Small-caliber forged steel flat gate valve

Abstract

The utility model discloses a small-caliber forged steel flat gate valve which comprises a valve rod, a hand wheel, a valve cover, a gate plate, seat rings and a valve body, the valve body is internally provided with two seat rings which are provided with second O-shaped rings, the gate plate which is positioned by an inner cavity of the valve body is arranged between the seat rings, and the valve rod is arranged on the gate plate; a valve cover is fixedly mounted on the valve body by screwing a stud and a nut; the upper portion of the valve rod is sequentially sleeved with a sleeve support, a valve rod nut and a hand wheel, padding, a spacer ring, a third O-shaped ring and a pressing sleeve are arranged in the sleeve support to guide and seal the sleeve support, and the sleeve support is fixedly assembled on the valve deck through a small round nut on the outer portion of the sleeve support. The hand wheel is connected and assembled with the sleeve support through the valve rod nut, and the gland is arranged between the sleeve support and the valve rod nut for limiting. And an indicating cylinder screwed with the valve rod nut is arranged above the hand wheel. The fireproof door is simple, reasonable and compact in structure and low in cost, and has high stability, safety, sealing performance and fireproof function.

Description

Technical Field

[0001] The utility model belongs to the technical field of flat gate valves, in particular to a small-caliber forged steel flat gate valve. Background Art

[0002] The flat gate valve is a sliding valve with parallel gates as the closing part. Its closing part can be a single gate or a double gate with a propping mechanism in between. The single gate flat gate valve mainly relies on the medium pressure to seal, while the double gate flat gate valve relies on an external mechanism to prop open the gate valve and compress and seal.

[0003] At present, most of the commonly used flat gate valves are large-diameter single-disc valves with a diameter exceeding DN50, with complex structures and high costs. For details, please refer to Figure 1 and Figure 2 , this type of flat gate valve has the following problems:

[0004] 1. Because the valve has a large diameter, the valve body is made of castings;

[0005] 2. The valve seat has a complex shape, and multiple O-rings are used for radial sealing. A disc spring or a large number of small cylindrical springs are installed at the tail to provide the initial sealing preload. The middle part also needs to be processed with an emergency grease injection groove and a guide channel. For details, please refer to Figure 3 ;

[0006] 3. The gate needs to rely on the boss provided on the side of the casting valve body to achieve guidance. The gap is large, and it is easy for the gate guide hole to be misaligned with the valve body channel. For details, please refer to Figure 4 ;

[0007] 4. In order to realize the emergency grease injection function, the valve needs to specially design a grease injection sealing channel and install a grease injection valve.

[0008] Therefore, it is necessary to develop a small-diameter flat gate valve and optimize its structure relative to the large-diameter one to achieve full functionality and compact structure. Utility Model Content

[0009] In view of the problems existing in the prior art, the utility model aims to provide a small-caliber forged steel flat gate valve.

[0010] In order to solve the above problems, the utility model adopts the following technical solutions:

[0011] A small-bore forged steel parallel gate valve, comprising a valve stem, a handwheel, a valve cover, a gate plate, a seat ring and a valve body. Two seat rings for fitting a second O-ring are provided inside the valve body. A gate plate positioned by the inner cavity of the valve body is installed between the two seat rings, and a valve stem is installed on the gate plate. The valve body is fixedly installed with a valve cover by tightening studs and nuts. A sleeve bracket, a valve stem nut and a handwheel are sequentially sleeved on the upper part of the valve stem. The inside of the sleeve bracket is provided with packing, a spacer ring, a third O-ring and a gland to guide and seal it, while the outside is fixedly assembled on the valve cover by a small round nut. The handwheel is connected and assembled with the sleeve bracket through the valve stem nut, and a gland is installed between the sleeve bracket and the valve stem nut for limiting, and an oil cup is provided for lubrication. An indicating cylinder screwed with the valve stem nut is installed above the handwheel, and the indicating cylinder is reinforced with screws to prevent loosening.

[0012] Preferably, a gasket and a first O-ring are provided at the connection between the valve body and the valve cover.

[0013] Preferably, the valve diameter of the small-bore forged steel parallel gate valve is below DN50.

[0014] Preferably, the sealing surfaces of the gate plate and the seat ring are treated by surfacing hard alloy process or spraying tungsten carbide process.

[0015] Preferably, the inner cavity of the valve body and the valve seat hole are both designed as simple straight cylinder types to limit and assemble the seat ring, and the gate plate is tightly assembled with the inner cavity of the valve body.

[0016] Preferably, there are two third O-rings, which are respectively arranged on the inner and outer surfaces of the spacer ring.

[0017] Preferably, the packing is made of graphite material and is filled above and below the spacer ring.

[0018] Preferably, the sleeve bracket sleeved on the valve stem is connected to the valve cover, and the two are threadedly connected. The sleeve bracket is provided with internal thread, and the valve cover is provided with external thread.

[0019] Preferably, the handwheel is provided with a round waist hole for inlaying the valve stem nut.

[0020] Preferably, the indicating cylinder is provided with a valve position observation window.

[0021] The beneficial effects of the present utility model:

[0022] Compared with the prior art, the advantages of the present utility model are as follows:

[0023] The utility model relates to the structure of a forged steel slab gate valve with a small diameter. Although the structure is simple, it is reasonable, compact and low-cost, and has obvious cost advantages in mass production. In addition, there are also detailed designs to ensure the stability, safety, sealing performance and fire prevention function during its use. The utility model is provided with three O-rings, without the need for disc springs or small springs to provide initial pre-tightening force, and there are no redundant grease oil grooves and diversion channels. It does not require bosses on the side like a cast valve body to guide the gate. Since the inner cavity of the valve body and the seat hole are both designed as simple straight cylinders, the processing is simple. The gate does not require positioning bosses and can be positioned in all directions only by relying on the valve seat and the inner cavity of the valve body. Such a design of the utility model solves the problem of difficult processing of the inner cavity of the forging valve body while avoiding the problem of misalignment between the diversion holes of the gate and the channels of the valve body. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a cross-sectional view of the slab gate valve mentioned in the background art;

[0025] Figure 2 is Figure 1 the schematic side view structure diagram of;

[0026] Figure 3 It is a schematic structural diagram of the valve seat mentioned in the background art;

[0027] Figure 4 It is a schematic structural diagram of the gate mentioned in the background art;

[0028] Figure 5 It is a schematic semi-sectional structure diagram of the utility model;

[0029] Figure 6 The position diagram of the valve plate, seat ring and valve body of the utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present utility model.

[0031] In the description of the present utility model, it should be noted that the terms "upper / lower end", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0032] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "set / sleeved with", "socket connection", "connection", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0033] As Figure 5 and Figure 6 As shown, the present utility model provides a technical solution: a small-bore forged steel parallel gate valve, which includes a valve stem 3, a handwheel 9, a valve cover 17, a gate plate 13, a seat ring 14, and a valve body 20. Two seat rings 14 equipped with second O-rings 21 are arranged inside the valve body 20. A gate plate 13 positioned by the inner cavity of the valve body 20 is installed between the two seat rings 14, and a valve stem 3 is installed on the gate plate 13; the valve body 20 is fixedly installed with a valve cover 17 by tightening a stud 5 and a nut 6; on the upper part of the valve stem 3, a sleeve bracket 1, a valve stem nut 11, and a handwheel 9 are sequentially sleeved. Inside the sleeve bracket 1, a packing 16, a spacer ring 15, a third O-ring 22, and a gland 2 are provided to guide and seal it, and on the outside, the sleeve bracket 1 is fixedly assembled on the valve cover 17 by a small round nut 4; the handwheel 9 is connected and assembled with the sleeve bracket 1 through the valve stem nut 11, and a gland 10 is installed between the sleeve bracket 1 and the valve stem nut 11 for limiting, and an oil cup 12 is provided for lubrication; above the handwheel 9, an indicating cylinder 7 screwed with the valve stem nut 11 is installed, and the indicating cylinder 7 is reinforced with a screw 8 to prevent loosening.

[0034] Among them, the diameter of the valve on the valve body 20 is below DN50. Due to the small diameter of the valve port, the valve body 20 cannot use castings, so forgings need to be used. For this, the processing of the middle cavity, channel, and seat ring installation part of the valve body 20 does not require special equipment, and conventional lathes can be used for processing, which has obvious advantages for medium and large batch processing and production.

[0035] The sealing surfaces of the gate plate 13 and the seat ring 14 are treated by the surfacing hard alloy process or the tungsten carbide spraying process. Such a design can improve the wear resistance at this place and can improve the service life and sealing effect to a certain extent.

[0036] The structure of the seat ring 14 is simple and reasonable. It can achieve the initial sealing force and the downstream sealing function of the medium by means of the second O-ring 21, rather than relying on a disc spring or a small spring to provide the initial pre-tightening force like most of the existing flat gate valve structures.

[0037] The design of the size of the inner circle of the valve body 20, the length of the seat ring 14, the width and thickness of the gate plate 13 should ensure that the gate plate 13 and the seat ring 14 can be fully installed into the valve body 20 in sequence. On this premise, the gap between the gate plate 13 and the inner circle of the valve body 20 should be as small as possible. The purpose of such a design is to limit the displacement of the gate plate 13 in the front and back directions and ensure that the diversion hole of the gate plate 14 is aligned with the channel of the valve body 20. Since the valve body 20 is a forging and a structure similar to the casting boss cannot be machined, the existing design scheme is the optimal scheme for limiting the displacement of the gate plate 13 in the front and back directions. Therefore, the gap between the gate plate 13 and the inner circle of the valve body 20 needs to be as small as possible. After the gate plate 13 and the seat ring 14 are completely installed into the valve body 20, the gap between the seat ring 14 and the valve body 20 is very small, which can ensure that the second O-ring is not extruded and extend the service time. In the case of downstream sealing, the seals between the gate plate 13 and the seat ring 14 and between the seat ring 14 and the valve body 20 are all metal-to-metal hard seals, which have the fire prevention function.

[0038] There are two of the third O-rings 22, which are respectively arranged on the inner and outer surfaces of the spacer ring 15. Specifically, two slots are provided on the spacer ring 15 to arrange the two third O-rings 22. The two third O-rings 22, one inside and one outside, are installed in the middle position of the packing 16. This can further improve the sealing performance of the utility model and improve the safety to a certain extent.

[0039] The gate plate 13 is connected to the valve stem 3 through a T-shaped head, and through "pull-off calculation", it is ensured that when an abnormality occurs, the valve stem 3 breaks at the thread. When the gate plate 13 is closed, it is limited by contacting the bottom of the valve body 20; when the gate plate 13 is opened, it is limited by the inverted seal contact between the valve stem 3 and the valve cover 17. Such a design can ensure that the diversion hole of the gate plate 13 is concentric with the channel hole of the valve body 20.

[0040] Between the valve body 20 and the valve cover 17, a first O-ring 19 is mainly used for sealing. This can not only reduce the specification of the bolts used but also make the connecting flange more compact. In addition, a gasket 18 is added to the connection structure for auxiliary sealing. Such a design can also enhance the fire prevention function, greatly improving the practicality and fire prevention performance of the present utility model. It is worth mentioning that the packing 16 at the valve stem 3, which is made of graphite, also has a fire prevention function design. It is filled above and below the spacer ring 15. The inner and outer surfaces of the spacer ring 15 use a third O-ring to achieve double sealing, which can adjust the pressing force of the gland, achieve a good sealing effect, and obtain a small operating torque.

[0041] Among them, the sleeve bracket 1 and the valve cover 17 are in threaded connection. Such a design can not only press the gland 2 but also connect the valve cover 17 and the valve stem nut 11, making the overall structure more compact.

[0042] In addition, the sleeve bracket 1 is fastened by a small round nut 4, which is a standard part. It can prevent the sleeve bracket 1 from loosening during the valve opening and closing operation, improving safety. Similarly, the handwheel 9 is installed on the valve stem nut 11 by opening a waist-shaped hole, and an indicating cylinder 7 is installed above it to press and prevent it from coming out. These multiple reinforcement designs make the present utility model more stable, safe, and reasonable.

[0043] It can be further explained that the indicating cylinder 7 and the valve stem nut 11 are in threaded connection and are locked by a screw 8. The indicating cylinder 7 is also provided with an observation window. Users can directly observe the position of the valve stem 3 to judge the opening and closing state of the valve, ensuring the safety of the operation.

[0044] The present utility model is a structure of a small-bore forged steel parallel slide gate valve. Although the structure is simple, it is reasonable, compact, and low-cost, having an obvious cost advantage in mass production. There are also detailed designs for its use to ensure the stability, safety, sealing performance, and fire prevention function of the connection.

[0045] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not explicitly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a......" does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0046] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A small-caliber forged steel flat gate valve, comprising a valve stem (3), a hand wheel (9), a valve cover (17), a gate plate (13), a seat ring (14) and a valve body (20), characterized in that: The valve body (20) is provided with two seat rings (14) equipped with a second O-ring (21); a gate plate (13) positioned against the inner cavity of the valve body (20) is provided between the two seat rings (14); a valve stem (3) is provided on the gate plate (13); the valve body (20) is fixedly mounted with a valve cover (17) by tightening a stud (5) and a nut (6); a sleeve bracket (1), a stem nut (11) and a hand wheel (9) are sequentially mounted on the upper part of the valve stem (3); a packing (16), a spacer ring (15), a third O-ring (22) are provided inside the sleeve bracket (1), and a valve stem nut (11) and a hand wheel (9) are provided on the inner part of the sleeve bracket (1). ) and a compression sleeve (2) for guiding and sealing, and a small round nut (4) is used on the outside to fix the sleeve bracket (1) on the valve cover (17); the hand wheel (9) is connected and assembled with the sleeve bracket (1) through the valve stem nut (11), and a compression cap (10) is installed between the sleeve bracket (1) and the valve stem nut (11) for limiting, and an oil cup (12) is provided for lubrication; an indicator tube (7) screwed with the valve stem nut (11) is installed above the hand wheel (9), and the indicator tube (7) is reinforced with the indicator tube (7) by a screw (8) to prevent it from loosening.

2. A small-caliber forged steel flat gate valve according to claim 1, characterized in that: A gasket (18) and a first O-ring (19) are provided at the connection between the valve body (20) and the valve cover (17).

3. A small-caliber forged steel flat gate valve according to claim 1, characterized in that: The valve diameter of the small-diameter forged steel flat gate valve is less than DN50.

4. A small-caliber forged steel flat gate valve according to claim 1, characterized in that: The sealing surfaces of the gate plate (13) and the seat ring (14) are treated by surfacing hard alloy or spraying tungsten carbide.

5. A small-caliber forged steel flat gate valve according to claim 1, characterized in that: The inner cavity and the valve seat hole of the valve body (20) are both of a simple straight-cylindrical design, so as to limit the assembly of the seat ring (14), and the gate plate (13) is tightly assembled in the inner cavity of the valve body (20).

6. A small-caliber forged steel flat gate valve according to claim 1, characterized in that: There are two third O-rings (22), which are respectively arranged on the inner and outer surfaces of the spacer ring (15).

7. A small-caliber forged steel flat gate valve according to claim 1, characterized in that: The filler (16) is made of graphite material and is arranged above and below the spacer ring (15).

8. A small-caliber forged steel flat gate valve according to claim 1, characterized in that: The sleeve bracket (1) sleeved on the valve stem (3) is connected to the valve cover (17), and the two are threadedly connected. The sleeve bracket (1) is provided with an internal thread, while the valve cover (17) is provided with an external thread.

9. A small-caliber forged steel flat gate valve according to claim 1, characterized in that: The hand wheel (9) is provided with a round waist hole for the valve stem nut (11) to be embedded and set.

10. A small-caliber forged steel flat gate valve according to claim 1, characterized in that: The indicator tube (7) is provided with a valve position observation window.

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