Corrosion-resistant long-lasting swing-closed check valve with self-checking function

Abstract

The present invention relates to the technical field of control valves for fluid pipelines, specifically a corrosion-resistant long-acting rotary closed check valve with a self-checking function, comprising a valve body, wherein at least one level of a check valve assembly is arranged in the valve body; the check valve assembly comprises a first bracket and a second bracket, wherein a sliding rod is movably connected to the middle of the first bracket, a valve core is fixedly connected to the sliding rod, a valve port is arranged in the valve body, the valve core can unidirectionally close the valve port, a spring is arranged on the outer sleeve of the sliding rod, and the spring is deformed when the valve core is away from the valve port; the check valve assembly also comprises a guide mechanism, wherein the guide mechanism is arranged in the valve body, and the guide mechanism can make the sliding rod rotate while sliding relative to the first bracket. The present invention is applied to the field of fluid pipelines in industrial production, aviation and shipbuilding, and urban construction, and can improve the effect of preventing reverse flow and leakage.

Description

Technical Field

[0001] The invention relates to the technical field of control valves for fluid pipelines, in particular to a corrosion-resistant long-acting rotary closed check valve with a self-checking function. Background Art

[0002] Various types of check valves are installed on oil wells, production equipment and pipelines in the petroleum, chemical and refining industries. According to the regulations on production safety management, check valves used in high-temperature, high-pressure and corrosive medium pipelines must be metal structures, that is, the valve core and valve port are both made of metal. At present, most check valves close the valve port by reciprocating axial motion, that is, the valve core and valve port collide when the valve port is closed. Due to the high pressure in the pipeline, in order to reduce the deformation caused by the valve core hitting the valve port when the valve port is closed, the key structures of the check valve are made of high-hardness metal materials. However, high-hardness metal materials are not corrosion-resistant, so the check valve will rust after a period of use, causing the valve port to be loosely closed or even fail.

[0003] The valve port of the check valve used in the corrosive medium pipeline is installed with a corrosion-resistant plastic gasket, or a sealing ring is used for soft sealing. However, since these non-metallic materials are not resistant to high temperatures and are easy to age, and are easily damaged in media containing dirt such as sand, the service life of the gasket or sealing ring is short and needs to be replaced frequently. The above problems have long plagued production companies in the production of petroleum, chemical, and refining industries, not only affecting the normal production of the company, but also posing many safety hazards.

[0004] In addition, check valves are often unable to close or open due to corrosion when used in different environments and scenarios. Regular inspection of the operation of the check valve can provide a strong guarantee for production safety. However, since the check valve is connected to the pipeline, it is impossible to judge from the appearance whether it can be opened normally, and disassembling it for inspection requires stopping the machine and stopping production, which is not realistic for actual production. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a corrosion-resistant long-acting rotary closed check valve with a self-checking function.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A corrosion-resistant long-acting rotary closed check valve with a self-checking function, comprising a valve body, wherein at least one level of a check valve assembly is arranged in the valve body;

[0008] The one-flow valve assembly comprises a first bracket and a second bracket, wherein a sliding rod is movably connected to the middle of the first bracket, a valve core is fixedly connected to the sliding rod, a valve port is arranged in the valve body, the valve core can unidirectionally close the valve port, a spring is sleeved on the outside of the sliding rod, and the spring is deformed when the valve core is away from the valve port;

[0009] The check valve assembly further includes a guide mechanism, which is disposed in the valve body, and can make the sliding rod rotate while sliding relative to the first bracket. The guide mechanism includes a spiral slideway and a positioning pin, and the positioning pin is slidably matched with the spiral slideway. The guide mechanism further includes a shaft sleeve, which is fixedly connected to the second bracket, and the sliding rod movably passes through the shaft sleeve, and the spiral slideway or the positioning pin is disposed on the shaft sleeve;

[0010] A checker is installed on the valve body and is arranged near the inlet end of the valve body. The checker includes a shaft seat and a rotating shaft. Both ends of the rotating shaft respectively pass through the shaft seat and are rotatably connected. One end of the rotating shaft is fixedly connected to a cam and the other end is fixedly connected to a handle. The handle can drive the rotating shaft to rotate relative to the shaft seat, and the cam contacts the end face of the sliding rod near the inlet end of the valve body.

[0011] The present invention can prevent reverse flow and has the effect of preventing leakage. Specifically, the guide mechanism of the one-flow valve assembly can cause the sliding rod and the valve core to rotate simultaneously when the sliding rod drives the valve core to move and close the valve port. Therefore, when the valve core closes the valve port, the valve core gradually approaches the valve port in a spiral feeding manner, thereby preventing the valve core from directly hitting the valve port, thereby preventing the valve core and the valve port from being deformed. Moreover, for viscous media containing turbid impurities such as sand, gravel, and iron filings, the valve core can utilize its spiral movement characteristics to rotate and push the media and impurities at the valve port forward and close the valve port in a Tai Chi manner, thereby avoiding hard collision between the valve core and the valve port and the impurities, while rotating and pushing out the impurities, thereby ensuring the tightness of the seal.

[0012] In addition, the checker is installed on the valve body of the one-way valve, the rotating shaft and the position of the sliding rod are set vertically, and the cam is used to contact the top of the sliding rod. Specifically, the sliding rod is connected to the valve core. When the valve core is not opened, the long axis of the cam is vertical to the sliding rod, and the sliding rod does not move. At this time, the one-way valve is in a closed state; when it is necessary to check whether the one-way valve is opened or closed normally, the handle rotates the rotating shaft, thereby rotating the long axis of the cam to be parallel to the sliding rod, and the radial length of the cam increases, thereby pressing the sliding rod to move downward and open the one-way valve. When the handle is no longer in motion, the sliding rod returns to its original position under the action of its own spring, rises and pushes the cam. At this time, the cam rotates and drives the rotating shaft to reset, which indicates that the one-way valve can operate normally.

[0013] The specific forms of the guide mechanism are set in two ways. Specifically, the positioning pin is fixed relative to the shaft sleeve, and the spiral slide is set on the sliding rod, or the positioning pin is fixed relative to the valve core, and the spiral slide is set on the shaft sleeve.

[0014] In specific implementation, the present invention can be mainly configured into the following four structural forms:

[0015] First, a primary check valve assembly is arranged in the valve body, the spiral slide is arranged outside the sliding rod, a positioning pin is fixedly connected inside the sleeve, and one end of the sliding rod provided with the spiral slide is movably arranged inside the sleeve.

[0016] Second, a primary check valve assembly is arranged in the valve body, a spiral slideway is provided on the outer surface of the shaft sleeve, the valve core is fixedly connected with a positioning pin through a guide rod, and the sliding rod movably penetrates the shaft sleeve.

[0017] Two-stage check valve assemblies with the same opening direction are sequentially arranged in the valve body. For the sake of compact structure, the second brackets of the two-stage check valve assemblies are arranged as the same bracket, which is arranged between the first brackets of the two-stage check valve assemblies.

[0018] The valve body includes a first shell and a second shell, the first shell and the second shell are connected in a detachable manner, and the two-stage check valve assemblies are respectively arranged in the first shell and the second shell. The above structure can ensure that when a check valve assembly at one stage has a problem, it can be disassembled separately, and the check valve assembly at the other stage can operate normally, thereby ensuring that production does not stop.

[0019] Third, the guide mechanism structure of the two-stage check valve assembly is the same, specifically:

[0020] A positioning pin is fixedly connected inside the shaft sleeve, the spiral slideway is arranged outside the sliding rod, and one end of the sliding rod provided with the spiral slideway is movably arranged inside the shaft sleeve.

[0021] Fourth, the guide mechanism structures of the two-stage check valve assemblies are different, specifically:

[0022] In the guide mechanism of the primary check valve assembly, a positioning pin is fixedly connected inside the shaft sleeve, the spiral slide is arranged outside the sliding rod, and one end of the sliding rod provided with the spiral slide is movably arranged inside the shaft sleeve;

[0023] In the guide mechanism of the first-stage check valve assembly, a spiral slideway is provided on the outer surface of the shaft sleeve, the valve core is fixedly connected with a positioning pin through a guide rod, and the sliding rod movably penetrates the shaft sleeve.

[0024] The sliding rod is threadedly connected with an adjusting nut, and the sliding rod is also movably sleeved with a shock-absorbing pad, and the spring and the shock-absorbing pad are located between the adjusting nut and the first bracket. The adjusting nut can be used to adjust the opening pressure of the check valve.

[0025] A spherical flow divider is provided at the inlet of the valve body; the flow divider is used to divide the incoming fluid to prevent the high-speed fluid from directly eroding the components inside the valve body.

[0026] The first bracket includes a first outer disc, a first connecting rod and a first inner disc, the first outer disc and the first inner disc are connected by the first connecting rod, the channel between the first outer disc and the first inner disc is set as a valve port, a guide hole is opened at the center of the first inner disc, the sliding rod movably passes through the guide hole, and the first outer disc is fixedly connected or threadedly connected to the inner wall of the valve body;

[0027] The second bracket includes a second outer disc, a second connecting rod and a second inner disc. The second outer disc is connected to the second inner disc via the second connecting rod. The outer wall of the second outer disc is screwed onto the inner wall of the valve body through a thread.

[0028] A torsion spring is fixedly sleeved on the rotating shaft, and the end of the torsion spring is fixedly arranged relative to the shaft seat;

[0029] The shaft seat is fixedly connected with a housing, the handle is arranged inside the housing, one end of the housing is open and connected with a sealing cover, and a transparent window is arranged on the sealing cover to facilitate observation of the state of the handle, thereby judging the return state of the check valve;

[0030] A sealing ring is arranged between the rotating shaft and the shaft seat;

[0031] The outer surface of the rotating shaft is threadedly connected with a nut, and the nut is arranged at the intersection of the rotating shaft and the shaft seat.

[0032] The beneficial effects achieved by the present invention are:

[0033] The present invention is applied to the field of fluid pipelines in industrial production, aviation and ships, and urban construction, and can improve the effects of preventing reverse surge and leakage.

[0034] The present invention adopts a spiral motion to rotate and close the check valve, so as to avoid impact when the valve core closes the valve port, thereby avoiding deformation and causing loose closure. When the check valve is rotated to close, for viscous media containing turbid impurities such as sand, gravel, and iron filings, the present invention can utilize the characteristics of spiral rotation to push out the impurities and medium vortex on the valve port in a Tai Chi manner and close the valve port to avoid leakage.

[0035] The present invention is provided with an adjusting nut and a shock-absorbing pad, which have the functions of limiting the opening size of the valve core, preventing the spring from being over-compressed and damaged, and absorbing shock.

[0036] The present invention arranges a flow diversion cover at the inlet of the check valve, which can divert the incoming fluid and prevent the high-speed fluid from directly eroding the control and moving parts inside the valve body.

[0037] The present invention is made of stainless steel, which is environmentally friendly and corrosion-resistant. It is suitable for high temperature, high pressure and high corrosion environments in the petroleum, chemical, refining and other industries. It is also used in environmental protection fields such as biopharmaceuticals, medical care and health. At the same time, it can also play a good check effect on various media in harsh scenes such as viscous and turbid mud.

[0038] The present invention is equipped with a checker structure, which can check whether the check valve can operate normally, is easy to operate, can be observed intuitively, and is highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

[0041] Figure 2 is a structural diagram of Embodiment 2 of the present invention;

[0042] Figure 3 is a schematic diagram of the structure of the third embodiment of the present invention (without the checker installed);

[0043] Figure 4 This is a schematic diagram of the structure of the third embodiment of the present invention (without the checker installed and the valve core open);

[0044] Figure 5 It is a schematic diagram of the internal structure of the second bracket and the shaft sleeve in the third embodiment of the present invention;

[0045] Figure 6 is a top view of the second bracket in the third embodiment of the present invention;

[0046] Figure 7 This is a schematic diagram of the structure of the sliding rod and the valve core near the inlet end of the valve body in the third embodiment of the present invention;

[0047] Figure 8 It is a schematic structural diagram of the sliding rod and the valve core away from the inlet end of the valve body in the third embodiment of the present invention;

[0048] Fig. 9 is a top view of the first bracket in the third embodiment of the present invention;

[0049] Fig.10 is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0050] Fig.11 is a schematic diagram of the structure of the third embodiment of the present invention (in the state of verification by the verifier);

[0051] Fig.12 is a schematic diagram of the structure of the fourth embodiment of the present invention (without the checker installed);

[0052] Fig.13 This is a schematic diagram of the structure of the fourth embodiment of the present invention (without the checker installed and the valve core open);

[0053] Fig.14 is a schematic structural diagram of a second bracket and a shaft sleeve in a fourth embodiment of the present invention;

[0054] Fig.15 1 is a schematic diagram of the structure of the sliding rod and the valve core near the inlet end of the valve body in the fourth embodiment of the present invention;

[0055] Fig.16 is a schematic structural diagram of a fourth embodiment of the present invention;

[0056] Fig.17 It is a schematic diagram of an application scenario of the present invention applied to a crude oil wellhead control device;

[0057] Fig.18 : is a schematic diagram of an application scenario of the present invention applied to a crude oil wellhead control device (with the primary check valve assembly removed);

[0058] Fig.19 It is a schematic diagram of the structure of the checker of the present invention;

[0059] Fig. 20 It is a structural schematic diagram of the checker cam of the present invention.

[0060] In the figure: 1, valve body; 101, first housing; 102, second housing; 2, second bracket; 201, second outer disc; 202, second connecting rod; 203, second inner disc; 3, positioning pin; 4, spring; 5, shock pad; 6, first bracket; 601, first outer disc; 602, first connecting rod; 603, first inner disc; 604, guide hole; 7, valve core; 8, diverter cover; 9, shaft sleeve; 10, sliding rod; 1 1. Adjusting nut; 12. Spiral slide; 13. Guide rod; 14. Verifier; 141. Cam; 142. Shaft seat; 143. Rotating shaft; 144. Sealing ring; 145. Nut; 146. Torsion spring; 147. Handle; 148. Sealing cover; 149. Sealing gasket; 1410. Transparent window; 1411. Shell; 15. Three-way valve; 16. Integrated fluid control device; 17. Equipment; 18. Crude oil wellhead. DETAILED DESCRIPTION

[0061] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0062] like Figure 1-Figure 20 As shown, a corrosion-resistant long-acting rotary closed check valve with a self-checking function comprises a valve body 1, in which at least one level of check valve assembly is arranged.

[0063] The one-flow valve assembly includes a first bracket 6 and a second bracket 2. A sliding rod 10 is movably connected to the middle of the first bracket 6. A valve core 7 is fixedly connected to the sliding rod 10. A valve port is provided in the valve body 1. The valve core 7 can close the valve port in one direction. A spring 4 is sleeved on the outside of the sliding rod 10. The spring 4 is deformed when the valve core 7 is away from the valve port.

[0064] The check valve assembly further comprises a guide mechanism, which is disposed in the valve body 1 . The guide mechanism can enable the sliding rod 10 to rotate while sliding relative to the first bracket 6 .

[0065] The guide mechanism includes a spiral slide 12 and a positioning pin 3, the positioning pin 3 and the spiral slide 12 are slidably matched, specifically, the spiral slide 12 is a spiral groove track, and the positioning pin 3 is partially arranged in the spiral slide 12, and the cooperation between the two can realize spiral feeding. The guide mechanism also includes a sleeve 9, the sleeve 9 is fixedly connected to the second bracket 2, the sliding rod 10 movably penetrates the sleeve 9, and the spiral slide 12 or the positioning pin 3 is arranged on the sleeve 9.

[0066] There are two specific forms of the guide mechanism. Specifically, the locating pin 3 is fixed relative to the shaft sleeve 9, and the spiral slide 12 is arranged on the sliding rod 10, or the locating pin 3 is fixed relative to the valve core 7, and the spiral slide 12 is arranged on the shaft sleeve 9.

[0067] The present invention can prevent reverse flow and has the effect of preventing leakage. Specifically, the guide mechanism of the one-flow valve assembly can cause the sliding rod 10 and the valve core 7 to rotate simultaneously when the sliding rod 10 drives the valve core 7 to move and close the valve port. Therefore, when the valve core 7 closes the valve port, the valve core 7 gradually approaches the valve port in a spiral feeding manner, thereby preventing the valve core 7 from directly hitting the valve port, thereby preventing the valve core 7 and the valve port from being deformed. In addition, for viscous media containing turbid impurities such as sand, gravel, and iron filings, the valve core 7 can use its spiral movement characteristics to rotate and push the media and impurities at the valve port forward and close the valve port in a Tai Chi manner, thereby avoiding the valve core 7 and the valve port from hard collision with the impurities and rotating the impurities out to ensure the tightness of the seal.

[0068] like Fig.19 , Fig. 20As shown, the valve body 1 is equipped with a checker 14, which is arranged near the inlet end of the valve body 1. The checker 14 includes a shaft seat 142 and a rotating shaft 143. Both ends of the rotating shaft 143 respectively penetrate the shaft seat 142, and the two are rotatably connected. One end of the rotating shaft 143 is fixedly connected to a cam 141, and the other end is fixedly connected to a handle 147. The handle 147 can drive the rotating shaft 143 to rotate relative to the shaft seat 142. The cam 141 contacts the end surface of the sliding rod 10 near the inlet end of the valve body 1. The shape of the cam 141 is as shown in FIG. Fig. 20 The conventional structure is shown.

[0069] The rotating shaft 143 is fixedly sleeved with a torsion spring 146, and the end of the torsion spring 146 is fixedly arranged relative to the shaft seat 142. The function of the torsion spring 146 is to generate a certain torsion force on the rotating shaft 143 so that the cam 141 is always downward and close to the top of the sliding rod 10. When the fluid enters and the check valve is opened, the cam 141 rotates under the action of the torsion spring 146 and is always close to the descending sliding rod 10.

[0070] In order to ensure the safety of the structure and avoid accidental touch, the shaft seat 142 is fixedly connected to the housing 1411, and the handle 147 is arranged inside the housing 1411. One end of the housing 1411 is open and connected to a sealing cover 148. The sealing cover 148 is provided with a transparent window 1410 to facilitate observation of the state of the handle 147, thereby judging the return state of the check valve. A sealing gasket 149 is arranged between the sealing cover 148 and the housing 1411.

[0071] A sealing ring 144 is disposed between the rotating shaft 143 and the shaft seat 142 to ensure the sealing performance of the check valve.

[0072] The outer surface of the rotating shaft 143 is threadedly connected with a nut 145, which is arranged at the intersection of the rotating shaft 143 and the shaft seat 142. The arrangement of the nut 145 can limit the extension distance of the rotating shaft 143 and the cam 141 relative to the shaft seat 142, thereby adapting to different check valve structures.

[0073] When in use, the verifier 14 is installed on the valve body 1 of the one-way valve. Specifically, the shaft seat 142 is fixedly connected to the inside of the valve body 1, the shell 1411 is fixedly connected to the outside of the valve body 1, the rotating shaft 143 rotates and passes through the side wall of the valve body 1, and the rotating shaft 143 is vertically arranged to the position of the sliding rod 10. The cam 141 is used to contact the top of the sliding rod 10 of the one-way valve. Specifically, the sliding rod 10 is connected to the valve core 7, and the valve core 7 controls the switch of the valve port. When the valve core 7 is not opened, the long axis of the cam 141 is vertical to the sliding rod 10, and the sliding rod 10 is not moved. At this time, the one-way valve is in a closed state. When it is necessary to check whether the one-way valve is normally opened or closed, the sealing cover 148 is opened, and the handle 147 is manually driven to rotate the shaft 143, thereby rotating the long axis of the cam 141 to be parallel to the sliding rod 10, and the cam 141 presses the sliding rod 10 to move downward, and the valve core 7 moves with the sliding rod 10, thereby moving away from the valve port, and the one-way valve is opened. When the handle 147 is no longer driven, the sliding rod 10 returns to its original position under the action of its own spring 4, and rises to push the cam 141. At this time, if the cam 141 rotates and drives the shaft 143 to reset, it means that the one-way valve can operate normally. By observing the return state of the handle 147, it can be judged whether the one-way valve is tightly closed.

[0074] On this basis, the present invention provides the following four specific embodiments:

[0075] Embodiment 1: Figure 1 As shown, a primary check valve assembly is arranged in the valve body 1, the spiral slide 12 is arranged outside the sliding rod 10, a positioning pin 3 is fixedly connected inside the sleeve 9, and one end of the sliding rod 10 provided with the spiral slide 12 is movably arranged inside the sleeve 9.

[0076] Among them, one end of the positioning pin 3 can extend out of the shaft sleeve 9; the position where the sliding rod 10 is provided with the spiral slideway 12 and the diameter of the main body of the sliding rod 10 can be set to be different.

[0077] The sliding rod 10 is threadedly connected with an adjusting nut 11, and a shock absorbing pad 5 is movably sleeved on the sliding rod 10. The spring 4 and the shock absorbing pad 5 are located between the adjusting nut 11 and the first bracket 6. The adjusting nut 11 can be used to adjust the opening pressure of the check valve. The shock absorbing pad 5 is arranged close to the first bracket 6.

[0078] The inlet of the valve body 1 is provided with a spherical flow divider 8, which is used to divide the incoming fluid to prevent the high-speed fluid from directly eroding the internal components of the valve body 1. The flow divider 8 is installed in the valve body 1 through a bracket.

[0079] The checker 14 is disposed at the lower portion of the splitter cover 8 , and the cam 141 contacts the end surface of the slide rod 10 .

[0080] Embodiment 2: This embodiment is basically the same as Embodiment 1, except that Figure 2 As shown, a spiral slideway 12 is provided on the outer surface of the shaft sleeve 9 , the valve core 7 is fixedly connected to the positioning pin 3 via a guide rod 13 , and the sliding rod 10 is movably arranged to penetrate the shaft sleeve 9 .

[0081] The guide rods 13 and the positioning pins 3 can be provided in two symmetrical groups, and the spiral slideways 12 can be provided in two groups accordingly.

[0082] The checker 14 is disposed at the lower portion of the splitter cover 8 , and the cam 141 contacts the end surface of the slide rod 10 .

[0083] Embodiment 3: This embodiment is basically the same as Embodiment 1, except that Figure 3-Figure 11 As shown, two-stage check valve assemblies with the same opening direction are sequentially arranged in the valve body 1, and the guide mechanism structure of the two-stage check valve assemblies is the same, specifically:

[0084] The shaft sleeve 9 is fixedly connected with a positioning pin 3 , the spiral slideway 12 is arranged outside the sliding rod 10 , and one end of the sliding rod 10 provided with the spiral slideway 12 is movably arranged inside the shaft sleeve 9 .

[0085] In order to achieve a compact structure, the second bracket 2 of the two-stage one-flow valve assembly is set as the same bracket, which is set between the first brackets 6 of the two-stage one-flow valve assembly, and the shaft sleeves 9 of the two-stage one-flow valve assembly are respectively fixedly connected to the two sides of the bracket. On this basis, in order to ensure that the opening direction of the valve core 7 of the two-stage one-flow valve assembly is the same, the valve core 7 and the shaft sleeve 9 of the two-stage one-flow valve assembly are distributed in different positions relative to the first bracket 6. The valve core 7 and the shaft sleeve 9 of the one-flow valve assembly close to the inlet end of the valve body 1 are both set on one side of the first bracket 6; while the valve core 7 and the shaft sleeve 9 of the one-flow valve assembly far from the inlet end of the valve body 1 are set on both sides of the first bracket 6.

[0086] The valve body 1 includes a first shell 101 and a second shell 102, which are connected in a detachable manner, and the two-stage check valve assemblies are respectively arranged in the first shell 101 and the second shell 102. The above structure can ensure that when a check valve assembly at one stage has a problem, it can be disassembled separately, and the check valve assembly at the other stage can operate normally, thereby ensuring that production does not stop. Specifically, the first shell 101 and the second shell 102 are connected in a threaded manner.

[0087] The first bracket 6 includes a first outer disc 601, a first connecting rod 602 and a first inner disc 603. The first outer disc 601 and the first inner disc 603 are connected by the first connecting rod 602. The passage between the first outer disc 601 and the first inner disc 603 is set as a valve port. A guide hole 604 is provided at the center of the first inner disc 603. The sliding rod 10 movably passes through the guide hole 604. The first outer disc 601 is fixedly connected or threadedly connected to the inner wall of the valve body 1. Specifically, the first outer disc 601 of the first bracket 6 of the one-way valve assembly close to the inlet end of the valve body 1 is fixedly connected to the inner wall of the valve body 1; and the first outer disc 601 of the first bracket 6 of the one-way valve assembly far from the inlet end of the valve body 1 is threadedly connected to the inner wall of the valve body 1.

[0088] The second bracket 2 includes a second outer disc 201 , a second connecting rod 202 and a second inner disc 203 . The second outer disc 201 and the second inner disc 203 are connected via the second connecting rod 202 . The outer wall of the second outer disc 201 is screwed onto the inner wall of the valve body 1 .

[0089] The checker 14 is arranged at the lower part of the diverter cover 8 , and the cam 141 contacts the end surface of the sliding rod 10 close to the inlet end of the valve body 1 .

[0090] When it is specifically applied to crude oil wellhead control devices, such as Fig.17 , Fig.18 As shown, the crude oil wellhead control device is a device installed at the crude oil wellhead 18 of the oil field for multi-scenario applications, and is divided into an upper and lower part, and a double-control check valve is installed between the upper and lower parts of the device.

[0091] Crude oil is extracted from the underground oil layer by the continuous up-and-down movement of the rod. The rod is pumped out when it moves upward. The up-and-down movement of the rod is called the upstroke and downstroke. The rod needs to pause between the two strokes. Under normal circumstances, the rod needs 4 to 5 strokes per minute. Crude oil is extracted from the oil well during the upstroke of the rod, so it flows intermittently. As the rod repeatedly strokes up and down, the double-control check valve installed on the crude oil wellhead control device also needs to be opened or closed continuously. In addition, crude oil is a mixture of three main media: oil, water and gas. Gas will also cause the double-control check valve to close, so the switching frequency of the double-control check valve is very high.

[0092] Due to the high pressure and large temperature difference of oil well pipes, crude oil not only contains sulfides, carbon dioxide and gravel, but also production units need to add various chemical agents into the oil wells due to working conditions. Therefore, the check valve with soft sealing structure cannot be used in this environment. The check valves currently used in oil fields are all reciprocating axial motion hard sealing structures. Although the check valve used in the crude oil wellhead control device uses high-hardness metal, due to the high pressure of the oil well pipe and the high switching frequency and the high-hardness metal is not corrosion-resistant. The check valves used on the production pipeline will basically cause the valve core 7 to deform, and rust will cause poor closure or failure. In addition, the crude oil wellhead control device often needs to be applied in a variety of scenarios, and the upper port of the integrated fluid control device 16 needs to be opened. After the upper port is opened, the pressure difference between the inlet and outlet of the double-control check valve will change from the small pressure difference of the same source fluid in the integrated fluid control device 16 to the large pressure difference between the pressure in the crude oil pipeline and the external atmospheric pressure. At this time, the back pressure at the outlet of the double-control check valve becomes very large. If the valve core 7 has a slight deformation or rust and is not closed tightly, crude oil will leak out and cause a production safety accident.

[0093] In order to avoid potential safety hazards and not affect the normal production of the enterprise, the double-control check valve is designed as a combined detachable structure. This structure switches the three-way valve 15 without affecting crude oil production, so that the first-stage check valve assembly in the double-control check valve can be removed without stopping production. The purpose of removing the first-stage check valve assembly is to regularly inspect the first-stage check valve assembly to ensure that the quality is intact and improve production safety.

[0094] The process of removing the primary check valve assembly without stopping production is as follows: first, switch the T-shaped three-way valve 15 of the crude oil wellhead control device to the lower flow state (such as Fig.18 As shown); remove the upper part of the integrated fluid control device 16 and the equipment 17; and then remove the check valve assembly at the upper end of the double-control check valve.

[0095] Another application scenario of the present invention is the application of a double-control check valve in a high-pressure plunger pump in an oil field. Specifically, there are many blocks of crude oil in the oil field where viscous water is required to be injected into the ground. Due to the deep oil layer, a very high-pressure plunger pump is required. The pressure of the currently used plunger pump is 25 to 40 MPa.

[0096] Working principle of plunger pump: The plunger pump chamber is provided with a fluid inlet and an outlet, and check valves in opposite directions are installed on the inlet and the outlet respectively. When the plunger pump is working, its piston first sucks hot water into the chamber, at which time the check valve at the inlet opens and the check valve at the outlet closes. Then the plunger pump piston injects the hot water in the chamber into the underground oil layer, at which time the check valve at the outlet opens and the check valve at the inlet closes, and the cycle continues.

[0097] The working environment of the plunger pump is high temperature and high pressure. The check valves are all made of hard sealing structure and made of high-hardness metal. As the plunger pump piston is constantly and repeatedly opened and closed quickly, the valve core 7 valve port is deformed by high pressure impact, causing the valve port to leak after a short period of use. In addition, hot water also constantly and quickly erodes the valve core 7 valve port, causing it to scale and rust, which also causes it to close loosely or even fail.

[0098] The use of the rotary closed double-control check valve of the present invention can effectively solve the above-mentioned problem and effectively prevent leakage.

[0099] Embodiment 4: This embodiment is basically the same as Embodiment 3, except that Figure 12-16 As shown, the guide mechanism structures of the two-stage check valve assemblies are different, specifically:

[0100] In the guide mechanism of the primary check valve assembly (away from the inlet end of the valve body 1), the shaft sleeve 9 is fixedly connected with the positioning pin 3, the spiral slide 12 is arranged outside the sliding rod 10, and one end of the sliding rod 10 provided with the spiral slide 12 is movably arranged inside the shaft sleeve 9;

[0101] In the guide mechanism of the other primary check valve assembly (close to the inlet end of the valve body 1), the outer surface of the sleeve 9 is provided with a spiral slideway 12, the valve core 7 is fixedly connected with the positioning pin 3 through the guide rod 13, and the sliding rod 10 movably penetrates the sleeve 9. The guide rod 13 and the positioning pin 3 can be provided in two symmetrical groups, and the spiral slideway 12 on the outer surface of the sleeve 9 is also provided with two groups accordingly, and the positioning pin 3 can slide along the corresponding spiral slideway 12.

[0102] The checker 14 is arranged at the lower part of the diverter cover 8 , and the cam 141 contacts the end surface of the sliding rod 10 close to the inlet end of the valve body 1 .

Claims

1. A corrosion-resistant long-acting swing-closed check valve with self-checking function, characterized in that: It comprises a valve body (1), wherein at least one stage of a check valve assembly is arranged in the valve body (1); The one-flow valve assembly comprises a first bracket (6) and a second bracket (2); a sliding rod (10) is movably connected to the middle of the first bracket (6); a valve core (7) is fixedly connected to the sliding rod (10); a valve port is arranged in the valve body (1); the valve core (7) can unidirectionally close the valve port; a spring (4) is sleeved on the outside of the sliding rod (10); the spring (4) is deformed when the valve core (7) is away from the valve port; The check valve assembly further comprises a guide mechanism, which is arranged in the valve body (1). The guide mechanism can make the sliding rod (10) slide relative to the first bracket (6) and rotate at the same time. The guide mechanism comprises a spiral slideway (12) and a positioning pin (3). The positioning pin (3) and the spiral slideway (12) are slidably matched. The guide mechanism further comprises a shaft sleeve (9). The shaft sleeve (9) is fixedly connected to the second bracket (2). The sliding rod (10) movably passes through the shaft sleeve (9). The spiral slideway (12) or the positioning pin (3) is arranged on the shaft sleeve (9). The valve body (1) is provided with a checker (14), which is arranged near the inlet end of the valve body (1). The checker (14) comprises a shaft seat (142) and a rotating shaft (143). Both ends of the rotating shaft (143) respectively pass through the shaft seat (142), and the two are rotatably connected. One end of the rotating shaft (143) is fixedly connected to a cam (141), and the other end is fixedly connected to a handle (147). The handle (147) can drive the rotating shaft (143) to rotate relative to the shaft seat (142), and the cam (141) contacts the end surface of the sliding rod (10) near the inlet end of the valve body (1). A torsion spring (146) is fixedly sleeved on the rotating shaft (143), and the end of the torsion spring (146) is fixedly arranged relative to the shaft seat (142); The shaft seat (142) is fixedly connected to a housing (1411); the handle (147) is arranged inside the housing (1411); one end of the housing (1411) is open and connected to a sealing outer cover (148); and a transparent window (1410) is arranged on the sealing outer cover (148); A sealing ring (144) is provided between the rotating shaft (143) and the shaft seat (142); The outer surface of the rotating shaft (143) is threadedly connected with a nut (145), and the nut (145) is arranged at the junction of the rotating shaft (143) and the shaft seat (142); Two stages of check valve assemblies with the same opening direction are sequentially arranged in the valve body (1), and the second brackets (2) of the two stages of the check valve assemblies are arranged as the same bracket, which is arranged between the first brackets (6) of the two stages of the check valve assemblies; The valve body (1) comprises a first shell (101) and a second shell (102), the first shell (101) and the second shell (102) are connected in a detachable manner, and the two-stage check valve components are respectively arranged in the first shell (101) and the second shell (102); The guide mechanism structures of the two-stage check valve assemblies are different, specifically: In the guide mechanism of the primary check valve assembly, a positioning pin (3) is fixedly connected to the interior of the shaft sleeve (9), the spiral slideway (12) is arranged outside the sliding rod (10), and one end of the sliding rod (10) provided with the spiral slideway (12) is movably arranged inside the shaft sleeve (9); In the guide mechanism of the first-stage check valve assembly, the outer surface of the shaft sleeve (9) is provided with a spiral slideway (12), the valve core (7) is fixedly connected to a positioning pin (3) via a guide rod (13), and the sliding rod (10) is movably arranged to penetrate the shaft sleeve (9); When it is necessary to check whether the check valve is normally opened or closed, the sealing cover (148) is opened, and the handle (147) is manually driven to rotate the rotating shaft (143), thereby rotating the long axis of the cam (141) to be parallel to the sliding rod (10). The cam (141) presses the sliding rod (10) to move downward, and the valve core (7) moves along with the sliding rod (10), thereby moving away from the valve port, and the check valve is opened. When the handle (147) is no longer driven, the sliding rod (10) returns to its original position under the action of its own spring (4), and rises to push the cam (141). At this time, if the cam (141) rotates and drives the rotating shaft (143) to return to its original position, it means that the check valve can operate normally. By observing the return state of the handle (147), it can be judged whether the check valve is tightly closed.

2. The corrosion-resistant long-acting rotary closed check valve with self-checking function according to claim 1 is characterized in that: A primary check valve assembly is arranged in the valve body (1), the spiral slideway (12) is arranged outside the sliding rod (10), a positioning pin (3) is fixedly connected inside the shaft sleeve (9), and one end of the sliding rod (10) provided with the spiral slideway (12) is movably arranged inside the shaft sleeve (9).

3. The corrosion-resistant long-acting swing-closed check valve with self-checking function according to claim 1 is characterized in that: A primary check valve assembly is arranged in the valve body (1), a spiral slideway (12) is provided on the outer surface of the shaft sleeve (9), the valve core (7) is fixedly connected to a positioning pin (3) via a guide rod (13), and the sliding rod (10) is movably arranged to penetrate the shaft sleeve (9).

4. The corrosion-resistant long-acting swing-closed check valve with self-checking function according to claim 1 is characterized in that: The guide mechanism structure of the two-stage check valve assembly is the same, specifically: A positioning pin (3) is fixedly connected to the interior of the shaft sleeve (9), the spiral slideway (12) is arranged outside the sliding rod (10), and one end of the sliding rod (10) provided with the spiral slideway (12) is movably arranged inside the shaft sleeve (9).

5. The corrosion-resistant long-acting swing-closed check valve with self-checking function according to claim 1 is characterized in that: The sliding rod (10) is threadedly connected with an adjusting nut (11), and a shock absorbing pad (5) is movably sleeved on the sliding rod (10). The spring (4) and the shock absorbing pad (5) are located between the adjusting nut (11) and the first bracket (6).

6. The corrosion-resistant long-acting swing-closed check valve with self-checking function according to claim 1 is characterized in that: A flow divider (8) with a spherical structure is provided at the inlet of the valve body (1); The first bracket (6) comprises a first outer disc (601), a first connecting rod (602) and a first inner disc (603); the first outer disc (601) and the first inner disc (603) are connected via the first connecting rod (602); a passage between the first outer disc (601) and the first inner disc (603) is provided as a valve port; a guide hole (604) is provided at the center of the first inner disc (603); a sliding rod (10) movably passes through the guide hole (604); and the first outer disc (601) is fixedly connected or threadedly connected to the inner wall of the valve body (1); The second bracket (2) comprises a second outer disc (201), a second connecting rod (202) and a second inner disc (203); the second outer disc (201) and the second inner disc (203) are connected via the second connecting rod (202); and the outer wall of the second outer disc (201) is screwed onto the inner wall of the valve body (1) via a thread.

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