A quick opening and closing safety valve

Abstract

The invention discloses a quick opening and closing safety valve, comprising a nozzle, a valve disc and a spring for providing elastic preload, a booster ring is sleeved on the outer wall of the nozzle, the booster ring is in a truncated cone shape, the end of the booster ring close to the valve disc is the small end of the booster ring, and the relative position of the upper end face of the booster ring and the sealing surface of the nozzle can be adjusted; the spring is a disc spring, the spring major diameter D1 of the disc spring is 3.3-3.5 times the throat diameter d0 of the nozzle, the spring index C of the disc spring is D1 / t≥40, the curvature ratio h0 / t≥1.3, wherein h0 is the deformable amount, and t is the thickness of the disc spring. Since the lift coefficient curve of the safety valve and the elastic stiffness curve of the disc spring have roughly the same trend of change, the quick opening and closing safety valve realizes the pressure increase under the minimum displacement, realizes the rapid opening and discharge of the valve disc, and after the pressure is released, the pressure can be reduced by the minimum displacement, and the valve disc can be quickly returned to the seat.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic valves, and more specifically to a quick opening and closing safety valve. Background Art

[0002] As an overpressure protection device, safety valves are mostly used in pressure-bearing equipment such as boilers, pressure vessels and pressure pipelines.

[0003] The safety valve realizes rapid opening and closing of the safety valve through the interaction between the lift F brought by the static pressure P of the medium and the external force F′ of the safety valve. When the lift F gradually increases to exceed the external force F′ of the safety valve, the valve disc lifts and opens the safety valve to release the overpressure medium; conversely, when the lift F drops to less than the external force F′ of the safety valve, the valve disc lowers and closes the safety valve.

[0004] In the current standard, if the set pressure of the safety valve is Ps, the allowable discharge pressure Pd≤1.03Ps-1.10Ps, and the closing pressure Pr≥0.90Ps-0.96Ps. The discharge of overpressure media and valve disc closing requirements are high, and the opening and closing speed of the safety valve is slow, which is not conducive to the improvement of the parameters of pressure-bearing equipment.

[0005] In summary, how to achieve rapid opening and closing of a safety valve is a problem that currently needs to be solved urgently by those skilled in the art. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a fast opening and closing safety valve, which improves the opening and closing performance of the safety valve and realizes the fast opening and closing of the safety valve.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A quick opening and closing safety valve comprises a nozzle, a valve disc and a spring for providing elastic preload force, wherein a booster ring is sleeved on the outer wall surface of the nozzle, the booster ring is in a truncated cone shape, the end of the booster ring close to the valve disc is the small end of the booster ring, and the relative position between the upper end surface of the booster ring and the sealing surface of the nozzle is adjustable;

[0009] The spring is a disc spring, the major diameter D1 of the disc spring is 3.3-3.5 times the throat diameter d0 of the nozzle, the spring index C of the disc spring is C=D1 / t≥40, and the curvature ratio h0 / t≥1.3 of the disc spring, wherein h0 is the deformable amount and t is the thickness of the disc spring.

[0010] Preferably, the booster ring is provided with an internal thread, and the outer wall surface of the nozzle is provided with an external thread matching the internal thread, and the number of turns of the external thread is greater than the number of turns of the internal thread.

[0011] Preferably, a limiting step is provided on the outer wall surface of the nozzle at the upper end of the external thread to limit the lowest position of the connection between the booster ring and the nozzle.

[0012] Preferably, the lifting height H of the valve disc and the throat diameter d0 of the nozzle satisfy H≥0.25d0.

[0013] Preferably, a lift recoil ring is connected to the outer shell of the valve disc, and the inner diameter d1 of the lift recoil ring and the throat diameter d0 of the nozzle satisfy d1=1.5-2.5d0, and the smaller the throat diameter d0 of the nozzle, the larger the value of d1 / d0.

[0014] Preferably, when the nominal diameter DN of the nozzle is 40 mm, the inner diameter d1 of the lift-recoil ring is 2.20d0;

[0015] When the nominal diameter DN of the nozzle is 50 mm, the inner diameter d1 of the lift-recoil ring is 2.09d0.

[0016] Preferably, the outer diameter d2 of the booster ring and the throat diameter d0 of the nozzle satisfy d2=1.15-1.3d0.

[0017] Preferably, the outer diameter d2 of the booster ring is 1.2 times the throat diameter d0 of the nozzle.

[0018] The quick opening and closing safety valve provided by the present invention comprises a nozzle, a valve disc and a spring for providing elastic preload force. A booster ring is sleeved on the outer wall surface of the nozzle, the booster ring is in a truncated cone shape, the end of the booster ring close to the valve disc is the small end of the booster ring, and the relative position of the upper end surface of the booster ring and the sealing surface of the nozzle is adjustable; the spring is a disc spring, the spring major diameter D1 of the disc spring is 3.3-3.5 times the throat diameter d0 of the nozzle, the spring index C of the disc spring is D1 / t≥40, the curvature ratio of the disc spring h0 / t≥1.3, wherein h0 is the deformable amount, and t is the disc spring sheet thickness.

[0019] Please refer to Figure 1 and Figure 2 , Figure 1 a1-a4 are curves of relative opening height and lift coefficient obtained in the simulation aerodynamic lift experiment of the existing safety valve, and a5 is a curve of relative opening height and lift coefficient obtained in the simulation aerodynamic lift experiment of the fast opening and closing safety valve provided by the present invention; Figure 2 b1 is the relative opening height and elastic stiffness curve of the spring in the existing safety valve, and b2 is the relative opening height and elastic stiffness curve of the disc spring in the present invention. Wherein, H is the valve disc lifting height, d0 is the throat diameter of the nozzle, the static pressure P of the medium of the overpressure medium of curve a1-a4 is increasing continuously, and the static pressure P of the medium corresponding to curve a5 is the same as that of curve a4.

[0020] Depend on Figure 1 It can be seen that the existing safety valve has a lift reduction problem in the initial stage of opening, and the lift reduction is not affected by the static pressure P of the medium, which makes the safety valve unable to open quickly; the present invention provides a booster ring on the nozzle sleeve to increase the area of ​​the sealing surface at the nozzle, thereby expanding the force-bearing surface to offset the lift reduction in the slightly open state of the valve disc, which is conducive to the rapid opening of the safety valve.

[0021] contrast Figure 1 and Figure 2 It can be seen that the elastic stiffness curve b2 of the disc spring is basically matched with the lift coefficient curve a5. Therefore, the quick opening and closing safety valve provided by the present invention realizes the pressure increase under the minimum displacement, realizes the rapid opening and discharge of the valve disc, and after the pressure is released, the pressure can be reduced by the minimum displacement, and the valve disc can be quickly returned to its seat.

[0022] At the same time, changing the position of the upper end surface of the booster ring relative to the nozzle sealing surface can change the lift generated by the pressure storage chamber formed after the medium rushes out of the nozzle, thereby achieving fine-tuning of the lift coefficient curve of the safety valve, thereby correcting the deviation between the elastic stiffness curve of the disc spring and the lift coefficient curve of the safety valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 It is the lift coefficient curve of the relative opening height H / d0 of the safety valve and the lift coefficient ρ;

[0025] Figure 2 It is the elastic stiffness curve of the relative opening height H / d0 of the safety valve and the elastic stiffness λ of the spring;

[0026] Figure 3 It is a combined diagram of the lift coefficient curve and the elastic stiffness curve of the safety valve;

[0027] Figure 4 A schematic diagram of the structure of a quick opening and closing safety valve provided in a specific embodiment of the present invention;

[0028] Figure 5 for Figure 4 A partial enlarged view of area A.

[0029] Figure 1-Figure 5 middle:

[0030] 1 is the valve body, 2 is the nozzle, 3 is the valve disc, 4 is the booster ring, 5 is the lift recoil ring, 6 is the disc spring, H is the lifting height, d0 is the throat diameter of the nozzle, d1 is the inner diameter of the lift recoil ring, d2 is the outer diameter of the booster ring, dmz is the middle diameter of the sealing surface of the nozzle, d3 is the outer diameter of the valve disc, δ1 is the height from the sealing surface to the lower end surface of the valve disc, δ2 is the height of the nozzle accumulation groove, Δ is the height from the sealing surface to the lower end surface of the lift recoil ring, ρ is the lift coefficient, λ is the elastic stiffness of the spring, a1-a4 are the lift coefficient curves of the existing safety valve under different medium pressures, a5 is the lift coefficient curve of the quick opening and closing safety valve provided by the present invention, b1 is the elastic stiffness curve of the spring in the existing safety valve, and b2 is the spring stiffness characteristic curve of the quick opening and closing safety valve provided by the present invention. DETAILED DESCRIPTION

[0031] 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.

[0032] The core of the present invention is to provide a fast opening and closing safety valve, improve the opening and closing performance of the safety valve, and realize the fast opening and closing of the safety valve.

[0033] Please refer to Figure 1-Figure 5 , Figure 1 It is the lift coefficient curve of the relative opening height H / d0 of the safety valve and the lift coefficient ρ; Figure 2 It is the elastic stiffness curve of the relative opening height H / d0 of the safety valve and the elastic stiffness λ of the spring; Figure 3 It is a combined diagram of the lift coefficient curve and the elastic stiffness curve of the safety valve; Figure 4 A schematic diagram of the structure of a quick opening and closing safety valve provided in a specific embodiment of the present invention; Figure 5 for Figure 4 A partial enlarged view of area A.

[0034] It should be noted that in the present application document, the upward direction refers to the same direction as the flow direction of the overpressure medium in the nozzle 2 , and the downward direction refers to the opposite direction to the flow direction of the overpressure medium in the nozzle 2 .

[0035] The quick opening and closing safety valve provided by the present invention comprises a nozzle 2, a valve disc 3 and a spring for providing elastic preload force. A booster ring 4 is sleeved on the outer wall surface of the nozzle 2. The booster ring 4 is truncated cone-shaped. The end of the booster ring 4 close to the valve disc 3 is the small end of the booster ring 4, and the relative position of the upper end surface of the booster ring 4 and the sealing surface of the nozzle 2 is adjustable; the spring is a disc spring 6, the spring major diameter D1 of the disc spring 6 is 3.3-3.5 times the throat diameter d0 of the nozzle 2, the spring index C of the disc spring 6 is D1 / t≥40, and the curvature ratio of the disc spring 6 is h0 / t≥1.3, wherein h0 is the deformable amount and t is the disc thickness of the disc spring 6.

[0036] The nozzle 2 is installed on the valve body 1, and the gap between the nozzle 2 and the booster ring 4 and the lift recoil ring 5 constitutes a channel for the discharge of the overpressure medium.

[0037] Please refer to Figure 2 The nozzle 2 is a convergent nozzle, and the throat of the nozzle 2 can be located near the nozzle opening. The convergence angle β of the convergent nozzle can be set between 6°-25°. Preferably, considering factors such as the installation space in the valve body 1, the convergence angle β can be set between 6°-10°.

[0038] Usually, the throat diameter d0 of the nozzle 2 satisfies d0=0.500-0.667DN with the nominal diameter DN of the nozzle 2; the sealing surface middle diameter dmz of the nozzle 2 satisfies dmz=1.00-1.30d0 with the throat diameter d0 of the nozzle 2, and a higher coefficient value should be taken for the nozzle 2 with a larger nominal diameter DN; the height δ1 from the sealing surface to the lower end surface of the valve disc 3 is 0.5-1.0mm.

[0039] The booster ring 4 is sleeved on the outer wall of the nozzle 2, which can increase the force-bearing area of ​​the static pressure P of the medium in the micro-opening stage, thereby increasing the lift and helping the valve disc 3 to rise quickly by increasing the force-bearing area.

[0040] In the slightly open stage of the valve disc 3, after the medium flows out from the nozzle of the nozzle 2, it flows through the outlet surface of the nozzle 2 and enters the pressure storage chamber between the valve disc 3, the nozzle 2 and the booster ring 4 to generate a local high-pressure air cushion. At this time, the effective area of ​​the static pressure P of the medium increases, and at the same time, an expansion force is generated to overcome the elastic force of the disc spring 6.

[0041] The relative position of the upper end surface of the booster ring 4 and the sealing surface of the nozzle 2 is adjustable. When the upper end surface of the booster ring 4 moves up relative to the sealing surface of the nozzle 2, the gap between the upper end surface of the booster ring 4 and the valve disc 3 is reduced, and when the valve disc 3 is opened, the static pressure formed under the valve disc 3 by the medium leaking from the sealing surface of the nozzle 2 increases, and the lift in the micro-opening stage increases; conversely, when the upper end surface of the booster ring 4 is lower than the sealing surface of the nozzle 2, the diffuser effect of the nozzle 2 disappears, the additional static pressure disappears, the lift in the micro-opening stage tends to a constant value, and the booster ring 4 loses its regulating effect on the discharge pressure Pd.

[0042] Please refer to Figure 5 The upper end surface of the booster ring 4 is provided with an inclined surface at the same height as the storage groove on the nozzle 2 on the side close to the nozzle 2, and the two together constitute a pressure storage chamber structure; the depth δ2 of the storage groove is mostly set between 1.0-1.5mm.

[0043] According to the test results of the simulation test, when the outer diameter d2 of the booster ring 4 and the throat diameter d0 of the nozzle 2 satisfy the quantitative relationship of d2 / d0=1.15-1.3, the booster ring 4 has the most obvious effect on improving the lift.

[0044] Preferably, the outer diameter of the booster ring 4 may be set to d2=1.2d0.

[0045] Of course, the above coefficients are not fixed values, and can be adjusted in actual production according to factors such as the diameter of the booster ring 4 and the elastic stiffness curve of the disc spring 6 .

[0046] Please refer to Figure 1 After the boost ring 4 is set, the relative opening height and lift coefficient curve a5 of the safety valve does not match the relative opening height and elastic stiffness curve of the ordinary spring, which affects the opening and closing performance of the safety valve; while the relative opening height and elastic stiffness curve b2 of the disc spring 6 basically matches the lift coefficient curve a5, and the change trend of the elastic stiffness λ of the disc spring 6 with the relative opening height H / d0 of the safety valve is roughly the same as the change trend of the lift coefficient ρ of the safety valve with the relative opening height H / d0 of the safety valve. Therefore, the fast opening and closing safety valve provided in this embodiment realizes the pressure increase under the minimum displacement, realizes the rapid opening and discharge of the valve disc 3, and after the pressure is released, the pressure can be reduced by the minimum displacement, and the valve disc 3 can be quickly returned to its seat.

[0047] According to the simulation test data of the rapid opening and closing safety valve provided in this embodiment and the calculation formula of the lift force of the valve disc 3, it can be obtained that when the opening height is H, the corresponding spring stiffness λ is where ρ H is the lift coefficient when the opening height is H, D m is the average diameter of the sealing surface.

[0048] According to experimental data and quantitative calculation, it can be obtained that when the design opening height H / d0=0.25, the lift coefficient ρ≈2.2. Substituting it into the above formula, the design elastic stiffness λ of the disc spring 6 can be calculated.

[0049] According to the relationship between the design elastic stiffness λ and the elastic coefficient λ of the disc spring 6 and the spring index C, the curvature ratio h0 / t, etc., the design size of the disc spring 6 can be obtained, that is, the spring major diameter D1 / d0 of the disc spring 6 is D1 / d0=3.3-3.5, the spring index C≥40, and the curvature ratio h0 / t≥1.3.

[0050] Similar to the winding ratio of an ordinary spring, the spring index C of the disc spring 6 is a dimensionless number reflecting the elastic stiffness of the disc spring 6. Preferably, the spring coefficient C of the disc spring 6 can be set to 40 and the curvature ratio h0 / t to 1.3. At this time, the elastic stiffness curve of the disc spring 6 is highly consistent with the change trend of the lift coefficient curve of the safety valve, meeting the needs of rapid opening and closing of the safety valve.

[0051] In this embodiment, by providing a booster ring 4 and using a disc spring 6, the opening and closing performance of the safety valve is effectively improved, and the rapid opening and closing of the safety valve is achieved. The discharge pressure Pd of the valve is ≤1.00Ps-1.02Ps, and the closing pressure Pr is ≥0.95Ps-0.97Ps. The required discharge pressure is reduced and the closing pressure is increased. The opening and closing performance is greatly improved compared with the existing technology and far exceeds the requirements of domestic and international standards and specifications.

[0052] At the same time, by adjusting the relative position between the upper end surface of the booster ring 4 and the sealing surface of the nozzle 2, the lift curve of the safety valve can be fine-tuned, thereby correcting the deviation of the elastic stiffness curve between it and the disc spring 6, and further improving the rapid opening and closing performance of the safety valve.

[0053] Preferably, the lifting height H of the valve flap 3 and the throat diameter d0 of the nozzle 2 may be designed to satisfy H≥0.25d0, so as to obtain good opening and closing performance.

[0054] On the basis of the above embodiment, taking into account the working environment of the safety valve and in order to prevent the relative position of the upper end surface of the booster ring 4 and the sealing surface of the nozzle 2 from changing during operation, an internal thread can be provided on the booster ring 4, and an external thread matching the internal thread can be provided on the outer wall surface of the nozzle 2, and the number of turns of the external thread is greater than the number of turns of the internal thread.

[0055] Therefore, by adjusting the height of the external thread connected to the internal thread of the booster ring 4 on the outer wall of the nozzle 2, the position of the upper end surface of the booster ring 4 relative to the sealing surface of the nozzle 2 can be adjusted, thereby adjusting the lift during the micro-opening stage and the lift coefficient curve of the safety valve.

[0056] The tooth type, number of turns and number of lines of the internal thread on the booster ring 4 can be determined according to actual production needs and with reference to the existing technology. As long as it can be connected with the external thread on the outer wall of the nozzle 2, it will not be described here.

[0057] In this embodiment, the connection between the booster ring 4 and the nozzle 2 and the adjustment of the relative position between the upper end surface of the booster ring 4 and the sealing surface of the nozzle 2 are achieved through the cooperation of the internal thread and the external thread. The connection method is simple, which facilitates the processing and production of the booster ring 4 and the nozzle 2. At the same time, the connection is stable and is not easy to change after the relative position adjustment of the two is completed.

[0058] Since the upper end surface of the booster ring 4 is lower than the sealing surface of the nozzle 2, the booster ring 4 cannot play a role in increasing the lift. Figure 5 It can be arranged that when the upper end surface of the internal thread is flush with the upper end surface of the external thread, the upper end surface of the booster ring 4 is flush with the sealing surface of the nozzle 2.

[0059] Preferably, in order to further limit the lowest position of the connection between the booster ring 4 and the nozzle 2, a limiting step may be provided on the outer wall surface of the nozzle 2 at the upper end of the external thread.

[0060] Preferably, the limiting step can be set as an annular step to facilitate the processing and manufacturing of the nozzle 2 and the booster ring 4.

[0061] Of course, the limiting step may also be replaced by other structures with limiting functions, such as limiting bolts connected to the outer wall surface of the nozzle 2.

[0062] On the basis of the above embodiment, a lift-recoil ring 5 may be sleeved on the outside of the valve disc 3, and the inner diameter d1 of the lift-recoil ring 5 and the throat diameter d0 of the nozzle 2 satisfy d1=1.5-2.5d0, and the smaller the throat diameter d0 of the nozzle 2, the larger the value of d1 / d0, so as to meet the needs of large-sized safety valves.

[0063] The lift recoil ring 5 is mainly used to adjust the closing pressure Pr of the safety valve and help the valve disc 3 to return to its seat quickly.

[0064] Please refer to Figure 4 or Figure 5 The lower end surface of the lift-recoil ring 5 is lower than the sealing surface of the nozzle 2. When the valve disc 3 is just opened, part of the medium flows out from the nozzle 2, impacts the reaction surface of the lift-recoil ring 5, and is deflected downward, generating a reaction force that pushes the lift-recoil ring 5 and the valve disc 3.

[0065] When the lower end face of the lift-recoil ring 5 moves downward relative to the sealing surface of the nozzle 2, the height Δ from the sealing surface to the lower end face of the lift-recoil ring 5 increases, and the high-speed medium is deflected by the reaction surface of the lift-recoil ring 5 and generates a recoil force. As Δ increases, the deflection angle and recoil force of the medium increase accordingly, the lift force on the valve disc 3 increases, and the closing pressure Pr of the safety valve decreases.

[0066] In order to ensure that the closing pressure Pr is not too low, the height Δ from the sealing surface to the lower end surface of the lift-recoil ring 5 is generally set to 0.20-0.25d0.

[0067] Preferably, the height Δ from the sealing surface to the lower end surface of the lift-recoil ring 5 can be set to be 0.20d0.

[0068] Preferably, when the nominal diameter DN of the nozzle 2 is 40 mm, the inner diameter d1 of the lift-recoil ring 5 is 2.20d0; when the nominal diameter DN of the nozzle 2 is 50 mm, the inner diameter d1 of the lift-recoil ring 5 is 2.09d0.

[0069] In a specific embodiment of the present invention, the nozzle 2 is a convergent nozzle with a slight expansion at the nozzle opening, the nominal diameter DN of the nozzle 2 is 40 mm, the throat diameter d0 of the nozzle 2 is 25 mm, the sealing surface middle diameter dmz of the nozzle 2 is 1.14d0, the convergence angle β of the nozzle 2 is 7°30′, the height δ1 from the sealing surface to the lower end surface of the valve disc 3 is 0.5 mm, and an accumulation groove is provided on the sealing surface of the nozzle 2, and the height of the nozzle accumulation groove is δ2=1.0 mm; the outer diameter d3 of the valve disc 3 is 2.45d0; the major spring diameter D1 of the disc spring 6 is 3.4d0, the spring index C is 40, and the curvature ratio h0 / t is 1.3; the outer diameter d2 of the booster ring 4 is 1.20d0; the inner diameter d1 of the lift-recoil ring 5 is 2.20d0, and the height Δ from the sealing surface to the lower end surface of the lift-recoil ring 5 is 0.2d0.

[0070] In another specific embodiment of the present invention, the nozzle 2 is a convergent nozzle with a slight expansion at the nozzle opening, the nominal diameter DN of the nozzle 2 is 50 mm, the throat diameter d0 of the nozzle is 32 mm, the sealing surface middle diameter dmz of the nozzle 2 is 1.125d0, the convergence angle β of the nozzle 2 is 9°30′, the height δ1 from the sealing surface to the lower end surface of the valve disc 3 is 0.5 mm, and an accumulation groove is provided on the sealing surface of the nozzle 2, and the height δ2 of the nozzle accumulation groove is 1.0 mm; the outer diameter d3 of the valve disc 3 is 2.45d0; the major spring diameter D1 of the disc spring 6 is 3.4d0, the spring index C is 40, and the curvature ratio h0 / t is 1.3; the outer diameter d2 of the booster ring 4 is 1.20d0; the inner diameter d1 of the lift-recoil ring 5 is 2.09d0, and the height Δ from the sealing surface to the lower end surface of the lift-recoil ring 5 is 0.2d0.

[0071] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0072] The above is a detailed introduction to the quick opening and closing safety valve provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A quick opening and closing safety valve, comprising a nozzle (2), a valve disc (3) and a spring for providing elastic preload, characterized in that: A booster ring (4) is sleeved on the outer wall surface of the nozzle (2), and the booster ring (4) is in a truncated cone shape. The end of the booster ring (4) close to the valve flap (3) is the small end of the booster ring (4), and the relative position of the upper end surface of the booster ring (4) and the sealing surface of the nozzle (2) is adjustable; The spring is a disc spring (6), the major spring diameter D1 of the disc spring (6) is 3.3-3.5 times the throat diameter d0 of the nozzle (2), the spring index C of the disc spring (6) is C=D1 / t≥40, and the curvature ratio h0 / t of the disc spring (6) is h0 / t≥1.3, wherein h0 is the deformable amount and t is the sheet thickness of the disc spring (6).

2. The quick opening and closing safety valve according to claim 1 is characterized in that: The booster ring (4) is provided with an internal thread, and the outer wall surface of the nozzle (2) is provided with an external thread matching the internal thread, and the number of turns of the external thread is greater than the number of turns of the internal thread.

3. The quick opening and closing safety valve according to claim 2 is characterized in that: A limiting step is provided on the outer wall surface of the nozzle (2) at the upper end of the external thread to limit the lowest position of the connection between the booster ring (4) and the nozzle (2).

4. The quick opening and closing safety valve according to any one of claims 1 to 3, characterized in that: The lifting height H of the valve flap (3) and the throat diameter d0 of the nozzle (2) satisfy H≥0.25d0.

5. The quick opening and closing safety valve according to claim 4 is characterized in that: The valve disc (3) is outer-connected with a lift-recoil ring (5), the inner diameter d1 of the lift-recoil ring (5) and the throat diameter d0 of the nozzle (2) satisfy d1=1.5-2.5d0, and the smaller the throat diameter d0 of the nozzle (2), the larger the value of d1 / d0.

6. The quick opening and closing safety valve according to claim 5, characterized in that: When the nominal diameter DN of the nozzle (2) is 40 mm, the inner diameter d1 of the lift-recoil ring (5) is 2.20d0; When the nominal diameter DN of the nozzle (2) is 50 mm, the inner diameter d1 of the lift recoil ring (5) is 2.09d0.

7. The quick opening and closing safety valve according to claim 4 is characterized in that: The outer diameter d2 of the booster ring (4) and the throat diameter d0 of the nozzle (2) satisfy d2=1.15-1.3d0.

8. The quick opening and closing safety valve according to claim 7 is characterized in that: The outer diameter of the booster ring (4) is d2=1.2d0.

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