Double piston pilot operated angle stop valve with spring return structure

Abstract

The present invention relates to a double-piston pilot-operated angle stop valve with a spring return structure, comprising: a valve body, a valve seat, a valve disc, a double-piston spring return actuator, a valve cover, and a bracket; the double-piston spring return actuator comprises: an upper piston cylinder sleeve, a piston, a nut, a lower piston cylinder sleeve, a piston rod, a spring, an extended body, and a push rod; the piston rod is a double-piston structure, the lower piston of the piston rod is located in the lower cavity, the upper part of the piston rod is provided with a piston, the upper piston and the piston rod are pressed and fixed with a nut, and one end of the push rod is fixed in the cavity of the nut; the other end of the push rod extends out of the valve cover; the spring is installed between the upper piston of the piston rod and the valve cover; the built-in upper and lower double-piston plus spring return actuator meets the valve opening and closing action time while minimizing the specifications of the actuator, and the built-in structure prevents leakage of the medium; the return spring plays an auxiliary role when the valve is closed, and plays a buffering role when the valve is opened, reducing the impact of rapid opening on the valve.

Description

Technical Field

[0001] The invention relates to a double-piston pilot-operated angle stop valve with a spring return structure, which is suitable for a special valve with an extra-large caliber that can be opened quickly under high temperature and high pressure conditions, and belongs to the field of machinery. Background Art

[0002] The extra-large-caliber double-piston pilot-operated angle stop valve with a spring return structure is required to open quickly within 0.1 to 0.3 seconds and close within 20 seconds. Special considerations need to be made to the valve design to achieve both rapid opening and closing within the specified time, as well as long-term safe operation. Summary of the invention

[0003] In order to ensure that the valve can operate normally and open quickly under harsh conditions of high temperature and high pressure, the purpose of the present invention is to provide a double-piston pilot angle stop valve with a spring return structure. The structure can be opened within 0.1~0.3 seconds and quickly closed within 20 seconds under the drive of the self-pressure of the medium, and the steam flow rate of the valve fully opened can reach 1060~1270t / h.

[0004] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present invention is: a double-piston pilot angle stop valve with a spring return structure, including: a valve body, a valve seat, a valve disc, a double-piston spring return actuator, a valve cover, a bracket and a sealing device; the double-piston spring return actuator includes: an upper piston cylinder sleeve, a piston, a nut, a lower piston cylinder sleeve, a piston rod, a spring, an extension body, and a push rod; the valve seat and the valve body are welded as one, and the valve body, the extension body, and the valve cover are connected by bolts; the valve disc is threadedly connected to the lower end of the piston rod, the lower piston cylinder sleeve is bolted to the lower end of the extension body, and the lower piston cylinder sleeve is connected to the lower end of the extension body by bolts, and the lower piston cylinder sleeve is connected to the lower end of the extension body by bolts. The sleeve and the bottom surface of the extended body form a lower cavity; the upper part of the extended body is provided with an inner cavity of the extended body, the upper piston cylinder sleeve is in the inner cavity of the extended body, and the upper piston cylinder sleeve and the extended body are connected by bolts; the piston rod is a double-piston structure, the lower piston of the piston rod is located in the lower cavity, the upper part of the piston rod is provided with a piston, the upper piston and the piston rod are pressed and fixed by a nut, and one end of the push rod is fixed in the cavity of the nut; the other end of the push rod extends out of the valve cover; the spring is installed between the upper piston of the piston rod and the valve cover; the bracket is fixedly connected to the valve cover by bolts, and the valve cover and the push rod are sealed by a sealing device;

[0005] Furthermore, sealing rings are provided between the valve body and the elongated body, and between the elongated body and the valve cover, respectively. The valve body and the elongated body, and between the elongated body and the valve cover are sealed and rigidly connected by the sealing rings.

[0006] Furthermore, a locking gasket is provided at the threaded connection position between the valve disc and the lower end of the piston rod to prevent the valve disc from loosening;

[0007] Furthermore, the lower piston cylinder sleeve, the elongated body, and the valve cover together form an upper cavity, and the upper piston of the piston rod is located in the upper cavity;

[0008] Furthermore, piston rings are provided between the upper piston of the piston rod and the upper piston cylinder sleeve, between the lower piston of the piston rod and the lower piston cylinder sleeve, and between the lower piston cylinder sleeve and the valve body;

[0009] Furthermore, in the double-piston spring return actuator, internal guide holes are provided on the upper piston cylinder sleeve, the lower piston cylinder sleeve, the upper piston of the piston rod, the lower piston of the piston rod, the piston rod and the extended body;

[0010] Furthermore, the diversion holes are small-diameter and evenly distributed at multiple points;

[0011] Furthermore, the flow guide holes of the upper piston of the piston rod and the lower piston of the piston rod can adjust the flow cross-sectional area.

[0012] Furthermore, a packing seal is adopted between the valve cover and the push rod through a sealing device, including: a packing pressure plate, a packing arranged in a packing cavity between the push rod and the valve cover, and the packing is fixed to the valve cover by bolts through the packing pressure plate;

[0013] Furthermore, above the bracket there is also a valve opening and closing displacement detection analog output device and a valve opening and closing position signal feedback device. It is a high-reliability multi-position and displacement detection device, including: a displacement detection device, a position detection device, a bracket and a block; the position switch and the linear displacement sensor are fixed on the bracket; the block is fixed on the upper end of the push rod and can be adjusted up and down.

[0014] Specifically, the structure of the high-reliability multi-position and displacement detection device is:

[0015] The two side plates of the bracket are symmetrically provided with vertical guide grooves, the block is slidably arranged in the guide groove, the block is connected to the valve stem of the valve through a connecting piece, and the valve stem drives the block to move up and down in the guide groove when the valve is opened and closed. The position detection device includes a first position sensor assembly located at the upper end of the guide groove and a second position sensor assembly located at the lower end of the guide groove, the first position sensor assembly is used to detect the position of the block when the valve is fully opened, and the second position sensor assembly is used to detect the position of the block when the valve is fully closed. The displacement detection device is vertically arranged on the bracket and located above the guide groove, and is used to detect the displacement of the block during the opening and closing process of the valve.

[0016] The first position sensor assembly is fixed to the upper part of the side plate on one side of the bracket, and the displacement sensor is vertically fixed to the upper part of the side plate on the bracket away from the first position sensor assembly. When the valve is fully opened, the valve stem drives the stopper to move above the guide groove and triggers the first position sensor assembly; when the valve is fully closed, the valve stem drives the stopper to move below the guide groove and triggers the second position sensor assembly; the displacement sensor provides signal feedback on the displacement of the valve stem at different openings as the stopper moves up and down.

[0017] The first position sensor assembly is one or more open position switches, and the second position sensor assembly includes four closed position switches. Two closed position switches are symmetrically arranged on both sides of each guide groove. The four closed position switches are located at the same height and are respectively fixed on the two side plates of the bracket.

[0018] The first position sensor assembly is a contact-type open position switch, the second position sensor assembly is a contact-type closed position switch, and the displacement sensor is a contact-type linear displacement sensor.

[0019] The valve body is integrally forged to ensure the integrity of the overall performance of the material and the overall pressure boundary of the valve.

[0020] The valve seal is a streamlined valve disc with surfacing welding and a valve seat plane seal, and the sealing surface is surfacing welded with hard alloy.

[0021] Furthermore, the driving mode of the double-piston spring return actuator of the present invention is self-driven by medium pressure, and three rows of redundant pilot release holes are provided at the upper end of the side wall of the valve body, one end of the pilot release hole is connected to the guide hole of the elongated body, and the other end of the pilot release hole is emptied;

[0022] Furthermore, the guide hole inside the piston rod is connected to the lower chambers of the upper and lower pistons, the guide holes on the piston and the piston at the lower part of the piston rod are connected to the upper and lower chambers of the upper and lower pistons respectively, the upper chambers of the upper and lower pistons are connected to the pilot release hole, and the lower chambers of the upper and lower pistons are connected to the valve chamber;

[0023] During normal operation, the valve is in a closed state, the pressures in the upper and lower cavities are equal, and the valve is sealed by spring force, medium pressure and gravity; when the valve is opened, the pilot area is emptied, releasing the medium pressure in the upper chamber of the piston, and a pressure difference is formed in the upper and lower cavities. Under the action of the pressure difference, the valve overcomes the spring force and gravity and opens quickly.

[0024] The beneficial effects of the present invention are as follows: the double-piston pilot-operated angle stop valve with spring reset structure can be quickly opened within 0.1-0.3 seconds and closed within 20 seconds; and the steam flow rate of the valve fully opened can reach 1060-1270 t / h; the built-in upper and lower double pistons plus spring reset actuator can meet the valve opening and closing action time while minimizing the actuator specifications, and the built-in structure prevents leakage of the medium; the reset spring plays an auxiliary role when the valve is closed, and plays a buffering role when the valve is opened, reducing the impact of rapid opening on the valve. The opening time and closing time of the valve can be adjusted by adjusting the flow area of ​​the internal guide hole; piston rings are installed between the piston and the cylinder body, between the piston rod and the guide surface, and between the piston rod piston part and the cylinder body to maintain a certain gap, reduce the contact area of ​​the relatively moving parts, reduce friction, and prevent the occurrence of jamming and adhesion. The piston and the piston cylinder body are made of materials with a certain hardness difference to prevent adhesion and increase the service life of the valve. The valve body adopts an integral forging process to ensure the overall performance of the material and the integrity of the overall pressure boundary of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the main structural diagram of the present invention.

[0026] Figure 2 This is the structural diagram of a double-piston pilot actuator with spring return.

[0027] In the figure, 1. valve body, 2. valve seat, 3. valve disc, 4. piston rod, 5. lower piston cylinder sleeve, 6. extension body, 7. upper piston cylinder sleeve, 8. upper piston, 9. valve cover, 10. push rod, 11. spring, 14. packing pressure plate, 18. block, 19. linear displacement sensor, 21. position switch, 27. bracket, 32. sealing ring, 33. nut, 37. piston ring, 53. anti-loosening gasket, a, pilot release hole, b, upper piston upper cavity, c, lower piston upper cavity. DETAILED DESCRIPTION

[0028] The present invention is described in detail below with reference to the accompanying drawings.

[0029] like Figure 1-2As shown, the double-piston pilot-operated angle stop valve with spring return structure comprises: a valve body 1, a valve seat 2, a valve disc 3, a double-piston spring return actuator, a valve cover 9, a bracket 27 and a sealing device; the double-piston spring return actuator comprises: an upper piston cylinder sleeve 7, a piston 8, a nut 33, a lower piston cylinder sleeve 5, a piston rod 4, a spring 11, an elongated body 6, and a push rod 10; the valve seat 2 is welded together with the valve body 1, and the valve body 1, the elongated body 6 and the valve cover 9 are connected by bolts; the valve disc 3 is threadedly connected to the lower end of the piston rod 4, the lower piston cylinder sleeve 5 is bolted to the lower end of the elongated body 6, and the lower piston cylinder sleeve 5 and the bottom surface of the elongated body 6 form a lower cavity c; an elongated body inner cavity is provided at the upper part of the elongated body 6, the upper piston cylinder sleeve 7 is in the elongated body inner cavity, and the upper piston cylinder sleeve 7 and the elongated body 6 are connected by bolts; the piston rod 4 is a double-piston structure, the lower piston of the piston rod 4 is located in the lower cavity, the upper part of the piston rod 4 is provided with a piston 8, the upper piston 8 and the piston rod 4 are pressed and fixed by a nut 33, and one end of the push rod 10 is fixed in the cavity of the nut 33; the other end of the push rod 10 passes through and extends out of the valve cover 9; the spring 11 is installed between the upper piston 8 of the piston rod 4 and the valve cover 9; the bracket 27 is fixedly connected to the valve cover 9 by bolts, and the valve cover 9 and the push rod 10 are sealed by a sealing device;

[0030] Sealing rings 32 are respectively arranged between the valve body 1 and the elongated body 6, and between the elongated body 6 and the valve cover 9. The valve body 1 and the elongated body 6, and between the elongated body 6 and the valve cover 9 are sealed and rigidly contacted by the sealing rings 32.

[0031] A locking gasket 53 is also provided at the threaded connection position between the valve disc 3 and the lower end of the piston rod 4 to prevent the valve disc 3 from loosening;

[0032] The lower piston cylinder sleeve 5, the elongated body 6, and the valve cover 9 together form an upper cavity b, and the upper piston 8 of the piston rod 4 is located in the upper cavity;

[0033] Piston rings 37 are provided between the upper piston 8 of the piston rod 4 and the upper piston cylinder sleeve 7, between the lower piston of the piston rod 4 and the lower piston cylinder sleeve 5, and between the lower piston cylinder sleeve 5 and the valve body 1;

[0034] In the double-piston spring return actuator, internal guide holes are provided on the upper piston cylinder sleeve 7, the lower piston cylinder sleeve 5, the upper piston 8 of the piston rod 4, the lower piston of the piston rod 4, the piston rod 4 and the elongated body 6;

[0035] The valve cover 9 and the push rod 10 are sealed by a packing seal device, including a packing pressure plate 14, a packing arranged in a packing cavity between the push rod 10 and the valve cover 9, and the packing is fixed to the valve cover 9 by bolts through the packing pressure plate 14;

[0036] Also included above the bracket 27 is a valve opening and closing displacement detection analog output device and a valve opening and closing position signal feedback device, including: a position switch 21, a linear displacement sensor 19, and a stopper 18; the position switch 21 and the linear displacement sensor 19 are fixed on the bracket 27; the stopper 18 is fixed on the upper end of the push rod 10 and can be adjusted up and down.

[0037] The valve seal is a streamlined valve disc 3 with surfacing welding and a plane seal of a valve seat 2, and the sealing surface is surfacing welded with hard alloy.

[0038] The driving mode of the double-piston spring return actuator of the present invention is self-driven by medium pressure. Three rows of redundant pilot release holes a are opened at the upper end of the side wall of the valve body. One end of the pilot release hole a is connected to the guide hole of the extended body 6, and the pilot release hole a is emptied;

[0039] The guide hole inside the piston rod 4 is connected to the lower chambers of the upper and lower pistons, the guide holes on the piston and the piston at the lower part of the piston rod are connected to the upper and lower chambers of the upper and lower pistons respectively, the upper chambers of the upper and lower pistons are connected to the pilot release hole, and the lower chambers of the upper and lower pistons are connected to the valve chamber;

[0040] The working principle of the present invention is:

[0041] During normal operation, the valve is in a closed state, the pressures in the upper and lower cavities are equal, and the valve is sealed by spring force, medium pressure and gravity; when the valve is opened, the pilot area is emptied, releasing the medium pressure in the upper chamber of the piston, and a pressure difference is formed in the upper and lower cavities. Under the action of the pressure difference, the valve overcomes the spring force and gravity and opens quickly.

[0042] The specific working state of the double-piston spring return actuator of the present invention to open the valve is:

[0043] The medium enters from the inlet end of the valve, enters the lower chamber of the lower piston through the guide hole on the lower end face of the lower piston cylinder sleeve 5, and then flows from the lower chamber of the lower piston through the guide hole at the bottom of the piston rod and the guide hole in the center of the piston rod to the upper chamber c of the lower piston and the lower chamber of the upper piston respectively. After entering the lower chamber of the upper piston, the medium enters the upper chamber b of the upper piston through the guide hole of the upper piston. When the upper and lower chambers of the upper piston, the upper and lower chambers of the lower piston and the pilot discharge hole a are filled with the medium, the pressures in the upper and lower chambers of the piston are equal, and the valve disc 3 is closed under the combined action of the piston rod 4, the piston 8, its own gravity and the elastic force of the spring 11.

[0044] When the valve is opened, the pilot discharge hole is opened and emptied, and the media in the upper chamber of the upper piston and the upper chamber of the lower piston are quickly discharged through the pilot discharge hole a. Due to the interception effect of the piston 8 and the guide hole on the lower piston of the piston rod 4, a pressure difference is formed in the upper and lower chambers of the piston. When the pressure difference force is greater than the combined force of the valve disc 3, the piston rod 4, the gravity of the piston 8 and the elastic force of the spring 11, the valve opens.

[0045] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. All technicians familiar with the technical field shall, within the technical scope disclosed in the present invention, make equivalent replacements or changes based on the technical scheme of the present invention and the concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. Double piston pilot type angle stop valve with spring return structure, characterized by: include: The valve body, valve seat, valve disc, double piston spring reset actuator, valve cover, bracket and sealing device; the double piston spring reset actuator comprises: upper piston cylinder sleeve, piston, nut, lower piston cylinder sleeve, piston rod, spring, extension body and push rod; the valve seat and valve body are welded as one, and the valve body, extension body and valve cover are connected by bolts; the valve disc is threadedly connected to the lower end of the piston rod, the lower piston cylinder sleeve is bolted to the lower end of the extension body, and the lower piston cylinder sleeve and the bottom surface of the extension body form a lower cavity; the upper part of the extension body is provided with an extension The valve body has an inner cavity, the upper piston sleeve is embedded in the inner cavity of the extended body, and the upper piston sleeve and the extended body are connected by bolts; the piston rod is a double-piston structure, the lower piston of the piston rod is located in the lower cavity, the upper part of the piston rod is provided with a piston, the upper piston and the piston rod are fixed by a nut, one end of the push rod is fixed in the cavity of the nut; the other end of the push rod extends out of the valve cover; the spring is installed between the upper piston of the piston rod and the valve cover; the bracket is fixedly connected to the valve cover by bolts, and the valve cover and the push rod are sealed by a sealing device; The upper piston cylinder sleeve, the extended body, and the valve cover together form an upper cavity, and the upper piston of the piston rod is located in the upper cavity; in the double-piston spring return actuator, the upper piston cylinder sleeve, the lower piston cylinder sleeve, the upper piston of the piston rod, the lower piston of the piston rod, the piston rod and the extended body are all provided with internal guide holes; the driving mode of the double-piston spring return actuator is self-driven by medium pressure, and a pilot release hole is opened on the side wall of the upper end of the valve body, one end of the pilot release hole is connected to the guide hole of the extended body, and the other end of the pilot release hole is emptied; The specific working state of the double-piston spring return actuator to open the valve is: The medium enters from the inlet end of the valve, enters the lower chamber of the lower piston through the guide hole on the lower end face of the lower piston cylinder sleeve, and then flows from the lower chamber of the lower piston through the guide hole at the bottom of the piston rod and the guide hole in the center of the piston rod to the upper chamber of the lower piston and the lower chamber of the upper piston respectively. After the medium enters the lower chamber of the upper piston, it enters the upper chamber of the upper piston through the guide hole of the upper piston. When the upper and lower chambers of the upper piston, the upper and lower chambers of the lower piston and the pilot discharge hole are filled with the medium, the pressures in the upper and lower chambers of the piston are equal, and the valve disc is closed under the combined action of the piston rod, the piston, its own gravity and the elastic force of the spring; When the valve is opened, the pilot discharge hole is opened and emptied, and the media in the upper chamber of the upper piston and the upper chamber of the lower piston are quickly discharged through the pilot discharge hole. The upper chambers of the upper and lower pistons are connected with the pilot release hole, and the lower chambers of the upper and lower pistons are connected with the valve chamber. Due to the interception effect of the guide holes on the upper and lower pistons, a pressure difference is formed in the upper and lower chambers of the pistons. When the pressure difference force is greater than the combined force of the valve disc, piston rod, piston gravity and spring elastic force, the valve opens.

2. The double-piston pilot-operated angle stop valve with spring return structure according to claim 1 is characterized in that: Sealing rings are respectively arranged between the valve body and the elongated body, and between the elongated body and the valve cover. The valve body and the elongated body, and between the elongated body and the valve cover are sealed and in rigid contact through the sealing rings.

3. The double-piston pilot-operated angle stop valve with spring return structure according to claim 1 is characterized in that: Piston rings are arranged between the upper piston of the piston rod and the upper piston cylinder sleeve, between the lower piston of the piston rod and the lower piston cylinder sleeve, and between the lower piston cylinder sleeve and the valve body.

4. The double-piston pilot-operated angle stop valve with spring return structure according to claim 1 is characterized in that: A packing seal is adopted between the valve cover and the push rod through a sealing device, including: a packing pressure plate, a packing arranged in a packing cavity between the push rod and the valve cover, and the packing is fixed to the valve cover by bolts through the packing pressure plate.

5. The double-piston pilot-operated angle stop valve with spring return structure according to claim 1 is characterized in that: Also included above the bracket are a valve opening and closing displacement detection analog output device and a valve opening and closing position signal feedback device, including: a position switch, a linear displacement sensor, and a stopper; the position switch and the linear displacement sensor are fixed on the bracket; and the stopper is fixed on the upper end of the push rod.

6. The double-piston pilot-operated angle stop valve with a spring return structure according to any one of claims 1 to 5, characterized in that: During normal operation, the valve is in a closed state, the pressures in the upper and lower cavities are equal, and the valve is sealed by spring force, medium pressure and gravity; when the valve is opened, the pilot release area is emptied, the medium pressure in the upper chambers of the upper and lower pistons is released, and a pressure difference is formed in the upper and lower cavities. Under the action of the pressure difference, the valve overcomes the spring force and gravity and opens quickly.

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