Balanced type blow-down throttle valve

Abstract

The utility model relates to a balance type blow-down throttle valve, which belongs to the technical field of valves and comprises a valve body, a valve clack, a valve rod, a valve cover, a support and a transmission device, the valve clack adopts a cylindrical structure, a balance hole is arranged between the upper end face and the lower end face of a cylinder, resistance of a medium to the valve clack in a closing process is eliminated, and closing torque is reduced; the valve clack is installed in the guide sleeve in a dynamic sealing mode, flow change caused by valve clack shaking due to fluid impact is prevented, and the flow adjusting stability is improved; a diversion positioning sleeve at the lower end of the valve clack is movably matched with a diversion cover below the valve seat, a diversion window is arranged in the circumferential direction of the diversion positioning sleeve, and a center diversion hole is formed in the lower plane of the diversion cover to limit the flow direction of fluid and reduce scouring of the fluid to the sealing face of the valve seat and the valve clack. The valve has the advantages of small opening and closing torque, high flow adjusting precision, good anti-scouring performance of a sealing surface and the like.

Description

Technical Field

[0001] This utility model belongs to the field of valves, and in particular relates to a balanced sewage throttling valve. Background Technology

[0002] Throttling valves are used to regulate and control pipeline flow. Their structure includes a valve body, valve disc, valve cover, and valve stem. A valve seat is installed in the valve cavity between the inlet and outlet channels of the valve body. The valve disc is mounted on the lower end of the valve stem, and the valve disc moves up and down via the valve stem to achieve valve opening and closing or flow regulation. However, existing throttling valves have several problems during use: First, during the movement of the valve disc towards the closing direction, the medium generates significant resistance, resulting in a large closing or regulating torque. Second, during flow regulation, the impact of the medium on the valve disc easily causes radial swaying, affecting valve disc stability and reducing flow regulation accuracy. Utility Model Content

[0003] This utility model addresses the problems existing in the prior art by providing a balanced sewage throttling valve that can balance the pressure on the upper and lower valve discs, prevent radial swaying of the valve discs, has low operating torque, and high flow regulation accuracy.

[0004] The technical solution for realizing this utility model is as follows:

[0005] A balanced sewage throttling valve includes a valve body, a valve disc, a valve stem, a valve cover, a bracket, and a transmission device. The valve body adopts a bottom-inlet, top-outlet structure. A valve seat is installed in the valve cavity between the valve body inlet and outlet. The valve disc is installed at the lower end of the valve stem. The upper end of the valve stem is connected to the transmission device via a valve stem nut installed on the bracket. A sewage discharge valve is installed at the bottom of the inlet flow channel of the valve body. The valve disc is characterized by a cylindrical structure with a pressure balance hole in its upper plane. The center of the upper plane of the cylinder is fixedly connected to the lower end of the valve stem. A valve cover is provided on the outer circumference of the lower end of the cylinder. The valve seat has a tapered valve disc sealing surface that cooperates with the valve disc sealing surface. Below the valve disc sealing surface, there is a flow guiding and positioning sleeve that movably cooperates with the inner wall of the valve seat flow channel hole. The flow guiding and positioning sleeve has a flow guiding window in the circumferential direction. A guide sleeve is set in the valve cavity above the valve seat sealing surface. The outer cylindrical surface of the cylinder is dynamically sealed with the inner wall of the guide sleeve. The lower end of the guide sleeve has several flow windows in the circumferential direction. The valve seat has a flow guiding shroud that extends into the valve body inlet flow channel. The outer cylindrical surface of the flow guiding and positioning sleeve is movably cooperated with the inner wall of the flow guiding shroud. A flow channel hole is provided at the center of the lower end face of the flow guiding shroud.

[0006] In the above technical solution, a sealing sleeve is provided between the valve cover and the valve body. The sealing sleeve is press-fitted between the valve cover and the valve body by a radial annular shoulder. A self-tightening composite sealing device is provided between the shaft hole of the sealing sleeve and the outer circular surface of the valve stem. The self-tightening composite sealing device is composed of a self-tightening sealing ring with an outer conical surface provided below the packing sealing device. Under the pressure of the medium, the outer conical surface of the self-tightening sealing ring is wedged tightly in the inner conical surface of the sealing sleeve to achieve self-tightening sealing.

[0007] In the above technical solution, the valve stem nut is installed in the mounting cavity of the bracket by the bearing cover through the bearings on the upper and lower sides of the radial annular shoulder.

[0008] The advantages of this invention compared to existing technologies are as follows: The valve disc adopts a cylindrical structure with a balance hole between the upper and lower end faces of the cylinder to eliminate the resistance of the medium to the valve disc during the closing process and reduce the closing torque; the valve disc dynamic seal is installed inside the guide sleeve to prevent the fluid from impacting the valve disc and causing it to shake, thus reducing flow rate changes and improving flow regulation stability; the flow guiding and positioning sleeve at the lower end of the valve disc is in movable cooperation with the flow guiding cover below the valve seat. The flow guiding and positioning sleeve has a flow guiding window in the circumferential direction, and the flow guiding cover has a central flow guiding hole on its lower plane to restrict the flow direction of the fluid and reduce the scouring of the fluid on the valve seat and valve disc sealing surfaces. It has advantages such as low opening and closing torque, high flow regulation accuracy, and good anti-scouring performance of the sealing surface. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of this utility model.

[0010] In the diagram: 1 Valve body, 2 Valve seat, 3 Flow window, 4 Valve disc, 5 Guide sleeve, 6 Second sealing ring, 7 First sealing ring, 8 Self-tightening sealing ring, 9 Sealing sleeve, 10 Packing, 11 Valve cover, 12 Bolt, 13 Gland, 14 Nut, 15 Screw, 16 Anti-rotation sleeve, 17 Valve stem, 18 Bearing, 19 Valve stem nut, 20 Bearing gland, 21 Flat key, 22 Handwheel, 23 Dust cover, 24 Bracket, 25 Pressure balance hole, 26 Flow guide window, 27 Flow guide positioning sleeve, 28 Flow guide cover, 29 Flow channel hole, 30 Drain valve. Detailed Implementation

[0011] like Figure 1The balanced drain valve shown includes a valve body 1, a valve disc 4, a valve stem 17, a valve cover 11, a bracket 24, and a transmission device. A valve seat 2 is installed in the valve cavity between the inlet and outlet of the valve body 1. The valve body 1 adopts a bottom-inlet, top-outlet structure, that is, the valve body inlet channel is located below the valve seat 2, and the outlet channel is located above the valve seat 2. The valve disc 4 is installed at the lower end of the valve stem 17, and the upper end of the valve stem 17 is connected to the transmission device through a valve stem nut 19 installed on the bracket 24. A drain valve 30 is installed at the bottom of the inlet flow channel of the valve body 1. The transmission device is a handwheel 22, which is fixedly connected to the valve stem nut 19 through a flat key 21. A dust cover 23 is installed on the upper end of the valve stem nut 19 to prevent dust from entering the valve stem nut. Within the thread between valve stem 19 and valve 17, an anti-rotation device consisting of screw 15 and anti-rotation sleeve 16 is provided between valve stem 17 and bracket 24 to convert the rotational motion of valve stem nut 19 into the vertical linear motion of valve stem 17. The valve disc 4 is characterized by a cylindrical structure with a pressure balance hole 25 on the upper plane of the cylinder. The center of the upper plane of the cylinder is fixedly connected to the lower end of valve stem 17. A conical valve disc sealing surface that cooperates with valve seat 2 is provided on the outer circumference of the lower end of the cylinder. Below the conical valve disc sealing surface, a flow guiding and positioning sleeve 27 that movably cooperates with the inner wall of the flow channel hole of valve seat 2 is provided to achieve radial positioning of valve disc 4, preventing valve disc 4 from shaking due to the impact of the medium and improving the stability of flow regulation. Qualitatively, the flow guiding and positioning sleeve 27 has a flow guiding window 26 in the circumferential direction, which restricts the flow direction of the fluid and reduces the scouring of the fluid on the sealing surfaces of the valve disc 4 and the valve seat 2. The valve seat 2 is fixedly pressed onto the platform of the inner cavity of the valve body 1 by the guide sleeve 5. A sealing ring is set between the valve seat 2 and the platform of the inner cavity of the valve body 1 to achieve a seal between the valve seat 2 and the platform of the inner cavity of the valve body 1. When the valve seat 2 is damaged, the guide sleeve 5 can be removed to take out the valve seat 2. The valve seat 2 is easy to replace and repair, reducing maintenance costs. The outer cylindrical surface of the cylinder is dynamically sealed with the inner wall of the guide sleeve 5. Several flow windows 3 are provided in the circumferential direction at the lower end of the guide sleeve 5. When the valve disc 4 is opened, the medium can flow smoothly. The fluid enters the valve body outlet channel through the flow window 3. A first sealing ring 7 is provided between the outer circular surface of the guide sleeve 5 and the inner wall of the valve body 1, and a second sealing ring 6 is provided between the inner circular wall of the guide sleeve 5 and the outer circular surface of the valve disc 4, respectively achieving sealing between the guide sleeve 5 and the inner cavity of the valve body 1 and the outer circular surface of the valve disc 4. The valve seat 2 has a flow guide shroud 28 extending into the inlet channel of the valve body 1. The outer circular surface of the flow guide positioning sleeve 27 is movably fitted with the inner wall of the flow guide shroud 28. A flow channel hole 29 is provided at the center of the lower end face of the flow guide shroud 28. The flow channel hole 29 has a right circular conical structure, so that the fluid in the inlet channel of the valve body 1 flows into the inner cavity of the cylinder after passing through the flow channel hole 29, reducing the scouring of the fluid on the sealing surfaces of the valve seat 2 and the valve disc 4.

[0012] A sealing sleeve 9 is provided between the valve cover 11 and the valve body 1. The sealing sleeve 9 is pressed between the valve cover 11 and the valve body 1 by a radial annular shoulder seal. A self-tightening composite sealing device is provided between the shaft hole of the sealing sleeve 9 and the outer circular surface of the valve stem 17. The self-tightening composite sealing device is composed of a self-tightening sealing ring 8 with an outer conical surface provided below the packing sealing device. Under the pressure of the medium, the outer conical surface of the self-tightening sealing ring 8 is wedged tightly in the inner conical surface of the sealing sleeve 9 to achieve self-tightening sealing. The packing sealing device is installed in the packing cavity of the sealing sleeve 9 by the packing 10 pressed by the pressure cap 13. The pressure cap 13 is installed on the valve cover 11 by bolts 12 and nuts 14.

[0013] The valve stem nut 19 is mounted in the mounting cavity of the bracket 24 by the bearing cap 20 through the bearings 18 on the upper and lower sides of the radial annular shoulder.

Claims

1. A balanced blowdown throttling valve, comprising a valve body (1), a valve clapper (4), a valve rod (17), a valve cover (11), a bracket (24), a transmission device, a valve seat (2) is arranged in the valve cavity between the inlet and outlet of the valve body (1), the valve body (1) adopts a lower inlet and upper outlet structure, the valve clapper (4) is installed at the lower end of the valve rod (17), the upper end of the valve rod (17) is connected with the transmission device through the valve rod nut (19) installed on the bracket (24), and a blowdown valve (30) is arranged at the bottom of the inlet flow passage of the valve body (1); characterized in that: The valve disc (4) adopts a cylindrical structure, a pressure balance hole (25) is arranged in the upper surface of the cylinder, the center of the upper surface of the cylinder is fixedly connected with the lower end of the valve rod (17), the outer circumference of the lower end of the cylinder is provided with a tapered valve disc sealing surface matched with the valve seat (2), a flow guiding positioning sleeve (27) movably matched with the inner wall of the flow passage hole of the valve seat (2) is arranged below the tapered valve disc sealing surface, the flow guiding positioning sleeve (27) is provided with a flow guiding window (26) in the circumferential direction, and the flow guiding window (26) limits the flow direction of the fluid; the valve seat (2) is fixedly pressed in the platform of the inner cavity of the valve body (1) by the guide sleeve (5), a sealing ring is arranged between the valve seat (2) and the platform of the inner cavity of the valve body (1), when the valve seat (2) is damaged, the valve seat (2) can be taken out for repair and replacement by removing the guide sleeve (5); the outer cylindrical surface of the cylinder is movably sealed with the inner wall of the guide sleeve (5), the lower end of the guide sleeve (5) is provided with a plurality of flow-through windows (3) in the circumferential direction; the valve seat (2) is provided with a flow guiding cover (28) extending to the inlet flow passage of the valve body (1), the outer surface of the flow guiding positioning sleeve (27) is movably matched with the inner wall of the flow guiding cover (28), a flow passage hole (29) with a right circular conical structure is arranged in the center of the lower end surface of the flow guiding cover (28), and the fluid in the inlet flow passage of the valve body (1) is concentrated to the inner cavity of the cylinder through the flow passage hole (29), so that the erosion of the fluid to the sealing surfaces of the valve seat (2) and the valve disc (4) is reduced. ​ 2. The balanced blow-off throttling valve according to claim 1, characterized in that: A sealing sleeve (9) is arranged between the valve cover (11) and the valve body (1), the sealing sleeve (9) is sealingly and pressingly arranged between the valve cover (11) and the valve body (1) through a radial annular shoulder, a self-tightening composite sealing device is arranged between the shaft hole of the sealing sleeve (9) and the outer surface of the valve rod (17), the self-tightening composite sealing device is composed of a self-tightening sealing ring (8) with an outer conical surface arranged below the packing sealing device, and the outer conical surface of the self-tightening sealing ring (8) is tightly matched in the inner conical surface of the sealing sleeve (9) under the pushing of the medium pressure, so that self-tightening sealing is achieved.

3. Balanced blow-off throttle according to claim 1 or 2, characterized in that The valve rod nut (19) is installed in the mounting cavity of the support (24) by the bearings (18) on the upper and lower sides of the radial annular shoulder of the bearing pressure cover (20).

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