Gauge valve in front of meter

Abstract

The utility model discloses a meter front gate valve which comprises a valve shell, a valve element and a valve accessory. The valve shell comprises a valve shell finished product formed by combining a valve shell I and a valve shell II. The valve element is designed in a split mode and comprises a first valve element body and a second valve element body which are made of metal or non-metal materials. The valve accessories comprise a flashboard and a valve rod which are made of non-metal materials, the flashboard is in interference fit with the valve element, and the flashboard is driven to move up and down through rotation of the valve rod to achieve opening and closing of the gate valve. When the meter front gate valve is manufactured, a large number of subsequent machining steps are omitted, machining procedures are few, the manufacturing process is simple, the manufacturing cost is low, and the meter front gate valve is safe, sanitary and environmentally friendly. Non-metal sealing is achieved between the valve element and the valve shell and between the valve element and the gate plate by means of the deformable characteristic of non-metal, the sealing performance is good, and the requirement for machining precision is greatly lowered; and the sealing surface is more corrosion-resistant, so that the problems that the metal sealing surface is rusted and stuck and the sealing is invalid due to less opening and closing times of the metal meter front valve are solved.

Description

Technical Field

[0001] The present invention relates to the field of valves, and in particular to a pre-meter gate valve. Background Art

[0002] The statements in this section only provide background information related to the present disclosure, and these statements may constitute prior art. In the process of implementing the present invention, the inventors found that there are at least the following problems in the prior art.

[0003] Gate valves are widely used in a variety of environments. Generally, the valve stem rotates to drive the gate connected to it to move up and down to control the flow of the valve core. In order to avoid the valve stem being located in the valve core and affecting the flow when the valve is opened, such as Figure 5 As shown in the figure, the gate will be higher than the valve core (especially the connection end between the gate and the valve stem) after assembly. Because if the gate is lower than the valve core, in order to connect with the gate and drive it to move up and down, a section of the lower end of the valve stem will inevitably extend into the valve core to keep connected with the gate and not fall off. When the valve stem controls the gate to move up to open the valve, this part of the valve stem located in the valve core will inevitably affect the flow of the valve core flow channel. This is also the reason why the gate of the gate valve is higher than the valve core.

[0004] The threaded connection between the valve cover and the valve core is usually tightened with thread glue. Existing valve materials are mostly copper or cast iron, and the housing and the valve core are manufactured as one piece by casting or sand casting. These manufacturing methods have the following shortcomings:

[0005] 1. The manufactured valve shells are relatively thick, resulting in a certain amount of material waste.

[0006] 2. The tissue density is not enough, and the valve housing is prone to defects such as pores, causing seepage or leakage of the transported material in the pipeline.

[0007] 3. The dimensional accuracy and roughness cannot meet the actual use requirements, so turning, milling, grinding and other post-processing procedures are required. The increase in processing procedures also leads to extremely high manufacturing costs, and the coolant and other media in the processing process are likely to cause certain pollution to the valves, especially the valves for drinking water in the tap water network. If their hygiene indicators do not meet national standards, it will endanger the safety of people's lives and property.

[0008] For example, the application number 201910752474.4 is named “A valve manufacturing process”. The manufacturing process of this invention includes: raw material selection, material forming, forging, heat treatment before entering the factory, processing (including turning, milling and grinding), surface hardening, assembly, cleaning, packaging and transportation, etc. The forging, heat treatment and other processing processes of this invention have a great impact on the environment.

[0009] In order to solve the many problems brought about by the above-mentioned manufacturing methods, such as large material waste, many processing equipment, many processing steps and environmental pollution, some technical solutions began to prepare the various components of the gate valve separately and then combine them. For example, the application number 202010988405.6 is named "A manufacturing process for an environmentally friendly valve body and its product". The invention prepares the valve seat, valve core seat, connector, etc. separately, and uses cold stamping, drawing, finishing, sawing and other processes to make the valve body. Although the above scheme solves some of the environmental protection and strength problems existing in the casting or forging process, the thread processing of the valve core, valve seat joint, and pipe joint must require a certain material thickness, resulting in material waste, and cutting must also be used. In addition, since the metal parts are manufactured separately and then welded together, in order to ensure the airtightness, especially the airtightness of the gate and the valve core sealing surface, very high requirements are also placed on the processing accuracy, which makes the defective rate of the finished product always at a high level.

[0010] In addition, the gate valve at the front end of the water meter is opened and closed less frequently. Since the metal sealing surface is in water for a long time, it is prone to oxidation and corrosion, which can cause problems such as rust and jamming of the metal sealing surface and seal failure. Utility Model Content

[0011] In view of the above problems, the object of the present invention is to solve part of the problems in the prior art, or at least alleviate these problems.

[0012] A pre-meter gate valve comprises a valve housing, a valve core and valve accessories, wherein the valve accessories comprise a valve stem and a gate plate, and the gate plate is moved up and down by rotating the valve stem to control the opening and closing of the gate valve; the valve housing is provided with a through hole for the gate plate to move up and down;

[0013] The valve housing includes a valve housing I and a valve housing II; the valve housing II is adapted to the valve stem and the gate plate, and the lower end of the valve housing II is adapted to the through hole of the valve housing I;

[0014] The valve core and the valve housing I are non-metallicly sealed;

[0015] The gate plate is made of non-metallic material and has an interference fit with the pores of the valve core to control the opening and closing of the gate valve.

[0016] Optionally, the valve housing I and the valve housing II are combined into a finished valve housing by laser welding; or, the valve housing I and the valve housing II are integrally formed; the valve housing II is formed by separate welding.

[0017] Furthermore, the valve housing I and the valve housing II are made by cutting stainless steel pipes.

[0018] The valve core is of split design, including a first valve core and a second valve core arranged in the valve housing I; the gap between the gate plate and the first valve core and the second valve core is interference fit.

[0019] Furthermore, the gate plate is arranged in a finished valve housing composed of the valve housing II and the valve housing I.

[0020] Furthermore, the valve core is made of non-metallic material; the first valve core is provided with a positioning structure adapted to the second valve core; a first sealing ring is embedded in the annular groove of the first valve core to achieve non-metallic sealing with the valve housing I.

[0021] Furthermore, a positioning groove is provided at the first end of the second valve core, which is matched with the positioning protrusion of the first valve core.

[0022] Furthermore, a positioning device is provided at the second end of the second valve core for positioning and connecting with the water inlet end nut.

[0023] Preferably, the valve stem is made of non-metallic material, and its upper end is provided with a valve stem head made of metal material, which is integrally formed with the valve stem during injection molding; the valve stem is provided with a second sealing ring; the valve stem is threadedly connected to the gate plate, and drives the gate plate to move up and down through rotation.

[0024] The gate valve in front of the meter also includes a water inlet end nut and a water outlet end nut, which are fixedly connected to the two ends of the valve housing I respectively.

[0025] The present invention has the following beneficial effects:

[0026] 1. The valve core of the present application is made of metal material or non-metal material, and the gate plate is made of non-metal material. The split design of the valve core and the interference fit of the gate plate are combined, thereby utilizing the deformable characteristics of non-metal to achieve non-metallic sealing between the gate plate and the valve core. The sealing performance is better than that of traditional metal hard seals, and the processing accuracy requirements are also greatly reduced, thereby greatly improving the yield rate of the finished product; the valve core is preferably made of non-metallic material, and its non-metallic sealing surface with the gate plate is more corrosion-resistant, and will not oxidize and rust even if it is in water for a long time, which solves the problem that the metal gate valve used at the front end of the water meter has a small number of switches, causing the metal sealing surface to rust and become stuck and the seal to fail, and is also safer and more hygienic.

[0027] 2. The valve core adopts a split design, which is convenient for assembly after the valve shell I and valve shell II are welded into the finished valve shell. It not only keeps the gate and the valve core in interference fit, but also can send the gate valve into the corresponding position of the finished valve shell through its split design, avoiding the impact on the non-metallic valve core, gate and valve stem when the valve shell I and valve shell II are finally welded, thereby improving the yield rate of the finished product.

[0028] 3. The gate valve is manufactured in separate parts, which saves materials compared with traditional casting or forging. The valve shell is made of thin-walled seamless steel pipe or seamed steel pipe, which is cut and then rolled or shrunk into one piece, or cut into separate parts and welded. It saves materials compared with casting, forging or thick-walled pipes, and there is no environmental pollution in the casting or forging process, which is environmentally friendly and hygienic. It has high strength, no defects such as pores and impurities, and the valve is not easy to break or leak.

[0029] 4. Due to the use of thin-walled seamless steel pipes or seamed steel pipes, the inner diameter size accuracy of the steel pipe itself is high, and there is no need for secondary processing such as turning, milling, and grinding, which reduces the post-processing steps and greatly reduces the processing cost. At the same time, it also ensures the sealing of the valve core and the valve housing.

[0030] 5. The valve housing composed of multiple components is assembled by laser welding, and the valve housing and the interface are also connected by laser welding. Compared with threaded connection, welding connection has more reliable sealing, faster speed, and lower manufacturing and labor costs.

[0031] 6. This application does not require post-processing such as turning, milling, grinding, and heat treatment, has fewer tooling equipment and processing steps, simple manufacturing process, low manufacturing cost, no waste liquid and waste chips generated during the processing, safe, sanitary and environmentally friendly, and better overall comprehensive performance of the valve;

[0032] 7. The triangular head of the valve stem is made of metal material and is integrally formed with the valve stem during injection molding. The combination of metal and non-metal increases the strength and durability of the valve stem.

[0033] 8. The gate, valve stem and valve core are made of non-metallic materials by injection molding, which is simple to process and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the assembly of the present invention;

[0035] Figure 2 is a structural schematic diagram of the second valve core;

[0036] Figure 3 is a structural schematic diagram of the first valve core;

[0037] Figure 4 The figure is the connection diagram of the valve core;

[0038] Figure 5 This is a schematic diagram of the gate being assembled in the valve housing;

[0039] Figure 6 It is a schematic diagram of the connection between the gate and the valve core;

[0040] Figure 7 It is a structural schematic diagram of the nut at the water inlet end;

[0041] Figure 8One embodiment of the split-design valve housing II;

[0042] Fig. 9 Another embodiment of the valve housing II of split design.

[0043] Among them: 1-valve housing I; 2-first valve core; 3-first sealing ring 1; 4-second valve core; 5-gate; 6-valve stem; 7-valve stem head; 8-second sealing ring 2; 9-valve housing II; 10-water inlet end nut; 11-water outlet end nut; 12-positioning groove; 13-positioning device; 14-positioning protrusion. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with the accompanying drawings. The embodiments of the present invention are only used to illustrate the present invention rather than to limit the present invention. Without departing from the technical idea of ​​the present invention, various substitutions and changes can be made according to common technical knowledge and customary means in the field, which should all be included in the scope of the present invention.

[0045] like Figure 1 As shown, a pre-meter gate valve comprises a valve housing, a valve core and valve accessories, wherein the valve accessories comprise a valve stem 6 and a gate plate 5, and the gate plate 5 is moved up and down by rotating the valve stem 6 to control the opening and closing of the gate valve; the valve housing is provided with a through hole for the gate plate 5 to move up and down;

[0046] The valve housing includes a valve housing Ⅰ1 and a valve housing Ⅱ9; the valve housing Ⅱ9 is adapted to the valve stem 6 and the gate plate 5, and the lower end of the valve housing Ⅱ9 is adapted to the through hole of the valve housing Ⅰ1;

[0047] The valve core and the valve housing Ⅰ1 are non-metallicly sealed;

[0048] The gate plate 5 is made of non-metallic material and has an interference fit with the pore of the valve core to control the opening and closing of the gate valve.

[0049] Each component of the present application is prepared and reassembled separately, without environmental pollution in the casting or forging process, and is environmentally friendly and hygienic; it has high strength, no defects such as pores and impurities, and the valve is not easy to break and leak. Since the gate plate 5 of the present application is made of non-metallic material, it can form an interference fit with the sealing surface of the valve core, that is, the pores of the valve core, to achieve non-metallic sealing, and it will not oxidize and rust even if it is in water for a long time. And while it has a high elastic modulus and low processing precision, it has better sealing than traditional metal hard seals, and also solves the problem of metal sealing surface rusting and sealing failure caused by the small number of metal pre-valve openings and closings.

[0050] However, the applicant discovered during the manufacturing process that since one or more of the gate plate 5, valve stem 6, and valve core are made of non-metallic materials, if the valve housing Ⅰ1 and valve housing Ⅱ9 are laser welded after being manufactured and assembled separately, the high temperature generated by the welding will affect the performance of the gate plate 5, valve stem 6, and valve core, thereby increasing the defect rate of the finished product. However, if the valve housing Ⅰ1 and valve housing Ⅱ9 are combined into a finished valve housing or integrally formed at the beginning, and then the gate plate 5 and valve core are assembled, since the gate plate 5 is higher than the valve core, this will result in the inability to install the gate plate 5 and the valve core into the finished valve housing together. However, if the gate plate 5 is designed to be not higher than the valve core, although it can be installed in the finished valve housing, it will affect the flow rate of the valve flow channel when the valve is opened, and the gate plate 5, which is lower than the valve core, cannot form an interference fit with the valve core. Therefore, the gate plate 5 needs to be higher than the valve core and larger than the inner diameter of the valve housing I, but this will inevitably lead to the problem that the gate plate 5 and the valve core cannot be installed in the finished valve housing.

[0051] like Figure 2 As shown in 3 or 4, the valve core is a split design, including a first valve core 2 and a second valve core 4 arranged in the valve housing Ⅰ1; the gate plate 5 and the first valve core 2 and the second valve core 4 have an interference fit between the pores, such as Figure 6 The gate plate 5 is arranged in the valve housing finished product which is composed of the valve housing II 9 and the valve housing I 1 .

[0052] In order to make the gate plate 5 and the valve core have an interference fit to achieve non-metallic sealing, and to ensure that high-temperature welding will not affect non-metallic materials such as the gate plate 5, and that the valve flow path is unobstructed when the valve is opened, the applicant has designed the valve core in two parts, namely the first valve core 2 and the second valve core 4, and changed the assembly method. First, install the first valve core 2 into the finished valve housing and cooperate with the valve housing I1 to achieve non-metallic sealing; put the threaded end of the gate plate 5 and the gate plate through hole of the valve housing I1 vertically upward into the gate plate groove corresponding to the first valve core 2, such as Figure 5 As shown, Figure 6 As shown, align the gate plate groove of the second valve core 4 with the gate plate 5 and install it into the valve housing I1; then install the valve stem 6 with the thread facing downward through the top hole of the valve housing II9 and screw it into the thread of the gate plate 5. The split design of the valve core can well fit with the gate plate 5 made of non-metallic materials, and while achieving non-metallic sealing between the gate plate 5 and the valve core, it also effectively reduces the defective rate when manufacturing the gate valve and ensures that the flow rate when the valve is opened is not affected.

[0053] The valve housing Ⅰ1 and the valve housing Ⅱ9 can be combined into a finished valve housing in a variety of ways. For example, the valve housing Ⅰ1 and the valve housing Ⅱ9 are combined into a finished valve housing by laser welding. The valve housing Ⅰ1 and the valve housing Ⅱ9 can be cut and cut into thin steel pipes according to the valve specifications and sizes, and a saddle mouth with the same diameter as the valve housing Ⅱ9 can be cut on the valve housing Ⅰ1. A saddle mouth that matches the valve housing Ⅰ1 is also cut on one end of the valve housing Ⅱ9. The other end is shrink-molded according to the size of the valve stem 6 and the gate plate 5, and then welded with the valve housing Ⅰ1 to form a finished valve housing.

[0054] Alternatively, the valve housing I1 and the valve housing II9 are integrally formed. According to the specifications of the valve, a thin steel plate can be integrally stamped and cut into a sheet, the sheet can be bent into shape, and then welded into a finished valve housing; or, the valve housing can be divided into multiple parts, and thin steel plates can be respectively stamped and cut into sheets, each sheet can be bent into shape, and then welded to form a finished valve housing.

[0055] The valve housing II 9 can also be welded in two parts. The valve housing II 9 is divided into a lower part with a saddle mouth, a middle part with a shrink pipe, and an upper part of a vertical pipe. Figure 8 As shown, they are made separately and then connected by welding or the like. The valve housing II 9 can also be Fig. 9 There are many ways to design the split parts.

[0056] The valve housing Ⅰ1 and the valve housing Ⅱ9 are made by cutting stainless steel pipes. The thickness of the thin steel plate or the wall thickness of the thin steel pipe used in the valve housing is less than 1.5 mm, and the material is stainless steel. The valve housing is made of thin steel plates or steel pipes, which are formed by integral extrusion, or multiple parts extrusion, cutting, and welding. It saves more materials than casting, forging or using thick-walled pipes, and there is no environmental pollution in the casting or forging process, which is environmentally friendly and hygienic; it has high strength, no defects such as pores and impurities, and the valve is not easy to break and leak. The valve housing composed of multiple components is combined by laser welding, and the valve housing and the interface are also connected by laser welding. Compared with threaded connections, welding connections are more reliable and faster, and have lower manufacturing and labor costs.

[0057] The valve core can be made of metal material or non-metal material. Preferably, the valve core is made of non-metal material so that it can better perform interference fit with the gate plate 5, and can also reduce the wear of the gate plate 5 made of non-metal material when it moves up and down relative to the metal valve core; it is more corrosion-resistant, which solves the problem of the metal front-gate valve used at the front end of the water meter being rusted and stuck due to the small number of switching times, and the problem of sealing failure, thereby improving the service life. At the same time, the first valve core 2 is made of non-metal material and can perform interference fit with the valve housing Ⅰ1 to achieve non-metallic sealing. However, considering that the tube body used in the valve housing Ⅰ1 may be irregular, or there may be deviations during injection molding, etc., Figure 3As shown, a first sealing ring 3 is embedded in the annular groove of the first valve core 2 to achieve non-metallic sealing with the valve housing Ⅰ1, thereby ensuring the sealing between the valve core and the valve housing.

[0058] Of course, the first valve core 2 made of metal material may also be interference-fitted with the valve housing Ⅰ1 through structures such as the first sealing ring 3.

[0059] The second valve core 4 can be fixed in position by the water inlet end nut 10, or can be fixed in position by the positioning member and the valve housing Ⅰ1. As the second valve core 4 is fixed in position, it can cooperate with the first valve core 2 to squeeze the gate plate 5, thereby achieving an interference fit between the valve core and the gate plate 5.

[0060] The first valve core 2 is provided with a positioning structure adapted to the second valve core 4, such as Figure 6 As shown, it is convenient to assemble the first valve core 2 and the second valve core 4, and is conducive to interference fit with the gate plate 5. Figure 2 As shown in Figures 3 or 4, a first end of the second valve core 4 is provided with a positioning groove 12, which is matched with the positioning protrusion 14 of the first valve core 2. Vice versa.

[0061] Of course, the second valve core 4 can also be fixed in position by a positioning device. For example, a positioning protrusion is provided on the second valve core 4, and a sliding groove with a larger inner part and a smaller outer part is provided at the corresponding position of the first valve core 2. The positioning protrusion of the second valve core 4 enters the sliding groove and rotates to fix its position.

[0062] You can also Figure 4 As shown in Fig. 7, the second end of the second valve core 4 is provided with a positioning device 13 for positioning and connecting with the water inlet end nut 10, so as to apply stable pressure to the second valve core 4 after the water inlet end nut 10 is fixed to the valve housing Ⅰ1, thereby promoting interference fit between the gate plate 5 and the valve core.

[0063] The valve stem 6 is made of non-metallic material, and a valve stem head 7 made of metal material is provided at its upper end. Figure 1 As shown, the valve stem 6 can be integrally formed with the valve stem 6 during injection molding. Injection molding the metal valve stem head 7 and the non-metal valve stem 6 as one body can enhance the torque that the valve stem 6 can withstand when the valve is opened and closed, and avoid damage to the non-metallic valve stem 6. The valve stem head 7 can be a triangular head or other styles, which is compatible with the key end.

[0064] The valve stem 6 is provided with a second sealing ring 8 .

[0065] The valve stem 6 is threadedly connected with the gate plate 5, and drives the gate plate 5 to move up and down by rotation. Of course, the valve stem 6 can also drive the gate plate to move up and down by other existing methods such as electric.

[0066] like Figure 1As shown, the gate valve before the meter further includes an inlet nut 11 and an outlet nut 10, which are respectively fixedly connected to the two ends of the valve housing Ⅰ1. The positions of the inlet nut 11 and the outlet nut 10 on the valve housing Ⅰ1 can be interchanged.

[0067] The non-metallic material used for the valve core and valve accessories may be engineering plastics.

[0068] The manufacturing method of the front gate valve comprises the following steps:

[0069] The valve housing, valve core, valve accessories and interface are prepared respectively; wherein the first valve core 2 and the second valve core 4 of the valve core are respectively cast and formed by metal materials or respectively injection-molded by non-metallic materials according to the valve flow path diameter; the valve housing Ⅰ1 and the valve housing Ⅱ9 of the valve housing are combined into a finished valve housing; the valve stem 6 and the gate plate 5 of the valve accessories are injection-molded by non-metallic materials according to the valve flow path diameter; the interface includes a water outlet nut 11 and a water inlet nut 10;

[0070] One end of the finished valve housing is welded to the outlet nut 10, and the first valve core 2 is installed into the finished valve housing near the outlet nut 10, and is sealed with the valve housing I1 in a non-metallic manner;

[0071] Put the gate plate 5 into the corresponding notch of the first valve core 2, and make its threaded opening consistent with the axial direction of the valve housing II 9; one end of the gate plate 5 threadedly connected to the valve stem 6 is exposed from the valve housing I 1 through the through hole;

[0072] Put the valve stem 6 into the finished valve housing through the upper end of the valve housing II 9, and connect it with the gate plate 5 by thread;

[0073] Put the second valve core 4 into the valve housing Ⅰ1, with the notch direction corresponding to the gate plate 5, and connect it to the first valve core 2 by positioning;

[0074] The water inlet end nut 10 is connected to the second valve core 4 by positioning so that the gate plate 5 and the valve core have an interference fit, and then the water inlet end nut 10 is welded to the valve housing Ⅰ1.

[0075] The split design of the valve core and the installation sequence can effectively avoid the assembly failure of the gate plate 5 due to improper assembly, so that the valve core and the gate plate 5 have an interference fit to ensure airtightness.

[0076] The valve core and valve housing are manufactured separately, and non-metallic materials are used for injection molding and extrusion molding, which saves more materials than traditional gate valve casting or forging molding, and greatly reduces the processing precision requirements. The first valve core 2 and the second valve core 4 can be integrally injection molded with non-metallic materials according to the valve flow path diameter, or divided into multiple parts for injection molding and then combined molding.

[0077] The steps of preparing the valve housing include: the valve housing I1 and the valve housing II9 are made of thin-walled pipes, or thin-walled seamless pipes or seamed pipes, and are cut by laser cutting; the valve housing I1 is cut with a through hole for the gate to move up and down; the valve housing I1 is cut with a through hole for the gate to move up and down; the lower end of the valve housing II9 is ​​cut with an arc shape matching the outer diameter of the valve housing I1, and the upper end is shrink-molded according to the size of the valve stem and the gate, such as Figure 1 Or, the valve housing II 9 is manufactured by welding in separate parts, and finally laser welded with the valve housing I 1 to form a finished valve housing.

[0078] The arc shape cut out at the lower end of the valve housing II 9 can be Figure 1 The saddle mouth shown is matched with the through hole cut out of the valve housing Ⅰ1, and is assembled into a finished valve housing by laser welding to ensure airtightness. The upper end of the valve housing Ⅱ9 is matched with the valve stem 6 and the key end, and the lower end is matched with the through hole of the valve housing Ⅰ1, and is sealed by welding.

[0079] To prepare the interface, the steel pipe or steel pipe profile can be cut into segments according to the valve specifications, the steel pipe segments are cold-pressed into shape by a mold, and the inner hole of the steel pipe is tapped into a thread matching the external pipeline joint, thereby completing the preparation of the water outlet nut 11 and the water inlet nut 10. The steel pipe profile used in the interface can be a regular polygonal stainless steel pipe profile.

[0080] Both ends of the second valve core 4 are connected to the first valve core 2 and the water inlet end nut 10 respectively through concave and convex positioning; the two ends of the valve housing Ⅰ1 are laser welded to the water inlet end nut 10 and the water outlet end nut 11 respectively. Compared with threaded connection, welding connection has more reliable sealing, faster speed, and lower manufacturing and labor costs.

[0081] The valve stem head 7 at the upper end of the valve stem 6 is made of metal material and is integrally formed with the valve stem 6 during injection molding. The combination of metal and non-metal increases the strength and durability of the valve stem 6.

[0082] The above-mentioned method for manufacturing a front gate valve without threaded connection does not require post-processing such as turning, milling, grinding, and heat treatment. It has fewer tooling equipment and processing steps, simple manufacturing process, low manufacturing cost, and no waste liquid and waste chips are generated during the processing. It is safe, hygienic, and environmentally friendly, and has good market application prospects.

[0083] The fixed connection not specifically mentioned above may be a connection method such as riveting, welding, bolt connection, etc., and the movable connection may be a connection method such as hinged connection.

Claims

1. A pre-meter gate valve, comprising a valve housing, a valve core and valve accessories, wherein the valve accessories include a valve stem (6) and a gate plate (5), so that the gate plate (5) can be moved up and down by rotating the valve stem (6) to control the opening and closing of the gate valve; the valve housing is provided with a through hole for the gate plate (5) to move up and down; and the characteristics are: The valve housing comprises a valve housing I (1) and a valve housing II (9); the valve housing II (9) is matched with the valve stem (6) and the gate plate (5), and the lower end of the valve housing II (9) is matched with the through hole of the valve housing I (1); The valve core and the valve housing Ⅰ(1) are non-metallic sealed; The gate plate (5) is made of non-metallic material and is interference-fitted with the pores of the valve core to control the opening and closing of the gate valve.

2. The gate valve before the meter according to claim 1, characterized in that: The valve housing I (1) and the valve housing II (9) are assembled into a finished valve housing by laser welding; or, the valve housing I (1) and the valve housing II (9) are integrally formed; the valve housing II (9) is formed by separate welding.

3. The pre-meter gate valve according to claim 1 or 2, characterized in that: The valve housing I (1) and the valve housing II (9) are made by cutting stainless steel pipes.

4. The pre-meter gate valve according to claim 1, characterized in that: The valve core is of split design, comprising a first valve core (2) and a second valve core (4) arranged in the valve housing I (1); the gate plate (5) is interference fit with the gaps between the first valve core (2) and the second valve core (4).

5. The gate valve before the meter according to claim 4, characterized in that: The gate plate (5) is arranged in a finished valve housing formed by combining the valve housing II (9) and the valve housing I (1).

6. The gate valve before the meter according to claim 5, characterized in that: The valve core is made of non-metallic material; the first valve core (2) is provided with a positioning structure matched with the second valve core (4); the annular groove of the first valve core (2) is embedded with a first sealing ring (3) to achieve non-metallic sealing with the valve housing I (1).

7. The gate valve before the meter according to claim 6, characterized in that: The first end of the second valve core (4) is provided with a positioning groove (12) which is matched with the positioning protrusion (14) of the first valve core (2).

8. The gate valve before the meter according to claim 6, characterized in that: The second end of the second valve core (4) is provided with a positioning device (13) for positioning and connecting with the water inlet end nut (10).

9. The gate valve before the meter according to claim 4, characterized in that: The valve stem (6) is made of non-metallic material, and a valve stem head (7) made of metal material is provided at its upper end, which is integrally formed with the valve stem (6) during injection molding; the valve stem (6) is provided with a second sealing ring (8); the valve stem (6) is threadedly connected to the gate plate (5), and drives the gate plate (5) to move up and down by rotation.

10. The pre-meter gate valve according to claim 1, characterized in that: It also includes a water inlet nut and a water outlet nut, which are respectively fixedly connected to the two ends of the valve housing I (1).

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