Low-torque large-diameter stop valve

Abstract

The utility model discloses a low-torque large-caliber stop valve, which relates to the technical field of valves, and comprises a valve body, a valve cover, a valve rod, a hand wheel, a valve clack assembly and a valve seat, the valve clack assembly comprises a main valve clack and an auxiliary valve clack, the main valve clack is provided with a sliding chute, the auxiliary valve clack is arranged in the sliding chute and is connected with the valve rod, a valve clack gland is arranged above the sliding chute, and the valve clack gland is connected with the valve seat. The side wall of the main valve clack is provided with a liquid inlet hole communicated with the sliding groove and the inlet cavity, the bottom of the main valve clack is provided with a liquid outlet hole communicated with the sliding groove and the outlet cavity, the top face of the bottom wall of the sliding groove is provided with a small valve seat sealing face, and the small valve seat sealing face and the sealing face on the bottom face of the auxiliary valve clack jointly form a small sealing pair. And a buffer mechanism is arranged on the flow guide arc surface. Operating torque for opening and closing the valve can be effectively reduced, the diameter and the size of a valve rod of the valve can be reduced, the manufacturing cost of the valve is saved, erosion of high-pressure media to a sealing face can be effectively reduced, and the service life of the valve is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to a low-torque large-diameter stop valve. Background Art

[0002] The stop valve, also known as the intercept valve, is a forced sealing valve. It relies on the valve stem pressure to make the valve disc sealing surface fit tightly against the valve seat sealing surface to prevent the medium from flowing through the valve. Due to the small friction between the sealing surfaces during the opening and closing process, it is relatively durable, has a small opening height, is easy to manufacture and maintain, and is suitable not only for medium and low pressures, but also for high pressures.

[0003] When the existing stop valve needs to be larger than DN200, the valve stem diameter needs to be very large, and the operating torque for opening and closing the valve is also greater. Due to the large diameter of the valve stem, the cost is high, the valve size is huge, and in order to reduce the opening and closing operating torque, large-diameter stop valves usually use inclined sealing between the valve disc and the valve seat. The high-pressure medium can easily erode the sealing surface, affecting the service life of the valve. Summary of the invention

[0004] In view of the deficiencies in the prior art, the utility model provides a low-torque large-diameter stop valve.

[0005] The technical solution provided by the utility model is:

[0006] 14. The operative position of claim 13 wherein the operative position of the valve body is such that the operative position, the pressure of the operative position being such that the operative position of the valve body is regulated by the pressure of the cam and the control valve is in a state of being moved along the cam face.

[0007] The buffer mechanism comprises an arc-shaped buffer plate and a buffer spring. One end of the buffer spring is fixed to the middle of the guide arc surface, and the other end is fixed to the middle of the buffer plate.

[0008] There are a plurality of liquid inlet holes, which are evenly distributed along the circumference of the side wall of the main valve disc and are arranged obliquely.

[0009] The main valve disc is in the shape of a plug, and a sealing surface arranged obliquely is arranged in its circumference to form an inclined surface seal with the sealing surface on the valve seat.

[0010] The valve cover is detachably connected to the valve body via bolts, and a sealing gasket is provided between the valve cover and the valve body.

[0011] A packing assembly is provided between the valve stem and the valve cover. The packing assembly comprises packing, a packing gland and a packing pressure plate. The packing pressure plate is pressed against the packing gland by a movable bolt to thereby press the packing.

[0012] The beneficial effects of the utility model are as follows: the utility model effectively reduces the operating torque for opening and closing the valve by arranging a valve disc assembly in which the main valve disc and the auxiliary valve disc cooperate, can meet the selection requirements of large-diameter pipelines, is beneficial to reducing the valve stem diameter and volume of the valve, and saves the valve manufacturing cost. By arranging a plurality of guide arc surfaces on the circumference of the main valve disc and arranging a buffer mechanism on the guide arc surfaces, the erosion of the sealing surface by the high-pressure medium can be effectively reduced, thereby extending the service life of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic cross-sectional structure diagram of an embodiment of the utility model;

[0014] Figure 2 for Figure 1 A partial enlarged view of . DETAILED DESCRIPTION

[0015] The embodiments of the present utility model will be further described below in conjunction with the accompanying drawings.

[0016] like Figure 1-2 As shown, a low torque large-caliber stop valve comprises a valve body 1, the valve body 1 is provided with an inlet cavity 15 and an outlet cavity 17, the inlet cavity 15 and the outlet cavity 17 are connected through a valve body middle cavity 16, a valve cover 7 is provided at the upper end of the valve body 1, a valve stem 5 is provided on the valve cover 7, the upper end of the valve stem 5 is connected to a hand wheel 12, the lower end passes through the valve cover 7 and extends to the valve body middle cavity 16, a valve disc assembly is provided at the lower end of the valve stem 5, a valve seat 2 is provided in the valve body 1, the valve disc assembly comprises a main valve disc 3 and an auxiliary valve disc 4, the main valve disc 3 is in a plug shape, and an inclined valve disc 4 is provided in the circumferential direction thereof. The obliquely arranged sealing surface 28 forms an oblique seal with the sealing surface on the valve seat 2, the main valve disc 3 is provided with a slide groove 21, the auxiliary valve disc 4 is placed in the slide groove 21 and is connected to the valve stem 5, a valve disc gland 6 is provided above the slide groove 21, the side wall of the main valve disc 3 is provided with a liquid inlet hole 23 connecting the slide groove 21 and the inlet chamber 15, the bottom of the main valve disc 3 is provided with a liquid outlet hole 24 connecting the slide groove 21 and the outlet chamber 17, and a small valve seat sealing surface 22 is provided on the top surface of the bottom wall of the slide groove 21, which together with the sealing surface on the bottom surface of the auxiliary valve disc form a small sealing pair.

[0017] When the valve is installed on the medium pipeline for actual use, the medium flows from the inlet chamber 15 to the outlet chamber 17. When the valve is opened, the hand wheel 13 is rotated to drive the valve stem 5 to rise slowly. During the rising process, the auxiliary valve disc 4 is first driven to rise to open the liquid inlet hole 23. At this time, the medium will flow into the chute 21 along the liquid inlet hole 23 and flow from the liquid outlet hole 24 to the outlet chamber 17 to achieve pressure balance at both ends of the sealing pair, thereby reducing the operating torque for opening the valve stem 5. When the valve stem 5 continues to rise, due to the limit of the valve disc gland 6, the auxiliary valve disc 4 will hit the valve disc gland 6, and then rise with the main valve disc 3 to complete the valve opening; when closing the valve, since the medium flows from top to bottom, the operating torque of the valve stem 5 does not need to be too large to be easily closed under the force of the medium. Since the torque required for closing and opening operations becomes smaller, the torque pressure of the valve stem 5 is reduced, the diameter of the valve stem 5 can be reduced when the valve is set, the volume of the valve can be reduced, and the cost can be saved, which can meet the selection requirements of the stop valve for large-diameter pipelines.

[0018] Furthermore, there are a plurality of liquid inlet holes 23 which are evenly distributed along the circumference of the side wall of the main valve flap 3 and are arranged at an angle. The plurality of inclined liquid inlet holes 23 can effectively prevent the medium from impacting only one side of the auxiliary valve flap 4, causing the auxiliary valve flap 4 to deviate and affect the sealing performance.

[0019] In this embodiment, the main valve disc 3 is provided with a plurality of guide arc surfaces 25 in the circumference, and a buffer mechanism is provided on the guide arc surface 25. The buffer mechanism includes an arc-shaped buffer plate 26 and a buffer spring 27. One end of the buffer spring 27 is fixed to the middle of the guide arc surface 25, and the other end is fixed to the middle of the buffer plate 26. When the valve is opened or closed, the guide arc surface 25 can guide the medium that impacts the main valve disc 3, reduce the erosion of the valve sealing surface by the high-pressure medium, and the buffer mechanism buffers and relieves the pressure of the medium, further reducing the opening and closing torque of the valve.

[0020] In this embodiment, the valve cover 7 and the valve body 1 are detachably connected by bolts 8, and a sealing gasket 14 is provided between the valve cover 7 and the valve body 1 to facilitate disassembly, assembly, maintenance and repair.

[0021] In this embodiment, a packing assembly is provided between the valve stem 5 and the valve cover 7, and the packing assembly includes a packing 9, a packing gland 10, and a packing pressure plate 11. The packing pressure plate 11 presses the packing gland 10 through a movable bolt 12, thereby pressing the packing 9, ensuring that the medium will not leak from between the valve stem 5 and the valve cover 7, thereby ensuring the reliability of the valve sealing.

[0022] The embodiments should not be regarded as limiting the present invention, and any non-creative improvements made based on the spirit of the present invention should be regarded as falling within the protection scope of the present invention.

Claims

1. A low torque large-caliber stop valve, comprising a valve body, the valve body being provided with an inlet cavity and an outlet cavity, the inlet cavity and the outlet cavity being communicated through a central cavity of the valve body, the upper end of the valve body being provided with a valve cover, the valve cover being provided with a valve stem, the upper end of the valve stem being connected to a hand wheel, the lower end of the valve stem passing through the valve cover and extending to the central cavity of the valve body, the lower end of the valve stem being provided with a valve flap assembly, the valve body being provided with a valve seat which forms a sealing fit with the valve flap assembly, and the characteristics are: The valve flap assembly includes a main valve flap and an auxiliary valve flap. The main valve flap is provided with a slide groove. The auxiliary valve flap is placed in the slide groove and is connected to the valve stem. A valve flap pressure cover is provided above the slide groove. The side wall of the main valve flap is provided with a liquid inlet hole connecting the slide groove and the inlet cavity. The bottom of the main valve flap is provided with a liquid outlet hole connecting the slide groove and the outlet cavity. The top surface of the bottom wall of the slide groove is provided with a small valve seat sealing surface, which together with the sealing surface on the bottom surface of the auxiliary valve flap constitutes a small sealing pair. The main valve flap is provided with a plurality of guide arc surfaces in the circumference, and a buffer mechanism is provided on the guide arc surface.

2. A low torque large diameter stop valve according to claim 1, characterized in that: The buffer mechanism comprises an arc-shaped buffer plate and a buffer spring. One end of the buffer spring is fixed to the middle of the guide arc surface, and the other end is fixed to the middle of the buffer plate.

3. A low torque large diameter stop valve according to claim 1, characterized in that: There are a plurality of liquid inlet holes, which are evenly distributed along the circumference of the side wall of the main valve disc and are arranged obliquely.

4. A low torque large diameter stop valve according to claim 1, characterized in that: The main valve disc is in the shape of a plug, and a sealing surface arranged obliquely is arranged in its circumference to form an inclined surface seal with the sealing surface on the valve seat.

5. The low torque large diameter stop valve according to claim 1, characterized in that: The valve cover is detachably connected to the valve body via bolts, and a sealing gasket is provided between the valve cover and the valve body.

6. A low torque large diameter stop valve according to claim 1, characterized in that: A packing assembly is provided between the valve stem and the valve cover. The packing assembly comprises packing, a packing gland and a packing pressure plate. The packing pressure plate is pressed against the packing gland by a movable bolt to thereby press the packing.

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