Safety valve with stable sealing performance

Abstract

According to the technical scheme, the safety valve is characterized in that the safety valve comprises a valve body, a valve seat located in the valve body, a valve clack capable of forming hard sealing on the valve seat and a valve rod elastically connected with the valve body, and the valve seat and the valve clack are both provided with sealing faces capable of being attached to each other. A filtering throttling ring capable of abutting against the valve clack and a buffer spring pushing the filtering throttling ring to the valve clack are arranged in an inner cavity of the valve seat, the ring face, facing the valve clack, of the filtering throttling ring inclines relative to the horizontal plane, and the height of the inner edge of the ring face is larger than that of the outer edge of the ring face. A plurality of filtering throttling grooves which are circumferentially distributed around the axis of the filtering throttling ring are formed in the ring face, facing the valve clack, of the filtering throttling ring, and the length direction of the filtering throttling grooves is the same as the width direction of the ring face of the filtering throttling ring where the filtering throttling grooves are located; the valve clack abuts against the filtering throttling ring so that a medium can flow through the filtering throttling groove and the gap between the two sealing faces in sequence, and the problems that in the prior art, the sealing faces are prone to being abraded, and the sealing performance is poor are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of safety valves, and more specifically to a safety valve with stable sealing performance. Background Art

[0002] Safety valves are widely used in various fields such as petroleum, chemical industry, power stations, metallurgy, nuclear power, and national defense. When the pressure in the protected system exceeds the set pressure of the safety valve, the safety valve opens to relieve the pressure in the system to prevent the pressure in the system from continuing to rise and damaging the system. When the pressure in the system decreases, the safety valve returns to its seat to prevent the medium in the system from continuing to be discharged and wasting energy.

[0003] The existing safety valve includes a valve body, a valve disc located in the valve body, a valve stem elastically connected to the valve body and connected to the valve disc, a guide sleeve sleeved outside the valve disc and a valve seat capable of contacting the valve disc. In the process of closing the valve disc relative to the valve seat, solid impurities in the medium will be mixed between the valve disc and the valve seat, resulting in the problem that the valve disc and the valve seat cannot fully fit together, resulting in local leakage and aggravated wear of the sealing surfaces of the valve disc and the valve seat; secondly, when the gap between the valve disc and the valve seat is small, the medium flow rate is fast, and the scouring force on the sealing surfaces of the valve disc and the valve seat is large, resulting in accelerated wear of the sealing surfaces of the valve disc and the valve seat, resulting in a poor sealing effect. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a safety valve in which a valve flap and a valve seat can fully fit together to form an effective seal.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a safety valve with stable sealing performance, comprising a valve body, a valve seat positioned in the valve body, a valve disc capable of forming a hard seal with the valve seat, and a valve stem elastically connected to the valve body, the valve seat and the valve disc are both provided with sealing surfaces that can fit each other, a filter throttling ring capable of contacting with the valve disc and a buffer spring for pushing the filter throttling ring toward the valve disc are provided in the inner cavity of the valve seat, the annular surface of the filter throttling ring facing the valve disc is inclined relative to a horizontal plane and the height at which the inner edge of the annular surface is located is greater than the height at which the outer edge of the annular surface is located, a plurality of filter throttling grooves distributed in a circular pattern around the axis of the filter throttling ring are provided on the annular surface of the filter throttling ring facing the valve disc, the length direction of the plurality of the filter throttling grooves is the same as the width direction of the annular surface of the filter throttling ring, and the medium flows through the filter throttling groove and the gap between the two sealing surfaces in turn through the contact between the valve disc and the filter throttling ring.

[0006] As a further improvement of the utility model, the two sealing surfaces are inclined relative to the horizontal plane and the height of the inner edges of the sealing surfaces is greater than the height of the outer edges.

[0007] As a further improvement of the present invention, a conical stress-bearing groove is arranged on the surface of the valve disc facing the valve seat, the angle between the inner wall of the stress-bearing groove and the horizontal plane is smaller than the angle between the filter throttling groove and the horizontal plane, and the sealing surface on the valve disc is connected with the notch edge of the stress-bearing groove.

[0008] As a further improvement of the utility model, a limiting hole extending along the thickness direction of the filter throttling ring is arranged on the inner wall of the filter throttling ring, and a limiting piece penetrating the limiting hole is arranged on the inner wall of the valve seat.

[0009] As a further improvement of the utility model, the groove wall of the limiting hole adjacent to the buffer spring is inclined relative to the horizontal plane and the larger opening of the limiting hole is located on the inner wall of the filter throttling ring.

[0010] The beneficial effects of the utility model are as follows: compared with the prior art, the design of the valve disc and the filter throttling groove jointly filtering impurities can ensure that the medium flowing through the two sealing surfaces is pure, which is conducive to the two sealing surfaces fitting each other to form an effective seal, and indirectly improves the structural stability of the two sealing surfaces; the design of the valve disc first contacts the filter throttling ring and limits the medium to only flow through the filter throttling groove, which can produce a throttling effect on the medium and reduce the amount of medium flowing between the two sealing surfaces. In the process of opening or closing the valve disc relative to the valve seat, the scouring force generated by the medium is reduced, effectively ensuring the structural stability of the two sealing surfaces, and indirectly ensuring the sealing between the two sealing surfaces; the design of inclining the filter throttling groove and the annular surface where the filter throttling groove is located relative to the horizontal plane is compared with the design of inclining the filter throttling groove with a filter throttling groove. The design that the annular surface where the filter throttling groove is located is parallel to the horizontal plane can prevent impurities from being clamped between the valve disc and the filter throttling ring, causing the gap between the filter throttling groove and the valve disc to become larger and causing the impurities to be unable to be filtered and flow to between the two sealing surfaces with the medium. At the same time, the distance between the filter throttling ring and the filter throttling groove and the valve disc gradually increases along the flow direction of the medium. The flow velocity of the medium will decrease in the process of flowing from a small space to a large space, further reducing the scouring force of the medium on the two sealing surfaces, thereby ensuring the structural stability of the two sealing surfaces; the filter throttling ring first touches the valve disc and uses the elastic force generated by the buffer spring to effectively reduce the impact force generated by the downward movement of the valve disc, thereby slowing down the collision between the valve disc and the valve seat, thereby further improving the structural stability of the two sealing surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is the main sectional view of the utility model;

[0012] Figure 2 for Figure 1 The enlarged view of point A in the middle;

[0013] Figure 3 This is a main cross-sectional view of another embodiment of the utility model;

[0014] Figure 4 for Figure 3 The enlarged view of point B in the middle;

[0015] Figure 5 It is a stereoscopic diagram of the filter throttling ring in the utility model.

[0016] Figure numerals: 1. valve body; 2. valve seat; 3. valve disc; 4. valve stem; 5. sealing surface; 6. filter throttling ring; 7. buffer spring; 8. filter throttling groove; 9. force groove; 10. limit hole; 11. limit member. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, wherein the same components are indicated by the same reference numerals.

[0018] Reference Figures 1 to 5 As shown, a safety valve with stable sealing performance in this embodiment comprises a valve body 1, a valve seat 2 positioned in the valve body 1, a valve flap 3 capable of forming a hard seal with the valve seat 2, and a valve stem 4 elastically connected to the valve body 1, the valve seat 2 and the valve flap 3 are both provided with sealing surfaces 5 capable of abutting against each other, the surface of the valve flap 3 facing the valve seat 2 is a plane, and a downward pressure spring is provided on the outer sleeve of the valve stem 4;

[0019] Based on the above-mentioned prior art, a mounting groove coaxial with the valve seat 2 is processed on the inner wall of the valve seat 2, the outer diameter of the filter throttling ring 6 is adapted to the inner diameter of the mounting groove, the inner diameter of the filter throttling ring 6 is larger than the diameter of the opening at the bottom of the mounting groove, one of the annular surfaces of the filter throttling ring 6 is beveled, the space enclosed by the beveled annular surface is truncated, and the port with a large diameter is connected to the outer peripheral wall of the filter throttling ring 6, and a plurality of filter throttling grooves 8 are processed on the beveled annular surface, and the plurality of filter throttling grooves 8 are distributed in a circle around the axis of the filter throttling ring 6, and the length direction of the filter throttling groove 8 is the same as the width of the annular surface. The direction is the same, the outer diameter of the buffer spring 7 is adapted to the inner diameter of the installation groove, the inner diameter of the buffer spring 7 is larger than the diameter of the opening at the bottom of the installation groove, and the elastic coefficient of the buffer spring 7 is smaller than the elastic coefficient of the downward pressure spring, ensuring that the valve disc 3 can be stably pressed on the valve seat 2. During the installation process, one end of the buffer spring 7 is welded to the ring surface of the filter throttling ring 6 that is not processed with the filter throttling groove 8, and then the buffer spring 7 and the filter throttling ring 6 are installed into the installation groove as a whole and the other end of the buffer spring 7 is welded to the bottom of the installation groove, so that the ring surface of the filter throttling ring 6 that is processed with the filter throttling groove 8 is inclined relative to the horizontal plane;

[0020] In the initial state, the medium pushes the valve disc 3 away from the valve seat 2 and is in a flow state, the valve disc 3 is separated from the valve seat 2, the filter throttling ring 6 is separated from the valve disc 3, and the buffer spring 6 is in a natural stretching state driven by the medium; when the medium pressure decreases and the valve disc 3 moves downward, the downward end face of the valve disc 3 first touches the port of the inner hole of the filter throttling ring 6, and the medium can only flow through the filter throttling groove 8 and then flow through the gap between the two sealing surfaces 5. The solid impurities in the medium are blocked at the port of the filter throttling groove 8 and cannot enter the filter throttling groove 8. As the valve disc 3 continues to move downward, the impurities between the two sealing surfaces 5 are washed away by the filtered medium, the buffer spring 7 is gradually compressed, and the filter throttling ring 6 moves downward synchronously with the valve disc 3 and retreats into the valve seat 2 until Until the two sealing surfaces 5 are in close contact, the medium is blocked under the valve disc 3. In the process of the medium pressure increasing and pushing the valve disc 3 upward, the two sealing surfaces 5 are initially separated, and the filter throttling ring 6 moves upward with the valve disc 3 under the combined action of the elastic force of the buffer spring 7 and the upward driving force of the medium. The medium first flows through multiple filter throttling grooves 8 and then flows through the gap between the two sealing surfaces 5. As the valve disc 3 continues to move upward, the distance between the two sealing surfaces 5 becomes larger, and the filter throttling ring 6 is separated from the valve disc 3. The height of the port of the filter throttling groove 8 on the ring surface of the filter throttling ring 6 is greater than or equal to the height of the sealing surface 5 on the valve seat 2. The medium is in a free flow state, and the impurities originally blocked at the port of the filter throttling groove 8 flow into the subsequent pipeline with the medium;

[0021] Compared with the prior art, the design in which the valve flap 3 and the filter throttling groove 8 jointly filter impurities can ensure that the medium flowing through the two sealing surfaces 5 is pure, which is conducive to the two sealing surfaces 5 fitting together to form an effective seal, and indirectly improves the structural stability of the two sealing surfaces 5; the design in which the valve flap 3 first contacts the filter throttling ring 6 and limits the medium to only flow through the filter throttling groove 8 can produce a throttling effect on the medium, reduce the amount of medium flowing between the two sealing surfaces 5, and reduce the scouring force generated by the medium during the opening or closing of the valve flap 3 relative to the valve seat 2, effectively ensuring the structural stability of the two sealing surfaces 5, and indirectly ensuring the sealing between the two sealing surfaces 5; the design in which the filter throttling groove 8 and the annular surface where the filter throttling groove 8 is located are inclined relative to the horizontal plane is compared with the design in which the filter throttling groove 8 and the filter throttling groove 8 are inclined relative to the horizontal plane. The design that all the annular surfaces are parallel to the horizontal plane can prevent impurities from being clamped between the valve disc 3 and the filter throttling ring 6, causing the gap between the filter throttling groove 8 and the valve disc 3 to become larger and causing the impurities to be unable to be filtered and flow with the medium to between the two sealing surfaces 5. At the same time, the distance between the filter throttling ring 6 and the filter throttling groove 8 and the valve disc 3 gradually increases along the flow direction of the medium. The flow velocity of the medium will decrease in the process of flowing from a small space to a large space, further reducing the scouring force of the medium on the two sealing surfaces 5, ensuring the structural stability of the two sealing surfaces 5; the filter throttling ring 6 first touches the valve disc 3 and uses the elastic force generated by the buffer spring 7 to effectively reduce the impact force generated by the downward movement of the valve disc 3, slowing down the collision between the valve disc 3 and the valve seat 2, and further improving the structural stability of the two sealing surfaces 5.

[0022] As a specific implementation of the improvement, when the medium pressure decreases, the closing speed between the valve disc 3 and the valve seat 2 is fast, and some impurities with strong adhesion are not able to leave the sealing surface 5 in time, causing the two sealing surfaces 5 to fail to effectively fit together. In order to solve the above problem, refer to Figure 4 As shown, the two sealing surfaces 5 are inclined relative to the horizontal plane and the height of the inner edge of the sealing surface 5 is greater than the height of the outer edge. Such a design can shorten the time that impurities stay on the two sealing surfaces 5. The medium has a small speed change and can drive the impurities to flow quickly to the outer circle of the sealing surface 5, thereby improving the sealing performance of the two sealing surfaces 5.

[0023] As a specific implementation method of the improvement, refer to Figure 4As shown, a cone-shaped stress groove 9 is provided on the surface of the valve disc 3 facing the valve seat 2, and the angle between the inner wall of the stress groove 9 and the horizontal plane is smaller than the angle between the filter throttling groove 8 and the horizontal plane. The sealing surface 5 on the valve disc 3 is connected with the notch edge of the stress groove 9, and the inclination of the sealing surface 5 can be the same as the inclination of the inner wall of the stress groove 9. The filter throttling ring 6 can partially extend into the stress groove 9 and touch the inner wall of the stress groove 9. The cone-shaped design of the stress groove 9 effectively concentrates the force generated by the medium on the valve disc 3 to the center of the stress groove 9, ensuring that the valve disc 3 can be lifted up by the medium in time to relieve pressure; the connection between the sealing surface 5 and the notch of the stress groove 9 is conducive to simplifying the processing steps and improving production efficiency.

[0024] As a specific implementation of the improvement, when the medium generates a large driving force on the filter throttling ring 6, the buffer spring 7 will be overstretched and damaged. To solve the above problem, refer to Figure 2 and Figure 4 As shown, a threaded hole is processed on the inner wall of the valve seat 2, and a limiting hole 10 is processed on the peripheral wall of the filter throttling ring 6. The length direction of the limiting hole 10 is the same as the thickness direction of the filter throttling ring 6. The limiting member 11 can be a bolt. After the filter throttling ring 6 is installed in place in the valve seat 2, the limiting hole 10 corresponds to the threaded hole. The bolt is passed through the limiting hole 10 and screwed into the threaded hole so that the filter throttling ring 6 is limited in the valve seat 2. During the up and down movement of the filter throttling ring 6, the limiting member 11 moves along the length direction of the limiting hole 10. Such a design can prevent the filter throttling ring 6 from being driven by the medium through the limiting member 11 contacting one end of the limiting hole 10, thereby indirectly ensuring the structural stability of the buffer spring 7. At the same time, the limiting member 11 moves linearly along the limiting hole 10 and can also provide a guiding effect for the movement of the filter throttling ring 6.

[0025] As a specific implementation of the improvement, since impurities are deposited in the limiting hole 10, it is easy to shorten the maximum distance that the filter throttling ring 6 moves upward. In order to solve the above-mentioned problem, refer to Figure 2 , Figure 4 and Figure 5 As shown, the groove wall of the limiting hole 10 adjacent to the buffer spring 7 is inclined relative to the horizontal plane and the larger opening of the limiting hole 10 is located on the inner wall of the filter throttling ring 6. Such a design can facilitate impurities to slide out of the limiting hole 10 along the inner wall of the limiting hole 10, effectively preventing the phenomenon of impurity deposition.

[0026] The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A safety valve with stable sealing performance, comprising a valve body (1), a valve seat (2) positioned in the valve body (1), a valve flap (3) capable of forming a hard seal with the valve seat (2), and a valve stem (4) elastically connected to the valve body (1), wherein the valve seat (2) and the valve flap (3) are both provided with sealing surfaces (5) capable of abutting against each other, and characterized in that: The inner cavity of the valve seat (2) is provided with a filter throttling ring (6) capable of contacting the valve disc (3) and a buffer spring (7) for pushing the filter throttling ring (6) toward the valve disc (3); the annular surface of the filter throttling ring (6) facing the valve disc (3) is inclined relative to a horizontal plane and the height of the inner edge of the annular surface is greater than the height of the outer edge of the annular surface; the annular surface of the filter throttling ring (6) facing the valve disc (3) is provided with a plurality of filter throttling grooves (8) distributed in a circumferential manner around the axis of the filter throttling ring (6); the length directions of the plurality of filter throttling grooves (8) are the same as the width directions of the annular surfaces of the filter throttling ring (6); and the valve disc (3) and the filter throttling ring (6) contact each other so that the medium flows through the filter throttling grooves (8) and the gap between the two sealing surfaces (5) in sequence.

2. A safety valve with stable sealing performance according to claim 1, characterized in that: The two sealing surfaces (5) are both inclined relative to a horizontal plane, and the height at which the inner edges of the sealing surfaces (5) are located is greater than the height at which the outer edges are located.

3. A safety valve with stable sealing performance according to claim 1 or 2, characterized in that: A conical stress-bearing groove (9) is provided on the surface of the valve disc (3) facing the valve seat (2); the angle between the inner wall of the stress-bearing groove (9) and the horizontal plane is smaller than the angle between the filter throttling groove (8) and the horizontal plane; the sealing surface (5) on the valve disc (3) is connected to the notch edge of the stress-bearing groove (9).

4. A safety valve with stable sealing performance according to claim 1 or 2, characterized in that: The inner wall of the filter throttling ring (6) is provided with a limiting hole (10) extending in the thickness direction of the filter throttling ring (6), and the inner wall of the valve seat (2) is provided with a limiting member (11) penetrating the limiting hole (10).

5. A safety valve with stable sealing performance according to claim 4, characterized in that: The groove wall of the limiting hole (10) adjacent to the buffer spring (7) is inclined relative to the horizontal plane, and the larger opening of the limiting hole (10) is located on the inner wall of the filter throttling ring (6).

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