Shut-off check valve

Abstract

The utility model discloses a kind of stop check valves, comprising: valve body, is equipped with a passageway for fluid passing, passageway is formed in a valve seat;Valve disc, in the passageway, configured to movable and the valve seat sealing contact;Valve stem, with the valve disc connection, for driving the valve disc activity;Valve cover, located the outside of the valve stem, and in the valve body fixed connection;The valve disc in with the valve seat sealing contact, the passageway is divided into first cavity of fluid inlet side and second cavity of fluid outlet side, the part of the valve disc located in second cavity is equipped with pressure relief hole.The utility model is by setting pressure relief hole on valve disc, forms shunt to fluid, reduce the impact of fluid when valve disc opening and closing, can significantly reduce water hammer effect in opening and closing process.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to a shut-off check valve. Background Technology

[0002] Very large liquefied natural gas (LNG) carriers transport natural gas at -163 degrees Celsius, requiring valves to simultaneously meet both shut-off and check-back functions. Existing valve discs are solid structures; during rapid closure, the inertia of the medium generates a massive water hammer impact, subjecting the valve disc to enormous impact loads.

[0003] Therefore, there is an urgent need for a valve disc structure that integrates pressure reduction function into the valve disc body, can significantly reduce water hammer at ultra-low temperatures, and also has the function of shut-off check. Utility Model Content

[0004] The purpose of this invention is to reduce the impact of valve opening and closing and to reduce the water hammer effect during the valve opening and closing process.

[0005] To achieve the above objectives, this utility model proposes an ultra-low temperature shut-off check valve with a pressure-reducing valve disc. The pressure-reducing valve disc creates a flow diversion, thereby reducing the water hammer effect.

[0006] The shut-off check valve provided by this utility model includes: The valve body has a channel for fluid to pass through, and a valve seat is formed within the channel; A valve disc, located within the channel, is configured to be in movable sealing contact with the valve seat; A valve stem, connected to the valve disc, is used to drive the valve disc to move; The valve cover is located on the outside of the valve stem and is fixedly connected to the valve body; When the valve disc is in sealing contact with the valve seat, it divides the channel into a first chamber on the fluid inlet side and a second chamber on the fluid outlet side. The portion of the valve disc located in the second chamber is provided with a pressure reducing hole.

[0007] Optionally, the pressure-reducing hole is arranged circumferentially along the valve disc.

[0008] Optionally, a packing space is provided between the end of the valve cover away from the valve body and the valve stem, and packing is provided in the packing space.

[0009] Optionally, the packing space is provided with a packing sleeve at the end away from the valve body and a packing pad at the end near the valve body.

[0010] Optionally, the valve cover is further provided with a packing compression nut and a locking nut on its outer side.

[0011] Optionally, the valve stem is provided with a cap nut and a handwheel at the end away from the valve body.

[0012] Optionally, a threaded sleeve is provided between the valve stem and the valve cover at one end near the valve body.

[0013] This invention reduces the impact of the fluid when the valve disc is opened and closed by setting pressure-reducing holes on the valve disc to divert the fluid. This can significantly reduce the water hammer effect during the opening and closing process. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a shut-off check valve according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the valve disc structure according to an embodiment of the present invention. Detailed Implementation

[0015] The following detailed description of the stop check valve proposed in this utility model, in conjunction with the accompanying drawings and specific embodiments, will further illustrate its advantages and features. The advantages and features of this utility model will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, intended only to facilitate and clearly illustrate the embodiments of this utility model. Please refer to the drawings to make the objectives, features, and advantages of this utility model more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes and to aid those skilled in the art, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this utility model, should still fall within the scope of the technical content disclosed in this utility model.

[0016] like Figure 1 , 2 As shown, this utility model discloses a shut-off check valve suitable for cryogenic environments (below -163°C). The valve includes a valve body 1, a valve disc 2, a valve stem 5, and a valve cover 4. The valve body 1 has a channel for fluid passage, within which a valve seat 101 is formed. The valve disc 2 is located within the channel and is configured to movably and seal against the valve seat 101. When the valve disc 2 moves downward, it seals against the valve seat 101, dividing the channel into a first chamber 103 on the fluid inlet side and a second chamber 105 on the fluid outlet side, at which point the fluid is shut off. When the valve disc 2 moves upward, it separates from the valve seat 101, and the first chamber 103 communicates with the second chamber 105. The portion of the valve disc 2 located within the second chamber 105 has a pressure-reducing hole. Figure 2As shown, the pressure-reducing hole 21 is arranged circumferentially along the valve disc 2. The pressure-reducing hole 21 allows the fluid to gradually release pressure during the valve disc 2 closing process (valve disc 2 and valve seat 101 are in sealing contact), avoiding a sharp increase in pressure difference; the pressure-reducing hole 21 reduces the peak value of the pressure wave by slowing down the pressure release and prolonging the closing time; when the valve disc 2 begins to close, the pressure-reducing hole 21 allows a small amount of medium to flow back, gradually balancing the pressure and suppressing the water hammer effect; the flow diversion effect of the pressure-reducing hole 21 reduces the impact of the fluid on the valve disc 2, thereby reducing vibration and noise.

[0017] Furthermore, the valve stem 5 is connected to the valve disc 2 to drive the valve disc 2 to move; the end of the valve stem 5 away from the valve body 1 is provided with a cap nut 12 and a handwheel 11, and a spring washer 18 is provided at the connection between the cap nut 12 and the valve stem 5. A threaded sleeve 13 is provided between the valve stem 5 and the valve cover 2 at the end near the valve body 1. The threaded sleeve 13 can provide good radial support and guidance when the valve stem 5 moves up and down, preventing the valve stem 5 from shaking.

[0018] Furthermore, the valve cover 4 is located outside the valve stem 5 and is fixedly connected to the valve body 1. Specifically, the valve cover 4 is connected to the outside of the valve body by an anti-loosening washer 15 and an internal hexagon head screw 14.

[0019] Furthermore, a packing space is provided between the end of the valve cover 4 furthest from the valve body 1 and the valve stem 5, and packing 7 is provided in the packing space. A packing sleeve 8 is provided at the end of the packing space furthest from the valve body 1, and a packing pad 6 is provided at the end closer to the valve body 1. The packing sleeve 8 is used to ensure uniform force on the packing and fully guarantee the sealing performance. The packing pad 6 is used to place the packing 7. A packing compression nut 10 and a locking nut 9 are also provided on the outside of the valve cover 4. The packing compression nut 10 and the locking nut 9 are used to ensure that the packing is always in a compressed state to ensure the sealing performance. The packing 7 is a ring made of nickel wire reinforced graphite with a special structure. This ring, as an end ring, has excellent scratch resistance and descaling cleaning function. The high-purity stacked graphite (multiple graphite blocks stacked together) used in the middle can achieve high-efficiency sealing characteristics under low preload conditions, fully guaranteeing the sealing performance of the valve packing.

[0020] Furthermore, the valve cover 4 is responsible for sealing, supporting the valve stem 5, connecting the actuator, and pressing the sealing packing. An O-ring 17 is provided on the outer side of the valve stem 5 away from the valve body 1 to prevent external leakage and fully ensure sealing performance.

[0021] This invention reduces the impact of the fluid when the valve disc is opened and closed by setting pressure-reducing holes on the valve disc to divert the fluid. This can significantly reduce the water hammer effect during the opening and closing process.

[0022] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0023] In the description of this utility model, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above content. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A shut-off check valve, characterized in that, include: The valve body has a channel for fluid to pass through, and a valve seat is formed within the channel; A valve disc, located within the channel, is configured to be in movable sealing contact with the valve seat; A valve stem, connected to the valve disc, is used to drive the valve disc to move; The valve cover is located on the outside of the valve stem and is fixedly connected to the valve body; When the valve disc is in sealing contact with the valve seat, it divides the channel into a first chamber on the fluid inlet side and a second chamber on the fluid outlet side. The portion of the valve disc located in the second chamber is provided with a pressure reducing hole.

2. The shut-off check valve as described in claim 1, characterized in that, The pressure relief hole is arranged circumferentially along the valve disc.

3. The shut-off check valve as described in claim 1, characterized in that, A packing space is provided between the end of the valve cover away from the valve body and the valve stem, and packing is provided in the packing space.

4. The shut-off check valve as described in claim 3, characterized in that, The packing space is provided with a packing sleeve at the end away from the valve body and a packing pad at the end closer to the valve body.

5. The shut-off check valve as described in claim 4, characterized in that, The valve cover is also provided with a packing compression nut and a locking nut on the outside.

6. The shut-off check valve as described in claim 1, characterized in that, The valve stem is provided with a cap nut and a handwheel at the end away from the valve body.

7. The shut-off check valve as described in claim 1, characterized in that, A threaded sleeve is provided between the valve stem and the valve cover near one end of the valve body.

Images