Double-pilot-valve pilot operated safety valve with standby pilot valve

Abstract

The utility model relates to a double pilot valve pilot operated safety valve with a spare pilot valve, which belongs to the technical field of valves and comprises a main valve and a pilot valve, the main valve comprises a main valve body, a main valve seat, a main valve clack and a main valve cover, a piston cavity is formed between the back of the main valve clack and the main valve cover, and the pilot valve comprises a pilot valve body, a pilot valve clack and a pressure setting device. The pilot valve inlet is respectively communicated with the main valve inlet cavity and the piston cavity; the check valve is characterized in that the pilot valve is composed of a first pilot valve and a second pilot valve, inlets of the first pilot valve and the second pilot valve are communicated with an inlet cavity of the main valve through a switching device, and a piston cavity of the main valve is communicated with the inlets of the first pilot valve and the second pilot valve through a three-way check device. And when one pilot valve is damaged, the other pilot valve is switched to work, so that on-line maintenance without stopping production is realized, the continuous operation of the system is kept, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to a safety valve, in particular to a pilot-operated safety valve. Background Art

[0002] The pilot-operated safety valve consists of a main valve and a pilot valve. The pressure of the main valve inlet cavity is introduced into the inlet side of the pilot valve disc. When the inlet cavity pressure exceeds the set pressure value of the pilot valve, the pilot valve opens to release the piston cavity pressure on the back of the main valve disc, and the pilot valve controls the opening and closing state of the main valve. Its main disadvantage is that when the pilot valve parts are damaged and need to be replaced or repaired, or the set pressure needs to be changed, the pipeline operation equipment needs to be shut down for maintenance or adjustment, which affects the continuity and efficiency of the system operation. Summary of the invention

[0003] The utility model aims at the shortcomings of the prior art and provides a double-pilot-valve pilot safety valve with a spare pilot valve, which can be repaired or the set pressure adjusted without stopping the machine, keeps the system running continuously and improves the system operation efficiency.

[0004] The technical solution to realize the utility model is:

[0005] A double pilot valve pilot safety valve with a spare pilot valve comprises a main valve and a pilot valve, wherein the main valve comprises a main valve body, a main valve seat, a main valve disc and a main valve cover, a piston chamber is formed between the back of the main valve disc and the main valve cover, the pilot valve comprises a pilot valve body, a pilot valve disc and a pressure setting device, and the pilot valve inlet is respectively connected with the main valve inlet chamber and the piston chamber; the characteristic is that the pilot valve consists of a first pilot valve and a second pilot valve, the first pilot valve and the second pilot valve inlet are connected with the main valve inlet chamber through a switching device, and the main valve piston chamber is connected with the first pilot valve and the second pilot valve inlet through a three-way check device.

[0006] In the above technical solution, the switching device is composed of a four-way ball valve and connecting pipe fittings. The four-way ball valve is composed of a switching valve body, a switching ball and a switching valve stem. The switching valve body is provided with outlets at 90° angles to each other, wherein the first outlet is connected to the inlet cavity of the main valve, the second outlet is located at 180° of the first outlet and is connected to the atmosphere, and the third outlet and the fourth outlet are located at 90° on both sides of the first outlet and are respectively connected to the first pilot valve and the second pilot valve inlet; two symmetrical 90° arc channels are provided in the switching ball, one end of the switching valve stem is fixedly connected to the switching ball, and its center line passes perpendicularly through the center of the ball of the plane where the two 90° arc channels are located, and a positioning device is provided between the switching valve stem and the switching valve body to position the two end outlets of the 90° arc channel of the switching ball to be connected to the two adjacent outlets of the switching ball.

[0007] In the above technical scheme, the three-way check device is composed of a three-way valve body and a check valve disc. The three-way valve body is provided with a horizontal channel and a vertical channel. The two ends of the horizontal channel are respectively connected to the inlets of the first pilot valve and the second pilot valve, and the vertical channel is connected to the piston chamber of the main valve. A left valve seat and a right valve seat are arranged in the horizontal channels on both sides of the vertical channel. The check valve disc is installed between the left valve seat and the right valve seat. The left and right end surfaces of the check valve disc are respectively provided with sealing surfaces that cooperate with the left valve seat and the right valve seat. The axial length between the sealing surfaces on both sides of the check valve disc is less than the distance between the left valve seat and the right valve seat and the center line of the vertical channel.

[0008] Compared with the prior art, the utility model has the beneficial effect that the dual pilot valves are used to switch and control the main valve. When one pilot valve is working, the other pilot valve is on standby. When one of the pilot valves is damaged, the standby pilot valve is switched to work, thereby realizing online maintenance without stopping production, keeping the system running continuously, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural schematic diagram of the utility model.

[0010] Figure 2 This utility model Figure 1 Cross-sectional view along the EE direction.

[0011] Figure 3 This utility model Figure 1 A magnified view of the local structure at point A.

[0012] Figure 4 This utility model Figure 1 Enlarged view of the local structure at point B in the middle.

[0013] In the figure: 1 main valve, 2 switching device, 3 lower left connecting pipe, 4 first pilot valve, 5 upper left connecting pipe, 6 three-way check device, 7 upper right connecting pipe, 8 second pilot valve, 9 lower right connecting pipe, 10 main valve body, 11 lower main pipe, 12 air inlet joint, 13 switching valve body, 14 first drainage hole, 15 switching valve stem, 16 switching ball, 17 second drainage hole, 18 exhaust hole, 19 main valve seat, 20 main valve disc, 21 guide sleeve, 22 limit screw, 23 piston chamber, 24 three-way valve body, 25 check chamber, 26 upper main pipe, 27 preload spring, 28 main valve cover, 29 outlet chamber, 30 inlet chamber, 31 left connecting sleeve, 32 check valve disc, 33 right connecting sleeve. DETAILED DESCRIPTION

[0014] like Figure 1 , Figure 2The double pilot valve pilot safety valve with spare pilot valve shown in the figure comprises a main valve 1 and a pilot valve. The main valve 1 comprises a main valve body 10, a main valve seat 19, a main valve disc 20, and a main valve cover 28. The main valve body 10 has an inlet cavity 30 and an outlet cavity 29. A guide sleeve 21 is installed between the main valve body 10 and the main valve cover 28. The outer cylindrical surface of the main valve disc 20 and the inner cylindrical wall of the guide sleeve 21 are dynamically sealed. A piston cavity 23 is formed between the back of the main valve disc 20 and the main valve cover 28. A preload spring 27 is arranged in the piston cavity 23 to provide a preload spring for the main valve disc 20. To provide sealing preload force, a limit screw 22 is arranged on the back of the main valve disc 20 to limit its opening height. The pilot valve comprises a pilot valve body, a pilot valve disc and a pressure setting device. The pilot valve inlet is respectively connected with the inlet cavity 30 and the piston cavity 23 of the main valve 1. The pilot valve is characterized in that the pilot valve comprises a first pilot valve 4 and a second pilot valve 8. The inlets of the first pilot valve 4 and the second pilot valve 8 are connected with the inlet cavity 30 of the main valve 1 through a switching device 2. The piston cavity 23 of the main valve 1 is connected with the inlets of the first pilot valve 4 and the second pilot valve 8 through a three-way check device 6. When the inlet of the first pilot valve 4 is connected with the inlet cavity 30 of the main valve 1 through the switching device 2, the inlet of the second pilot valve 8 is blocked from the inlet cavity 30 of the main valve 1, and the medium pressure of the inlet cavity 30 pushes the three-way check device 6 to block the piston cavity 23 from the inlet of the first pilot valve 4, and the inlet of the second pilot valve 8 from the piston cavity 23. The first pilot valve 4 controls the main valve 1 to work, and the second pilot valve 8 is on standby. When the first pilot valve 4 is damaged for repair, the second pilot valve 8 is put into operation through the switching device 2 to keep the main valve 1 operating normally, realize online maintenance or replacement of the pilot valve, and keep the system running continuously.

[0015] like Figure 1 , Figure 2 , Figure 4As shown, the switching device 2 is composed of a four-way ball valve and connecting pipe fittings. The four-way ball valve is composed of a switching valve body 13, a switching ball 16 and a switching valve stem 15. The switching valve body 13 is provided with four outlets, and the angle between two adjacent outlets is 90 degrees. The first outlet is connected to the inlet cavity 30 of the main valve 1, and the two are connected to each other by the lower main pipe 11 and the air inlet joint 12. The second outlet is located at 180 degrees from the first outlet, that is, the second outlet and the first outlet are at two ends of the same diameter of the inner cavity of the switching valve body 13, serving as the pilot valve exhaust hole 18. The third outlet and the fourth outlet are located at 90 degrees on both sides of the first outlet and are connected to the inlets of the first pilot valve 4 and the second pilot valve 8 respectively. The third outlet is connected to the first pilot valve 4 and the second pilot valve 8 through the lower left pipe 3. The first pilot valve 4 is connected to the inlet, and the fourth outlet is connected to the inlet of the second pilot valve 8 through the lower right connecting pipe 9; two symmetrical 90° arc channels are arranged in the switching ball 16, and the outlets at both ends of the 90° arc channel are the first drainage hole 14 and the second drainage hole 17 in the switching ball 16, which are at a 90° angle; one end of the switching valve stem 15 is fixedly connected to the switching ball 16, and its center line passes perpendicularly through the center of the sphere of the plane where the two 90° arc channels are located; the four outlets of the switching valve body 13 are on a plane perpendicular to the switching valve stem 15, and a positioning device is arranged between the switching valve stem 15 and the switching valve body 13, so as to position the outlets at both ends of the 90° arc channel of the switching ball 16 to be connected to two adjacent outlets of the switching valve body 13. When the switching valve stem 15 connects the outlets at both ends of the first drainage hole 14 of the switching ball 16 with the first outlet and the fourth outlet of the switching valve body 13, the second pilot valve 8 works and the first pilot valve 4 stands by; when the outlets at both ends of the second drainage hole 17 are connected with the first outlet and the third outlet of the switching valve body 13, the first pilot valve 4 works and the second pilot valve 8 stands by.

[0016] like Figure 1 ,, Figure 2 , Figure 3As shown, the three-way check device 6 is composed of a three-way valve body 24 and a check valve flap 32. The three-way valve body 24 is provided with a horizontal channel and a vertical channel. The two ends of the horizontal channel are respectively connected with the inlet of the first pilot valve 4 and the second pilot valve 8. The left end of the horizontal channel is connected with the inlet of the first pilot valve 4 through the left connecting sleeve 31 and the left upper connecting pipe 5, and the right end of the horizontal channel is connected with the inlet of the second pilot valve 8 through the right connecting sleeve 33 and the right upper connecting pipe 7. The vertical channel is connected with the piston chamber 23 of the main valve 1, and the piston chamber 23 is connected with the vertical channel through the upper main pipe 26. A left valve seat and a right valve seat are arranged in the horizontal channels on both sides of the vertical channel. The left valve seat is arranged at the right end of the left connecting sleeve 31, and the right valve seat is arranged at the left end of the right connecting sleeve 33. The check valve flap 32 is installed between the left valve seat and the right valve The check valve flap 32 can move left and right in the check valve flap 25 between the seats, and its left and right end surfaces are respectively provided with sealing surfaces that cooperate with the left valve seat and the right valve seat. The axial length between the sealing surfaces on both sides of the check valve flap 32 is less than the distance between the left valve seat and the right valve seat and the center line of the vertical channel, ensuring the circulation of the vertical channel and the horizontal channel on one side. When the inlet of the first pilot valve 4 is connected with the inlet chamber 30 of the main valve 1, the medium pressure of the inlet chamber 30 pushes the check valve flap 32 to move rightward and seal with the right valve seat, and the piston chamber 23 is connected with the inlet of the first pilot valve 4. When the inlet of the second pilot valve 8 is connected with the inlet chamber 30 of the main valve 1, the medium pressure of the inlet chamber 30 pushes the check valve flap 32 to move leftward and seal with the left valve seat, and the piston chamber 23 is connected with the inlet of the second pilot valve 8.

[0017] Directional terms such as "left", "right", "up", "down", "horizontal", and "vertical" in the present invention are only for the convenience of description and should not be construed as limitations on the technical solution.

Claims

1. A double pilot valve pilot safety valve with a spare pilot valve, comprising a main valve (1) and a pilot valve, wherein the main valve (1) comprises a main valve body (10), a main valve seat (19), a main valve disc (20), and a main valve cover (28), wherein a guide sleeve (21) is installed between the main valve body (10) and the main valve cover (28), wherein the outer cylindrical surface of the main valve disc (20) and the inner cylindrical wall of the guide sleeve (21) are dynamically sealed, and a piston chamber (23) is formed between the back surface of the main valve disc (20) and the main valve cover (28), wherein the pilot valve comprises a pilot valve body, a pilot valve disc, and a pressure setting device, wherein the pilot valve inlet is respectively connected to the inlet chamber (30) of the main valve (1) and the piston chamber (23); wherein the pilot valve comprises a pilot valve body, a pilot valve disc, and a pressure setting device, and ... The pilot valve comprises a first pilot valve (4) and a second pilot valve (8); the inlets of the first pilot valve (4) and the second pilot valve (8) are connected to an inlet cavity (30) of a main valve (1) via a switching device (2); and the piston cavity (23) of the main valve (1) is connected to the inlets of the first pilot valve (4) and the second pilot valve (8) via a three-way check device (6).

2. The double pilot valve pilot safety valve with a spare pilot valve according to claim 1 is characterized in that: The switching device (2) is composed of a four-way ball valve and a connecting pipe fitting. The four-way ball valve is composed of a switching valve body (13), a switching ball (16) and a switching valve stem (15). The switching valve body (13) is provided with four outlets, and the angle between two adjacent outlets is 90 degrees. The first outlet is connected to the inlet cavity (30) of the main valve (1). The second outlet is located at a position 180 degrees from the first outlet. The third outlet and the fourth outlet are located at positions 90 degrees on both sides of the first outlet and are connected to the inlets of the first pilot valve (4) and the second pilot valve (8) respectively. The switching ball (16) is provided with two symmetrical 90 degree arc channels. One end of the switching valve stem (15) is fixedly connected to the switching ball (16), and its center line passes perpendicularly through the center of the sphere of the plane where the two 90 degree arc channels are located. A positioning device is provided between the switching valve stem (15) and the switching valve body (13), and the two end outlets of the 90 degree arc channel of the positioning switching ball (16) are connected to the two adjacent outlets of the switching valve body (13).

3. The double pilot valve pilot safety valve with a spare pilot valve according to claim 1 or 2, characterized in that: The three-way check device (6) comprises a three-way valve body (24) and a check valve flap (32). The three-way valve body (24) is provided with a horizontal channel and a vertical channel. The two ends of the horizontal channel are respectively connected to the inlets of the first pilot valve (4) and the second pilot valve (8). The vertical channel is connected to the piston chamber (23) of the main valve (1). A left valve seat and a right valve seat are arranged in the horizontal channel on both sides of the vertical channel. The check valve flap (32) is installed in the check chamber (25) between the left valve seat and the right valve seat. The left and right end surfaces of the check valve flap (32) are respectively provided with sealing surfaces that cooperate with the left valve seat and the right valve seat. The axial length between the sealing surfaces on both sides of the check valve flap (32) is less than the distance between the left valve seat and the right valve seat and the center line of the vertical channel.

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