support ring through threaded connection, while being inserted into the limiting slot to prevent the valve seat insert from falling off under the condition of excessive pressure difference, and the limiting slot is provided with a displacement allowance to ensure that the valve seat insert can still be axially displaced after the limiting bolt is installed.

[0010] Further, a plurality of pressure inlet grooves and pressure inlet holes are arranged on the valve seat support ring, the pressure inlet grooves are arranged on the outer wall of the valve seat support ring and penetrate through the side close to the ball to the pressure inlet holes, the pressure inlet holes penetrate through the outer wall of the valve seat support ring to the insert slot, the pressure inlet grooves and the pressure inlet holes are connected in communication with the inner cavity of the valve body and the insert slot, and the medium passes through the pressure inlet grooves and the pressure inlet holes to form a pressure difference between the front and back of the valve seat insert.

[0011] Further, a leak detection hole is arranged on the valve seat support ring, the leak detection hole is in communication with the second cavity, and a valve body leak detection channel is arranged at the bottom of the valve body, one end of the valve body leak detection channel is in communication with the leak detection hole, and the other end penetrates to the outer side of the valve body, thereby facilitating online leak detection of the ball valve.

[0012] Further, two O-ring grooves are arranged on the attachment surface of the valve seat support ring and the valve body, one O-ring groove is arranged on the attachment surface of the valve seat insert, one O-ring groove is arranged on the inner side of the attachment surface of the valve seat insert and the valve seat support ring, and one O-ring groove is arranged on the attachment surface of the limiting bolt and the valve seat support ring, and O-rings are embedded in all the O-ring grooves for sealing.

[0013] The beneficial effects of the present application are:

[0014] 1. The valve seat support ring is attached to the ball to form a hard seal, the valve seat insert is attached to the ball to form a hard seal, and the two simultaneously act to achieve combined hard sealing, the valve seat pressing ring is connected to the valve body by bolts to press the valve seat assembly, the limiting bolt passes through the valve seat support ring to limit the valve seat insert, thereby preventing the valve seat assembly and the valve seat insert from moving axially or even falling off, and improving the sealing reliability of the forced sealing ball valve.

[0015] 2. The valve seat assembly and the ball form a multi-stage sealing, and no matter whether the medium flows forward or the medium flows backward after the valve is closed, the medium will pass through the multi-stage sealing, this structure can improve the sealing performance of the forced sealing ball valve, realize forward and reverse sealing, and achieve the purpose of zero leakage of the medium, and effectively prevent the medium from flowing backward.

[0016] 3. A disc spring is installed between the valve seat insert and the valve seat support ring, and the valve seat insert will be more tightly attached to the ball under the action of the spring pre-tightening force; the inlet pressure groove is in communication with the inlet pressure hole to connect the valve body cavity and the insert clamping groove, and the medium passing through the inlet pressure groove and the inlet pressure hole can form a pressure difference before and after the valve seat insert, achieving the effect of piston self-sealing; the combination of spring pre-tightening force and piston self-sealing effect can eliminate the risk of sealing leakage caused by deformation or wear of the valve seat insert, and prolong the service life of the ball valve.

[0017] 4. Multiple O-rings are arranged in the valve seat assembly to make the sealing more reliable, and the valve seat assembly and the valve body are provided with a leak detection channel to communicate with the outside of the valve, realizing online leak detection of the valve. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The figure is a structural schematic diagram of the present application;

[0019] Figure 2 The figure is a partial enlarged view of A in the present application; Figure 1

[0020] Figure 3 The figure is a structural schematic diagram of the valve seat support ring of the present application;

[0021] Figure 4 The figure is a structural schematic diagram of the valve seat insert of the present application;

[0022] BRIEF DESCRIPTION OF DRAWINGS: 1 - valve body, 2 - ball, 3 - valve seat assembly, 31 - valve seat support ring, 311 - insert clamping groove, 312 - first "L" shaped groove, 313 - second "L" shaped groove, 314 - limiting hole, 315 - inlet pressure groove, 316 - inlet pressure hole, 317 - leak detection hole, 32 - valve seat insert, 321 - limiting clamping groove, 33 - disc spring, 34 - limiting bolt, 4 - valve seat compression ring, 5 - hexagonal head bolt, 6 - first cavity, 7 - second cavity, 8 - third cavity, 9 - first sealing surface, 10 - second sealing surface, 11 - third sealing surface, 12 - fourth sealing surface, 13 - fifth sealing surface, 14 - valve body leak detection channel, 15 - O-ring 1, 16 - O-ring 2, 17 - O-ring 3, 18 - O-ring 4, 19 - O-ring 5 DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, working mechanism, purposes and effects of the present application easy to understand, the technical solutions and working mechanisms in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application.

[0024] As Figure 1 ​The shown forced sealing ball valve seat assembly hard sealing structure comprises a valve body 1 and a ball 2, a valve seat assembly 3 is arranged between the valve body 1 and the ball 2, a valve seat pressing ring 4 is arranged outside the valve seat assembly 3, the valve seat pressing ring 4 and the valve body 1 clamp the valve seat assembly 3 and are connected and fixed by a hexagonal head bolt 5.

[0025] Further, the valve seat assembly 3 comprises a valve seat support ring 31, an insert clamping groove 311 is formed outside the ball side of the valve seat support ring 31, a valve seat insert 32 is arranged in the insert clamping groove 311, a disc spring 33 is arranged between the valve seat insert 32 and the valve seat support ring 31, and the valve seat insert 32 is provided with spring pre-tightening force.

[0026] Further, the valve seat support ring 31 is provided with a first "L" shaped groove 312 and a second "L" shaped groove 313 on the ball side, when the valve seat assembly 3 is attached to the ball 2, a first cavity 6, a second cavity 7 and a third cavity 8 are formed, thereby dividing the sealing surface into a first sealing surface 9, a second sealing surface 10, a third sealing surface 11, a fourth sealing surface 12 and a fifth sealing surface 13, and forming multi-stage sealing.

[0027] Further, a plurality of limiting holes 314 are uniformly arranged on the valve seat support ring 31, a limiting clamping groove 321 corresponding to the limiting hole 314 is arranged on the valve seat insert 32, a limiting bolt 34 is arranged in the limiting hole 314, the limiting bolt 34 is fixed to the valve seat support ring 31 through thread connection, and is inserted into the limiting clamping groove 321 to prevent the valve seat insert 32 from falling off under excessive pressure difference, and the limiting clamping groove 321 has a displacement allowance to ensure that the valve seat insert 32 can still move axially forward and backward after the limiting bolt 34 is arranged.

[0028] Further, a plurality of pressure inlet grooves 315 and pressure inlet holes 316 are arranged on the valve seat support ring 31, the pressure inlet grooves 315 are arranged on the outer wall of the valve seat support ring 31 and penetrate through the ball side of the valve seat support ring 31 to the pressure inlet holes 316, the pressure inlet holes 316 penetrate through the outer wall of the valve seat support ring 31 to the insert clamping groove 311, the pressure inlet grooves 315 and the pressure inlet holes 316 are connected to the inner cavity of the valve body 1 and the insert clamping groove 311, and the medium passing through the pressure inlet grooves 315 and the pressure inlet holes 316 can form a pressure difference between the front and back of the valve seat insert 32.

[0029] Further, a leak detection hole 317 is arranged on the valve seat support ring 31, the leak detection hole 317 is connected to the second cavity 7, a valve body leak detection channel 14 is arranged at the bottom of the valve body 1, one end of the valve body leak detection channel 14 is connected to the leak detection hole 317, and the other end penetrates to the outside of the valve body 1, thereby facilitating online leak detection of the ball valve.

[0030] Further, two O-ring grooves are formed on the surface of the valve seat support ring 31 that is attached to the valve body 1, and O-rings 115 and 216 are embedded in the O-ring grooves. One O-ring groove is formed on the surface of the valve seat insert 32 that is attached to the valve seat support ring 31, and O-ring 317 is embedded in the O-ring groove. One O-ring groove is formed on the inner side of the valve seat insert 32 that is attached to the valve seat support ring 31, and O-ring 418 is embedded in the O-ring groove. One O-ring groove is formed on the surface of the limiting bolt that is attached to the valve seat support ring, and O-ring 519 is embedded in the O-ring groove.

[0031] The working mechanism of the hard sealing structure of the valve seat combination of the valve is described below.

[0032] When the forced sealing ball valve is closed, the ball 2 is tightly attached to the valve seat assembly 3 under the action of the valve shaft, the valve seat support ring 31 forms a hard seal with the ball 2, and the valve seat insert 32 forms a hard seal with the ball 2. The two seals work simultaneously to achieve a combined hard seal. When the medium flows in the forward direction, it will pass through the first sealing surface 9, the second sealing surface 10, and the third sealing surface 11. At this time, it passes through three levels of sealing, and zero leakage can be achieved at the valve body leak detection passage 14. When the medium flows in the reverse direction after the valve is closed, it will pass through the fourth sealing surface 12 and the fifth sealing surface 13. At this time, it passes through two levels of sealing, and zero leakage can be achieved at the valve body leak detection passage 14. Under this multi-level sealing structure, the purpose of forward and reverse sealing and zero leakage of the medium can be achieved, and the sealing performance of the ball valve is more reliable.

[0033] A disc spring 33 is installed between the valve seat insert 32 and the valve seat support ring 31. Under the action of the spring pre-tightening force, the valve seat insert 32 will be more tightly attached to the ball 2. The pressure inlet groove 315 and the pressure inlet hole 316 are connected to the inner cavity of the valve body 1 and the insert clamping groove 311. The medium passing through the pressure inlet groove 315 and the pressure inlet hole 316 can form a pressure difference between the front and back of the valve seat insert 32, achieving the effect of piston self-sealing. When the pressure in the pressure inlet hole 316 is greater than the front pressure of the valve seat insert 32, the valve seat insert 32 moves towards the ball 2, and is more tightly attached to the ball 2. However, due to the limitation of the limiting bolt 34, the valve seat insert 32 will not fall off even if the pressure difference is too large. The combination of spring pre-tightening force and piston self-sealing can eliminate the risk of sealing leakage caused by deformation or wear of the valve seat insert, and prolong the service life of the ball valve.

[0034] Based on the above basic working principle, various modifications and improvements can be made based on the structure, and these modified structures based on the structure are also within the protection scope of the present application.

[0035] The above is only a preferred embodiment of the present application, and it should be pointed out that the above preferred embodiment should not be regarded as a limitation of the present application. The protection scope of the present application should be limited by the scope defined by the claims. For ordinary skilled persons in the technical field, several improvements and refinements can be made without departing from the spirit and scope of the present application, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A forced seal ball valve seat combination hard seal structure, characterized in that: The valve body and the ball body are provided with a valve seat assembly, the valve seat assembly is provided with a valve seat pressing ring outside, and the valve seat pressing ring and the valve body clamp the valve seat assembly and are fixed by a hexagonal head bolt.

2. A forced seal ball valve seat assembly hard seal structure according to claim 1, characterized in that: The valve seat assembly comprises a valve seat support ring, an insert clamping groove is formed outside the ball side of the valve seat support ring, a valve seat insert is installed in the insert clamping groove, a disc spring is installed between the valve seat insert and the valve seat support ring, and spring pre-tightening force can be provided for the valve seat insert.

3. A hard seal structure of a forced seal ball valve seat combination according to any of claims 1 to 2, characterized in that A plurality of "L" shaped grooves are formed on the ball side of the valve seat support ring, when the valve seat assembly is attached to the ball body, first, second and third cavities are formed, thereby dividing the sealing surface into a plurality of sealing surfaces to form a multi-stage seal.

4. The forced seal ball valve seat assembly hard seal structure of claim 2, wherein: A plurality of limiting holes are formed on the valve seat support ring in a circumferential direction, limiting clamping grooves corresponding to the limiting holes are formed on the valve seat insert, limiting bolts are installed in the limiting holes, the limiting bolts are fixed to the valve seat support ring through threaded connection, the limiting bolts are inserted into the limiting clamping grooves to prevent the valve seat insert from falling off under excessive pressure difference, and the limiting clamping grooves have a displacement allowance to ensure that the valve seat insert can still move axially forward and backward after the limiting bolts are installed.

5. A forced seal ball valve seat assembly hard seal structure according to claim 2, characterized in that: A plurality of pressure inlet grooves and pressure inlet holes are formed on the valve seat support ring, the pressure inlet grooves are formed on the outer wall of the valve seat support ring and penetrate through the ball side of the valve seat support ring to the pressure inlet holes, the pressure inlet holes penetrate through the outer wall of the valve seat support ring to the insert clamping groove, the pressure inlet grooves and the pressure inlet holes are connected to the inner cavity of the valve body and the insert clamping groove in cooperation, and the medium passing through the pressure inlet grooves and the pressure inlet holes can form a pressure difference between the front and back of the valve seat insert.

6. A hard seal structure for a forced seal ball valve seat combination according to any of claims 1 to 2, characterized in that: A leak detection hole is formed on the valve seat support ring, the leak detection hole is connected to the second cavity, a valve body leak detection channel is formed at the bottom of the valve body, one end of the valve body leak detection channel is connected to the leak detection hole, and the other end penetrates to the outside of the valve body, thereby facilitating online leak detection of the ball valve.

7. A hard seal structure for a forced seal ball valve seat combination according to any of claims 1 to 3, characterized in that: Two O-ring grooves are formed on the attached surface of the valve seat support ring and the valve body, one O-ring groove is formed on the attached surface of the valve seat insert, one O-ring groove is formed on the inner side of the attached surface of the valve seat insert and the valve seat support ring, and one O-ring groove is formed on the attached surface of the limiting bolt and the valve seat support ring, and O-rings are embedded in all O-ring grooves for sealing.

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