Silt-preventing soft and hard sealing combined full-bore double-floating valve seat structure

Abstract

The utility model discloses an anti-sediment soft and hard sealing combined full-bore double floating valve seat structure which comprises a valve body, a metal hard valve seat and a rubber soft valve seat, the metal hard valve seat and the rubber soft valve seat are installed on the valve body, and the metal hard valve seat is arranged between the valve body and the rubber soft valve seat. The rubber soft valve seat is pressed on the valve body through a limiting pressing plate, and springs are installed on the step faces, making contact with the valve body, of the two valve seats so that the two valve seats can float left and right. O-shaped rings are mounted on a third cylindrical surface between the valve body and the metal hard valve seat and a fourth cylindrical surface between the metal hard valve seat and the rubber soft valve seat; and a rubber sealing ring is additionally fixed on the rubber soft valve seat through an adjusting pressing plate. The valve element is arranged in the center of the valve body, and hard metal is overlaid on the sealing face of the valve element. According to the novel floating valve seat structure provided by the utility model, two valve seats are arranged at one time, so that the sealing problem of a valve when a medium contains silt can be effectively solved.

Description

Technical Field

[0001] The utility model relates to the field of valves, in particular to a full-diameter double floating valve seat structure combining anti-silt soft and hard seals. Background Art

[0002] At present, rotary switch valves, butterfly valves, eccentric semi-ball valves, ball valves, etc. used in large-scale water delivery projects, urban water supply and drainage, petroleum and petrochemical industries, when encountering raw water or sewage containing mud and sand, the coping ability of a single soft seal or a single hard seal is obviously insufficient. The existing structure sets the soft and hard seals on a single floating valve seat at the same time. When the valve core rotates to close, the sealing surface contacts the soft seal valve seat and the hard seal valve seat in turn, which can not only achieve zero leakage of the soft seal, but also cut or extrude and grind the mud and sand in the medium.

[0003] In some complex pipelines, valves are required to have a two-way sealing function. Usually, a floating valve seat structure is used to form a piston effect by utilizing the difference in the positive and negative force areas, so that the sealing surface reaches a sealing specific pressure.

[0004] However, when both of the above working conditions exist, the existing structure cannot effectively seal. When the rubber valve seat is damaged, the metal hard valve seat cannot reach the sealing pressure ratio at low pressure, and leakage will occur; when mud and sand enter the floating cavity of the floating valve seat with the medium, it will cause obstruction, resulting in the loss of piston effect during reverse sealing.

[0005] China Utility Model Patent Publication No. CN214146626U discloses a floating valve seat structure of a two-way soft-sealed butterfly valve, including a floating valve seat, the floating valve seat is sealed and pressed in the valve body by a sealing pressure ring, the inner side of the valve body is provided with a flange arranged in cooperation with the floating valve seat, the flange is arranged on the side away from the sealing pressure ring, a gap is left between the floating valve seat and the flange of the valve body, the floating valve seat is provided with a trapezoidal groove at one end close to the valve body, a first sealing ring is arranged in the trapezoidal groove, and a second sealing ring is arranged on the side close to the sealing pressure ring of the floating valve seat; a valve plate is arranged in cooperation with the floating valve seat in the valve body, and the end face of the valve plate close to the floating valve seat is a spherical structure. However, this structure still has the problems mentioned above. Utility Model Content

[0006] The technical problem to be solved by the utility model is to prevent sediment and realize double sealing, and for this purpose, a full-diameter double floating valve seat structure combining sediment-proof soft and hard sealing is provided.

[0007] The technical solution of the utility model is: a full-diameter double floating valve seat structure combining anti-mud and soft and hard seals, comprising: a valve body and a valve core, the valve body is provided with a continuously distributed first step surface, a second step surface and a third step surface, a metal hard valve seat is fitted in the gap between the first step surface and the second step surface, a countersunk hole is provided in the second step surface, a metal hard valve seat spring in contact with the metal hard valve seat is adapted in the countersunk hole, an end of the metal hard valve seat away from the first step surface is sealed with the valve core, a rubber soft valve seat is fitted in the gap in the third step surface, and the bottom of the rubber soft valve seat is respectively sealed with the metal hard valve seat spring and the valve core; a countersunk hole is provided in the third step surface, a rubber soft valve seat spring in contact with the rubber soft valve seat is adapted in the countersunk hole, and the rubber soft valve seat is fixed to the valve body by a limiting pressure plate.

[0008] The improvement of the above solution is that an adjusting pressure plate is installed on the outer side of the rubber soft valve seat.

[0009] A further improvement of the above solution is that a rubber sealing ring is installed on the side of the rubber soft valve seat that contacts the valve core.

[0010] A further improvement of the above solution is that the side of the valve core that contacts the metal hard valve seat and the rubber soft valve seat has a valve core sealing surface.

[0011] Another improvement of the above solution is that the side of the metal hard valve seat in contact with the valve core has a metal hard valve seat sealing surface.

[0012] Another improvement of the above solution is that a wedge-shaped fit is formed between the end of the metal hard valve seat away from the valve core and the valve body, close to the first step surface.

[0013] Another improvement of the above solution is that the portion of the rubber soft valve seat located at the bottom of the limiting pressure plate is wedge-shaped.

[0014] The beneficial effects of the utility model are that the metal hard valve seat and the rubber soft valve seat act independently and cooperate with each other; the rubber soft sealing valve seat spring plays a boosting role, the elastic force of the metal hard valve seat spring is greater than that of the rubber soft sealing valve seat spring, and the metal hard valve seat will be limited in floating distance by the limit pressure plate and the rubber soft valve seat. When the valve core is in an open state, regardless of whether the medium flows in the forward or reverse direction, the metal hard valve seat will float in the valve body under the action of the spring elastic force, and its maximum floating position is tightly fitted with the valve core sealing surface when the valve core is fully closed, which can effectively cut impurities in the medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the utility model;

[0016] Figure 2 It is a schematic diagram of the state of the utility model when the medium flows in the forward direction;

[0017] Figure 3 It is a schematic diagram of the state of the utility model when the medium flows in the reverse direction;

[0018] In the figure, 1, valve stem, 2, metal hard valve seat, 3, metal hard valve seat spring, 4, first O-ring, 5, rubber soft sealing valve seat spring, 6, rubber soft sealing valve seat, 7, limit pressure plate, 8, adjustment pressure plate, 9, rubber valve seat, 10, second O-ring, 11, valve core, 12, valve core sealing surface, 13, metal hard valve seat sealing surface, 14, first step surface, 15, second step surface, 16, third step surface, 17, first cavity, 18, second cavity, 19, third cavity, 20, fourth cavity. DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings.

[0020] like Figure 1 As shown, the utility model includes a valve body 1 and a valve core 11, and the valve body is provided with a continuously distributed first step surface 14, a second step surface 15 and a third step surface 16, and a metal hard valve seat 2 is fitted in the gap between the first step surface and the second step surface, a countersunk hole is provided in the second step surface, and a metal hard valve seat spring 3 in contact with the metal hard valve seat is adapted in the countersunk hole, and the end of the metal hard valve seat away from the first step surface is sealed with the valve core, and a rubber soft valve seat 6 is fitted in the gap in the third step surface, and the bottom of the rubber soft valve seat is sealed with the metal hard valve seat spring and the valve core respectively; a countersunk hole is provided in the third step surface, and a rubber soft valve seat spring 5 in contact with the rubber soft valve seat is adapted in the countersunk hole, and the rubber soft valve seat is fixed to the valve body through a limiting pressure plate 7.

[0021] The so-called first step surface includes a vertical surface and a parallel surface, and the same is true for the second step surface and the third step surface. There is a certain gap between the rubber soft valve seat and the vertical surface of the third step surface. The rubber soft valve seat spring extends from the countersunk hole to contact the rubber soft valve seat, and there is a certain gap between the metal hard valve seat and the second step surface and the vertical surface of the first step surface. The metal hard valve seat spring extends from the countersunk hole to contact the metal hard valve seat, and the two valve seats can float left and right through the rubber soft valve seat spring and the metal hard valve seat spring;

[0022] As an embodiment of the utility model, the minimum inner diameter of the metal hard valve seat is equal to the nominal diameter of the valve body, and stainless steel is welded on the sealing surface of the metal hard valve seat in contact with the valve core to form a metal hard valve seat sealing surface 13, and stainless steel is also welded on the valve core sealing surface to form a valve core sealing surface 12, wherein the hardness of the valve core sealing surface (welding) is slightly higher than that of the metal hard valve seat sealing surface (welding);

[0023] As an embodiment of the utility model, a rubber sealing ring 9 of a special shape is installed at the place where the rubber soft valve seat contacts the valve core. The rubber sealing ring is bolted to the rubber soft valve seat by an adjusting pressure plate made of stainless steel and has a certain compression adjustment amount.

[0024] As an embodiment of the utility model, a wedge-shaped fit is formed between the end of the metal hard valve seat away from the valve core and the valve body, close to the first step surface. For example, the corresponding part of the metal hard valve seat is a 45° sharp angle, forming a 90° V-shaped groove with the inclined surface of the valve body. The part of the rubber soft valve seat located at the bottom of the limit pressure plate is wedge-shaped. For example, the corresponding part of the rubber soft valve seat is a 45° sharp angle. The sharp angle of the floating metal hard valve seat is used to move left and right on the surface of the valve body to push the mud and sand remaining in the 90° V-shaped groove into the inner cavity of the valve body and flush it away with the medium to prevent the accumulated mud and sand from clogging the floating space. The sharp angle of the floating rubber soft valve seat is used to move on the inner surface of the limit pressure plate to push the accumulated mud and sand away from the valve seat to prevent it from getting stuck.

[0025] As an embodiment of the utility model, a first O-ring 4 is adapted between the metal hard valve seat and the horizontal surface of the second step surface, and a second O-ring 10 is adapted between the metal hard valve seat and the bottom of the rubber soft valve seat, which acts as a piston seal when the two valve seats move left and right.

[0026] As an embodiment of the utility model, the limit pressure plate is fastened to the valve body by screws to limit the floating distance between the metal hard valve seat and the rubber soft valve seat.

[0027] The working process is as follows: During operation, both valve seats are in contact with the valve core sealing surface. Figure 2 As shown in the figure, when the valve is subjected to positive pressure, the medium flows from right to left. The metal hard valve seat moves to the left, and a third cavity 19 is formed between the part of the metal hard valve seat located on the second step surface and the rubber soft valve seat, and a fourth cavity 20 is formed between the part of the rubber soft valve seat located on the third step surface and the vertical surface of the third step surface. The pressure enters the fourth cavity and the third cavity in turn, generating a reverse thrust to the right. The force-bearing area of ​​the rubber soft valve seat subjected to the third and fourth cavities is larger than the area of ​​the surface in direct contact with the medium, so the reverse thrust is greater than the forward bearing pressure of the medium flow, achieving a positive seal. Figure 3 As shown in the figure, when the valve is subjected to reverse pressure, the medium flows from left to right. The first cavity 17 is formed between the part of the metal hard valve seat located on the first step surface and the vertical surface of the first step, and the second cavity 18 is formed between the part of the metal hard valve seat located on the second step surface and the vertical surface of the second step surface. The pressure enters the first cavity and the second cavity in turn, generating a thrust to the right. The force-bearing area of ​​the metal hard valve seat subjected to the first cavity and the second cavity is larger than the sealing surface (welding) of the metal hard valve seat and the surface between the rubber sealing ring and the sealing surface (welding) of the metal hard valve seat, so the flow pressure of the medium is greater than the reverse thrust, achieving reverse sealing.

[0028] The elastic force of the metal hard valve seat spring is greater than that of the rubber soft sealing valve seat spring. The floating distance of the metal hard valve seat will be limited by the limit pressure plate and the rubber soft valve seat. When the valve core is in the open state, regardless of whether the medium flows in the forward or reverse direction, the metal hard valve seat will float in the valve body under the action of the spring elastic force. Its maximum floating position is tightly fitted with the valve core sealing surface (welding) when the valve core is fully closed, which can effectively cut off impurities in the medium.

Claims

1. A full-diameter double floating valve seat structure combining anti-sand soft and hard seals, comprising: A valve body (1) and a valve core (11), characterized in that: the valve body is provided with a first step surface (14), a second step surface (15) and a third step surface (16) which are continuously distributed; a metal hard valve seat (2) is fitted in the gap between the first step surface and the second step surface; a countersunk hole is provided in the second step surface; a metal hard valve seat spring (3) in contact with the metal hard valve seat is adapted in the countersunk hole; an end of the metal hard valve seat away from the first step surface is sealed with the valve core; a rubber soft valve seat (6) is fitted in the gap within the third step surface; the bottom of the rubber soft valve seat is respectively sealed with the metal hard valve seat spring and the valve core; a countersunk hole is provided in the third step surface; a rubber soft valve seat spring (5) in contact with the rubber soft valve seat is adapted in the countersunk hole; the rubber soft valve seat is fixed to the valve body via a limiting pressure plate (7).

2. A full-diameter double floating valve seat structure combining soft and hard seals to prevent sediment as claimed in claim 1, characterized in that: An adjusting pressure plate (8) is installed on the outer side of the rubber soft valve seat.

3. A full-diameter double floating valve seat structure combining soft and hard seals to prevent sediment as claimed in claim 1, characterized in that: A rubber sealing ring (9) is installed on the side of the rubber soft valve seat that contacts the valve core.

4. A full-diameter double floating valve seat structure combining soft and hard seals to prevent sediment as claimed in claim 1, characterized in that: The side of the valve core that contacts the metal hard valve seat and the rubber soft valve seat has a valve core sealing surface (12).

5. A full-diameter double floating valve seat structure combining soft and hard seals to prevent sediment as claimed in claim 1, characterized in that: The side of the metal hard valve seat that contacts the valve core has a metal hard valve seat sealing surface (13).

6. A full-diameter double floating valve seat structure combining soft and hard seals to prevent sediment as claimed in claim 1, characterized in that: A wedge-shaped fit is formed between the end of the metal hard valve seat away from the valve core and the valve body, close to the first step surface.

7. A full-diameter double floating valve seat structure combining soft and hard seals to prevent sediment as claimed in claim 1, characterized in that: The part of the rubber soft valve seat located at the bottom of the limiting pressure plate is wedge-shaped.

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