A kind of flat gate valve

Abstract

The present invention discloses a flat gate valve. The present invention is composed of a handle, a valve stem nut, a valve cover, a valve stem, a valve body, a gate plate, a valve seat, and a lower valve cover. The flat gate valve is provided with a water inlet and a water outlet. A gate plate is installed in the middle of the inner cavity of the valve body. A valve stem is installed at the upper end of the gate plate, and a piston is installed at the lower end of the gate plate. A valve seat is installed in the direction of the water inlet on the gate plate. A lower valve cover is installed at the lower end of the valve body. A diversion hole is provided at the lower part of the water inlet end of the valve body. The upper end of the diversion hole communicates with the water inlet end, and the lower end of the diversion hole communicates with the sealing cavity. A check column and a spring are installed inside the valve body stub. A through hole is provided at the upper end of the valve body cavity near the water outlet end, and a sealing cavity is provided at the lower end of the valve body cavity. The advantages of the present invention are as follows: An innovative flat gate valve is designed, which has the dual functions of cut-off and check, the sealing surface is not easily damaged, the valve has good sealing performance and a long service life.

Description

Technical Field

[0001] The present invention provides a pipeline valve suitable for conveying media in industries such as petroleum and chemical industry. It is a flat gate valve, which functions as a stop valve and a check valve. Background Art

[0002] Currently, valves with stop and check functions in China generally consist of main parts such as valve bodies, valve covers, valve stems, valve seats, and valve discs. The main sealing types include plane and conical surfaces. The biggest drawback is that when the valve performs the check function, the valve seat and the valve disc will collide, and impurities in the pipeline will be caught between the sealing pair of the valve seat and the valve disc. The sealing pair of the valve is extremely vulnerable to damage, resulting in the failure of the valve's sealing performance, short service life, and affecting the normal operation of other equipment. Summary of the Invention

[0003] The purpose of the present invention is to overcome the technical drawbacks of the existing valve structure and innovatively design a flat gate valve with double functions of stop and check, whose sealing surface is not easily damaged, the valve has good sealing performance and long service life.

[0004] The technical solution adopted by the present invention to solve the technical problems is as follows: The present invention is composed of a handle, a valve stem nut, a valve cover, a valve stem, a valve body, a gate plate, a valve seat, and a lower valve cover. The flat gate valve is provided with a water inlet and a water outlet. A gate plate is installed in the middle of the inner cavity of the valve body. The upper end of the gate plate is equipped with a valve stem, and the lower end of the gate plate is equipped with a piston. A sealing ring II is installed on the outer circle of the piston. A valve seat is installed on the gate plate in the direction of the water inlet. A sealing ring III is installed on the outer circle of the valve seat. The contact surfaces of the gate plate and the valve seat are both planes to achieve sealing. The lower end of the valve body is equipped with a lower valve cover. A sealing ring I is installed on the outer circle of the lower end of the lower valve cover. A diversion hole is provided at the lower part of the water inlet end of the valve body. The upper end of the diversion hole communicates with the water inlet end, and the lower end of the diversion hole communicates with the sealing cavity. A check column and a spring are installed inside the short joint of the valve body. The contact surface between the short joint of the valve body and the check column is a conical surface or a plane, and two-sided contact can achieve sealing. A through hole is provided at the upper end of the valve body cavity near the water outlet end, and a sealing cavity is provided at the lower end of the valve body cavity.

[0005] The gate plate is a parallel gate plate. A medium flow channel hole is provided at the lower end of the gate plate. The gate plate and the piston are connected by a trapezoidal groove, and the gate plate and the valve stem are not fixedly connected.

[0006] The sealing cavity is composed of a valve body, a lower valve cover, a piston, a sealing ring I, and a sealing ring II.

[0007] The advantages of the present invention are: innovatively designing a flat gate valve with double functions of stop and check, whose sealing surface is not easily damaged, the valve has good sealing performance and long service life. Brief Description of the Drawings

[0008] The present invention will be further described below with reference to the drawings and embodiments.

[0009] Figure 1 It is the main sectional view of the present invention.

[0010] Figure 1 Among them, 1 is the handle, 2 is the valve stem nut, 3 is the valve cover, 4 is the valve stem, 5 is the valve body, 6 is the gate, 7 is the piston, 8 is the lower valve cover, 9 is the sealing ring I, 10 is the sealing ring II, 11 is the spring, 12 is the check column, 13 is the valve body short joint, 14 is the valve seat, 15 is the sealing ring III, A is the water inlet, B is the water outlet, C is the sealing cavity, D is the flow passage hole, E is the through hole, and F is the diversion hole. Specific implementation mode

[0011] Figure 1 Among them, a flat gate valve is composed of a handle (1), a valve stem nut (2), a valve cover (3), a valve stem (4), a valve body (5), a gate (6), a valve seat (14), and a lower valve cover (8). The flat gate valve is provided with a water inlet (A) and a water outlet (B). The middle part of the inner cavity of the valve body (5) is equipped with a gate (6). The upper end of the gate (6) is equipped with a valve stem (4). The lower end of the gate (6) is equipped with a piston (7). The outer circle of the piston (7) is equipped with a sealing ring II (10). The gate (6) is equipped with a valve seat (14) in the direction of the water inlet (A). The outer circle of the valve seat (14) is equipped with a sealing ring III (15). The contact surfaces of the gate (6) and the valve seat (14) are both flat surfaces to achieve sealing. The lower end of the valve body (5) is equipped with a lower valve cover (8). The outer circle of the lower end of the lower valve cover (8) is equipped with a sealing ring I (9). The lower part of the valve body (5) at the water inlet (A) end is provided with a diversion hole (F). The upper end of the diversion hole (F) communicates with the water inlet (A) end, and the lower end of the diversion hole (F) communicates with the sealing cavity (C). The valve body short joint (13) internally contains a check column (12) and a spring (11). The contact surface between the valve body short joint (13) and the check column (12) is a conical surface or a flat surface, and two-surface contact can achieve sealing. The valve body (5) cavity is provided with a through hole (E) near the water outlet (B) end, and the lower end of the valve body (5) cavity is provided with a sealing cavity (C). The gate (6) is a parallel gate. The lower end of the gate (6) is provided with a medium flow passage hole (D). The gate (6) and the piston (7) are connected by a trapezoidal groove. The gate (6) and the valve stem (4) have no fixed connection. The sealing cavity (C) is composed of the valve body (5), the lower valve cover (8), the piston (7), the sealing diagram I (9), and the sealing ring II (10).

[0012] The working principle of the present invention is: Instruction manual drawings Figure 1 The position of the valve shown is the closed state of the valve. The present invention has a double-seal sealing pair structure. First, the contact surface between the gate (6) and the valve seat (14) forms a sealing pair; second, the contact surface between the valve body short joint (13) and the check column (12) forms a sealing pair.

[0013] When the valve is opened, turn the handle (1) counterclockwise. The valve stem nut (2) rotates counterclockwise to drive the valve stem (4) to move upward. The valve stem (4) disengages from the gate plate (6). The medium pressure at the water inlet (A) pushes the check column (12) and the spring (11) to move toward the water outlet (B), causing the sealing pair between the valve body stub (13) and the check column (12) to open. The medium enters the cavity of the valve body stub (13). The medium pressure pushes the valve seat (14) toward the gate plate (6). The valve seat (14) presses against the gate plate (6) to achieve sealing and block the flow of the medium toward the water outlet (B). At the same time, the medium at the water inlet (A) reaches the sealing cavity (C) through the diversion hole (F). At this time, the medium pressure in the sealing cavity (C) is greater than the medium pressure in the upper cavity of the valve body (5) of the piston (7). The medium in the sealing cavity (C) pushes the piston (7) to move upward. The piston (7) simultaneously pushes the gate plate (6) to move upward, and the valve gradually opens. When the flow passage hole (D) on the gate plate (6) is aligned with the water inlet (A) and the water outlet (B), the valve is fully opened, and the medium is output from the water inlet (A) through the flow passage hole (D) to the water outlet (B).

[0014] When closing the valve, turn the handle (1) clockwise. The valve stem nut (2) rotates clockwise, and the valve stem nut (2) drives the valve stem (4) to move downward. The valve stem (4) pushes the gate plate (6) and the piston (7) to move downward simultaneously to close the valve. The medium in the sealing cavity (C) is pushed by the piston (7) and is output from the sealing cavity (C) through the diversion hole (F) to the water inlet (A). When the flow passage hole (D) on the gate plate (6) is at the position shown in the attached drawing of the specification Figure 1 As shown, the medium pressure at the water inlet (A) pushes the valve seat (14) toward the gate plate (6). The valve seat (14) presses against the gate plate (6). The contact surface between the valve seat (14) and the gate plate (6) achieves sealing and closes the valve. The inlet pressure on the outer circle of the valve seat (14) is blocked by the sealing ring III (15) to achieve sealing. At this time, the valve is in the closed state.

[0015] The check valve function of the present invention is as follows: when the valve is in a fully open state or a semi-open state, if the medium pressure at the water inlet (A) suddenly stops and the medium pressure at the water inlet (A) drops, and the medium flows back from the water outlet (B) to the water inlet (A), the medium flows from the water outlet (B) through the flow passage hole (D) to the water inlet (A). Under the combined action of the pressure of the reverse-flowing medium and the elastic force of the spring (11), the check column (12) moves towards the water inlet (A). The valve body short connection (13) contacts both end faces of the check column (12) to achieve sealing. The sealing pair of the valve body short connection (13) and the check column (12) prevents the medium from flowing back from the water outlet (B) to the water inlet (A). At the same time, the reverse-flowing medium enters the cavity of the valve body (5) above the piston (7) through the through hole (E) on the cavity of the valve body (5). The medium pressure in the cavity of the valve body (5) above the piston (7) is greater than the medium pressure in the sealing cavity (C). The medium pressure pushes the piston (7) to move downward, and the piston (7) drives the gate plate (6) to move downward simultaneously. When the flow passage hole (D) on the gate plate (6) is at the position shown in the attached drawing of the specification Figure 1 shown, the gate plate (6) presses against the valve seat (14), and the contact surface between the gate plate (6) and the valve seat (14) forms a sealed valve closure, and the valve performs the check valve function.

Claims

1. A parallel slide gate valve, which is composed of a handle (1), a valve stem nut (2), a valve cover (3), a valve stem (4), a valve body (5), a gate (6), a valve seat (14), and a lower valve cover (8). Its characteristics are as follows: The parallel slide gate valve is provided with a water inlet (A) and a water outlet (B). A gate (6) is installed in the middle of the inner cavity of the valve body (5). The upper end of the gate (6) is equipped with a valve stem (4), and the lower end of the gate (6) is equipped with a piston (7). A sealing ring II (10) is installed on the outer circumference of the piston (7). A valve seat (14) is installed in the direction of the water inlet (A) of the gate (6). A sealing ring III (15) is installed on the outer circumference of the valve seat (14). The contact surfaces of the gate (6) and the valve seat (14) are both flat surfaces to achieve sealing. The lower end of the valve body (5) is equipped with a lower valve cover (8). A sealing ring I (9) is installed on the outer circumference of the lower end of the lower valve cover (8). A diversion hole (F) is provided at the lower part of the water inlet (A) end of the valve body (5). The upper end of the diversion hole (F) communicates with the water inlet (A) end, and the lower end of the diversion hole (F) communicates with the sealing cavity (C). A check column (12) and a spring (11) are installed inside the valve body stub (13). The contact surface between the valve body stub (13) and the check column (12) is a conical surface or a flat surface, and two-surface contact can achieve sealing. A through hole (E) is provided at the upper end of the valve body (5) cavity near the water outlet (B) end, and a sealing cavity (C) is provided at the lower end of the valve body (5) cavity. The gate (6) is a parallel gate. A medium flow channel hole (D) is provided at the lower end of the gate (6). The gate (6) and the piston (7) are connected by a trapezoidal groove, and the gate (6) and the valve stem (4) are not fixedly connected. The sealing cavity (C) is composed of the valve body (5), the lower valve cover (8), the piston (7), the sealing ring I (9), and the sealing ring II (10).

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