Needle type stop valve

Abstract

The utility model is applicable to the field of valve equipment, and provides a needle type stop valve, which comprises a valve body and a main valve rod, the valve body comprises a valve mounting port, a first working port and a second working port, a valve rod nut is fixedly arranged above the valve mounting port, the main valve rod is in threaded connection with the valve rod nut, the first working port is provided with a valve seat, and the second working port is provided with a valve seat. The main valve rod is arranged above the valve seat after being provided with a valve mounting port, a valve clack assembly is arranged at the lower end of the main valve rod and comprises a sealing valve clack and a valve clack cover, the sealing valve clack is provided with a valve clack mounting groove, the lower end of the main valve rod is arranged in the valve clack mounting groove, and the inner side wall of the valve clack mounting groove is in threaded connection with the outer side wall of the valve clack cover. And a thrust pad is arranged at the bottom of the valve clack mounting groove and is used as a buffer between the main valve rod and the sealing valve clack, so that excessive wear of the contact surface of the sealing valve clack and the valve seat caused by excessive rotation of the valve rod can be prevented.

Description

Technical Field

[0001] The utility model is applicable to the field of valve equipment and provides a needle-type stop valve. Background Art

[0002] A globe valve is a type of valve that relies on a valve disc as an opening and closing member, and a needle-type globe valve is a more common type of valve. The needle-type globe valve is derived from its conical structure of the valve disc, and is usually used in small-diameter pipelines and instrument measurement pipeline systems to open or cut off pipeline passages. The valve stem opening or closing stroke of this type of valve is relatively short, and it has a very reliable cut-off function. Since the change in the valve seat opening is directly proportional to the stroke of the valve disc, it is very suitable for regulating flow. In common structures, the valve disc is generally fixedly connected to the lower end of the main valve stem, and there is a lack of buffer between the two. When the main valve stem is rotated to make the valve disc fit against the valve seat to close the valve, in order to ensure a complete seal, it is often tightened with force to cause excessive contact between the valve disc and the valve seat. Long-term use can easily cause wear of the sealing surface and affect subsequent sealing performance. Utility Model Content

[0003] To this end, the utility model provides a needle-type stop valve, which prevents excessive wear of the contact surface between the sealing valve disc and the valve seat caused by excessive rotation of the valve stem by arranging a thrust pad between the bottom of the main valve stem and the sealing valve disc.

[0004] In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme: a needle-type stop valve, comprising a valve body and a main valve stem, the valve body comprising a valve installation port, a first working port and a second working port, the first working port is provided with a valve seat, the lower end of the main valve stem is arranged above the valve seat after passing through the valve installation port, a valve stem nut is fixedly arranged above the valve installation port, the outer side wall of the main valve stem is threadedly screwed with the inner side wall of the valve stem nut, a valve disc assembly is fixedly connected to one end of the main valve stem facing the valve seat direction, the valve disc assembly comprises a sealing valve disc and a valve disc cover, the valve disc cover is sleeved on the outer side of the main valve stem, the sealing valve disc is provided with a valve disc installation groove, the lower end of the main valve stem is arranged in the valve disc installation groove, and the inner side wall of the valve disc installation groove is threadedly screwed with the outer side wall of the valve disc cover, a thrust pad is arranged at the bottom of the valve disc installation groove, and the lower end surface of the main valve stem abuts against the thrust pad.

[0005] Furthermore, a valve cover is fixedly provided on the valve mounting port, a stuffing box is provided inside the valve cover, the stuffing box is provided with a through hole for allowing the main valve stem to pass through, a stuffing groove is provided between the upper part of the stuffing box and the main valve stem, the stuffing groove is filled with sealing stuffing, and a stuffing pressure plate is fixedly provided on the upper end of the stuffing box, and the stuffing pressure plate is used for sealing the stuffing groove.

[0006] Furthermore, a stuffing box fixing nut is screwed onto the outer side of the upper portion of the stuffing box through a thread, and the lower end surface of the stuffing box fixing nut abuts against the upper end surface of the valve cover. A stuffing box positioning ring is provided in the valve mounting port, and the upper end surface of the stuffing box positioning ring abuts against the lower end surface of the stuffing box.

[0007] Furthermore, a valve flap cover limiting step is provided on the lower outer wall of the main valve stem, and the upper end surface of the valve flap cover limiting step abuts against the lower end surface of the valve flap cover. A valve flap cover limiting step is provided on the outer wall of the valve flap cover, and the lower end surface of the valve flap limiting step abuts against the upper end surface of the sealing valve flap.

[0008] Furthermore, the outer side wall of the sealing valve flap is conical, and a rubber sealing pad is provided on the outer side wall of the sealing valve flap.

[0009] Furthermore, an adjusting hand wheel is fixedly connected to the upper end of the main valve stem.

[0010] Furthermore, a sealing ring is provided on the outer side of the stuffing box.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] 1. In the solution of the utility model, the sealing valve disc is sleeved on the outside of the main valve stem, and a thrust pad is provided between the bottom of the sealing valve disc and the lower end surface of the main valve stem as a buffer between the main valve stem and the sealing valve disc. In this way, when the sealing valve disc continues to rotate and press the main valve stem downward after contacting the valve seat, this part of the downward force will be offset by the thrust pad, thereby preventing the contact surface between the sealing valve disc and the valve seat from excessive wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of a needle-type stop valve mentioned in the utility model;

[0014] Figure 2 It is a schematic diagram of the assembly structure between the main valve stem, valve disc assembly and valve seat mentioned in the utility model.

[0015] In the figure: 1. valve body, 101. valve installation port, 102. first working port, 103. second working port, 2. valve seat, 3. valve cover, 4. stuffing box, 5. sealing ring, 6. main valve stem, 7. valve disc assembly, 701. sealing valve disc, 702. valve disc cover, 703. rubber sealing gasket, 704. thrust pad, 8. sealing packing, 9. packing pressure plate, 10. valve stem nut, 11. adjusting hand wheel, 12. stuffing box fixing nut. DETAILED DESCRIPTION

[0016] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0017] Refer to the attached Figure 1 The utility model provides a needle-type stop valve, including a valve body 1 and a main valve stem 6. The valve body 1 includes a valve installation port 101, a first working port 102 and a second working port 103. The first working port 102 and the second working port 103 correspond to the inlet and outlet of the fluid respectively. The first working port 102 is provided with a valve seat 2. The upper end of the main valve stem 6 is fixedly connected with an adjusting hand wheel 11. The lower end of the main valve stem 6 passes through the valve installation port 101 and is arranged above the valve seat 2. A valve stem nut 10 is fixedly arranged above the valve installation port 101. The outer wall of the main valve stem 6 is threadedly connected with the inner wall of the valve stem nut 10. Since the outer wall of the main valve stem 6 is threadedly connected with the inner wall of the valve stem nut 10, the up and down movement of the main valve stem 6 can be completed by rotating the main valve stem 6 by adjusting the hand wheel 11. The end of the main valve stem 6 facing the valve seat 2 is fixedly connected with a valve disc assembly 7, as shown in the attached figure. Figure 2As shown, the valve disc assembly 7 includes a sealing valve disc 701 and a valve disc cover 702. The valve disc cover 702 is sleeved on the outside of the main valve stem 6. The sealing valve disc 701 is provided with a valve disc mounting groove. The lower end of the main valve stem 6 is arranged in the valve disc mounting groove, and the inner side wall of the valve disc mounting groove is threadedly screwed with the outer side wall of the valve disc cover 702. A thrust pad 704 is provided at the bottom of the valve disc mounting groove. The lower end surface of the main valve stem 6 abuts against the thrust pad 704. A valve disc cover limiting step is provided on the outer side wall of the lower part of the main valve stem 6. The upper end surface of the valve disc cover limiting step abuts against the lower end surface of the valve disc cover 702. The valve disc cover limiting step is used for the installation and positioning of the valve disc cover 702. The outer wall of the valve disc cover 702 is provided with a valve disc limiting step, and the lower end surface of the valve disc limiting step abuts against the upper end surface of the sealing valve disc 701. The valve disc limiting step is used for the installation limit of the sealing valve disc 701. Through appropriate size adjustment, the upper end surface of the thrust pad 704 can be just in contact with the lower end surface of the main valve stem 6 under normal circumstances. When the valve is closed, the main valve stem 6 moves downward excessively, and the thrust pad 704 can provide a buffer for the lower end of the main valve stem 6. The outer wall of the sealing valve disc 701 is conical, and the outer wall of the sealing valve disc 701 is provided with a rubber sealing pad 703. When the sealing valve disc 701 moves downward When the valve seat 2 is fitted to close the first working port 102, the rubber sealing gasket 703 is fitted to the valve seat 2. The rubber sealing gasket 703 can make the valve seat 2 seal better. At the same time, the rubber material is elastic and can also avoid the wear problem caused by the long-term contact between the sealing valve disc 701 and the valve seat 2. At the same time, the valve installation port 101 is fixedly provided with a valve cover 3, and a stuffing box 4 is provided in the valve cover 3. The stuffing box 4 is provided with a through hole through which the main valve stem 6 can pass. A stuffing groove is provided between the upper part of the stuffing box 4 and the main valve stem 6. The stuffing groove is filled with sealing stuffing 8. A stuffing pressure plate 9 is fixedly provided on the upper end of the stuffing box 4. The stuffing The pressure plate 9 is used to seal the stuffing groove. The stuffing pressure plate 9 is connected to the stuffing box 4 by a bolt fastening mechanism. This design is convenient for disassembly and maintenance. The stuffing box fixing nut 12 is screwed on the outer thread of the upper part of the stuffing box 4. The lower end face of the stuffing box fixing nut 12 abuts against the upper end face of the valve cover 3. A stuffing box positioning ring is arranged in the valve installation port 101. The upper end face of the stuffing box positioning ring abuts against the lower end face of the stuffing box 4. At the same time, a sealing ring 5 is arranged on the outer side of the stuffing box 4. The sealing ring 5 is used to seal the gap between the outer wall of the stuffing box 4 and the inner wall of the valve installation port 101 to prevent the fluid in the valve body 1 from leaking from the gap.

[0018] In this embodiment, a thrust pad 704 is provided between the lower end of the main valve stem 6 and the sealing valve disc 701 to prevent excessive wear of the contact surface between the sealing valve disc 701 and the valve seat 2 due to excessive advancement of the main valve stem 6, thereby improving the overall durability of the valve.

[0019] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise stated, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0020] The above are only preferred embodiments of the present invention. Any person skilled in the art may modify the present invention or modify it into an equivalent technical solution by using the above technical solution. Therefore, any simple modification or equivalent replacement based on the technical solution of the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A needle-type stop valve, comprising a valve body and a main valve stem, characterized in that: The valve body includes a valve installation port, a first working port and a second working port, the first working port is provided with a valve seat, the lower end of the main valve stem is arranged above the valve seat after passing through the valve installation port, a valve stem nut is fixedly arranged above the valve installation port, the outer wall of the main valve stem is threadedly screwed with the inner wall of the valve stem nut, and a valve flap assembly is fixedly connected to one end of the main valve stem facing the valve seat, the valve flap assembly includes a sealing valve flap and a valve flap cover, the valve flap cover is sleeved on the outside of the main valve stem, the sealing valve flap is provided with a valve flap installation groove, the lower end of the main valve stem is arranged in the valve flap installation groove, and the inner wall of the valve flap installation groove is threadedly screwed with the outer wall of the valve flap cover, a thrust pad is arranged at the bottom of the valve flap installation groove, and the lower end surface of the main valve stem abuts against the thrust pad.

2. A needle-type stop valve according to claim 1, characterized in that: A valve cover is fixedly provided on the valve mounting port, a stuffing box is provided inside the valve cover, the stuffing box is provided with a through hole for allowing the main valve stem to pass through, a stuffing groove is provided between the upper part of the stuffing box and the main valve stem, the stuffing groove is filled with sealing stuffing, a stuffing pressure plate is fixedly provided on the upper end of the stuffing box, and the stuffing pressure plate is used for sealing the stuffing groove.

3. A needle-type stop valve according to claim 2, characterized in that: A stuffing box fixing nut is screwed onto the outer side of the upper portion of the stuffing box through a thread, and the lower end surface of the stuffing box fixing nut abuts against the upper end surface of the valve cover. A stuffing box positioning ring is provided in the valve mounting port, and the upper end surface of the stuffing box positioning ring abuts against the lower end surface of the stuffing box.

4. A needle-type stop valve according to claim 1, characterized in that: A valve flap cover limiting step is arranged on the outer side wall of the lower part of the main valve stem, and the upper end surface of the valve flap cover limiting step abuts against the lower end surface of the valve flap cover. A valve flap limit step is arranged on the outer side wall of the valve flap cover, and the lower end surface of the valve flap limit step abuts against the upper end surface of the sealing valve flap.

5. A needle-type stop valve according to claim 1, characterized in that: The outer side wall of the sealing valve flap is conical, and a rubber sealing pad is arranged on the outer side wall of the sealing valve flap.

6. A needle-type stop valve according to claim 1, characterized in that: The upper end of the main valve stem is fixedly connected with an adjusting hand wheel.

7. A needle-type stop valve according to claim 2, characterized in that: A sealing ring is arranged on the outer side of the stuffing box.

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