High-pressure valve front self-sealing type single-valve-seat gate valve

Abstract

The invention relates to the technical field of petroleum machinery, in particular to a high-pressure valve front self-sealing type single-valve-seat gate valve. An elastic energy storage sealing mechanism is installed on the outer end face of a valve seat of the device, a gap between the outer end face of the valve seat and a valve body is sealed through the elastic sealing mechanism, a side sealing mechanism is installed on the outer side face of the valve seat, a gap between the outer side face of the valve seat and the valve body is sealed through the side sealing mechanism, and a stress notch is formed in the outer end face of the valve seat. And the stress notch is positioned on the outer side of the central channel of the valve seat and is communicated with the central channel. The front end of the valve is sealed under high pressure, impurities are prevented from entering a valve cavity, the service life of the valve is prolonged, and meanwhile the machining difficulty is effectively reduced.

Description

Technical Field:

[0001] The present invention relates to the technical field of petroleum machinery, and particularly relates to a self-sealing single-valve-seat gate valve before high pressure. Background Art:

[0002] The flat gate valve is one of the most commonly used valve structures in wellhead equipment in the petroleum industry, and is characterized by small flow resistance, no pressure loss, labor-saving opening and closing, and unrestricted flow direction of pipeline medium, etc.

[0003] The sealing design principle of the valve plate and valve seat sealing pair of the flat gate valve is divided into two types: front-end sealing of the valve and rear-end sealing of the valve. The front-end sealing of the valve is characterized in that the valve plate and the front-end valve seat in the direction of the medium inflow rely on an elastic body such as a spring to provide the contact pressure of the sealing surface and maintain the seal between the plate and the seat; the advantage is that when the valve is closed, the medium will not enter the valve cavity, which can avoid the blockage of the valve cavity by impurities and cause valve damage. It is usually used in low-pressure valves. When the working pressure exceeds 70 MPa, it is difficult to achieve front-end sealing of the valve by relying on the spring. The rear-end sealing of the valve is characterized in that the valve plate is pushed towards the rear-end valve seat of the valve under the pressure of the medium, and the contact pressure between the plate and the seat is provided by the medium pressure to achieve sealing; the advantage is that the higher the medium pressure, the better the sealing effect, and the disadvantage is that impurities will enter the valve cavity. Especially in the fracturing working condition, the entry of fine fracturing sand will cause problems such as valve opening and closing jamming and seal failure.

[0004] At present, there is a flat gate valve with a double-valve-seat structure that can achieve front-end sealing of the valve under high pressure, but there are too many parts, and the processing accuracy requirements for the valve are extremely high, and it is difficult to guarantee the processing quality. Summary of the Invention:

[0005] The technical problem to be solved by the present invention is to provide a self-sealing single-valve-seat gate valve before high pressure. This device realizes front-end sealing of the valve under high pressure, avoids impurities from entering the valve cavity, improves the service life of the valve, and effectively reduces the processing difficulty.

[0006] The technical solution adopted by the present invention is: a self-sealing single-valve-seat gate valve before high pressure, including a valve body, a valve seat, a valve plate and a valve rod; an elastic energy storage sealing mechanism is installed on the outer end surface of the valve seat to seal the gap between the outer end surface of the valve seat and the valve body through this elastic sealing mechanism, a side sealing mechanism is installed on the outer side surface of the valve seat to seal the gap between the outer side surface of the valve seat and the valve body through this side sealing mechanism, and a force receiving notch is opened on the outer end surface of the valve seat. This force receiving notch is located outside the central channel of the valve seat and communicates with the central channel.

[0007] Further, the elastic energy storage sealing mechanism is an axial spring energy storage sealing ring.

[0008] Further, the side sealing mechanism includes a radial high-pressure sealing rubber O-ring and a radial S-shaped sealing ring (7), and the radial high-pressure sealing rubber O-ring is closer to the outer end surface of the valve seat than the radial S-shaped sealing ring.

[0009] The beneficial effects of the present invention are as follows:

[0010] (1) It solves the problem that it is difficult to achieve pre-valve sealing under high pressure at present. When the pressure reaches or exceeds 105 MPa, the front end of the valve can be sealed, preventing impurities from entering the valve cavity and causing sand blockage or damage to the sealing surface. The "high pressure" in the patent name of the present invention, "A high-pressure pre-self-sealing single-seat gate valve", refers to a pressure reaching or exceeding 105 MPa.

[0011] (2) The valve structure uses the medium pressure to achieve sealing under high pressure. The higher the medium pressure, the greater the contact pressure between the sealing surfaces of the valve plate and the valve seat, and the better the sealing effect.

[0012] (3) The single-seat structure is adopted, which is relatively simple and reduces the processing difficulty. Description of the Drawings:

[0013] The following further describes the present invention in detail with reference to the drawings and specific embodiments.

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0015] Figure 2 It is a schematic diagram of the structures of the valve body, valve seat and valve plate of the present invention.

[0016] Figure 3 It is a schematic diagram of the structure of the valve seat of the present invention.

[0017] Figure 4 It is a schematic diagram of the high-pressure sealing principle of the present invention. Specific Embodiments:

[0018] As shown in Figure 1 、 Figure 2 、 Figure 3 , a high-pressure pre-self-sealing single-seat gate valve includes a valve body 1, a valve seat 2, a valve plate 3 and a valve rod 4. An elastic energy storage sealing mechanism is installed on the outer end surface of the valve seat 2 to seal the gap between the outer end surface of the valve seat 2 and the valve body 1 through this elastic sealing mechanism. A side sealing mechanism is installed on the outer side surface of the valve seat 2 to seal the gap between the outer side surface of the valve seat 2 and the valve body 1 through this side sealing mechanism. A force-receiving notch 8 is formed on the outer end surface of the valve seat 2. The force-receiving notch 8 is located outside the central channel of the valve seat 2 and is communicated with the central channel.

[0019] The elastic energy storage sealing mechanism is an axial spring energy storage sealing ring 5.

[0020] The side sealing mechanism includes a radial high-pressure sealing lip seal 6 and a radial S-shaped sealing ring 7. The radial high-pressure sealing lip seal 6 is closer to the outer end surface of the valve seat 2 than the radial S-shaped sealing ring 7.

[0021] During use, at low pressure, the valve plate-valve seat sealing pair relies on the axial spring energy storage sealing ring 5 to provide elasticity, so that contact between the valve plate 3 and the valve seat 2 provides sealing pressure, and the rear end relies on the lip of the spring energy storage sealing ring 5 itself to provide initial low-pressure sealing.

[0022] At high pressure, the medium pressure acts on the plane of the force receiving notch 8 of the valve seat 2, and can generate sufficient thrust to provide sufficient sealing pressure between the valve seat 2 and the valve plate 3. As Figure 4 shown, the higher the medium pressure, the greater the contact pressure between the plate and the seat, and the better the sealing effect; the valve seat 2 relies on the radial high-pressure sealing lip seal ring 6 and the radial S-shaped sealing ring 7 to achieve high-pressure sealing radially.

[0023] The valve seat 2 is arranged in a symmetric structure, and the front end of the valve can be sealed regardless of the direction from which the medium comes.

[0024] It can be understood that the above specific description of the present invention is only for explaining the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced to achieve the same technical effect; as long as it meets the usage requirements, it is within the protection scope of the present invention.

Claims

1. A high-pressure front-valve self-sealing single-seat gate valve, comprising a valve body (1), a valve seat (2), a valve plate (3) and a valve stem (4); characterized in that: An elastic energy storage sealing mechanism is installed on the outer end surface of the valve seat (2), and the gap between the outer end surface of the valve seat (2) and the valve body (1) is sealed by the elastic sealing mechanism. A side sealing mechanism is installed on the outer side surface of the valve seat (2), and the gap between the outer side surface of the valve seat (2) and the valve body (1) is sealed by the side sealing mechanism. A stress-bearing groove (8) is opened on the outer end surface of the valve seat (2), and the stress-bearing groove (8) is located outside the central channel of the valve seat (2) and communicates with the central channel.

2. The high-pressure front-valve self-sealing single-seat gate valve according to claim 1, characterized in that: The elastic energy storage sealing mechanism is an axial spring energy storage sealing ring (5).

3. The high-pressure front-valve self-sealing single-seat gate valve according to claim 1, characterized in that: The side sealing mechanism comprises a radial high-pressure sealing universal seal ring (6) and a radial S-shaped sealing ring (7). The radial high-pressure sealing universal seal ring (6) is closer to the outer end surface of the valve seat (2) relative to the radial S-shaped sealing ring (7).

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