Nuclear power plant pilot type pressure regulator safety valve, system and debugging device

Abstract

The application relates to the field of valve systems and particularly discloses a nuclear power plant pilot type safety valve of a stabilizer, a system and a debugging device, which comprises a main valve, a spring guide valve, an electromagnetic pilot valve, an automatic switching valve, a first isolation valve and a second isolation valve, the main valve comprises a valve body, a valve cover, a valve flap, a valve seat and an elastic piece, the valve body is provided with a liquid inlet, a liquid outlet and a valve cavity, the valve seat is fixed at a connecting position of the valve cavity and the liquid outlet, a lower guide sleeve is fixed in the valve cavity of the valve body, the valve flap is slidably inserted into the lower guide sleeve, a first cavity is formed among the valve flap, the valve cover and the lower guide sleeve, the elastic piece is located in the first cavity and tightly seals the valve flap on the valve seat, a conical lifting surface is arranged on one side of the valve flap close to the valve seat, a constant pressure flow channel is formed in the valve body and communicates the liquid inlet and the first cavity, and a pressure relief flow channel is formed in the valve body. The application can control the opening and closing of the valve core by controlling the pressure difference between the first cavity and the valve cavity, and has the effect of reliable work.

Description

Technical Field

[0001] This application relates to the field of valve systems, and in particular to safety valves, systems and commissioning devices for pilot-operated pressurizers in nuclear power plants. Background Technology

[0002] Existing nuclear power plant pressurizer safety valves include two types: spring-loaded safety valves and pilot-operated safety valves. Currently, all pilot-operated safety valves for pressurizers in all operating and under-construction nuclear power plants in my country are imported. Therefore, this invention provides a pilot-operated safety valve for nuclear power plant pressurizers.

[0003] In related technologies, a pilot-operated safety valve for a nuclear power plant pressurizer includes a main valve, a spring-loaded pilot valve, a first electromagnetic pilot valve, a second electromagnetic pilot valve, a first isolation valve, a second isolation valve, and a third isolation valve. The pressure sensing ports of two symmetrically arranged spring-loaded pilot valves are connected to the inlet of the main valve via the second isolation valve. The pressure control ports of these two spring-loaded pilot valves are connected to the main valve chamber of the main valve via the second electromagnetic pilot valve and the first isolation valve, which are connected in sequence. The exhaust ports of these two spring-loaded pilot valves are connected to a discharge pipeline. The inlet of the first electromagnetic pilot valve is connected to the main valve chamber of the main valve, and the outlet of the first electromagnetic pilot valve is connected to the discharge pipeline. The inlet of the third isolation valve is connected to the main valve chamber of the main valve, and the outlet of the third isolation valve is connected to a pressure display instrument.

[0004] In practical use, it was found that the main valve is a pressure-loaded main valve with a main valve inlet and a main valve outlet. A main valve chamber is formed between the valve disc and the valve cover, and the opening and closing of the main valve disc is controlled by controlling the pressure in the main valve chamber. The specific structure of the main valve is not disclosed, and its operation is unknown. Therefore, the inventor provides a pilot-operated pressurizer safety valve, system, and commissioning device for nuclear power plants. Summary of the Invention

[0005] In a first aspect, this application provides a pilot-operated pressurizer safety valve for a nuclear power plant, comprising a main valve, the main valve including a valve body, a valve cover, a valve disc, a valve seat, and an elastic element. The valve body has an inlet and an outlet. The valve cover is fixed to the valve body and forms a valve cavity between the valve body and the valve cover, the valve cavity communicating with the inlet and the outlet. The valve seat is fixed at the connection between the valve cavity and the outlet. A lower guide sleeve is fixed to the valve body within the valve cavity, and the valve disc is slidably inserted into the lower guide sleeve. A second cavity is formed between the valve disc, the valve cover, and the lower guide sleeve. The elastic element is located within the second cavity and pressurizes and seals the valve disc against the valve seat. A conical lifting surface is provided on the side of the valve disc near the valve seat. A constant pressure flow channel communicating between the inlet and the first cavity is provided on the valve body, and a pressure relief flow channel for discharging pressure from the first cavity is provided through the valve body.

[0006] By adopting the above technical solution, a constant pressure flow channel and a pressure relief flow channel are opened on the valve body. During normal use, a control valve needs to be installed on the pressure relief flow channel to control the pressure relief of the medium in the pressure relief flow channel. During use, the medium in the inlet will enter the second chamber through the constant pressure flow channel, so that the pressure in the second chamber and the valve chamber are balanced. At this time, the valve disc is pressed against the valve seat by the medium pressure and the elastic force of the elastic element to seal. When it is necessary to open the valve disc, the pressure relief flow channel is opened by the control valve, so that the medium in the second chamber is discharged outward. At this time, a pressure difference is formed between the second chamber and the valve chamber. The medium in the valve chamber will squeeze the rising surface on the valve disc and push the valve disc to slide along the lower guide sleeve, thereby opening the main valve. When it is necessary to close, the pressure relief flow channel is closed by the control valve, so that the pressure in the second chamber and the valve chamber are balanced. The valve core will close the outlet under the action of the medium force and the action of the elastic element. Compared with conventional valves that control the opening and closing of the valve by electric actuator, this application has a simple structure and is easy to control, which can effectively reduce the use cost of safety valves.

[0007] Optionally, the valve cover has a first cavity, and an upper guide sleeve is coaxially disposed at one end of the first cavity near the lower guide sleeve. The inner diameter of the upper guide sleeve is smaller than the inner diameter of the lower guide sleeve. A valve stem is coaxially fixed at one end of the valve disc near the valve cover, and the valve stem is slidably inserted into the upper guide sleeve. The two ends of the elastic element abut against the bottom of the second cavity and the end of the valve stem, respectively. The first cavity and the second cavity can communicate with each other.

[0008] By adopting the above technical solution, a second cavity is opened on the valve cover, and an upper guide sleeve that slides on the valve stem is installed on the valve cover. This can further improve the coaxiality of the valve disc and the valve seat, improve the positional accuracy between the valve disc and the valve seat, and thus effectively improve the sealing performance. During normal operation, the medium in the first cavity will enter the second cavity and maintain a balance with the pressure in the second cavity. When it is necessary to close the outlet, the medium will quickly fill the first and second cavities, causing the pressure in the first and second cavities to rise rapidly, thereby pushing the valve disc to close the outlet.

[0009] Optionally, the valve cover is provided with a mounting base for installing the lower guide sleeve and the upper guide sleeve at one end near the valve cavity. The first cavity is an annular groove formed on the periphery of the mounting base, and the upper guide sleeve is coaxially fixed to the inner side of the mounting base. A liquid inlet hole is provided through the bottom of the first cavity on the mounting base, and multiple liquid inlets are distributed along the axial direction of the mounting base. A liquid inlet groove communicating with the liquid inlet hole is provided on the inner wall of the mounting base. A liquid passage hole communicating with the second cavity and the liquid inlet groove is provided on the upper guide sleeve, and multiple liquid passage holes are distributed along the circumferential direction of the upper guide sleeve.

[0010] By adopting the above technical solution, a mounting seat is set on the valve cover to facilitate the installation of the upper guide sleeve and the lower guide sleeve; the first cavity is set as an annular groove opened on the mounting seat, and the medium in the first cavity will quickly enter the liquid inlet groove from the periphery of the mounting seat, and then quickly enter the first cavity through the liquid passage hole on the upper guide sleeve, which can effectively improve the flow rate of the medium, thereby improving the response time of the valve.

[0011] Optionally, a third cavity is formed between the valve disc, the lower guide sleeve, and the mounting base; two sets of liquid passage holes are distributed along the axial direction of the upper guide sleeve, and a separating ring protrusion is provided on the inner wall of the upper guide sleeve to separate the two sets of liquid passage holes, the separating ring protrusion slidingly engaging with the valve stem; the working medium in the liquid inlet groove communicates with the second cavity through the liquid passage hole on the side of the upper guide sleeve near the second cavity and the gap between the upper guide sleeve and the valve stem, and the working medium in the liquid inlet groove communicates with the third cavity through the liquid passage hole on the side of the upper guide sleeve near the valve disc and the gap between the upper guide sleeve and the valve stem.

[0012] By adopting the above technical solution and setting a third chamber, the medium in the first chamber is connected to the second and third chambers. During normal operation, the medium pressure in the first, second, and third chambers will change rapidly with the control of the control valve, thereby driving the valve disc to move quickly and effectively improving the response rate of the main valve. A partition ring protrusion is set in the upper guide sleeve. On the one hand, the partition ring protrusion increases the sealing and contact area between the upper guide sleeve and the valve stem. On the other hand, the partition ring protrusion can create a gap between the upper guide sleeve and the valve stem for medium flow, which facilitates the rapid flow of the medium in the first, second, and third chambers and facilitates the rapid pressure balance in the first, second, and third chambers, further improving the response rate of the main valve.

[0013] Optionally, a damping ring protrusion is provided on the valve stem corresponding to the separating ring protrusion, and the damping ring protrusion slides with the separating ring protrusion; when the valve disc is closed, the damping ring protrusion is in partial contact with the separating ring protrusion, and when the valve disc is opened, the contact area between the damping ring protrusion and the separating ring protrusion gradually increases.

[0014] By adopting the above technical solution, a damping ring protrusion is set on the valve stem. During the valve disc opening process, the valve stem moves towards the second chamber, and a piston effect is formed between the end of the valve stem and the second chamber. The medium in the second chamber will provide a certain buffer for the valve stem, thereby preventing the valve disc from opening too quickly when the pressure difference between the second chamber and the valve chamber is too large, and reducing the impact of the valve disc on other components. Furthermore, during the opening and closing process of the valve stem, the contact area between the damping ring protrusion and the separating ring protrusion will change. During the opening process, the contact area between the damping ring protrusion and the separating ring protrusion gradually increases, thereby increasing the resistance to valve stem opening and buffering the valve stem and valve disc. During the closing process, the contact area between the damping ring protrusion and the separating ring protrusion gradually decreases, allowing the valve disc to quickly close the outlet and improve the response rate of the main valve.

[0015] Optionally, a buffer ring protrusion is coaxially fixed on the inner side wall of the upper guide sleeve on the side of the liquid passage hole away from the separator ring protrusion, and the damping ring protrusion can form a seal and slide fit with the buffer ring protrusion.

[0016] By adopting the above technical solution, during the valve stem opening process, the damping ring protrusion moves upward and inserts into the buffer ring protrusion, making the second cavity a sealed chamber. As the valve stem continues to move upward, it will squeeze the medium in the second cavity, thereby achieving the effect of buffering the valve stem.

[0017] Optionally, a guide member is provided on the periphery of the valve disc to seal with the lower guide sleeve, and a drag-reducing groove is formed in the middle of the guide member on the periphery of the valve disc; a drain channel communicating with the drag-reducing groove is formed inside the valve disc and the valve stem, and the end of the drain channel away from the drag-reducing groove is connected to the first cavity or the second cavity.

[0018] By adopting the above technical solution, a guide component is set on the periphery of the valve disc to guide the operation of the valve disc and prevent the valve disc from getting stuck, affecting the normal opening and closing of the valve core; a drag-reducing groove is opened on the valve disc to reduce the contact area between the guide component and the lower guide sleeve, preventing the valve disc from getting stuck between the valve disc and the lower guide sleeve due to temperature rise during use; during normal operation, there may be a medium in the second chamber, which can be discharged through the drainage groove to prevent water accumulation in the second chamber.

[0019] Optionally, the guide is configured as a hard metal layer welded on.

[0020] Optionally, the guide is configured as a piston ring, and the piston ring is distributed in multiple rows along the axial direction of the valve disc.

[0021] By adopting the above technical solution, in production, a suitable piston ring can be selected according to the working requirements of the main valve. Different piston rings have different fitting clearances with the lower guide sleeve, and the damping between the valve disc and the lower guide sleeve is also different. The response rate of the main valve can be controlled by selecting a suitable piston ring.

[0022] Optionally, an adjusting screw is detachably fixed inside the constant pressure flow channel, and an adjusting hole is provided through the adjusting screw.

[0023] By adopting the above technical solution, the larger the diameter of the regulating hole, the faster the medium in the inlet enters the first chamber; the smaller the diameter of the regulating hole, the slower the medium in the inlet enters the first chamber. The flow rate of the medium in the constant pressure channel can be controlled by changing different adjusting screws, thereby controlling the response of the main valve.

[0024] Optionally, an outlet flange is fixed to the outlet on the valve body, and a conical buffer portion protruding towards the outlet is provided on the outlet flange corresponding to the outlet, and a plurality of buffer holes are provided through the buffer portion.

[0025] By adopting the above technical solution, an outlet flange is installed at the outlet of the valve body, and a conical buffer section is set on the outlet flange. After the valve disc is opened, the high-pressure medium at the outlet will quickly flush the buffer section, and the medium will slowly flow out through the buffer hole, preventing high-speed fluid from causing large impacts and damage to other components.

[0026] Optionally, the diameter of the plurality of buffer holes gradually increases away from the liquid outlet.

[0027] By adopting the above technical solution, the medium flow rate at the tip of the buffer section is faster, and the medium flow rate towards the end of the buffer section will gradually decrease. By setting the buffer hole to gradually increase in size away from the liquid outlet, the flow rate of the medium after passing through the buffer hole can be made relatively consistent.

[0028] Optionally, the inlet and the outlet are set at a 45-degree angle.

[0029] By adopting the above technical solution, the inlet and outlet are set at a 45-degree angle, which can shorten the lever arm of the medium force at the inlet flange connection, reduce the torque borne by the inlet flange, thereby reducing the strength requirements of the connecting bolts and improving the overall reliability and safety.

[0030] Secondly, the nuclear power plant pilot-operated pressurizer safety valve system provided in this application includes a first isolation valve, a solenoid pilot valve, a spring pilot valve, an automatic switching valve, a second isolation valve, and the aforementioned main valve. During normal operation, the water tank of the spring pilot valve must be filled with condensate, and then the portion below the upper valve disc is filled under the pressure of the medium, so that it is always in the cold section, that is, the temperature is at a relatively low level compared to the temperature of saturated steam.

[0031] Optionally, two sets of the first isolation valve, the spring pilot valve, the automatic switching valve, and the second isolation valve are symmetrically arranged.

[0032] Optionally, the first isolation valve and the second isolation valve are closed to cut off the medium flowing from the main valve into the spring pilot valve, the spring pilot valve is isolated separately, and then the medium is introduced from the external pressure source interface of the first isolation valve to pressurize it, thereby realizing the online setting function of the spring pilot valve.

[0033] Optionally, each of the solenoid pilot valves consists of two identical solenoid valves connected in series within a valve body. By closing or opening the solenoid pilot valve, the pressure in the first chamber of the main valve is maintained or released, thereby controlling the closing or opening of the main valve. When both solenoid valves in the solenoid pilot valve are open simultaneously, the pressure in the first chamber is released, thereby opening the main valve. When both solenoid valves in the solenoid pilot valve are closed simultaneously or either solenoid valve is in the closed position, the main valve is not allowed to open.

[0034] Optionally, a coil is connected between the first isolation valve and the spring pilot valve; the coil is also connected between the second isolation valve and the spring pilot valve.

[0035] Thirdly, this application provides a debugging device for the above-mentioned safety valve system, including a control unit, a data acquisition unit, a measurement and sensing unit, and an execution unit. The execution unit includes an opening component for opening the spring pilot valve. The opening component includes a driving member and a transition member connecting the driving member and the spring pilot valve.

[0036] By adopting the above technical solution, during the test, the measurement and sensing unit and the acquisition unit measure and collect data of each component in the experiment, and then feed the signal back to the control unit. After data comparison and calculation, the control unit drives the execution unit to act to meet the needs of the test. When the test is conducted under low pressure, the pressure does not reach the set pressure of the spring pilot valve. At this time, the driving component needs to drive the spring pilot valve to open, so as to achieve the purpose of the test.

[0037] Optionally, the driving component is configured as a cylinder, and a socket for connecting a transition component is coaxially provided at the end of the piston rod of the driving component; the transition component includes a pin and a transition head, the transition head is inserted into the socket, and the pin passes through the piston rod and the transition head perpendicular to the axis of the socket; a connecting hole for connecting the driving end of the spring pilot valve is provided at the end of the transition head away from the driving component.

[0038] By adopting the above technical solution, the driving component is set as a cylinder. During the test, a certain amount of compressed air can be introduced into the driving component according to the system calculation, so that the driving component drives the spring pilot valve to open a certain amount. By setting an adapter, when connecting the driving component and the spring pilot valve, it is only necessary to insert the adapter into the insertion hole at the end of the piston rod, and then fix it by inserting a pin into the piston rod and the adapter. This makes it convenient to connect the driving component with spring pilot valves of different models.

[0039] Optionally, a cotter pin is mounted on the end of the pin.

[0040] By adopting the above technical solution, a cotter pin is installed at the end of the pin to prevent the pin from falling off the piston rod.

[0041] Optionally, an elastic reset element is installed inside the drive component, and the elastic reset element is located on the side of the drive component piston away from the spring pilot valve.

[0042] By adopting the above technical solution, an elastic reset component is set inside the drive component. After the drive component completes the action of opening the spring pilot valve, the elastic reset component will drive the drive component to reset.

[0043] Optionally, the elastic reset member is configured as a compression spring, and the upper cover of the drive member and the piston are both provided with positioning protrusions coaxially corresponding to the position of the elastic reset member, and the two ends of the elastic reset member are respectively sleeved on the two positioning protrusions.

[0044] By adopting the above technical solution, positioning protrusions are provided on the upper cover and piston of the drive component, and the two ends of the elastic reset component are sleeved on the positioning protrusions. The positioning protrusions can position the two ends of the elastic reset component and prevent the elastic reset component from shifting during use.

[0045] Optionally, during the test, the inlet pressure of the spring pilot valve is the same as the inlet pressure of the main valve. When the pressure is low and has not reached the set pressure of the spring pilot valve, the spring pilot valve is forcibly opened by the drive component. After the spring pilot valve is opened, the main valve is further opened, thus completing the entire operation of the pilot-operated pressure regulator safety valve. During the test, various sensors are used to collect and analyze data and record various test parameters.

[0046] Optionally, the measurement sensor unit includes a complete set of pressure sensors, displacement sensors, analog sensors, etc.; the acquisition unit records the main technical parameters such as set pressure, reseating pressure, main valve opening time, total opening time, opening dead time, total closing time, closing dead time, and main valve opening height; after the acquisition unit acquires the data, it is optimized by the control unit to meet the test requirements.

[0047] In summary, this application includes at least one of the following beneficial technical effects: By creating a constant pressure flow channel and a pressure relief flow channel on the valve body, a control valve needs to be installed on the pressure relief flow channel during normal use. The control valve controls the pressure relief of the medium in the pressure relief flow channel. During use, the medium in the inlet enters the first chamber through the constant pressure flow channel, balancing the pressure in the first chamber and the valve chamber. At this time, the valve disc is sealed against the valve seat by the medium pressure and the elastic force of the elastic element. When the valve disc needs to be opened, the pressure relief flow channel is opened by the control valve, allowing the medium in the first chamber to be discharged outward. At this time, a pressure difference is formed between the first chamber and the valve chamber. The medium in the valve chamber will squeeze the rising surface on the valve disc and push the valve disc to slide along the lower guide sleeve, realizing the opening of the main valve. When it needs to be closed, the pressure relief flow channel is closed by the control valve, balancing the pressure in the first chamber and the valve chamber. The valve core will then close the outlet under the action of the medium force and the elastic element. Compared with conventional valves that control the opening and closing of the valve through an electric actuator, this application has a simple structure and is easy to control, which can effectively reduce the operating cost of the safety valve.

[0048] By setting a third chamber, the medium in the first chamber is connected to the second and third chambers. During normal operation, the medium pressure in the second and third chambers changes rapidly with the control valve, thereby driving the valve disc to move quickly and effectively improving the response rate of the main valve. A partition ring protrusion is set in the upper guide sleeve. On the one hand, the partition ring protrusion increases the sealing and contact area between the upper guide sleeve and the valve stem. On the other hand, the partition ring protrusion can create a gap between the upper guide sleeve and the valve stem for medium flow, which facilitates the rapid flow of the medium in the first chamber with the medium in the second and third chambers. This facilitates the rapid pressure balance in the first, second, and third chambers, further improving the response rate of the main valve.

[0049] By incorporating a damping ring protrusion on the valve stem, the sealing between the valve stem and the upper guide sleeve can be improved. Simultaneously, the valve stem forms a sealed fit with the upper guide sleeve through the damping ring protrusion. During valve opening, the valve stem moves towards the second chamber, creating a piston effect between the end of the valve stem and the second chamber. The medium within the second chamber provides a buffer to the valve stem, preventing excessively rapid valve opening when the pressure difference between the second chamber and the valve chamber is too large, thus reducing the impact of the valve disc on other components. Furthermore, the contact area between the damping ring protrusion and the separating ring protrusion changes during valve opening and closing. During opening, the contact area gradually increases, increasing the resistance to valve stem opening and buffering the valve stem and valve disc. During closing, the contact area gradually decreases, allowing the valve disc to quickly close the outlet, improving the main valve's response rate.

[0050] By installing adjusting screws in the constant pressure flow channel, the larger the diameter of the adjusting hole on the adjusting screw, the faster the medium in the inlet enters the first chamber, and the smaller the diameter of the adjusting hole, the slower the medium in the inlet enters the first chamber. The flow rate of the medium in the constant pressure flow channel can be controlled by changing different adjusting screws, thereby controlling the response of the main valve. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the overall structure of the main valve in an embodiment of this application; Figure 2 yes Figure 1 A magnified view of area A in the middle; Figure 3 yes Figure 1 A magnified view of area B in the middle; Figure 4 This is a schematic diagram highlighting the structure of the piston rings; Figure 5 This is a schematic diagram of the symbol for the safety valve system of a pilot-operated pressurizer in a nuclear power plant. Figure 6 This is a schematic diagram of the safety valve system of a pilot-operated pressurizer in a nuclear power plant. Figure 7 This is a schematic diagram of the execution unit of the debugging device.

[0052] Reference numerals: 1. Main valve; 11. Valve body; 111. Inlet; 112. Outlet; 113. Valve chamber; 114. Constant pressure flow channel; 115. Pressure relief flow channel; 116. Third chamber; 12. Valve cover; 121. Mounting base; 122. First chamber; 123. Second chamber; 124. Inlet hole; 125. Inlet groove; 13. Valve disc; 131. Lifting surface; 132. Guide element; 1321. Hard metal layer; 1322. Piston ring; 133. Drag reduction groove; 134. Drainage channel; 14. Valve seat; 15. Elastic element; 16. Lower guide sleeve; 17. Upper guide. 171. Separating ring protrusion; 172. Fluid passage hole; 173. Buffer ring protrusion; 18. Valve stem; 181. Damping ring protrusion; 19. Adjusting screw; 191. Adjusting hole; 10. Outlet flange; 101. Buffer section; 102. Buffer hole; 2. First isolation valve; 3. Solenoid pilot valve; 4. Spring pilot valve; 5. Automatic switching valve; 6. Second isolation valve; 7. Coil; 8. Opening assembly; 81. Drive component; 811. Insertion hole; 812. Positioning protrusion; 821. Transition head; 8211. Connecting hole; 822. Pin; 823. Cotter pin; 83. Elastic reset component. Detailed Implementation

[0053] In a first aspect, embodiments of this application disclose a pilot-operated pressurizer safety valve for nuclear power plants, with reference to... Figure 1-3The system includes a main valve 1, which includes a valve body 11, a valve cover 12, a valve disc 13, a valve seat 14, and an elastic element 15. The valve body 11 has an inlet 111 and an outlet 112, which are at a 45° angle to each other. The valve cover 12 is fixed to one side of the valve body 11 by bolts. A valve cavity 113 is formed between the valve cover 12 and the valve body 11, and the valve cavity 113 connects the inlet 111 and the outlet 112. An mounting base 121 is integrally provided on the valve cover 12 within the valve cavity 113. The mounting base 121 is slidably inserted into the valve cavity 113. A lower guide sleeve 16 is coaxially fixed on the mounting base 121, and the valve disc 13 is coaxially slidably inserted into the lower guide sleeve 16. The valve seat 14 is coaxially fixed to one end of the outlet 112 near the valve cavity 113. An elastic element 15 is installed on the valve cover 12 and elastically presses the valve disc 13 against the valve seat 14 to seal the outlet 112.

[0054] A first cavity 122 is provided on the mounting base 121. The first cavity 122 is an annular groove coaxially formed on the outer wall of the mounting base 121. A constant pressure flow channel 114 is formed on the valve body 11, connecting the liquid inlet 111 and the first cavity 122. A pressure relief flow channel 115 is formed through the side wall of the valve body 11, connecting the first cavity 122, for discharging the medium in the first cavity 122. A second cavity 123 is coaxially formed on the valve cover 12 near the mounting base 121. The second cavity 123 is a cylindrical blind hole. The first cavity 122 and the second cavity 123 are interconnected. An upper guide sleeve 17 is coaxially fixed on the mounting base 121 at the opening of the second cavity 123. The upper guide sleeve 17 is a cylindrical sleeve. A lower guide sleeve 16 is coaxially fixed on the outer side of the mounting base 121, located at the end of the mounting base 121 near the liquid outlet 112. A valve stem 18 is integrally and coaxially mounted on one end of the valve disc 13 near the valve cover 12, and the valve stem 18 is slidably inserted into the upper guide sleeve 17. The elastic element 15 is a compression spring, which is coaxially installed in the second cavity 123, with its two ends abutting against the bottom of the second cavity 123 and the end of the valve stem 18, respectively. A conical lifting surface 131 is integrally formed on one end of the valve disc 13 near the valve seat 14. When the pressure in the valve cavity 113 is high, the medium will provide a thrust to the lifting surface 131 to open the valve disc 13.

[0055] When in use, a control valve for controlling the opening and closing of the pressure relief channel 115 needs to be installed inside the pressure relief channel 115. In the free state, the pressure in the inlet 111 enters the second chamber 123 through the constant pressure channel 114 and the first chamber 122, balancing the pressure in the second chamber 123 with the pressure in the valve chamber 113. At this time, the valve disc 13 closes the outlet 112 under the elastic force of the elastic element 15. When the main valve 1 needs to be opened, the pressure relief channel 115 is opened by the control valve, allowing the medium in the first chamber 122 and the second chamber 123 to be discharged from the valve body 11 through the pressure relief channel 115, creating a pressure difference between the valve chamber 113 and the second chamber 123. The hydraulic pressure in the valve chamber 113 is greater than that in the second chamber 123, and the medium in the valve chamber 113 pushes open the valve disc 13 and is discharged from the outlet 112. When the main valve 1 needs to be closed, the pressure relief channel 115 is closed by the control valve, balancing the pressure of the medium in the second chamber 123 and the valve chamber 113. The valve disc 13 then closes the outlet 112 under the pressure of the medium and the action of the elastic element 15.

[0056] A liquid inlet hole 124 is provided through the bottom of the first cavity 122 on the mounting base 121. A liquid inlet groove 125 communicating with the liquid inlet hole 124 is coaxially provided on the inner side wall of the mounting base 121. Multiple liquid inlets 124 are distributed along the circumference of the liquid inlet groove 125. A partition ring protrusion 171 is integrally provided coaxially on the inner wall of the upper guide sleeve 17. The partition ring protrusion 171 slides with the valve stem 18. The partition ring protrusion 171 is located in the middle of the upper guide sleeve 17, so that a gap is formed between the upper guide sleeve 17 and the valve stem 18. Liquid passage holes 172 are provided at both ends of the partition ring protrusion 171 on the side wall of the upper guide sleeve 17. The liquid passage holes 172 communicate with the liquid inlet groove 125. Multiple liquid passage holes 172 are provided along the circumference of the guide sleeve. A third chamber 116 is formed between the valve disc 13, the lower guide sleeve 16, and the mounting base 121. During normal operation, the medium in the first chamber 122 flows into the liquid passage 172 of the upper guide sleeve 17 through the liquid inlet hole 124 and the liquid inlet groove 125. The medium then flows into the second chamber 123 and the third chamber 116 through the gap between the upper guide sleeve 17 and the valve stem 18. During operation, the control valve can simultaneously control the pressure in the second chamber 123 and the third chamber 116, so that the hydraulic pressure in the second chamber 123 and the third chamber 116 directly acts on the valve disc 13 and the valve stem 18, which can effectively improve the response rate of the valve disc 13.

[0057] A buffer ring protrusion 173 is integrally and coaxially disposed on the inner side wall of the upper guide sleeve 17, on the side of the liquid passage hole 172 away from the separating ring protrusion 171. The damping ring protrusion 181 and the buffer ring protrusion 173 form a seal and slide fit. At the end of the valve stem 18 opening, the damping ring protrusion 181 moves upward and inserts into the buffer ring protrusion 173, making the second cavity 123 a sealed chamber. As the valve stem 18 continues to move upward, it will squeeze the medium in the second cavity 123, thereby achieving the effect of buffering the valve stem 18.

[0058] A damping ring protrusion 181 is integrally provided on the side wall of the valve stem 18 at the position corresponding to the partition ring protrusion 171. The damping ring protrusion 181 and the partition ring protrusion 171 form a seal and slide fit. When the valve disc 13 is closed, the upper end of the damping ring protrusion 181 partially contacts the partition ring protrusion 171; when the valve disc 13 is opened, the contact area between the damping ring protrusion 181 and the partition ring protrusion 171 gradually increases. During the opening process of the valve disc 13, a piston effect is formed between the valve stem 18 and the second chamber 123. The end of the valve stem 18 will squeeze the medium in the second chamber 123 to form a buffer, preventing the valve disc 13 from opening too quickly when the pressure difference between the second chamber 123 and the valve chamber 113 is too large, thereby reducing the impact of the valve disc 13 on other components. Furthermore, during the opening process, the contact area between the damping ring protrusion 181 and the separating ring protrusion 171 gradually increases, and the resistance also gradually increases, which can buffer the valve stem 18; during the closing process, the contact between the damping ring protrusion 181 and the separating ring protrusion 171 gradually decreases, which can cause the valve disc 13 to quickly close the liquid outlet 112 and improve the response rate of the main valve 1.

[0059] A guide element 132 that mates with the lower guide sleeve 16 is coaxially arranged around the valve disc 13.

[0060] Reference Figure 3 On the one hand, the guide member 132 can be configured as a hard metal layer 1321 welded on. A drag-reducing groove 133 is coaxially formed in the middle of the guide member 132 along the axial direction of the valve stem 18. A drain channel 134 communicating with the drag-reducing groove 133 is formed inside the valve disc 13 and the valve stem 18. The inlet of the drain channel 134 communicates with the first chamber 122, the second chamber 123 and the third chamber 116. Multiple inlets of the drain channel 134 are provided along the circumferential direction of the valve stem 18 and two sets are distributed along the axial direction of the partition ring protrusion 171, which can effectively improve the rate at which the medium enters the drain channel 134.

[0061] Reference Figure 4 On the other hand, the guide member 132 is configured as a piston ring 1322 mounted on the outer wall of the valve disc 13. The piston ring 1322 can be selected with different outer diameters according to the operating conditions. Different piston rings 1322 have different fitting clearances with the lower guide sleeve 16, and the damping between the valve disc 13 and the lower guide sleeve 16 is different. The response rate of the main valve 1 can be controlled by selecting a suitable piston ring 1322.

[0062] Reference Figure 2 and Figure 3An adjusting screw 19 is screwed into the constant pressure flow channel 114, and an adjusting hole 191 is coaxially opened on the adjusting screw 19. In production, adjusting screws 19 with different inner diameter adjusting holes 191 can be selected according to the working conditions. The larger the diameter of the adjusting hole 191, the faster the medium in the inlet 111 enters the first chamber 122. The smaller the diameter of the adjusting hole 191, the slower the medium in the inlet 111 enters the first chamber 122. The flow rate of the medium in the constant pressure flow channel 114 can be controlled by changing different adjusting screws 19, thereby controlling the response of the main valve 1.

[0063] An outlet flange 10 is bolted to the valve body 11 at the outlet port 112. A conical buffer portion 101, protruding towards the outlet port 112, is coaxially disposed on the outlet flange 10. Multiple buffer holes 102 are formed through the buffer portion 101. The buffer portion 101 has a conical cross-sectional profile with a 90° apex angle, with the apex angle facing the outlet port 112. The diameter of the buffer holes 102 gradually increases with distance from the apex angle. The buffer portion 101 effectively buffers the medium flowing out of the outlet port 112.

[0064] The implementation principle of a pilot-operated pressurizer safety valve for a nuclear power plant disclosed in this application is as follows: A constant pressure flow channel 114 and a pressure relief flow channel 115 are opened on the valve body 11. During normal use, a control valve needs to be installed on the pressure relief flow channel 115 to control the pressure relief of the medium in the pressure relief flow channel 115. During use, the medium in the inlet 111 enters the first chamber 122 through the constant pressure flow channel 114, causing the pressure in the first chamber 122 and the pressure in the valve chamber 113 to interact. When the valve is in equilibrium, the valve disc 13 is pressed against the valve seat 14 by the elastic force of the elastic element 15 to seal it. When the valve disc 13 needs to be opened, the pressure relief passage 115 is opened by the control valve to discharge the medium in the first chamber 122. At this time, a pressure difference is formed between the first chamber 122 and the valve chamber 113. The medium in the valve chamber 113 will squeeze the lifting surface 131 on the valve disc 13 and push the valve disc 13 to slide along the lower guide sleeve 16 to realize the opening of the main valve 1. It is simpler in structure and more reliable in control than conventional valves.

[0065] Secondly, this application discloses a pilot-operated pressurizer safety valve system for nuclear power plants, referring to... Figure 5 and Figure 6 It includes a first isolation valve 2, a solenoid pilot valve 3, a spring pilot valve 4, an automatic switching valve 5, a second isolation valve 6, and the aforementioned main valve 1. The first isolation valve 2, the spring pilot valve 4, the automatic switching valve 5, and the second isolation valve 6 are symmetrically arranged in two sets.

[0066] During normal operation, the water tank of the spring pilot valve 4 must be filled with condensate, and then the portion below the upper valve disc is filled under the pressure of the medium, ensuring that it remains in the cold section, i.e., at a lower temperature than the saturated steam. A coil 7 is connected between the first isolation valve 2 and the spring pilot valve 4 to accelerate cooling. A coil 7 is also connected between the second isolation valve 6 and the spring pilot valve 4.

[0067] The first isolation valve 2 and the second isolation valve 6 are closed, cutting off the medium flowing into the spring pilot valve 4 from the main valve 1, isolating the spring pilot valve 4 separately, and then the medium is introduced into the external pressure source interface of the first isolation valve 2 to pressurize it, thereby realizing the online setting function of the spring pilot valve 4.

[0068] Each solenoid pilot valve 3 consists of two identical solenoid valves connected in series within a valve body. By closing or opening the solenoid pilot valve 3, the pressure in the first chamber 122 of the main valve 1 is maintained or released, thereby controlling the closing or opening of the main valve 1. When both solenoid valves in the solenoid pilot valve 3 are open simultaneously, the pressure in the first chamber 122 is released, thereby opening the main valve. When both solenoid valves in the solenoid pilot valve 3 are closed simultaneously or either solenoid valve is in the closed position, the main valve 1 is not allowed to open.

[0069] Thirdly, this application discloses a commissioning device for a pilot-operated pressurizer safety valve system in a nuclear power plant, including a control unit, a data acquisition unit, a measurement and sensing unit, and an execution unit. During testing, the data acquisition unit and the measurement and sensing unit monitor and acquire data from various components of the safety valve system, and then feed the acquired data signals back to the control unit. The control unit compares and calculates the data according to the system settings, and then outputs a signal to the execution unit. The execution unit controls the safety valve system to operate according to the signal from the control unit. The control unit then continues to compare the data acquired by the acquisition unit and the measurement and sensing unit. If the data does not reach the set value, the mechanical structure of the safety valve system needs to be manually adjusted until the test data reaches the set value.

[0070] Reference Figure 7The execution unit includes an opening assembly 8 for opening the spring-loaded pilot valve 4. The opening assembly 8 includes a drive member 81 and a transition member for connecting the drive member 81 and the spring-loaded pilot valve 4. The drive member 81 is configured as a cylinder and is fixed to the spring-loaded pilot valve 4. The transition member connects the piston rod of the drive member 81 and the spring-loaded pilot valve 4. A hole 811 is coaxially formed at the end of the piston rod of the drive member 81. The transition member includes a transition head 821 and a pin 822. The transition head 821 is inserted into the hole 811, and the pin 822 passes through the piston rod and the transition head 821, connecting the piston rod to the transition head 821. A cotter pin 823 is installed at the end of the pin 822 to prevent the pin 822 from falling off during use. A connecting hole 8211 is coaxially formed at the end of the transition head 821 away from the drive member 81. The connecting hole 8211 is a threaded hole for connecting the drive end of the spring-loaded pilot valve 4. In use, the control unit controls the drive member 81 to open the spring-loaded pilot valve 4.

[0071] An elastic reset element 83 is installed inside the drive component 81. The elastic reset element 83 is configured as a compression spring and is installed on the side of the piston of the drive component 81 away from the spring pilot valve 4. Positioning protrusions 812 are integrally formed on the upper cover and piston of the drive component 81 at positions corresponding to the elastic reset element 83. The two ends of the elastic reset element 83 are respectively fitted onto the two positioning protrusions 812. During use, the positioning protrusions 812 prevent displacement of the elastic reset element 83. After the drive component 81 opens the spring pilot valve 4, the drive component 81 automatically resets under the action of the elastic reset element 83.

[0072] The function of the opening component 8 is to enable the main valve 1 to operate at lower pressure levels, specifically: various operating performance tests under 3.9MPa conditions; precise testing and adjustment of the main valve 1 set pressure under 13.9MPa conditions; and preliminary adjustment of the main valve 1 set pressure under atmospheric pressure conditions.

[0073] Its specific working principle is as follows: During the test, the inlet pressure of the spring pilot valve 4 is consistent with the inlet pressure of the main valve 1. At a lower pressure level, the pressure does not reach the set pressure of the spring pilot valve 4. Through system calculation, the control drive component 81 applies a force to forcefully open the spring pilot valve 4. After the spring pilot valve 4 is opened, the main valve 1 is further opened, thereby completing the entire operation of the main valve system of the nuclear power plant pilot pressurizer. At the same time, various test parameters are recorded through the acquisition unit and the measurement sensor unit.

[0074] For the testing requirements of the pilot-operated pressure regulator safety valve system, the following key technical parameters must be recorded: set pressure, reseating pressure, opening time of main valve 1, total opening time, opening dead time, total closing time, closing dead time, and opening height of main valve 1.

[0075] To address the very small displacement of the spring-guided valve 4, with an opening height of less than 1mm, an integrated pneumatic tensioning unit was designed, incorporating a built-in tension force sensor, making the pneumatic unit more responsive. It is also equipped with a high-frequency data acquisition unit with a high-speed sampling frequency of 100KHz and a data acquisition accuracy of 0.05%.

[0076] By setting up a commissioning system, regular daily commissioning can be carried out more conveniently and quickly, and the operation of the main valve system of the pilot pressurizer of the nuclear power plant can be reflected more intuitively in each commissioning and testing stage.

[0077] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A pilot-operated pressurizer safety valve for nuclear power plants, characterized in that: The system includes a main valve (1), which comprises a valve body (11), a valve cover (12), a valve disc (13), a valve seat (14), and an elastic element (15). The valve body (11) has an inlet (111) and an outlet (112). The valve cover (12) is fixed to the valve body (11) and forms a valve cavity (113) between the valve body (11) and the valve cavity (113), which communicates with the inlet (111) and the outlet (112). The valve seat (14) is fixed at the connection between the valve cavity (113) and the outlet (112). A valve is fixed on the valve body (11) within the valve cavity (113). The lower guide sleeve (16) is provided, and the valve disc (13) is slidably inserted into the lower guide sleeve (16); the valve cover (12) is provided with a first cavity (122), and an upper guide sleeve (17) is coaxially provided at one end of the first cavity (122) near the lower guide sleeve (16); a second cavity (123) is formed between the valve disc (13), the valve cover (12) and the lower guide sleeve (16); the elastic element (15) is located in the second cavity (123) and presses the valve disc (13) against the valve seat (14); a conical lifting surface (131) is provided on the side of the valve disc (13) near the valve seat (14); the A constant pressure flow channel (114) is provided on the valve body (11) to connect the liquid inlet (111) and the first chamber (122). A pressure relief flow channel (115) for discharging the pressure in the first chamber (122) is provided through the valve body (11). The first chamber (122) and the second chamber (123) can communicate with each other. A valve stem (18) is coaxially fixed at one end of the valve disc (13) near the valve cover (12). The valve stem (18) is slidably inserted into the upper guide sleeve (17). A liquid passage hole (172) is provided on the upper guide sleeve (17) to connect the second chamber (123) and the first chamber (122). Two sets of liquid passages (172) are distributed along the axial direction of the upper guide sleeve (17). The inner wall of the upper guide sleeve (17) is provided with a separating ring protrusion (171) that separates the two sets of liquid passages (172). The separating ring protrusion (171) is slidably engaged with the valve stem (18). The valve stem (18) is provided with a damping ring protrusion (181) corresponding to the separating ring protrusion (171). A buffer ring protrusion (173) is coaxially fixed on the inner side wall of the upper guide sleeve (17) on the side of the liquid passage (172) away from the separating ring protrusion (171). The damping ring protrusion (181) can form a seal and slide with the buffer ring protrusion (173).

2. The pilot-operated pressurizer safety valve for nuclear power plants according to claim 1, characterized in that: The inner diameter of the upper guide sleeve (17) is smaller than the inner diameter of the lower guide sleeve (16), and the two ends of the elastic element (15) abut against the bottom of the second cavity (123) and the end of the valve stem (18), respectively.

3. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 2, characterized in that: The valve cover (12) is provided with a mounting base (121) for mounting the lower guide sleeve (16) and the upper guide sleeve (17) at one end near the valve cavity (113). The first cavity (122) is an annular groove formed on the periphery of the mounting base (121). The upper guide sleeve (17) is coaxially fixed to the inner side of the mounting base (121). A liquid inlet hole (124) is provided through the bottom of the first cavity (122) on the mounting base (121). Multiple liquid inlets (124) are distributed along the axial direction of the mounting base (121). A liquid inlet groove (125) communicating with the liquid inlet hole (124) is provided on the inner wall of the mounting base (121). Multiple liquid passage holes (172) are distributed along the circumferential direction of the upper guide sleeve (17).

4. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 3, characterized in that: A third cavity (116) is formed between the valve disc (13), the lower guide sleeve (16), and the mounting base (121); the working medium in the liquid inlet (125) communicates with the second cavity (123) through the liquid passage hole (172) on the side of the upper guide sleeve (17) near the second cavity (123) and the gap between the upper guide sleeve (17) and the valve stem (18); the working medium in the liquid inlet (125) communicates with the third cavity (116) through the liquid passage hole (172) on the side of the upper guide sleeve (17) near the valve disc (13) and the gap between the upper guide sleeve (17) and the valve stem (18).

5. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 4, characterized in that: The damping ring protrusion (181) and the separating ring protrusion (171) are in sliding engagement; when the valve disc (13) is closed, the damping ring protrusion (181) and the separating ring protrusion (171) are in partial contact; when the valve disc (13) is opened, the contact area between the damping ring protrusion (181) and the separating ring protrusion (171) gradually increases.

6. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 4, characterized in that: A guide (132) is provided on the periphery of the valve disc (13), and a drag-reducing groove (133) is provided in the middle of the guide (132) on the periphery of the valve disc (13); a drain channel (134) communicating with the drag-reducing groove (133) is provided inside the valve disc (13) and the valve stem (18), and the end of the drain channel (134) away from the drag-reducing groove (133) is connected to the first cavity (122) or the second cavity (123).

7. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 6, characterized in that: The guide (132) is configured as a hard metal layer (1321) welded on.

8. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 6, characterized in that: The guide (132) is configured as a piston ring (1322), and the piston ring (1322) is distributed in multiple rows along the axial direction of the valve disc (13).

9. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 1, characterized in that: An adjusting screw (19) is detachably fixed inside the constant pressure flow channel (114), and an adjusting hole (191) is provided through the adjusting screw (19).

10. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 1, characterized in that: An outlet flange (10) is fixed on the valve body (11) at the outlet port (112). A conical buffer part (101) protruding towards the outlet port (112) is provided on the outlet flange (10) at the location corresponding to the outlet port (112). Multiple buffer holes (102) are provided through the buffer part (101).

11. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 10, characterized in that: The diameter of the plurality of buffer holes (102) gradually increases away from the liquid outlet (112).

12. A pilot-operated pressurizer safety valve for nuclear power plants according to claim 10, characterized in that: The inlet (111) and the outlet (112) are set at a 45-degree angle.

13. A pilot-operated pressurizer safety valve system for nuclear power plants, characterized in that, Including the first isolation valve (2), the solenoid pilot valve (3), the spring pilot valve (4), the automatic switching valve (5), the second isolation valve (6), and the pilot-operated pressure regulator safety valve as described in any one of claims 1-12, during normal operation, the water tank of the spring pilot valve (4) must be filled with condensate, and then the part below the upper valve disc is filled under the pressure of the medium, so that it is always in the cold section, that is, the temperature is at a lower level than the temperature of saturated steam.

14. The nuclear power plant pilot-operated pressurizer safety valve system according to claim 13, characterized in that: The first isolation valve (2), the spring pilot valve (4), the automatic switching valve (5), and the second isolation valve (6) are symmetrically arranged in two sets.

15. The nuclear power plant pilot-operated pressurizer safety valve system according to claim 13, characterized in that: Close the first isolation valve (2) and the second isolation valve (6), cut off the medium flowing into the spring pilot valve (4) from the pilot-operated pressure regulator safety valve, isolate the spring pilot valve (4) separately, and then introduce medium from the external pressure source interface of the first isolation valve (2) to pressurize it, so as to realize the online setting function of the spring pilot valve (4).

16. The nuclear power plant pilot-operated pressurizer safety valve system according to claim 13, characterized in that: Each of the aforementioned electromagnetic pilot valves (3) consists of two identical electromagnetic valves connected in series within a valve body. By closing or opening the electromagnetic pilot valves (3), the pressure in the first chamber (122) of the pilot-operated pressure regulator safety valve is maintained or released, thereby achieving the closing or opening control of the pilot-operated pressure regulator safety valve. When both electromagnetic valves in the electromagnetic pilot valve (3) are opened simultaneously, the pressure in the first chamber (122) is released, thereby opening the main valve. When both electromagnetic valves in the electromagnetic pilot valve (3) are closed simultaneously or either electromagnetic valve is in the closed position, the pilot-operated pressure regulator safety valve is not allowed to open.

17. The nuclear power plant pilot-operated pressurizer safety valve system according to claim 13, characterized in that: A coil (7) is connected between the first isolation valve (2) and the spring pilot valve (4); the coil (7) is also connected between the second isolation valve (6) and the spring pilot valve (4).

18. A commissioning device for the pilot-operated pressurizer safety valve system of a nuclear power plant as described in any one of claims 13-17, characterized in that, It includes a control unit, a data acquisition unit, a measurement and sensing unit, and an execution unit. The execution unit includes an opening component (8) for opening the spring pilot valve (4). The opening component (8) includes a drive member (81) and a transition member connecting the drive member (81) and the spring pilot valve (4).

19. The debugging device according to claim 18, characterized in that: The driving component (81) is configured as a cylinder, and a socket (811) for connecting a transition component is coaxially provided at the end of the piston rod of the driving component (81); the transition component includes a pin (822) and a transition head (821), the transition head (821) is inserted into the socket (811), and the pin (822) passes through the piston rod and the transition head (821) perpendicular to the axis of the socket (811); a connecting hole (8211) for connecting the driving end of the spring pilot valve (4) is provided at the end of the transition head (821) away from the driving component (81).

20. The debugging device according to claim 19, characterized in that: The end of the pin (822) is fitted with a cotter pin (823).

21. The debugging device according to claim 19, characterized in that: An elastic reset member (83) is installed inside the drive member (81), and the elastic reset member (83) is located on the side of the piston of the drive member (81) away from the spring pilot valve (4).

22. The debugging device according to claim 21, characterized in that: The elastic reset member (83) is configured as a compression spring. The upper cover of the drive member (81) and the piston are both provided with positioning protrusions (812) coaxially corresponding to the position of the elastic reset member (83). The two ends of the elastic reset member (83) are respectively sleeved on the two positioning protrusions (812).

23. The debugging device according to claim 19, characterized in that: During the test, the inlet pressure of the spring pilot valve (4) is consistent with the inlet pressure of the pilot-operated pressure regulator safety valve. When the pressure is low and the set pressure of the spring pilot valve (4) is not reached, the spring pilot valve (4) is forcibly opened by the drive component (81). After the spring pilot valve (4) is opened, the pilot-operated pressure regulator safety valve is further opened, thereby completing the entire action of the pilot-operated pressure regulator safety valve.

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