Stop valve

Abstract

A stop valve mainly comprises a valve body, a valve cover, a flashboard, a valve rod and an executing mechanism, the valve rod is connected with the flashboard, the executing mechanism controls the valve rod to move so as to drive the flashboard to open and close the valve, a middle cavity opening of the valve body is of a valve body hemispherical shell structure, correspondingly, a middle cavity opening of the valve cover is of a valve cover hemispherical shell structure, and a middle cavity is a sphere after the valve cover and the valve cover are matched. The use reliability of the valve is improved, and the service life of the valve is prolonged. And a better guarantee is provided for normal work of the device.

Description

Technical Field

[0001] The invention relates to the technical field of valve manufacturing, in particular to a cut-off valve which is mainly used in the fields of petroleum, chemical industry, etc. Background Art

[0002] In the field of petrochemicals, there are many devices with high-temperature, high-flow and easy-to-stick working media. This special cut-off valve plays a very important role as an opening and closing element in these devices. It has a direct impact on the process of downstream devices. Accurately controlling the medium flow is very necessary for subsequent work. During the operation of the device, due to the characteristics of the conveyed working medium, it is easy to stick, high temperature and high flow rate. When the valve is opened and closed, there will be abnormal pressure increase in the valve cavity, causing the valve cavity to deform and the valve seal to fail.

[0003] Due to the characteristics of the medium, the valve channel, middle cavity and gate are severely eroded and worn, and it is difficult to remove them, which shortens the life of the valve. The inner cavity surface and guide rail in contact with the medium will stick and coke; the medium is likely to accumulate at the bottom of the valve. When the valve is opened and closed, the sealing surface will be severely worn and leak; when the bottom of the valve is excessively accumulated, the valve will not close properly and leak; when the valve guide rail is coked, the gate will jam. This makes the valve frequently replaced, affecting the normal operation of the equipment.

[0004] Generally speaking, conventional products do not provide adequate protection for the valve sealing system, and the medium adhering to the inner wall of the valve cavity cannot be removed. The valve is subjected to erosion and wear of the medium during long-term operation, and the valve cavity is prone to deformation and leakage due to pressure increase. Not only does internal leakage affect the downstream process, but external leakage also occurs, increasing the hidden dangers of production safety. Summary of the invention

[0005] The present invention provides a cut-off valve, which improves the reliability of the valve and prolongs the service life of the valve, and also provides better guarantee for the normal operation of the device.

[0006] The present invention adopts the following technical solution: A cut-off valve mainly includes a valve body, a valve cover, a gate plate, a valve stem, and an actuator. The valve stem is connected to the gate plate. The actuator controls the movement of the valve stem to drive the gate plate to open and close the valve. The middle cavity of the valve body is a hemispherical shell structure of the valve body. Correspondingly, the middle cavity of the valve cover is also a hemispherical shell structure of the valve cover. After the two are matched, the middle cavity is spherical.

[0007] The valve body is provided with a plurality of valve body branch channels at multiple angles, specifically: valve body branch channels are provided in the horizontal direction on both sides of the sealing surface channel, and a valve body branch channel is provided at the bottom of the valve body; the valve body branch channel is externally connected to a double-stage high-flow precision control system.

[0008] The valve cover is provided with a plurality of valve cover branch channels at multiple angles, specifically: valve cover branch channels are provided at 45° on both sides of the sealing surface on the valve cover, valve cover branch channels are provided at the position of the packing spacer ring in the stuffing box, and each valve cover branch channel is externally connected to a double-stage high-flow precision control system.

[0009] The double-level strong flow precision control system is divided into a first-level strong flow precision control system and a second-level strong flow precision control system; the first-level strong flow precision control system includes a positive flange, one end of which is connected to a reverse flange through a sealing flow limiting orifice plate; the second-level strong flow precision control system is: the other end of the reverse flange is connected to a flow control pressure relief valve.

[0010] The neck of the valve cover is extended from the bottom position of the stuffing box of the valve cover, and a temperature control heat sink is arranged on the outer wall of the neck.

[0011] A chromium carbide layer is sprayed on the part of the gate plate that contacts the working medium positively, and high-temperature wear-resistant linings are arranged at the pits on both sides of the gate plate.

[0012] The present invention effectively solves the problem of poor sealing performance caused by abnormal pressure increase in the middle cavity of the valve when the process pipeline medium (high-temperature, high-flow-rate medium that is easy to adhere) passes through the valve cavity of the cut-off valve, and the problem of severe wear of the sealing surface, incomplete closure, and movement jamming due to the characteristics of the medium. The present invention improves the reliability of valve use and extends the service life of the valve. It also provides better protection for the normal operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 Side view of Figure 3 This is a schematic diagram of the valve body structure of the present invention; Figure 4 This is a schematic diagram of the valve cover structure of the present invention; Figure 5 for Figure 4 Side view of Figure 6 It is a schematic diagram of the double-level high-flow precision control system of the present invention; Figure 7 It is a schematic diagram of the gate of the present invention; Figure 8 This is a schematic diagram of the spherical structure of the middle mouth of the present invention; In the figure: 1-valve body, 2-gate, 3-valve stem, 4-valve cover, 5-temperature control heat sink, 6-packing, 7-bracket, 8-actuator, 9-double-stage strong flow precision control system, 10-valve body branch channel, 11-valve body hemispherical shell structure, 12-valve cover hemispherical shell structure, 13-valve cover neck, 14-valve cover branch channel, 15-positive flange, 16-reverse flange, 17-flow control pressure relief valve, 18-sealed flow limiting orifice plate, 19-high temperature wear-resistant lining, 20-sprayed chromium carbide layer. DETAILED DESCRIPTION

[0014] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0015] Reference Figure 1 , Figure 2 , Figure 8 A cut-off valve mainly includes a valve body 1, a valve cover 4, a gate plate 2, a valve stem 3, and an actuator 8. The valve stem 3 is connected to the gate plate 2. The actuator 8 controls the movement of the valve stem 3 to drive the gate plate 2 to open and close the valve. The middle cavity of the valve body 1 is a valve body hemispherical shell structure 11. Correspondingly, the middle cavity of the valve cover is also a valve cover hemispherical shell structure 12. After the two are matched, the middle cavity is spherical. This shape design makes the middle cavity space larger than the conventional design middle cavity and can accommodate more media. The design shape of the sphere is more stable, with smaller deformation and higher strength, which can prevent the problem of sealing failure caused by abnormal pressure increase in the middle cavity. It is more conducive to clearing the working medium adhering to the valve cavity wall.

[0016] The flanges of the valve body 1 and the valve cover 4 are connected and sealed with an octagonal ring. This has good sealing performance and a simple structure, and is suitable for working conditions with large temperature fluctuations. This structure can better purge the medium adhering to the inner wall of the valve through the double-level high-flow precision control system, and can better ensure the sealing of the valve.

[0017] Reference Figure 3 The valve body 1 is provided with a plurality of valve body branch channels 10 at multiple angles, specifically: a valve body branch channel 10 is designed in the horizontal direction on both sides of the sealing surface channel to protect the channels on both sides, and a valve body branch channel 10 is designed at the bottom of the valve body to prevent the medium from sticking and accumulating at the bottom of the valve body. At the same time, the sealing surface can be purged from the bottom to protect the left and right sealing surfaces of the valve body to reduce wear, and the guide rails of the valve body and the guide grooves of the gate are also protected to prevent the working medium from sticking, thereby preventing the insulation gate 2 from getting stuck and not closing tightly, and leaking. The valve body branch channel 10 is externally connected to a double-level strong flow precision control system 9 to accurately control the flow of the protective medium.

[0018] Reference Figure 4 , Figure 5The valve cover 4 is provided with a plurality of valve cover branch channels 14 with multiple angles, specifically: valve cover branch channels 14 are provided at 45° on both sides of the upper sealing surface of the valve cover 4 to protect the upper sealing surface of the valve cover, the inner cavity surface of the valve cover and the sealing surface of the valve body; the valve body middle cavity and the valve body sealing surface are purged from top to bottom through the valve cover branch channels 14 to protect them. The valve cover branch channels 14 are provided at the position of the packing spacer ring in the stuffing box to prevent the packing and the upper sealing surface from being damaged and causing medium leakage. Each valve cover branch channel 14 is externally connected to a double-level high-flow precision control system 9 to accurately control the flow of the protective medium.

[0019] Reference Figure 6 The double-level strong flow precision control system 9 is divided into a first-level strong flow precision control system and a second-level strong flow precision control system; the first-level strong flow precision control system includes a positive flange 15, one end of which is connected to a reverse flange 16 through a sealing flow limiting orifice 18; this layer controls the purge flow of the protective medium, which is the maximum flow to protect the inside of the valve cavity from adhesion of the working medium. The other end of the positive flange 15 is connected to the valve body branch channel 10 and the valve cover branch channel 14.

[0020] The second-level strong flow precision control system is: the other end of the anti-flange 16 is connected to the flow control pressure relief valve 17, the flow is controlled according to the protection medium of different properties, and the appropriate flow protection valve is used to reasonably control the protection medium flow according to the characteristics of different working media.

[0021] The flow control pressure relief valve 17 can not only control the flow of the protective medium more accurately, but also can relieve pressure when the pressure in the valve cavity reaches a certain level.

[0022] When the valve is opened and closed, the valve cavity will experience abnormal pressure increase due to the characteristics of the working medium. When the pressure in the valve cavity is higher than the flow pressure of the protective medium, the flow control pressure relief valve 17 releases pressure outward to ensure that the valve cavity is within a normal controllable pressure range.

[0023] Reference Figure 1 , Figure 4 , Figure 5 , the neck 13 of the valve cover is increased from the bottom position of the stuffing box of the valve cover 4 and a temperature control heat sink 5 is arranged on the outer wall of the neck. In this way, the temperature inside the balanced stuffing box can be reduced, the reliability of the stuffing seal can be ensured, and the service life of the stuffing 6 can be extended.

[0024] Reference Figure 7 The part of the gate plate 2 in front contact with the working medium is sprayed with a chromium carbide layer 20, and high temperature wear-resistant linings 19 are arranged at the pits on both sides of the gate plate 2. The gate plate 2 is erosion-resistant, high temperature-resistant, and the sealing surface is more wear-resistant, thereby improving the performance of the gate plate.

Claims

1. A cut-off valve mainly includes a valve body, a valve cover, a gate, a valve stem, and an actuator. The valve stem is connected to the gate. The actuator controls the movement of the valve stem to drive the gate to open and close the valve. It is characterized in that: The central cavity opening of the valve body (1) is a valve body hemispherical shell structure (11), and correspondingly, the central cavity opening of the valve cover is also a valve cover hemispherical shell structure (12), and when the two are matched, the central cavity is spherical.

2. A cut-off valve according to claim 1, characterized in that: The valve body (1) is provided with a plurality of valve body branch channels (10) at multiple angles, specifically: valve body branch channels (10) are provided in the horizontal direction on both sides of the sealing surface channel, and a valve body branch channel (10) is provided at the bottom of the valve body; the valve body branch channel (10) is externally connected to a double-stage high-flow precision control system (9).

3. A cut-off valve according to claim 1, characterized in that: The valve cover (4) is provided with a plurality of valve cover branch channels (14) at multiple angles. Specifically, valve cover branch channels (14) are provided at 45° on both sides of the sealing surface on the valve cover (4), and valve cover branch channels (14) are provided at the position of the packing spacer ring in the stuffing box. Each valve cover branch channel (14) is externally connected to a double-stage high-flow precision control system (9).

4. A cut-off valve according to claim 2 or 3, characterized in that: The double-level strong flow precision control system (9) is divided into a first-level strong flow precision control system and a second-level strong flow precision control system; the first-level strong flow precision control system comprises a positive flange (15), one end of the positive flange (15) is connected to a counter flange (16) via a sealing flow limiting orifice plate (18); The second-level high-flow precision control system is as follows: the other end of the counter flange (16) is connected to a flow control pressure relief valve (17).

5. A cut-off valve according to claim 1, characterized in that: A neck (13) of the valve cover is extended from the bottom of the stuffing box of the valve cover (4), and a temperature control heat sink (5) is provided on the outer wall of the neck.

6. A special cut-off valve according to claim 1, characterized in that: A chromium carbide layer (20) is sprayed on the portion of the gate plate (2) that contacts the front face of the working medium, and high-temperature wear-resistant linings (19) are provided at the recesses on both sides of the gate plate (2).

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