Ball valve with a pressure relief function

Abstract

This disclosure provides a ball valve with a pressure relief function, comprising a valve body, a valve ball, a bypass passage, and a pressure relief device. The valve body includes an inlet end, an outlet end, and an internal chamber, which is disposed between the inlet and outlet ends. The valve body further includes a pressure relief hole that communicates with the internal chamber. The valve ball is rotatably disposed within the internal chamber and switches between an open position and a closed position. In the open position, the medium is allowed to flow along a flow path from the inlet end to the outlet end. In the closed position, the valve ball blocks the medium from exiting through the outlet end.　The bypass passage is connected between the flow path and the pressure relief hole. The pressure relief device is disposed on the valve body and controls whether the pressure relief hole is in communication with the bypass passage. When residual medium inside the internal chamber expands, it can activate the pressure relief device, thereby allowing the pressure relief hole and the bypass passage to conduct and release pressure into the flow path.

Description

[Technical Field]

[0001] This disclosure relates to a ball valve, and more particularly to a ball valve with a pressure relief function. [Previous Technology]

[0002] During the transportation of cryogenic media (such as liquefied natural gas), it is usually necessary to maintain a cryogenic environment to ensure its stability and safety. In this case, ball valves, as an indispensable key component of the pipeline system, are responsible for controlling the flow of fluid and the opening and closing of pipelines to maintain normal operation.

[0003] However, in reality, as the transportation or storage environment changes, the outside temperature may rise, causing the low-temperature medium to gradually vaporize due to the increased temperature. This vaporization phenomenon will significantly increase the gas pressure inside the storage valve body. If the pressure cannot be released effectively in time, the excessive internal pressure may damage the valve body structure, affect the service life of the ball valve, and even cause potential safety problems. [Summary of the Invention]

[0004] To solve the above problems, this disclosure provides a ball valve with a pressure relief function, which activates a pressure relief device when the internal medium expands, so as to release the internal pressure and avoid damage to the ball valve and affect its normal operation.

[0005] To achieve the aforementioned objectives, this disclosure provides a ball valve with a pressure relief function in one embodiment, comprising a valve body, a valve ball, a bypass pipeline, and a pressure relief device. The valve body has an inlet end, an outlet end opposite to the inlet end, and an inner cavity disposed between the inlet end and the outlet end. The valve body has a pressure relief hole communicating with the inner cavity. The valve ball is rotatably disposed in the inner cavity and has a through hole. The valve ball switches between an open position and a closed position. In the open position, the through hole communicates with the inlet end and the outlet end to allow the medium to flow along a flow path. In the closed position, the valve ball prevents the medium from flowing out from the outlet end. One end of the bypass pipeline is connected to the flow path. The other end of the bypass line is connected to the pressure relief port; the pressure relief device is installed in the valve body and between the pressure relief port and the bypass line, and the pressure relief device selectively controls whether the pressure relief port and the bypass line are connected; the valve seat is spaced apart and placed in the inner cavity; wherein, when the valve ball is in the open position, the pressure relief device keeps the pressure relief port in a closed state; when the valve ball is in the closed position, and the medium remaining in the inner cavity expands, it can cause the pressure relief device to operate, so that the pressure relief port and the bypass line are connected, thereby releasing pressure in the flow path.

[0006] Accordingly, this disclosure discloses that when the upstream pipeline is closed and the medium remaining in the inner cavity expands, the increase in internal pressure will cause the pressure relief device to activate, opening the pressure relief hole and the bypass pipeline, so that the expanded medium is discharged to the flow path through the bypass pipeline, thereby reducing the internal pressure of the inner cavity and avoiding damage to the ball valve or affecting its service life due to pressure.

Implementation Method

[0007] To facilitate the explanation of the central ideas expressed in the above-mentioned application content section, specific embodiments are provided below. Furthermore, to better explain the principles of this disclosure, specific language will be used to describe these examples. However, it should be understood that this does not imply that the scope of this disclosure is limited.

[0008] Please refer to Figures 1 to 5, which show a ball valve 100 with pressure relief function in the first embodiment of this disclosure. It includes a valve body 10, a valve ball 20, a bypass pipeline 30, a pressure relief device 40, a shaft 50, an operating element 60, and two valve seats 70 and 71. In one embodiment, the ball valve 100 is used in a pipeline for transporting liquefied natural gas, serving as a connection and switching point between upstream and downstream pipelines. However, its use in pipelines transporting other media, such as petroleum, gasoline, chemical solutions, or other chemical gases, is not excluded.

[0009] The valve body 10 includes a valve shell 11, a first valve cover 12, and a second valve cover 13. The first valve cover 12 is sealed to one side of the valve shell 11, and the second valve cover 13 is sealed to the other side of the valve shell 11. The valve body 10 has an inlet end 121 on the first valve cover 12 and an outlet end 131 on the second valve cover 13, opposite to the inlet end 121. The inlet end 121 is connected to the upstream via a pipeline to introduce medium M, while the outlet end 131 is connected to the downstream via a pipeline to output medium M. In one embodiment, medium M is liquefied natural gas. An inner cavity 14 is provided between the inlet end 121 and the outlet end 131, and the valve body 10 has a pressure relief hole 15 connected to the inner cavity 14. Both the pressure relief hole 15 and the inner cavity 14 are located on the valve shell 11.

[0010] A valve ball 20 is rotatably disposed in the inner cavity 14. In this disclosed embodiment, valve seats 70 and 71 are spaced apart and disposed in the inner cavity 14, respectively abutting against both sides of the valve ball 20. Valve seat 70 is adjacent to the inlet end 121, and valve seat 71 is adjacent to the outlet end 131. The valve ball 20 has a through hole 21, and the valve ball 20 switches between an open position P1 and a closed position P2. In the open position P1, the through hole 21 connects the inlet end 121 and the outlet end 131 to allow the medium M to flow along a flow path L1. In the closed position P2, the valve ball 20 prevents the medium M from flowing out of the outlet end 131.

[0011] In this disclosed embodiment, the shaft 50 is connected to the valve ball 20 along a rotation axis L2 perpendicular to one of the flow paths L1. The shaft 50 is rotated by the operating member 60 to drive the valve ball 20 to rotate about the rotation axis L2 as its axis, for opening or blocking the flow of the medium M. In one embodiment, the pressure relief hole 15 is provided on the side of the valve body 10 away from the shaft 50.

[0012] A bypass pipe 30 is connected at one end to the flow path L1 and at the other end to the pressure relief port 15. In one embodiment, the bypass pipe 30 is disposed in the valve body 10, with one end connected to the inlet end 121, and the bypass pipe 30 is a pipe structure internally disposed in the valve housing 11. Furthermore, the valve housing 11 of the valve body 10 has a movable chamber 111 connected between the pressure relief port 15 and the bypass pipe 30, and the movable chamber 111 is arranged parallel to the rotation axis L2. The bypass pipe 30 has a first segment 31 and a second segment 32, the first segment 31 being parallel to the rotation axis L2 and connected to the flow path L1, and the second segment 32 being parallel to the flow path L1 and connected to the first segment 31 and the movable chamber 111. In other embodiments, the bypass pipe 30 may be a continuous segment or a pipe of other shapes, such as an arc-shaped pipe or a straight pipe.

[0013] The pressure relief device 40 is installed in the valve body 10. The pressure relief device 40 is located between the pressure relief port 15 and the bypass pipeline 30. The pressure relief device 40 selectively controls whether the pressure relief port 15 and the bypass pipeline 30 are connected, so as to release pressure. The pressure relief device 40 includes a sealing element 41, an actuating rod 42, an elastic element 43 and a fixed seat 44 installed in the movable chamber 111. The actuating rod 42 is able to close the sealing element 41 towards the pressure relief port 15 under the elastic force of the elastic element 43, so as to keep the pressure relief port 15 and the bypass pipeline 30 out of communication under normal circumstances.

[0014] In some embodiments, the inner wall of the active chamber 111 adjacent to the pressure relief hole 15 is provided with a first clamping portion 111a, and the sealing member 41 has a second clamping portion 411 that is adapted to the first clamping portion 111a to improve the sealing effect of the sealing member 41 in sealing the pressure relief hole 15. In the embodiment disclosed herein, the first clamping portion 111a and the second clamping portion 411 are in a tapered fit, and the sealing member 41 is provided with a flat portion 412 opposite to the second clamping portion 411.

[0015] The fixed seat 44 is fixedly disposed on the valve shell 11 of the valve body 10. The fixed seat 44 has a movable groove 441 communicating with the movable chamber 111. The actuating rod 42 has a sliding part 421 and an abutting part 422 away from the sliding part 421. The abutting part 422 is planar. The sliding part 421 of the actuating rod 42 extends through the movable groove 441, and the abutting part 422 of the actuating rod 42 abuts against the planar part 412 of the sealing member 41. One end of the aforementioned elastic member 43 abuts against the fixed seat 44, and the other end of the elastic member 43 abuts against a stop 423 of the actuating rod 42, so that under normal conditions, the sealing member 41 is closed by the abutment of the elastic member 43 to close the pressure relief hole 15.

[0016] As shown in Figure 3, when the upstream pipeline transmits medium M and the valve ball 20 is in the open position P1, in addition to flowing from the inlet end 121 through the through hole 21 to the outlet end 131, part of the medium M enters the bypass pipeline 30 and flows to the pressure relief device 40. In this state, since the pressure of the ball valve 100 and the pipeline is in a balanced state, the pressure relief device 40 does not operate and keeps the pressure relief hole 15 in a closed state.

[0017] Referring to Figures 3 and 4, when the valve ball 20 switches from the open position P1 to the closed position P2, the valve ball 20 and the valve seat 70 form a closed state, blocking the medium M from continuing to flow through the flow path L1. Some residual medium M remains in the inner cavity 14. Furthermore, when the upstream pipeline continuously supplies medium M and continuously applies pressure to the valve ball 20, the medium M may be able to push the valve ball 20 towards the other valve seat 71, creating a gap G between the valve ball 20 and the valve seat 70, thus connecting the inner cavity 14 with the inlet end 121. In the state shown in Figure 4, the pressure of the ball valve 100 and the pipeline is in equilibrium, and there is no problem of pressure expansion of the medium M remaining in the inner cavity 14; therefore, the pressure relief device 40 will not activate.

[0018] As shown in Figure 5, when the upstream pipeline is closed and no medium M flows into the inlet end 121, the valve ball 20 and the valve seats 70 and 71 form a sealed state, making the inner cavity 14 an independent internal space. Accordingly, when the medium M remaining in the inner cavity 14 causes the pressure to increase due to temperature or other reasons, if the expansion pressure is greater than the elastic force of the elastic element 43 of the pressure relief device 40, it can cause the actuating rod 42 and the sealing element 41 to move downward, so that the pressure relief hole 15 and the bypass pipeline 30 are connected, thereby releasing the pressure in the flow path L1. That is, the internal pressure can be discharged to the inlet end 121 through the bypass pipeline 30, avoiding damage to the ball valve 100 caused by the internal pressure, and has the effect of extending the service life and avoiding damage to the ball valve 100 body.

[0019] Please refer to Figures 6 to 8, which show the second embodiment of this disclosure. A bypass pipe 30a is provided in the valve body 10, and one end of the bypass pipe 30a is connected to the outlet end 131. A pressure relief device 40a is provided between the pressure relief hole 15 and the bypass pipe 30a. As mentioned above, when the valve ball 20 is in the open position P1, the internal pressure is in a balanced state, so the pressure relief device 40a does not operate and the pressure relief hole 15 remains closed. However, when the valve ball 20 switches from the open position P1 to the closed position P2, and the pressure of the medium M remaining in the inner cavity 14 increases, the pressure relief device 40a can perform a pressure relief action when the pressure in the inner cavity 14 reaches the critical point for pushing the pressure relief device 40a, so that the pressure can be discharged to the outlet end 131 through the bypass pipe 30a, thereby avoiding damage to the ball valve 100a caused by the internal pressure.

[0020] Please refer to Figure 9, which shows the third embodiment of this disclosure. The bypass pipe 30b is an independent pipe adjacent to the inlet end 121. The valve body 10 has a first channel 16 connected to the flow path L1 and a second channel 17 connected to the pressure relief hole 15. The bypass pipe 30b is exposed outside the valve body 10, with one end connected to the first channel 16 and the other end connected to the second channel 17. It is also connected to the pressure relief hole 15 via the movable groove 441, thus having the same pressure relief function. In other embodiments of this disclosure, the bypass pipe 30b may also be designed as an independent pipe adjacent to the outlet end 131.

[0021] In summary, this disclosure discloses that when the upstream pipeline is closed and the medium M remaining in the inner cavity 14 expands, the pressure relief device 40a can be activated to discharge the internal pressure through the bypass pipeline 30a to the flow path L1, thereby avoiding damage to the ball valves 100 and 100a caused by pressure.

[0022] Although this disclosure is based on a preferred embodiment, those skilled in the art can make various modifications without departing from the spirit and scope of this disclosure. The embodiments described above are merely illustrative of this disclosure and are not intended to limit its scope. [Simplified Explanation of the Diagram]

[0023] [Figure 1] is a perspective view of a ball valve with pressure relief function according to the first embodiment of this disclosure. [Figure 2] is a partial exploded view of the ball valve with pressure relief function according to the first embodiment of this disclosure. [Figure 3] is a side sectional view of the first embodiment of this disclosure, showing the ball valve in the open position, allowing the medium to flow from the inlet end to the outlet end. [Figure 4] is a side sectional view of the first embodiment of this disclosure, showing the ball valve in the closed position, and the upstream pipeline is continuously pressurized, causing a gap to form between the valve seat near the inlet end and the ball valve. [Figure 5] is a side sectional view of the first embodiment of this disclosure, showing the expansion of the medium in the inner cavity, causing the pressure relief device to operate, and the pressure can be discharged to the inlet end through the bypass pipeline. [Figure 6] is a side sectional view of the second embodiment of this disclosure, showing the ball valve in the open position, allowing the medium to flow from the inlet end to the outlet end. [Figure 7] is a side cross-sectional view of the second embodiment of this disclosure, showing the valve ball in the closed position and continuous pressure in the upstream pipeline, creating a gap between the valve seat and the valve ball near the inlet end. [Figure 8] is a side cross-sectional view of the second embodiment of this disclosure, showing the expansion of the medium in the inner cavity, causing the pressure relief device to activate, and the pressure can be discharged to the outlet end through the bypass pipeline. [Figure 9] is a side cross-sectional view of the third embodiment of this disclosure, showing the bypass pipeline as an independent pipe near the inlet end.

Claims

1. A ball valve with pressure relief function, comprising: A valve body has an inlet end, an outlet end opposite to the inlet end, and an inner cavity disposed between the inlet end and the outlet end. The valve body has a pressure relief hole communicating with the inner cavity and a movable chamber. A valve ball is rotatably disposed in the inner cavity. The valve ball has a through hole and switches between an open position and a closed position. In the open position, the through hole communicates with the inlet end and the outlet end to allow the medium to flow along a flow path. In the closed position, the valve ball prevents the medium from flowing out from the outlet end. A bypass pipe is disposed in the valve body, one end of the bypass pipe is connected to the flow path, and the other end of the bypass pipe is connected to the pressure relief port. The movable chamber is connected between the pressure relief port and the bypass pipe. A pressure relief device is disposed in the valve body and between the pressure relief port and the bypass pipe. The pressure relief device selectively controls whether the pressure relief port and the bypass pipe are connected. The pressure relief device includes a sealing element, an actuating rod, and an elastic element disposed in the movable chamber. The actuating rod is able to close the sealing element towards the pressure relief port due to the elastic force of the elastic element, so as to keep the pressure relief port and the bypass pipe from communicating. When the valve ball is in the open position, the pressure relief device keeps the pressure relief hole closed. When the valve ball is in the closed position and the medium remaining in the inner cavity expands, the pressure relief device can be activated. The pressure generated by the expansion of the medium is greater than the elastic force of the elastic member, and the seal and the actuating rod are displaced so that the pressure relief hole is connected to the bypass pipeline, thereby releasing pressure in the flow path.

2. A ball valve with pressure relief function as described in claim 1, wherein, The bypass line is connected to the inlet end, and when the pressure relief device is activated, the pressure can be discharged to the inlet end through the bypass line.

3. A ball valve with pressure relief function as described in claim 1, wherein, The bypass line is connected to the outlet end, and when the pressure relief device is activated, the pressure can be discharged to the outlet end through the bypass line.

4. A ball valve with pressure relief function as described in claim 1, wherein, The inner wall of the active chamber near the pressure relief hole is provided with a first clamping part, and the seal has a second clamping part that is adapted to the first clamping part.

5. A ball valve with pressure relief function as described in claim 4, wherein, The pressure relief device further includes a fixed seat fixedly disposed on the valve body. The fixed seat has a movable groove communicating with the movable chamber. One end of the actuating rod extends through the movable groove. One end of the elastic member abuts against the fixed seat, and the other end of the elastic member abuts against the actuating rod.

6. A ball valve with pressure relief function as described in claim 5, wherein, The actuator has a sliding part and an abutting part away from the sliding part. The sliding part is located in the movable groove, and further includes two valve seats that are spaced apart and disposed in the inner cavity. The two valve seats abut against the two sides of the valve ball respectively.

7. The ball valve with pressure relief function as described in claim 1 further includes a shaft connected to the valve ball along a rotation axis perpendicular to the flow path, the movable chamber being arranged parallel to the rotation axis, and the pressure relief port being located on the side of the valve body away from the shaft.

8. A ball valve with pressure relief function as described in claim 7, wherein, The bypass pipeline has a first section and a second section. The first section is parallel to the axis of rotation and connected to the flow path, and the second section is parallel to the flow path and connected to the first section and the active chamber.

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