Novel anti-explosion flat safety valve

Abstract

The invention relates to the technical field of valves, in particular to a novel anti-explosion flat safety valve which comprises a valve body assembly, a hydraulic driving mechanism, an indicating mechanism, a first manual driving mechanism and a second manual driving mechanism. The first manual driving mechanism comprises a first hand wheel, a first hand wheel rod, a first bearing box and a first thrust bearing. The second manual driving mechanism comprises a second hand wheel, a second hand wheel rod, a second bearing box, a second thrust bearing and a second reset spring. The first manual driving mechanism and the second manual driving mechanism are arranged, and it is ensured that when the hydraulic driving mechanism loses efficacy or the first reset spring loses elasticity, the valve can still be opened or closed in time through manual operation. By means of the design, the redundancy and the emergency processing capacity of the system are improved, and the safety of petroleum production is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of valves, and in particular to a novel explosion-proof flat safety valve. Background Art

[0002] The explosion-proof flat safety valve is an automatic valve that provides shut-off protection. It is mainly used on wellhead fluid pipelines. The valve is a flat gate valve with a single valve seat floating seal. It relies on the free fit between the metal gate and the metal valve seat plane to achieve sealing under the force of the medium.

[0003] The safety valve in the prior art usually uses a single-acting hydraulic cylinder to drive the valve to open, and the valve is opened by pressing the hydraulic cylinder, and the valve is closed by spring reset. However, since the safety valve is often used as a normally open valve, the hydraulic cylinder is in a working state of pressing and opening the valve for a long time. In this case, the sealing ring inside the hydraulic cylinder is prone to gradually age due to long-term pressure and wear, and then loses its sealing effect. At the same time, after the spring maintains a compressed state under the maximum working load for a long time, partial plastic deformation will occur, resulting in a weakening of the rebound force, and there is a risk that the valve cannot be completely closed. Therefore, the driving part of the safety valve needs to be disassembled and maintained regularly, and this process will inevitably lead to the suspension of production work, resulting in huge economic losses.

[0004] The patent "CN109357052A A New Hydraulic Safety Valve" in the prior art provides a solution, in which the hydraulic drive mechanism can be removed when a fault occurs, and then replaced with a manual drive mechanism to achieve the function of opening the valve when a fault occurs. However, the technical solution still has the following points that need to be solved:

[0005] 1. It is impossible to detect whether the valve is fully opened or fully closed;

[0006] 2. When the valve fails, it is necessary to remove the hydraulic drive mechanism first, and then install the manual drive mechanism to drive the valve to open, which takes a long time overall;

[0007] 3. The manual drive mechanism installed later can only drive the valve to open, but cannot drive the valve to close. Summary of the invention

[0008] The problem to be solved by the present invention is: in order to solve the problems in the prior art that it is impossible to detect whether the valve is in place, the manual drive mechanism is time-consuming to install, and the valve cannot be closed by the manual drive mechanism, a new explosion-proof flat safety valve is provided which can accurately detect whether the valve is in place, is simple and convenient to operate, and can realize manual opening and closing at the same time.

[0009] The present invention is implemented through the following technical solutions: a novel explosion-proof flat safety valve, comprising a valve body assembly, a hydraulic drive mechanism, an indicating mechanism, a first manual drive mechanism, and a second manual drive mechanism;

[0010] The valve body assembly comprises a valve body, a valve cover, a valve seat, a valve plate, and a valve stem. Two valve seats are arranged in the valve body, the valve plate is located between the two valve seats, the first end of the valve stem is connected to the valve plate, and the second end of the valve stem passes through the valve cover upwards;

[0011] The hydraulic drive mechanism comprises a bracket, a housing, a piston, and an indicator rod. The housing and the valve cover are relatively fixedly connected through the bracket. The piston is movably arranged in the housing. The lower end of the piston is connected to the top of the valve stem. The upper end of the piston is connected to the indicator rod. The indicator rod passes through the housing upwards. The indicator rod is provided with a sensing part that can be recognized by a sensor.

[0012] The indicating mechanism comprises an indicating frame, a first position sensor and a second position sensor. The indicating frame is installed above the housing. The first position sensor and the second position sensor are installed on the indicating frame. When the piston moves to the minimum stroke and the maximum stroke, the sensing part can be recognized by the first position sensor and the second position sensor.

[0013] The first manual drive mechanism comprises a first hand wheel, a first hand wheel rod, a first bearing box, and a first thrust bearing. The middle portion of the first hand wheel rod is connected to the indicator frame via a thread. The lower end of the first hand wheel rod is rotatably connected to the first bearing box via the first thrust bearing. The bottom surface of the first bearing box is parallel to the upper surface of the indicator rod. The top of the first hand wheel rod is provided with a first hand wheel.

[0014] The second manual drive mechanism includes a second handwheel, a second handwheel rod, a second bearing box, a second thrust bearing, and a second return spring; a second handwheel is installed above the second handwheel rod, and a shaft ring is arranged near the second handwheel, and the shaft ring is rotatably connected to the second bearing box through the second thrust bearing, the second bearing box is parallel to the top of the first handwheel rod, the first handwheel rod is a hollow structure, the second handwheel rod passes through the first handwheel rod, a small section of external thread is arranged at the lower end of the second handwheel rod, the first bearing box is provided with a through hole for accommodating the lower end of the second handwheel rod to pass through, the indicator rod is provided with an internal thread matching the second handwheel rod, the second return spring is used to drive the second handwheel rod to move upward relative to the first handwheel rod, and when the first handwheel rod moves to the uppermost stroke, the lower end surface height of the second handwheel rod is higher than the bottom surface height of the first bearing box.

[0015] Furthermore, there is only one hydraulic chamber between the housing and the piston, and the hydraulic drive mechanism also includes an adjusting nut, a fixing nut, a first return spring, and a spring retaining ring. The adjusting nut is connected to the second end of the valve stem for adjusting the extension length, and the fixing nut is installed above the adjusting nut. The fixing nut and the spring retaining ring are provided with matching step surfaces, and the first return spring is located between the spring retaining ring and the lower cover of the bracket.

[0016] Furthermore, there are two hydraulic chambers between the housing and the piston, forming a double-acting hydraulic cylinder.

[0017] Furthermore, an annular groove is provided on the top surface of the first handwheel rod, the depth of the annular groove is at least greater than the height of the spring after maximum compression, the spring is sleeved outside the second handwheel rod and placed in the annular groove, and the upper end of the spring is against the second bearing box.

[0018] Furthermore, the shaft ring is a positioning ring, the second handwheel rod is provided with a first shaft shoulder, the lower surface of the positioning ring abuts against the first shaft shoulder, and the upper surface is locked by a locking nut.

[0019] Furthermore, a second shoulder is provided above the threaded section of the second handwheel rod, and a matching step surface is provided at the first handwheel rod for limiting the maximum relative height of the second handwheel rod with respect to the first handwheel rod.

[0020] Furthermore, the sensing portion is annular, and its diameter is larger than the indicator rod and the first bearing box.

[0021] Furthermore, the first handwheel rod and the second handwheel rod are clearance-fitted, the first handwheel rod is provided with an annular groove, and a sealing member is provided in the annular groove.

[0022] Furthermore, a locking bolt is provided on the indicating frame, and the locking bolt can be abutted against the first hand wheel rod.

[0023] Furthermore, a limiting groove is provided on the indicating frame, a limiting screw is installed on the indicating rod, and the head of the limiting screw is located in the limiting groove of the indicating frame.

[0024] The beneficial effects of the present invention are:

[0025] 1. The present invention is provided with a first manual drive mechanism and a second manual drive mechanism, which ensures that when the hydraulic drive mechanism fails or the first return spring loses its elastic force, the valve can still be opened or closed in time by manual operation. This design improves the redundancy and emergency handling capability of the system and ensures the safety of oil production.

[0026] 2. The present invention can monitor the opening and closing status of the valve in real time through the indicating mechanism and position sensor. When the valve is opened or closed abnormally, the system will sound an alarm to help the operator find the fault and take measures in the first time, further improving the safety and operating efficiency of the system.

[0027] 3. Compared with the manual drive mechanism in the prior art which can only open the valve, the second hand wheel rod of the present invention can be screwed and fixed with the indicator rod, and the second hand wheel rod can be pulled up by the first manual drive mechanism to realize manual closing of the valve, which has more comprehensive functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural schematic diagram of a new type of explosion-proof flat safety valve described in Example 1 (the valve is in an open state);

[0029] Figure 2 for Figure 1 A partial enlarged view of the upper middle part;

[0030] Figure 3 for Figure 2 A partial enlarged view of the second bearing box;

[0031] Figure 4 for Figure 2 A partial enlarged view of the first bearing box;

[0032] Figure 5 This is a structural schematic diagram of a new type of explosion-proof flat safety valve described in Example 1 (the valve is in a closed state);

[0033] Figure 6 This is a structural schematic diagram of a new type of explosion-proof flat safety valve described in Example 1 (the valve is in a manually opened state);

[0034] Figure 7 for Figure 6 A partial enlarged view of the upper part;

[0035] Figure 8 This is a schematic diagram of the upper part of the structure of a new type of explosion-proof flat safety valve described in Example 1 (the valve is in the manual closing process, state 1);

[0036] Fig. 9 This is a schematic diagram of the upper part of the structure of a novel explosion-proof flat safety valve according to Example 1 (the valve is in the manual closing process, state 2);

[0037] Fig.10 This is a schematic diagram of the upper part of the structure of a new type of explosion-proof flat safety valve described in Example 1 (the valve is in the manual closing process, state three);

[0038] Fig.11This is a structural schematic diagram of a new type of explosion-proof flat safety valve described in Example 2;

[0039] In the figure:

[0040] 100 valve body assembly; 101 valve body; 102 valve cover; 103 valve seat; 104 valve plate; 105 valve stem;

[0041] 200 hydraulic drive mechanism; 201 bracket; 202 housing; 203 piston; 204 indicator rod; 2041 sensing part; 205 adjusting nut; 206 fixing nut; 207 first return spring; 208 spring retaining ring;

[0042] 300 indicating mechanism; 301 indicating frame; 3011 limiting groove; 302 first position sensor; 303 second position sensor; 304 limiting screw; 305 locking bolt;

[0043] 400 first manual drive mechanism; 401 first hand wheel; 402 first hand wheel rod; 4021 annular groove; 403 first bearing box; 404 first thrust bearing;

[0044] 500 second manual drive mechanism; 501 second hand wheel; 502 second hand wheel rod; 5021 positioning ring; 5022 first shaft shoulder; 5023 second shaft shoulder; 503 second bearing box; 504 second thrust bearing; 505 second return spring. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] Embodiment 1

[0047] like Figure 1-5 As shown, a novel explosion-proof flat safety valve includes a valve body assembly 100, a hydraulic drive mechanism 200, an indication mechanism 300, a first manual drive mechanism 400, and a second manual drive mechanism 500;

[0048] like Figure 1As shown, the valve body assembly 100 includes a valve body 101, a valve cover 102, a valve seat 103, a valve plate 104, and a valve stem 105. Two valve seats 103 are arranged in the valve body 101, and the valve plate 104 is located between the two valve seats 103. The valve seat 103 adopts a floating seal form, which achieves sealing under the action of the medium by the free fit between the metal gate plate and the metal valve seat 103 plane. Two LIP-SEAL sealing rings are used to seal between the valve seat 103 and the valve body 101, which effectively ensures the sealing ability under low pressure and high pressure conditions. The first end of the valve stem 105 is connected to the valve plate 104, and the second end of the valve stem 105 passes through the valve cover 102 upward. The valve cover 102 is also provided with a valve stem 105 packing and a packing gland for sealing between the valve stem 105 and the valve cover 102.

[0049] like Figure 1 As shown, the hydraulic drive mechanism 200 includes a support 201, a housing 202, a piston 203, an indicator rod 204, an adjusting nut 205, a fixing nut 206, a first return spring 207, and a spring retaining ring 208. The housing 202 and the piston 203 form an oil cylinder, which can be a single-acting oil cylinder or a double-acting oil cylinder. The present embodiment adopts a single-acting oil cylinder. There is only one hydraulic cavity between the housing 202 and the piston 203, which is opened by hydraulic one-way drive, and closed by the spring rebound force and the axial force of the medium acting on the valve stem 105 (under pressure). Specifically: the adjusting nut 205 is connected to the second end of the valve stem 105 by threading, and is used to adjust the extension length. The fixing nut 206 is installed above the adjusting nut 205 by threading. The fixing nut 206 and the spring retaining ring 208 are provided with matching step surfaces, which are used to limit the spring retaining ring 208. The first return spring 207 is located between the spring retaining ring 208 and the lower cover of the support 201. The housing 202 and the valve cover 102 are relatively fixedly connected through the bracket 201, the piston 203 is movably arranged in the housing 202, the lower end of the piston 203 is threadedly connected to the fixing nut 206, and the upper end of the piston 203 is connected to the indicator rod 204, the indicator rod 204 passes through the housing 202 upward, and the indicator rod 204 is provided with a sensing part 2041 that can be recognized by the sensor. When it is necessary to open the valve, hydraulic oil is injected into the housing 202, the piston 203 overcomes the elastic force of the first return spring 207 and moves downward, and the driving force is transmitted to the valve plate 104 through the piston 203-fixing nut 206-adjusting nut 205-valve stem 105, thereby driving the valve plate 104 to move downward to open the valve, and when it is necessary to close the valve, the oil pressure in the housing 202 is released, and the first return spring 207 drives the spring retaining ring 208 to move upward to close the valve.

[0050] In order to accurately identify whether the valve is open or closed, an indicator mechanism 300 is provided. Figure 2 As shown, the indicating mechanism 300 includes an indicating frame 301, a first position sensor 302, and a second position sensor 303. The indicating frame 301 is a cylindrical bracket 201, which is installed above the housing 202 through a threaded connection. The first position sensor 302 and the second position sensor 303 are installed on the indicating frame 301. A proximity sensor is used. When the piston 203 moves to the minimum stroke and the maximum stroke, the sensing part 2041 can be recognized by the first position sensor 302 and the second position sensor 303; therefore, when the valve is opened, after the solenoid valve is opened, hydraulic oil is injected into the housing 202. After a period of time, the piston 203 should be at the maximum stroke, as shown in FIG. Figure 1 As shown, the sensing part 2041 should be located just in front of the second position sensor 303 at this time. If the second position sensor 303 has a blocking signal, it means that the valve plate 104 is fully opened. Otherwise, it means that the valve is abnormally opened and an abnormal opening alarm is issued. When the valve is closed, the solenoid valve controls the release of the oil pressure in the housing 202, and the first reset spring 207 drives the reset. After a period of time, the piston 203 should be at the minimum stroke, as shown in FIG. Figure 5 As shown, the sensing part 2041 should be located just in front of the first position sensor 302. If the first position sensor 302 has a blocking signal, it means that the valve plate 104 is completely closed. Otherwise, it means that the valve is abnormally closed and an abnormal closing alarm is issued. Through the precise identification of the sensor, the opening state of the valve can be more clearly understood, and the fault can be discovered in the first time, thereby improving the safety of oil production.

[0051] In order to realize timely operation of the valve in case of failure, the present invention is provided with a first manual drive mechanism 400 and a second manual drive mechanism 500.

[0052] like Figure 2-4As shown, the first manual drive mechanism 400 includes a first hand wheel 401, a first hand wheel rod 402, a first bearing box 403, and a first thrust bearing 404. The first hand wheel rod 402 is a hollow structure. The middle part of the first hand wheel rod 402 is connected to the indicator frame 301 through a thread. The lower end of the first hand wheel rod 402 is rotatably connected to the first bearing box 403 through the first thrust bearing 404. The first bearing is cylindrical, with an opening at the upper end and a through hole at the lower end. The first thrust bearing 404 is installed at the bottom of the first bearing box 403. Bearing 404, a shaft ring is arranged under the first handwheel rod 402, after the shaft ring extends into the first bearing box 403, a hole retaining ring is arranged at the upper opening of the first bearing to limit the shaft ring, the distance between the first thrust bearing 404 and the hole retaining ring is greater than the thickness of the shaft ring, and a certain axial clearance is reserved for the first bearing box 403 to avoid friction between the hole retaining ring and the shaft ring, the bottom surface of the first bearing box 403 is parallel to the upper surface of the indicator rod 204, and the first handwheel 401 is installed on the top of the first handwheel rod 402. The first manual drive mechanism 400 is used when the valve cannot be started normally, for example, when the pressure source of the hydraulic drive mechanism 200 does not work. At this time, the first hand wheel 401 is rotated counterclockwise, and the first hand wheel rod 402 rotates downward. After descending a short distance, the bottom surface of the first bearing box 403 and the indicator rod 204 are against each other. At this time, the first bearing box 403 and the indicator rod 204 remain relatively still and move downward together. The first hand wheel rod 402 and the first bearing box 403 rotate relatively to reduce friction. The indicator rod 204 moves downward to realize the downward movement of the valve plate 104, and the valve is finally manually opened. Its final state is as follows: Figure 6-7 shown.

[0053] When the first return spring 207 is deformed and loses its elastic force, the valve needs to be closed manually. At this time, a second manual drive mechanism 500 is needed. The second manual drive mechanism 500 includes a second hand wheel 501, a second hand wheel rod 502, a second bearing box 503, a second thrust bearing 504, and a second return spring 505. A second hand wheel 501 is installed above the second hand wheel rod 502, and an axial ring is arranged near the second hand wheel 501, and the axial ring is a positioning ring 5021. The second hand wheel rod 502 is provided with a first shaft shoulder 5022, and the lower surface of the positioning ring 5021 is against the first shaft shoulder 5022, and the upper surface is locked by a locking nut. The shaft ring is rotatably connected to the second bearing box 503 through the second thrust bearing 504. The structure of the second bearing box 503 is similar to that of the first bearing box 403. The second bearing is cylindrical, with an open upper end and a through hole at the bottom for the second handwheel rod 502 to pass through. The second thrust bearing 504 is installed at the bottom of the second bearing box 503. After the positioning ring 5021 is extended into the second bearing box 503, a hole retaining ring is provided at the upper mouth of the second bearing to limit the positioning ring 5021. The distance between the second thrust bearing 504 and the hole retaining ring is greater than the thickness of the positioning ring 5021, and a certain axial clearance is reserved for the second bearing box 503 to avoid friction between the hole retaining ring and the positioning ring 5021. The second bearing box 503 is parallel to the top of the first handwheel rod 402. The first handwheel rod 402 is a hollow structure. The second handwheel rod 502 passes through the first handwheel rod 402. A small section of external thread is provided at the lower end of the second handwheel rod 502. The first bearing box 403 is provided with a through hole for the lower end of the second handwheel rod 502 to pass through. The indicating rod 204 is provided with an internal thread matching the second handwheel rod 502. The second return spring 505 is used to drive the second handwheel rod 502 to move upward relative to the first handwheel rod 402. When the first handwheel rod 402 moves to the uppermost stroke, the lower end surface height of the second handwheel rod 502 is higher than the bottom surface height of the first bearing box 403. Therefore, when the manual start valve is executed, the first bearing and the indicating rod 204 are against each other, and at this time, the second handwheel rod 502 and the indicating rod 204 are not in contact.

[0054] When the valve needs to be closed, the first hand wheel 401 needs to be turned counterclockwise to allow the first bearing box 403 to drop and abut against the indicator rod 204. Figure 8 As shown, the second hand wheel 501 is manually pressed to move the second hand wheel rod 502 downward, and the second hand wheel 501 is rotated at the same time to screw the outer thread section at the lower end of the second hand wheel rod 502 into the threaded hole at the top of the indicator rod 204, screw it into the deepest part, and tighten it. Fig. 9As shown, at this time, the second hand wheel rod 502 and the indicator rod 204 are connected as a rigid whole. At this time, the bottom surface of the second bearing box 503 should be a short distance from the top surface of the first hand wheel rod 402. Then, the first hand wheel 401 is rotated clockwise, and the first hand wheel rod 402 rises. Subsequently, the first hand wheel rod 402 and the second bearing box 503 are abutted against each other. The first hand wheel 401 continues to be rotated clockwise. The second bearing box 503 and the first hand wheel rod 402 remain relatively still, which is a synchronous rotation and rising state. The second hand wheel rod 502 is relatively still with the indicator rod 204, and is driven by the second bearing to slowly move upward until the valve plate 104 is completely closed. Its state is as shown in FIG. Fig.10 As shown, at this time, the second hand wheel 501 is rotated again to disengage the second hand wheel rod 502 and the indicator rod 204. At this time, the second return spring 505 pushes the second hand wheel rod 502 to rise, and the lower end of the second hand wheel rod 502 is received in the first bearing box 403, returning to the Figure 5 state, and finally the hydraulic drive mechanism 200 can be removed for maintenance.

[0055] In summary, this solution can manually close or open the valve as soon as a valve failure occurs, saving time and improving the safety of oil production.

[0056] In actual application, an annular groove 4021 is provided on the top surface of the first handwheel rod 402, and the depth of the annular groove 4021 is at least greater than the height of the spring after maximum compression. The spring is sleeved outside the second handwheel rod 502 and placed in the annular groove 4021, and the upper end of the spring is against the second bearing box 503.

[0057] In actual application, in order to limit the vertical position of the second handwheel rod 502, a second shoulder 5023 is provided above the threaded section of the second handwheel rod 502, and a matching step surface is provided at the first handwheel rod 402. When the second return spring 505 pushes the second handwheel rod 502 to rise, the second shoulder 5023 and the step surface in the first handwheel rod 402 are abutted against each other to achieve limiting and prevent the second handwheel rod 502 from sliding upward.

[0058] In actual application, the sensing part 2041 is annular, and its diameter is larger than the indicator rod 204 and the first bearing box 403 to avoid false signal touch. The annular shape can increase the area of ​​the top of the indicator rod 204, facilitating the thrust transmission when the first bearing box 403 and the indicator rod 204 are in contact.

[0059] In practical applications, the first handwheel rod 402 and the second handwheel rod 502 are clearance-fitted, and the first handwheel rod 402 is provided with an annular groove 4021 , and a seal is provided in the annular groove 4021 to prevent dust from entering.

[0060] In practical application, the indicating frame 301 is provided with a limiting groove 3011, and the indicating rod 204 is provided with a limiting screw 304, and the head of the limiting screw 304 is located in the limiting groove 3011 of the indicating frame 301. Therefore, the indicating rod 204 can be prevented from rotating when the connection between the second hand wheel rod 502 and the indicating rod 204 is disconnected.

[0061] In actual application, a locking bolt 305 is provided on the indicator frame 301, and the locking bolt 305 can be against the first hand wheel rod 402. When the valve is in a normal state, the locking bolt 305 needs to be tightened to prevent the first manual drive mechanism 400 from interfering with the hydraulic drive mechanism 200.

[0062] Embodiment 2

[0063] like Fig.11 As shown, the difference between this embodiment and the first embodiment is that the hydraulic drive mechanism 200 in this solution adopts a double-acting oil cylinder. Similarly, the valve is manually closed or opened when the hydraulic power source fails.

[0064] In summary, the novel explosion-proof flat safety valve described in the present invention can accurately detect whether the valve is in place, is simple and convenient to operate, can realize manual opening and closing at the same time, and improves the safety of oil production.

[0065] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above implementation is only to illustrate the technical concept and features of the present invention, and its purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and it cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A new type of explosion-proof flat safety valve, characterized by: It comprises a valve body assembly (100), a hydraulic drive mechanism (200), an indication mechanism (300), a first manual drive mechanism (400), and a second manual drive mechanism (500); The valve body assembly (100) comprises a valve body (101), a valve cover (102), a valve seat (103), a valve plate (104), and a valve stem (105); The hydraulic drive mechanism (200) comprises a bracket (201), a housing (202), a piston (203), and an indicator rod (204); the lower end of the piston (203) is connected to the top of the valve stem (105); the upper end of the piston (203) is connected to the indicator rod (204); the indicator rod (204) passes through the housing (202) upwards; and the indicator rod (204) is provided with a sensing portion (2041) that can be identified by a sensor; The indicating mechanism (300) comprises an indicating frame (301), a first position sensor (302), and a second position sensor (303); The first manual drive mechanism (400) comprises a first hand wheel (401), a first hand wheel rod (402), a first bearing box (403), and a first thrust bearing (404); the middle portion of the first hand wheel rod (402) and the indicator frame (301) are connected via threads; the lower end of the first hand wheel rod (402) is rotatably connected to the first bearing box (403) via the first thrust bearing (404); The second manual drive mechanism (500) comprises a second hand wheel (501), a second hand wheel rod (502), a second bearing box (503), a second thrust bearing (504), and a second return spring (505); a shaft ring is provided on the second hand wheel rod (502) near the second hand wheel (501), and the shaft ring is rotatably connected to the second bearing box (503) via the second thrust bearing (504); the first hand wheel rod (402) is a hollow structure, and the second hand wheel rod (502) passes through the first hand wheel rod (402); The lower end of the second hand wheel rod (502) is provided with a short section of external thread, the first bearing box (403) is provided with a through hole for accommodating the lower end of the second hand wheel rod (502) to pass through, the indicating rod (204) is provided with an internal thread matching the second hand wheel rod (502), the second return spring (505) is used to drive the second hand wheel rod (502) to move upward relative to the first hand wheel rod (402), and when the first hand wheel rod (402) moves to the uppermost stroke, the lower end surface of the second hand wheel rod (502) is higher than the bottom surface of the first bearing box (403).

2. According to claim 1, the novel explosion-proof flat safety valve is characterized by: There is only one hydraulic chamber between the housing (202) and the piston (203). The hydraulic drive mechanism (200) further comprises an adjusting nut (205), a fixing nut (206), a first return spring (207), and a spring retaining ring (208). The adjusting nut (205) is connected to the second end of the valve stem (105) for adjusting the extension length. The fixing nut (206) is installed above the adjusting nut (205). The fixing nut (206) and the spring retaining ring (208) are provided with matching step surfaces. The first return spring (207) is located between the spring retaining ring (208) and the lower cover of the bracket (201).

3. According to claim 1, the novel explosion-proof flat safety valve is characterized by: There are two hydraulic chambers between the housing (202) and the piston (203), forming a double-acting hydraulic cylinder.

4. A novel explosion-proof flat safety valve according to any one of claims 1 to 3, characterized in that: An annular groove (4021) is provided on the top surface of the first handwheel rod (402), the depth of the annular groove (4021) being at least greater than the height of the spring after maximum compression, the spring is sleeved outside the second handwheel rod (502) and placed in the annular groove (4021), and the upper end of the spring abuts against the second bearing box (503).

5. A novel explosion-proof flat safety valve according to any one of claims 1 to 3, characterized in that: The shaft ring is a positioning ring (5021), the second hand wheel rod (502) is provided with a first shaft shoulder (5022), the lower surface of the positioning ring (5021) abuts against the first shaft shoulder (5022), and the upper surface is locked by a locking nut.

6. The novel explosion-proof flat safety valve according to claim 5 is characterized by: A second shoulder (5023) is provided above the threaded section of the second handwheel rod (502), and a matching step surface is provided at the first handwheel rod (402) for limiting the maximum relative height of the second handwheel rod (502) relative to the first handwheel rod (402).

7. A novel explosion-proof flat safety valve according to any one of claims 1 to 3, characterized in that: The sensing portion (2041) is annular, and its diameter is larger than the indicator rod (204) and the first bearing box (403).

8. A novel explosion-proof flat safety valve according to any one of claims 1 to 3, characterized in that: The first handwheel rod (402) and the second handwheel rod (502) are clearance-fitted, the first handwheel rod (402) is provided with an annular groove (4021), and a sealing element is provided in the annular groove (4021).

9. A novel explosion-proof flat safety valve according to any one of claims 1 to 3, characterized in that: The indicating frame (301) is provided with a locking bolt (305), and the locking bolt (305) can abut against the first hand wheel rod (402).

10. A novel explosion-proof flat safety valve according to any one of claims 1 to 3, characterized in that: A limiting groove (3011) is provided on the indicating frame (301), a limiting screw (304) is installed on the indicating rod (204), and the head of the limiting screw (304) is located in the limiting groove (3011) of the indicating frame (301).

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