Slow closing device of inclined seat type metal hard sealing butterfly slow closing check valve

Abstract

The invention provides a slow closing device of an inclined seat type metal hard sealing butterfly slow closing check valve, and relates to the technical field of valves, the slow closing device comprises a cylinder body assembly, the lower end of the cylinder body assembly is hinged to the outer wall of a valve body, hydraulic oil is poured into the cylinder body assembly, and a piston control assembly is arranged in the cylinder body assembly; the piston control assembly is connected with a valve shaft of the valve body through a connecting piece. The device is arranged outside the valve body, is completely separated from a medium and does not pollute the medium, the cylinder body shell is vertically arranged, only one part of the bottom needs to be sealed in a static sealing structure, the oil leakage probability of the cylinder body shell is remarkably reduced, and in the working process of the slow closing device, hydraulic oil is only circulated in the cylinder body shell, so that the working efficiency is greatly improved. And no external pipeline is arranged, so that the probability of external oil leakage is avoided, the use safety of the slow closing device is improved, no pressure exists in the inner cavity of the cylinder body shell when the valve normally operates, and the possibility of hydraulic oil leakage of the cylinder body shell is further reduced.

Description

Technical Field

[0001] The invention relates to the technical field of valves, and in particular to a slow-closing device for an inclined seat type metal hard-sealed butterfly slow-closing check valve. Background Art

[0002] Butterfly check valves are widely used in pipeline systems in the petroleum, chemical, and electric power industries to prevent backflow of the medium. Traditional butterfly check valves usually close suddenly during the closing process due to the fast flow rate of the medium, which can easily cause water hammer, resulting in valve body damage or pipeline rupture. In order to reduce the water hammer effect, some butterfly check valves are equipped with slow-closing devices. However, existing slow-closing devices, such as the slow-closing device in a top-mounted butterfly double-valve check valve disclosed in CN218267395U, are arranged inside the valve body and need to contact with the pipeline medium during use, which can easily cause contamination of the medium. Summary of the invention

[0003] The invention provides a slow-closing device of an inclined seat metal hard-sealed butterfly slow-closing check valve, which is used to solve the defect in the prior art that the slow-closing device is arranged inside the valve body and needs to contact with pipeline medium during use, which easily causes contamination of the medium.

[0004] On the one hand, the present invention provides a slow-closing device of an inclined seat type metal hard-sealed butterfly slow-closing check valve, comprising a cylinder assembly, the lower end of the cylinder assembly is hinged on the outer wall of the valve body, the cylinder assembly is filled with hydraulic oil, a piston control assembly is arranged inside the cylinder assembly, and the piston control assembly is connected to the valve shaft of the valve body through a connecting piece.

[0005] Preferably, the cylinder assembly includes a cylinder shell, hydraulic oil is poured into the cylinder shell, an upper cylinder cover is installed on the upper end of the cylinder shell by bolts, and a mounting base is fixedly connected to the lower end of the cylinder shell by bolts, and the mounting base is used to complete the connection with the valve body.

[0006] Preferably, an oil cup is fixedly connected to the cylinder shell, and the oil cup is communicated with the interior of the cylinder shell.

[0007] Preferably, the piston control assembly includes a piston rod, a control piston and a throttle rod. The piston rod slides and seals in the up and down directions and penetrates the cylinder head. The upper end of the piston rod is fixedly connected to a connecting joint, and a throttle hole is provided at the lower end of the piston rod. The throttle rod is fixedly installed on the bottom surface of the cylinder assembly, and the throttle rod is inserted into the throttle hole. A conical structure is provided on the throttle rod, and the control piston is fixedly installed on the lower part of the piston rod by a mounting nut.

[0008] Preferably, the control piston includes a piston body, which is fixedly mounted on the piston rod, and a plurality of sealing grooves spaced apart from each other are arranged on the outer wall of the piston body, a piston ring is installed in the sealing groove, and a plurality of one-way valves connecting the upper and lower inner cavities of the cylinder shell are arranged on the piston body.

[0009] Preferably, the piston ring is made of cast iron, and an annular opening is provided on the piston ring, and the annular openings on different piston rings are distributed in a circular uniform state.

[0010] Preferably, the throttle rod includes: a mounting portion, a sealing portion, a connecting portion and an adjusting portion, the mounting portion is fixedly connected to the cylinder housing, the sealing portion is located on the upper side of the mounting portion, a sealing groove 2 is provided on the sealing portion, a sealing ring is provided in the sealing groove 2, the connecting portion is located on the upper side of the sealing portion, the connecting portion is a cylinder without taper, the adjusting portion is provided on the upper side of the connecting portion, and the adjusting portion is a tapered cylinder with an upper end diameter smaller than a lower end diameter.

[0011] Preferably, the cone angle of the adjusting portion is calculated and determined based on the following formula: ;in, is the cone angle of the throttle rod adjustment part; is the inverse sine function; is the radius of the throttle hole; is the maximum compressive strength of the water pipeline material; The preset calculated reference value for the inner diameter of the water delivery penstock; It is a preset calculation reference value for the dynamic viscosity of the fluid in the water pipeline; is the density of the fluid in the water pipeline; D is the actual inner diameter of the water pressure pipe; is the actual dynamic viscosity of the fluid in the water pipeline; is the radius of the inner cavity of the cylinder shell; is the flow coefficient; is the maximum permissible flow rate of the fluid in the water pipeline; is the density of hydraulic oil; is the average flow velocity of the fluid in the water pipeline; E is the bulk elastic modulus of the medium in the water pipeline; is the wall thickness of the water pipeline; is the Young's modulus of the water pipeline material; C is the support coefficient of the pipeline; L is the target design length of the throttling rod adjustment part.

[0012] Compared with the prior art, the present invention has the following beneficial effects: This device is arranged outside the valve body, completely separated from the medium, and will not pollute the medium. The cylinder shell is vertically arranged, and there is only one place at the bottom that needs to be sealed, and the seal at this place is a static seal structure, which significantly reduces the probability of oil leakage from the cylinder shell. During the operation of the slow-closing device, the hydraulic oil only circulates inside the cylinder shell, without any external pipelines, so there is no probability of external oil leakage, which improves the safety of the slow-closing device. When the valve is operating normally, there is no pressure in the inner cavity of the cylinder shell, which further reduces the possibility of hydraulic oil leakage from the cylinder shell. Damping pressure is generated in the lower cavity of the cylinder shell only at the moment of slow closing of the valve butterfly plate, which improves the performance reliability of the slow-closing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the connection between the present invention and the valve body; Figure 3 It is a structural schematic diagram of the throttle rod of the present invention.

[0015] Reference numerals: 1. Valve body; 2. Connecting parts; 3. Cylinder housing; 4. Upper cylinder cover; 6. Mounting base; 7. Oil cup; 8. Piston rod; 9. Throttle rod; 901. Mounting part; 902. Sealing part; 903. Connecting part; 904. Adjusting part; 10. Connecting joint; 11. Throttle hole; 12. Mounting nut; 13. Piston body; 14. Sealing groove 1; 15. Piston ring; 16. One-way valve; 17. Sealing groove 2; 18. Sealing ring. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0017] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0018] Example 1 An embodiment of the present invention provides a slow-closing device for an inclined seat type metal hard-sealed butterfly slow-closing check valve, comprising a cylinder assembly, the lower end of which is hinged on the outer wall of a valve body 1, the cylinder assembly is filled with hydraulic oil, a piston control assembly is arranged inside the cylinder assembly, and the piston control assembly is connected to the valve shaft of the valve body 1 via a connecting piece 2.

[0019] Preferably, the cylinder assembly includes a cylinder housing 3, hydraulic oil is poured into the cylinder housing 3, an upper cylinder cover 4 is installed on the upper end of the cylinder housing 3 by bolts, and a mounting base 6 is fixedly connected to the lower end of the cylinder housing 3 by bolts, and the mounting base 6 is used to complete the connection with the valve body 1.

[0020] Preferably, an oil cup 7 is fixedly connected to the cylinder housing 3 , and the oil cup 7 is communicated with the interior of the cylinder housing 3 .

[0021] Preferably, the piston control assembly includes a piston rod 8, a control piston and a throttle rod 9. The piston rod 8 slides and seals through the cylinder head in the up and down directions. The upper end of the piston rod 8 is fixedly connected to a connecting joint 10, and a throttle hole 11 is provided at the lower end of the piston rod 8. The throttle rod 9 is fixedly installed on the bottom surface of the cylinder assembly, and the throttle rod 9 is inserted into the throttle hole 11. A conical structure is provided on the throttle rod 9, and the control piston is fixedly installed on the lower part of the piston rod 8 by means of a mounting nut 12.

[0022] Preferably, the control piston includes a piston body 13, which is fixedly mounted on the piston rod 8. A plurality of sealing grooves 14 spaced apart from each other are arranged on the outer wall of the piston body 13, a piston ring 15 is installed in the sealing groove 14, and a plurality of one-way valves 16 connecting the upper and lower inner cavities of the cylinder housing 3 are arranged on the piston body 13.

[0023] Preferably, the piston ring 15 is made of cast iron, and an annular opening is provided on the piston ring 15 , and the annular openings on different piston rings 15 are distributed in a circular uniform state.

[0024] The beneficial effects of the above technical solution are: When the valve is operating normally, the control piston is in a high position, and the hydraulic oil is located in the lower chamber of the cylinder housing 3 (i.e., the part of the inner chamber of the cylinder housing 3 located below the control piston). At this time, there is no pressure in the inner chamber of the cylinder housing 3. When the valve body 1 is operating normally or the pump is stopped due to an accident, the valve body 1 first completes the rapid closing stage (closing 80-85% (adjustable) angular stroke of the valve body 1). At this time, driven by the connecting piece 2, the control piston is displaced downward inside the cylinder housing 3, causing the volume of the lower chamber of the cylinder housing 3 to decrease, thereby compressing the hydraulic oil in the lower chamber of the cylinder housing 3, thereby causing the hydraulic oil to have a damping effect on the control piston, slowing down the descending speed of the piston rod 8, thereby realizing the slow closing effect on the butterfly slow-closing check valve and avoiding the occurrence of water hammer effect. When the valve body 1 is opened, the hydraulic oil entering the upper chamber of the cylinder housing 3 flows back to the lower chamber of the cylinder housing 3 through the one-way valve 16, thereby realizing the automatic resetting of the slow-closing device and improving the convenience of using the slow-closing device.

[0025] During the closing process of the valve body 1, as the control piston descends, the throttling area (i.e., the gap between the throttling rod 9 and the throttling hole 11) changes with the displacement of the butterfly plate angular stroke during the closing process through the conical structure on the throttling rod 9, and the slow closing damping is effectively guaranteed, the butterfly plate seats smoothly and reliably, and the closing performance is good, which reduces the possibility of damage during use. The throttling rod 9 is adjustable and replaceable, and can be adjusted according to different working conditions, which improves the scope of application of the device.

[0026] This device is arranged outside the valve body 1, completely separated from the medium, and will not pollute the medium. The cylinder shell 3 is vertically arranged, and there is only one place on the bottom that needs to be sealed, and the seal there is a static sealing structure, which significantly reduces the probability of oil leakage from the cylinder shell 3. During the operation of the slow-closing device, the hydraulic oil only circulates inside the cylinder shell 3 without any external pipelines, so there is no probability of external oil leakage, which improves the safety of the slow-closing device. When the valve is operating normally, there is no pressure in the inner cavity of the cylinder shell 3, which further reduces the possibility of hydraulic oil leakage in the cylinder shell 3. Damping pressure is generated in the lower cavity of the cylinder shell 3 only at the moment of slow closing of the valve butterfly plate, which improves the performance reliability of the slow-closing device.

[0027] Example 2 On the basis of Example 1, the throttle rod 9 includes: a mounting portion 901, a sealing portion 902, a connecting portion 903 and an adjusting portion 904. The mounting portion 901 is fixedly connected to the cylinder housing 3, the sealing portion 902 is located on the upper side of the mounting portion 901, and a sealing groove 17 is provided on the sealing portion 902. A sealing ring 18 is provided in the sealing groove 17. The connecting portion 903 is located on the upper side of the sealing portion 902, and the connecting portion 903 is a cylinder without taper. The adjusting portion 904 is arranged on the upper side of the connecting portion 903, and the adjusting portion 904 is a tapered cylinder with an upper end diameter smaller than a lower end diameter.

[0028] Preferably, the cone angle of the adjustment portion 904 is calculated and determined based on the following formula: ;in, is the cone angle of the adjusting portion 904 of the throttle rod 9; is the inverse sine function; is the radius of the throttle hole 11; is the maximum compressive strength of the water pipeline material; The preset calculated reference value for the inner diameter of the water delivery penstock; It is a preset calculation reference value for the dynamic viscosity of the fluid in the water pipeline; is the density of the fluid in the water pipeline; D is the actual inner diameter of the water pressure pipe; is the actual dynamic viscosity of the fluid in the water pipeline; is the radius of the inner cavity of the cylinder housing 3; is the flow coefficient; is the maximum permissible flow rate of the fluid in the water pipeline; is the density of hydraulic oil; is the average flow velocity of the fluid in the water pipeline; E is the bulk elastic modulus of the medium in the water pipeline; is the wall thickness of the water pipeline; is the Young's modulus of the water pipeline material; C is the support coefficient of the pipeline; and L is the target design length of the adjustment portion 904 of the throttling rod 9.

[0029] In this embodiment, the flow coefficient is a dimensionless coefficient used to describe the flow loss when the fluid passes through a throttle opening (such as a throttle valve, an orifice, a nozzle, etc.). Since the throttle openings of the device have the same shape and the throttle opening size varies slightly, in this formula, the flow coefficient is a preset constant value, and its value range is greater than 0 and less than 1. The specific value of the flow coefficient is obtained by experimental measurement.

[0030] The beneficial effects of the above technical solution are: During the closing process of the valve body 1, the throttle rod 9 and the throttle hole 11 are in a separated state during the fast closing stage, and the hydraulic oil quickly completes the circulation between the upper and lower chambers through the throttle hole 11, thereby realizing the fast closing of the valve body 1. When the closing degree of the valve body 1 reaches the node of switching to slow closing, the throttle rod 9 just begins to extend into the throttle hole 11, thereby reducing the flow area between the upper and lower chambers, causing pressure to be generated in the lower chamber, thereby slowing down the closing speed of the valve and realizing the slow closing process of the valve. As the closing degree of the valve increases, the depth of the regulating part 904 extending into the throttle hole 11 increases, and under the action of the regulating part 904, the flow area is further reduced, thereby realizing a further slowing down of the valve closing speed and further reducing the degree of damage caused by the water hammer effect.

[0031] When designing the cone angle of the adjusting portion 904 of the throttle rod 9, the pressure bearing capacity and working conditions of the water pipeline are considered. The minimum radius of the adjusting portion of the throttling rod 9 is calculated to ensure that at the beginning of the slow closing process of the valve body 1, the closing speed of the valve body 1 is within a suitable range, and no water hammer effect will occur to damage the water pipeline. The cone angle of the adjusting portion 904 of the throttling rod 9 is determined by the radius of the throttling hole 11 and the target design length of the adjusting portion 904 of the throttling rod 9, thereby improving the safety of the closing process of the valve body 1 and avoiding damage to the water pipeline caused by the water hammer effect.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A slow-closing device for an inclined seat metal hard-sealed butterfly slow-closing check valve, characterized in that: It comprises a cylinder assembly, the lower end of which is hinged on the outer wall of a valve body (1), the cylinder assembly is filled with hydraulic oil, a piston control assembly is arranged inside the cylinder assembly, and the piston control assembly is connected to the valve shaft of the valve body (1) via a connecting piece (2).

2. According to claim 1, a slanted seat metal hard seal butterfly slow closing check valve slow closing device is characterized in that: The cylinder assembly comprises a cylinder housing (3), hydraulic oil is poured into the cylinder housing (3), an upper cylinder cover (4) is mounted on the upper end of the cylinder housing (3) by means of bolts, and a mounting base (6) is fixedly connected to the lower end of the cylinder housing (3) by means of bolts, and the mounting base (6) is used to complete the connection with the valve body (1).

3. The slow-closing device of the inclined seat type metal hard seal butterfly type slow-closing check valve according to claim 2 is characterized in that: An oil cup (7) is also fixedly connected to the cylinder housing (3), and the oil cup (7) is communicated with the interior of the cylinder housing (3).

4. The slow-closing device of the inclined seat type metal hard seal butterfly type slow-closing check valve according to claim 1 is characterized in that: The piston control assembly comprises a piston rod (8), a control piston and a throttle rod (9). The piston rod (8) slides and seals through the cylinder cover in the up-down direction. The upper end of the piston rod (8) is fixedly connected with a connecting joint (10). The lower end of the piston rod (8) is provided with a throttle hole (11). The throttle rod (9) is fixedly installed on the inner bottom surface of the cylinder assembly. The throttle rod (9) is inserted into the throttle hole (11). The throttle rod (9) is provided with a conical structure. The control piston is fixedly installed on the lower part of the piston rod (8) through a mounting nut (12).

5. The slow-closing device of the inclined seat type metal hard seal butterfly type slow-closing check valve according to claim 4 is characterized in that: The control piston comprises a piston body (13), the piston body (13) is fixedly mounted on the piston rod (8), a plurality of sealing grooves (14) spaced apart from each other are arranged on the outer wall of the piston body (13), a piston ring (15) is installed in the sealing groove (14), and a plurality of one-way valves (16) are arranged on the piston body (13) to communicate with the upper and lower inner cavities of the cylinder housing (3).

6. The slow-closing device of the inclined seat type metal hard seal butterfly type slow-closing check valve according to claim 5 is characterized in that: The piston ring (15) is made of cast iron and is provided with an annular opening. The annular openings on different piston rings (15) are distributed in a circularly uniform state.

7. The slow-closing device of the inclined seat type metal hard seal butterfly type slow-closing check valve according to claim 4, characterized in that: The throttle rod (9) comprises: a mounting portion (901), a sealing portion (902), a connecting portion (903) and an adjusting portion (904); the mounting portion (901) is fixedly connected to the cylinder housing (3); the sealing portion (902) is located on the upper side of the mounting portion (901); a sealing groove (17) is provided on the sealing portion (902); a sealing ring (18) is provided in the sealing groove (17); the connecting portion (903) is located on the upper side of the sealing portion (902); the connecting portion (903) is a cylinder without a taper; the adjusting portion (904) is arranged on the upper side of the connecting portion (903); the adjusting portion (904) is a tapered cylinder with an upper end diameter smaller than a lower end diameter.

8. The slow-closing device of the inclined seat type metal hard seal butterfly type slow-closing check valve according to claim 7, characterized in that: The cone angle of the adjustment portion (904) is calculated and determined based on the following formula: ;in, is the cone angle of the adjusting portion (904) of the throttle rod (9); is the inverse sine function; is the radius of the throttle hole (11); is the maximum compressive strength of the water pipeline material; The preset calculated reference value for the inner diameter of the water delivery penstock; It is a preset calculation reference value for the dynamic viscosity of the fluid in the water pipeline; is the density of the fluid in the water pipeline; D is the actual inner diameter of the water pressure pipe; is the actual dynamic viscosity of the fluid in the water pipeline; is the radius of the inner cavity of the cylinder housing (3); is the flow coefficient; is the maximum permissible flow rate of the fluid in the water pipeline; is the density of hydraulic oil; is the average flow velocity of the fluid in the water pipeline; E is the bulk elastic modulus of the medium in the water pipeline; is the wall thickness of the water pipeline; is the Young's modulus of the water pipeline material; C is the support coefficient of the pipeline; and L is the target design length of the adjustment portion (904) of the throttling rod (9).

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