A high-temperature and high-pressure pilot-operated safety valve

Abstract

The present invention relates to a high-temperature and high-pressure pilot-operated safety valve, which includes a main valve and a pilot valve. The main valve includes a valve body, a valve seat, and a valve disc. The pilot valve includes a pilot valve seat, a pilot valve disc, and a pressure setting device. The upper end face of the pilot valve disc is connected to the pressure setting device. Its characteristics are as follows: A piston cylinder is arranged in the inlet cavity. The outer cylindrical surface of the valve disc is in dynamic sealing cooperation with the piston cylinder. The upper end face and the lower sealing surface of the valve seat are mutually cooperating sealing surfaces. A thrust device is installed at the center of the upper end face. The lower end face and the piston cylinder and the cylinder head form a piston cavity. The valve disc control cavity is composed of the piston cavity in the inlet cavity. The sealing performance of the valve disc control cavity does not affect the opening and closing state of the valve disc, avoiding the problem in the prior art that the use temperature is affected by using a rubber O-ring seal between the valve disc and the control cavity. The pilot valve is directly arranged in the valve body installation cavity, reducing the volume of the product. It has the advantages of high use temperature, small volume, and small installation space.

Description

Technical Field

[0001] The present invention belongs to the field of valves, and in particular relates to a pilot safety valve, which is suitable for high temperature and high pressure working conditions. Background Art

[0002] The pilot-operated safety valve is composed of a main valve and a pilot valve. The spring set pressure of the pilot valve is used to control the pressure in the control chamber of the main valve disc, so as to achieve the stability of the pressure of the main valve control system. Compared with the direct use of spring-type safety valves, the product volume and installation space can be greatly reduced. The pilot-operated safety valve controls the main valve by the pilot valve. The inlet channel of the pilot valve connects the inlet chamber of the main valve and the control chamber. The main valve disc is located in the discharge chamber at the upper end of the main valve seat. When the pressure in the inlet chamber of the main valve exceeds the set pressure of the pilot valve, the pilot valve disc is pushed to open and the pressure in the control chamber of the main valve is released. The main valve disc opens to discharge the system medium pressure and maintains the system medium pressure stable. The main valve control chamber is composed of the inner chamber of the guide sleeve between the upper end face of the valve disc and the lower end face of the valve cover. The guide column on the outer cylindrical surface of the valve disc cooperates with the guide hole of the guide sleeve to ensure the sealing performance of the main valve control chamber and prevent the control chamber medium pressure from leaking to the discharge port, causing the main valve disc to open and discharge by mistake. Generally, an O-type rubber sealing ring is set between the outer cylindrical surface of the main valve disc guide column and the guide hole of the guide sleeve. Therefore, the existing pilot-operated safety valve has poor temperature resistance and low operating temperature and is not suitable for high temperature working conditions. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a high-temperature and high-pressure pilot safety valve which is small in size, resistant to high temperatures and suitable for high-temperature working conditions.

[0004] The present invention is achieved by adopting the following technical solutions:

[0005] A high-temperature and high-pressure pilot safety valve comprises a main valve and a pilot valve, the main valve comprises a valve body, a valve seat, and a valve disc, the valve body has an inlet cavity and a discharge cavity, the pilot valve comprises a pilot valve seat, a pilot valve disc and a pressure setting device, the lower end surface of the pilot valve disc and the upper end surface of the pilot valve seat cooperate with each other to form a sealing pair, and the upper end surface of the pilot valve disc is connected to the pressure setting device; its characteristics are: a piston cylinder is arranged in the inlet cavity, the outer cylindrical surface of the piston cylinder and the inner wall of the inlet cavity are connected to each other through radial connecting ribs, the outer cylindrical surface of the valve disc cooperates with the piston cylinder in a dynamic seal, and the upper end surface is provided with a sealing surface that cooperates with the sealing surface of the lower end of the valve seat , a thrust device is installed at the center of the upper end surface, and the lower end surface, the piston cylinder and the cylinder cover form a piston cavity, and a spring is installed in the piston cavity; a pressure-inducing hole connecting the piston cavity and the inlet cavity is provided on the cylinder cover, and the inlet of the pilot valve seat is connected with the piston cavity through the pressure-inducing channel; a switching rod is arranged on the pressure-inducing hole of the cylinder cover, and a switching hole is provided on the switching rod. The switching rod is connected with the center of the plane on one side of the sealing surface of the pilot valve disc through a connecting rod mechanism. When the pilot valve is closed, the switching hole is aligned with the pressure-inducing hole, and the inlet cavity is connected with the piston cavity. When the pilot valve is opened, the switching hole and the pressure-inducing hole are staggered, and the switching rod cuts off the inlet cavity and the piston cavity.

[0006] Preferably, the switching rod adopts a plunger structure. One end of the plunger is connected to the connecting rod, and the other end is located in the guiding hole on the cylinder head that is perpendicular to the pressure guiding hole.

[0007] Preferably, the switching rod adopts a gate plate structure. One end of the gate plate is connected to the connecting rod, and the other end is located in the guiding groove on the cylinder head that is perpendicular to the pressure guiding hole.

[0008] Preferably, the pilot valve is installed in the installation cavity of the valve body. The installation cavity is communicated with the piston cavity through a pressure guiding channel. The pilot valve flap is installed in the installation cavity at the outlet of the pressure guiding channel. Its outer cylindrical surface is guided and fitted with the inner wall of the installation cavity by radial ribs. A discharge hole is arranged on one side of the installation cavity; the pressure setting device adopts a spring pressure setting device, which consists of a push rod, a setting spring, and a setting sleeve. One end of the push rod presses against the center of the back surface of the pilot valve flap, and the other end passes through the secondary guiding sleeve and is movably fitted with the inner hole of the setting sleeve. The setting sleeve is installed in the adjusting screw hole of the pilot valve cover by threads. The setting spring is installed on the push rod in the inner cavity of the pilot valve cover by an upper spring seat and a lower spring seat. The secondary guiding sleeve is pressed by the pilot valve cover on the radial step of the inner cavity wall of the installation cavity.

[0009] Preferably, the connecting rod mechanism consists of a straight rod and an inclined rod. The pressure guiding channel consists of a vertical channel and a horizontal channel; the straight rod is located in the vertical channel, its upper end is fixedly connected to the pilot valve flap, and its lower end passes through the vertical channel and is inserted into the switching cavity on the valve body; the inclined rod is arranged at the lower end of the straight rod and is movably fitted with the connecting hole on the switching rod.

[0010] Preferably, an auxiliary rolling device composed of an auxiliary spring and a ball is arranged in the switching rod between the two inclined surfaces of the inclined rod and the connecting hole.

[0011] Preferably, the thrust device adopts a spring thrust device, which consists of a thrust spring, a push rod, a valve cover, a screw sleeve, and a guiding sleeve. The guiding sleeve is press-fitted between the lower end face of the valve cover and the upper end face of the valve body. The screw sleeve is installed in the screw hole at the upper end of the valve cover through an external thread. The lower end of the push rod passes through the flow passage hole of the valve seat and touches the center of the upper end face of the valve flap. The upper end passes through the guiding hole of the guiding sleeve and is movably fitted with the inner hole of the screw sleeve. The thrust spring is installed between the upper and lower spring seats on the push rod. The lower end of the screw sleeve presses against the upper end face of the upper spring seat.

[0012] The beneficial effects of the present invention compared with the prior art are as follows: The sealing pair of the valve flap and the valve seat is located in the inlet cavity. The valve flap control cavity consists of the piston cavity in the inlet cavity. The sealing performance of the valve flap control cavity does not affect the opening and closing state of the valve flap, realizing all-metal sealing and avoiding the problem that the use temperature is affected by the rubber O-ring sealing between the valve flap and the control cavity in the prior art; The pilot valve is directly arranged in the installation cavity of the valve body, reducing the volume of the product. It has the advantages of high use temperature, small volume, and small installation space. Brief Description of the Drawings

[0013] Figure 1 It is a structural sectional view of the present invention.

[0014] Figure 2 is a local enlarged view of part A in the present invention Figure 1 in the present invention.

[0015] In the figure: 1 valve body, 2 piston cylinder, 3 piston chamber, 4 cylinder head, 5 inlet chamber, 6 spring, 7 switching hole, 8 pressure guiding hole, 9 switching rod, 10 guiding rod, 11 switching chamber, 12 inclined rod, 13 end cover, 14 pressure guiding channel, 15 straight rod, 16 pilot valve seat, 17 pilot valve flap, 18 discharge groove, 19 discharge hole, 20 installation chamber, 21 secondary guiding sleeve, 22 pilot valve cover, 23 ejector rod, 24 setting spring, 25 setting screw sleeve, 26 pilot valve cap, 27 valve flap, 28 valve seat, 29 push rod, 30 guiding sleeve, 31 discharge chamber, 32 valve cover, 33 thrust spring, 34 screw sleeve, 35 valve cap, 36 auxiliary spring, 37 ball. Embodiment

[0016] such as Figure 1The high temperature and high pressure pilot safety valve shown in the figure comprises a main valve and a pilot valve. The main valve comprises a valve body 1, a valve seat 28, and a valve disc 27. The valve body 1 has an inlet cavity 5 and a discharge cavity 31. The pilot valve comprises a pilot valve seat 16, a pilot valve disc 17 and a pressure setting device. The lower end surface of the pilot valve disc 17 and the upper end surface of the pilot valve seat 16 cooperate with each other to form a sealing pair. The upper end surface of the pilot valve disc 17 is connected to the pressure setting device. When the pressure of the inlet cavity 5 is lower than the pressure value set by the pressure setting device, the sealing pair is in a closed state. When the pressure of the inlet cavity 5 exceeds the pressure value set by the pressure setting device, the sealing pair is in a closed state. The sealing pair is in an open state; its characteristics are: a piston cylinder 2 is arranged in the inlet cavity 5, the outer cylindrical surface of the piston cylinder 2 and the inner wall of the inlet cavity 5 are connected to each other through radial connecting ribs, the outer cylindrical surface of the valve disc 27 is movably matched with the inner wall of the piston cylinder 2, the upper end surface is provided with a sealing surface that cooperates with the lower end sealing surface of the valve seat 28, a thrust device is installed at the top of the upper end surface, the lower end surface and the piston cylinder 2 and the cylinder cover 4 form a piston cavity 3, a spring 6 is installed in the piston cavity 3, and the thrust of the thrust device is set to be greater than the elastic force of the spring 6 and less than the sum of the minimum working pressure of the inlet cavity medium and the elastic force of the spring 6. When the pressure of the inlet cavity 5 is less than the set pressure, the sum of the inlet medium pressure and the elastic force of the spring 6 overcomes the thrust of the thrust device, pushing the valve disc 27 to seal with the valve seat 28. When the pressure of the inlet cavity 5 exceeds the set pressure, the pressure of the piston cavity 3 is discharged through the pilot valve, and the thrust of the thrust device overcomes the elastic force of the spring 6 to push the valve disc 27 downward to open. The cylinder head 4 is provided with a pressure-introducing hole 8 connecting the piston cavity 3 and the inlet cavity 5, so that the pressure of the inlet cavity 5 is introduced into the piston cavity 3, and the inlet of the pilot valve seat 16 is connected with the piston cavity 3 through the pressure-introducing channel 14. A cut-out is provided on the pressure-introducing hole 8 of the cylinder head 4. A switching rod 9 is provided with a switching hole 7. The switching rod 9 is connected to the center of the plane on one side of the sealing surface of the pilot valve disc 17 through a connecting rod mechanism. A guide rod 10 is provided between the switching rod 9 and the valve body 1 to improve the movement reliability of the switching rod 9. When the pilot valve is closed, the switching hole 7 is aligned with the pressure-inducing hole 8, and the inlet cavity 5 is connected with the piston cavity 3 to introduce the medium pressure of the inlet cavity 5 into the piston cavity 3. When the pilot valve is opened, the switching hole 7 is staggered with the pressure-inducing hole 8, and the switching rod 9 cuts off the inlet cavity 5 and the piston cavity 3. The pressure in the piston cavity 3 is discharged through the pressure-inducing channel 14 and the pilot valve.

[0017] The technical effect of this technical solution is that the valve flap is arranged in the valve body inlet cavity, the valve flap control cavity is formed by the piston cavity, and the control cavity is in the valve body inlet cavity. The sealing performance requirements between the control cavity and the inlet cavity are not high, which avoids the problem of low operating temperature caused by the use of rubber sealing rings between the valve flap and the control cavity, so that the product has the advantages of high operating temperature and is suitable for high temperature working conditions.

[0018] The switching rod 9 adopts a plunger structure. One end of the plunger is connected to the pilot valve flap 17 through a connecting rod mechanism, and the other end is located in a guiding hole on the cylinder head 4 that is perpendicular to the pressure guiding hole 8. In the closed state of the pilot valve, the switching hole 7 on the plunger is aligned with the pressure guiding hole 8, and the piston chamber 3 is communicated with the inlet chamber 5; when the pilot valve is opened, the pilot valve flap 7 is opened, and the connecting rod drives the plunger to move, closing the pressure guiding hole 8.

[0019] The switching rod 9 adopts a gate plate structure. One end of the gate plate is connected to the connecting rod, and the other end is located in a guiding groove on the cylinder head 4 that is perpendicular to the pressure guiding hole 8.

[0020] The pilot valve is installed in the installation cavity 20 of the valve body 1. The installation cavity 20 is communicated with the piston chamber 3 through a pressure guiding channel 14. The pilot valve seat 16 is installed in the installation cavity 20, and its inlet is communicated with the outlet of the pressure guiding channel 14. The pilot valve flap 17 is installed in the installation cavity 20 on the outlet side of the pilot valve seat. Its outer cylindrical surface is guided and fitted with the inner wall of the installation cavity 20 by radial ribs. Discharge grooves 18 are formed between adjacent radial ribs. A discharge hole 19 is provided on one side of the installation cavity 20. After the pilot valve flap 17 is opened, the medium pressure in the piston chamber 3 is discharged through the pressure guiding channel 14, the pilot valve seat 16, the discharge grooves 18, and the discharge hole 19; The pressure setting device adopts a spring pressure setting device, which consists of a push rod 15, a setting spring 24, and a setting sleeve 25. One end of the push rod 15 presses against the center of the back surface of the pilot valve flap 17, and the other end passes through the secondary guiding sleeve 21 and is movably fitted with the inner hole of the setting sleeve 25. The setting sleeve 25 is threadedly installed in the adjusting screw hole of the pilot valve cover 22. A pilot valve cap 26 is provided at the upper end of the pilot valve cover 22 to prevent dust from entering the setting sleeve 25. The setting spring 24 is installed between the upper spring seat and the lower spring seat on the push rod 15. The lower end of the setting sleeve 25 presses against the upper end surface of the upper spring seat. By adjusting the setting sleeve 25, the compression amount of the setting spring 24 is adjusted to realize the adjustment and setting of the setting pressure. The secondary guiding sleeve 21 is pressed by the pilot valve cover 22 on the radial step of the inner cavity wall of the installation cavity 20.

[0021] The technical effect produced by this technical feature is that the pilot valve and the connecting rod mechanism are directly installed in the installation cavity made on the main valve body, reducing the product volume and installation space.

[0022] The connecting rod mechanism consists of a straight rod 15 and an inclined rod 12. The pressure guiding channel 14 consists of a vertical channel and a horizontal channel; The straight rod 15 is located in the vertical channel. Its upper end is fixedly connected to the pilot valve flap 17, and its lower end passes through the vertical channel and is inserted into the switching cavity 11 on the valve body 1. The switching cavity 11 and the valve body 1 are sealed by an end cover 13; The inclined rod 12 is arranged at the lower end of the straight rod 15 and is movably fitted with the connecting hole on the switching rod 9. When the pilot valve flap 17 is closed, the inclined rod 12 pushes the switching rod 9 to move to the right, aligning the switching hole 7 with the pressure guiding hole 8; When the pilot valve flap 17 is opened, the inclined rod 12 moves upward and drives the switching rod 9 to move to the left, closing the pressure guiding hole 8.

[0023] An auxiliary rolling device composed of an auxiliary spring 36 and a ball 37 is arranged in the switching rod 9 between the inclined planes on both sides of the inclined rod 12 and the connecting hole, which reduces the friction force when the inclined rod 12 moves in the connecting hole of the switching rod 9, improves the moving reliability of the switching rod 9, and realizes the buffering function of the movement of the switching rod 9, as Figure 2 shown.

[0024] The thrust device adopts a spring thrust device, which is composed of a thrust spring 33, a push rod 29, a valve cover 32, a screw sleeve 34, and a guide sleeve 30. The guide sleeve 30 is press-fitted between the lower end face of the valve cover 32 and the upper end face of the valve body 1. The screw sleeve 34 is installed in the screw hole at the upper end of the valve cover 32 through an external thread. A valve cap 35 is installed at the upper end of the valve cover 32 to prevent dust from entering the screw sleeve 34. The lower end of the push rod 29 passes through the flow passage hole of the valve seat 28 and touches the center of the upper end face of the valve flap 27, and the upper end passes through the guide hole of the guide sleeve 30 and is movably matched with the inner hole of the screw sleeve 34. The thrust spring 33 is installed between the upper and lower spring seats on the push rod 29. The lower end of the screw sleeve 34 presses against the upper end face of the upper spring seat, raising the position of the adjusting screw sleeve 34, adjusting the elastic force of the thrust spring 33, and setting the thrust of the thrust device.

Claims

1. A high-temperature and high-pressure pilot-operated safety valve, comprising a main valve and a pilot valve. The main valve includes a valve body (1), a valve seat (28), and a valve disc (27). The valve body (1) has an inlet chamber (5) and a discharge chamber (31). The pilot valve includes a pilot valve seat (16), a pilot valve disc (17), and a pressure setting device. The lower end surface of the pilot valve disc (17) and the upper end surface of the pilot valve seat (16) cooperate with each other to form a sealing pair, and the upper end surface of the pilot valve disc (17) is connected to the pressure setting device; characterized in that: A piston cylinder (2) is arranged in the inlet cavity (5). The outer cylindrical surface of the piston cylinder (2) is connected to the inner wall of the inlet cavity (5) through radial connecting ribs. The outer cylindrical surface of the valve flap (27) is movably fitted with the inner wall of the piston cylinder (2). The upper end surface is provided with a sealing surface that cooperates with the lower sealing surface of the valve seat (28). A thrust device is installed at the center of the upper end surface. The lower end surface and the piston cylinder (2) and the cylinder head (4) form a piston cavity (3), and a spring (6) is installed in the piston cavity (3); a pressure guiding hole (8) that connects the piston cavity (3) and the inlet cavity (5) is provided on the cylinder head (4). The inlet of the pilot valve seat (16) is communicated with the piston cavity (3) through a pressure guiding channel (14); a switching rod (9) is arranged on the pressure guiding hole (8) of the cylinder head (4). A switching hole (7) is provided on the switching rod (9). The switching rod (9) is connected to the center of the plane on one side of the sealing surface of the pilot valve flap (17) through a linkage mechanism. In the closed state of the pilot valve, the switching hole (7) is aligned with the pressure guiding hole (8). When the pilot valve is opened, the switching hole (7) is offset from the pressure guiding hole (8), and the switching rod (9) seals and isolates the inlet cavity (5) and the piston cavity (3); the thrust of the thrust device is set to be greater than the elastic force of the spring (6) and less than the sum of the minimum working pressure of the inlet cavity medium and the elastic force of the spring (6).

2. The high-temperature and high-pressure pilot-operated safety valve according to claim 1, characterized in that: The switching rod (9) adopts a plunger structure. One end of the plunger is connected to the pilot valve flap (17) through a linkage mechanism, and the other end is located in a guiding hole on the cylinder head (4) that is perpendicular to the pressure guiding hole (8).

3. The high-temperature and high-pressure pilot-operated safety valve according to claim 1, characterized in that: The switching rod (9) adopts a gate plate structure. One end of the gate plate is connected to the connecting pilot valve flap (17) through a linkage mechanism, and the other end is located in a guiding groove on the cylinder head (4) that is perpendicular to the pressure guiding hole (8).

4. The high-temperature and high-pressure pilot-operated safety valve according to claim 1 or 2 or 3, characterized in that: The pilot valve is installed in the installation cavity (20) of the valve body (1). The installation cavity (20) is communicated with the piston cavity (3) through a pressure guiding channel (14). The inlet of the pilot valve seat (16) is communicated with the outlet of the pressure guiding channel (14). The pilot valve flap (17) is installed in the installation cavity (20) on the outlet side of the pilot valve seat (16). Its outer cylindrical surface is guided and fitted with the inner wall of the installation cavity (20) by radial ribs. A discharge hole (19) is arranged on one side of the installation cavity (20); the pressure setting device adopts a spring pressure setting device, which is composed of a push rod (23), a setting spring (24), and a setting sleeve (25). One end of the push rod (23) presses against the center of the back surface of the pilot valve flap (17), and the other end passes through the secondary guiding sleeve (21) and is movably fitted with the inner hole of the setting sleeve (25). The setting sleeve (25) is installed in the adjusting screw hole of the pilot valve cover (22) by threads. The setting spring (24) is installed between the upper spring seat and the lower spring seat on the push rod (23). The lower end of the setting sleeve (25) presses against the upper end surface of the upper spring seat. The secondary guiding sleeve (21) is pressed by the pilot valve cover (22) on the radial step of the inner cavity wall of the installation cavity (20).

5. The high-temperature and high-pressure pilot-operated safety valve according to claim 4, characterized in that: The linkage mechanism is composed of a straight rod (15) and an inclined rod (12), and the pressure guiding channel (14) is composed of a vertical channel and a horizontal channel; the straight rod (15) is located in the vertical channel, its upper end is fixedly connected to the pilot valve flap (17), and its lower end passes through the vertical channel and is inserted into the switching cavity (11) on the valve body (1); the inclined rod (12) is movably matched with the connecting hole on the lower end of the straight rod (15) and the switching rod (9).

6. The high-temperature and high-pressure pilot-operated safety valve according to claim 5, characterized in that: An auxiliary rolling device composed of an auxiliary spring (36) and a ball (37) is arranged in the switching rod (9) between the two inclined surfaces of the inclined rod (12) and the connecting hole.

7. The high-temperature and high-pressure pilot-operated safety valve according to claim 1 or 2 or 3 or 5 or 6, characterized in that: The thrust device is composed of a thrust spring (33), a push rod (29), a valve cover (32), a screw sleeve (34), and a guide sleeve (30). The guide sleeve (30) is press-fitted between the lower end face of the valve cover (32) and the upper end face of the valve body (1). The screw sleeve (34) is installed in the screw hole at the upper end of the valve cover (32) through an external thread. The lower end of the push rod (29) passes through the flow passage hole of the valve seat (28) and touches the center of the upper end face of the valve flap (27). The upper end passes through the guide hole of the guide sleeve (30) and is movably matched with the inner hole of the screw sleeve (34). The thrust spring (33) is installed between the upper and lower spring seats on the push rod (29), and the lower end of the screw sleeve (34) presses against the upper end face of the upper spring seat.

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