Cavitation-resistant multifunctional water pump control valve

Abstract

The utility model provides an anti-cavitation multifunctional water pump control valve, a slow-closing valve plate plug is arranged at the water flow passing position between a slow-closing valve plate and a valve plate, and in the valve closing process after a pump is stopped, when the valve plate is closed and the slow-closing valve plate is not closed, the slow-closing valve plate plug is plugged into the slow-closing valve plate plug, and the slow-closing valve plate plug is plugged into the slow-closing valve plate plug. The water flow behind the valve passes through the slow closing valve plate plug and then enters the inlet end of the water pump control valve; specifically, a slow-closing valve plate plug is fixed on the slow-closing valve plate, a through hole in the slow-closing valve plate plug guides outside water to regularly enter the position below the valve plate, sheet-shaped water flow in the later period of closing of the valve is changed into small columnar water flow, turbulent flow is reduced, and therefore cavitation is reduced. The defect that after a valve plate of an existing water pump control valve is closed and a slowly-closed valve plate is not closed, the valve plate, the slowly-closed valve plate and a valve rod are damaged due to the fact that the water flow speed is large, the pressure descending gradient is large, and the generated strong cavitation effect is generated is overcome. And the technical problem that when the valve is in the working conditions of high pressure, poorer water quality and more silt, high-pressure water carries the silt to abrade the valve rod, so that the valve rod is damaged is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to valve technical field more particularly, relate to a multifunctional water pump control valve of anti cavitation. BACKGROUND

[0002] Multifunctional water pump control valve is the power transmission equipment that three functions of electric valve, check valve and water hammer eliminator are fused in a body, can realize the slow opening, full opening, quick closing, slow closing, cut-off etc. Multifunctional control of water pump outlet, and action is completely interlocked with water pump, will not produce misoperation, safe and reliable, when water pump starts and stops, the pressure change of medium before and after valve is ingeniously used to control power, so that the valve automatically acts according to the requirement of water pump operating procedure, and no special person is needed to operate, is widely installed in the water taking, water sending, submerging, sewage pump house and the conveying system of petroleum, chemical fluid in the field such as municipal, building, steel, metallurgy, petroleum, chemical industry, coal gas (natural gas), food, medicine, power station, nuclear power, water conservancy and irrigation etc. The common structure of multifunctional water pump control valve under medium-high pressure is as shown in Figure 3 The valve body of multifunctional water pump control valve includes valve plate and slow closing valve plate, when the valve is closed, the valve plate is closed first 90%, and the slow closing valve plate is closed slowly, and the slow closing time is adjusted in the range of 3-120S.

[0003] Under general working condition, multifunctional water pump control valve is used well, and is highly praised by users. Most valves are used well after 20 years, and only part of sealing elements can be replaced. However, some valves, especially used under high pressure, poor water quality and more silt working condition, after pump stops, the valve plate is closed, and the slow closing valve plate has not been closed, because the valve plate is closed quickly, the pressure difference between the inlet end and the outlet end of the valve is large, water flows from the outlet end of the multifunctional water pump control valve into the inlet end, and water flows through the place of valve plate, slow closing valve plate and valve rod, because the water flow speed is large, the pressure drop gradient is large, which causes strong cavitation effect, damages the valve plate, slow closing valve plate and valve rod, and secondly, high pressure water carries silt, which causes wear of valve rod, slow closing valve and valve plate, and loses the function.

[0004] The utility model provides a multifunctional water pump control valve, solves the problem that impurities in the prior art water pump can affect the use performance of the water pump, and water hammer effect generated when the valve is opened can cause damage to the water pump. A filter device is arranged at the inlet of the water inlet channel to filter the medium and absorb the pressure of the medium, thereby reducing the impurities in the medium and the water hammer effect generated when the medium is opened. The utility model discloses a multifunctional water pump control valve with a filtering function, which also has a filter device arranged at the water inlet for filtering silt to prevent the silt from damaging the pressure driving device and slowing down the backflow of the fluid. The above two patents can only filter silt and reduce water hammer effect. Although cavitation is also caused by pressure, the principle of cavitation is completely different from that of water hammer effect. The above two patents cannot reduce the influence of cavitation on the components of the water pump control valve. Utility model content

[0005] The utility model solves the problem that the valve plate is damaged, the slow closing valve plate and the valve rod are damaged due to strong cavitation caused by a large water flow speed and a large pressure drop gradient when the valve plate is closed and the slow closing valve plate has not been closed.

[0006] A multifunctional water pump control valve with cavitation resistance, comprising a valve body, a valve seat, a valve rod, a valve plate and a slow closing valve plate arranged in the valve body, the valve seat is fixed with the valve body, the valve plate and the slow closing valve plate are arranged in sequence above the valve seat, the slow closing valve plate is fixed on the valve rod, and the valve rod passes through the valve plate; a slow closing valve plate plug is arranged at the water flow passage between the slow closing valve plate and the valve plate, so that the water flow at the outlet of the water pump control valve passes through the slow closing valve plate plug and then enters the inlet of the water pump control valve; the slow closing valve plate plug has a mesh arranged through hole for water flow.

[0007] When the pump is stopped, the water flow at the outlet of the multifunctional water pump control valve flows back into the inlet when the valve plate is quickly closed and the slow closing valve plate has not been closed, and the water flow speed is large, the pressure drop gradient is large, and the cavitation effect is strong. The slow closing valve plate plug is arranged, the water flow at the outlet of the water pump control valve passes through the slow closing valve plate plug with a mesh arranged through hole first, and then enters the inlet of the water pump control valve, the slow closing valve plate plug has a mesh arranged through hole to guide the outside water (water at the outlet of the water pump control valve) to enter the valve plate below in a standard manner, the sheet-shaped water flow in the later stage of valve closing is changed into small columnar water flow, and the turbulence is reduced, so that the cavitation is reduced.

[0008] Further, the slow closing valve plate plug is fixed on the slow closing valve plate and sleeved on the valve rod, and a gap is formed between the slow closing valve plate plug and the valve rod. The slow closing valve plate plug is fixed on the slow closing valve plate, and the slow closing valve plate plug and the slow closing valve plate move together with the valve rod. The slow closing valve plate plug is sleeved on the valve rod, so that the direct scouring of water flow on the valve rod and the slow closing valve plate is blocked, and the cavitation damage is reduced. Meanwhile, the slow closing valve plate plug blocks the direct friction of particles such as silt on the valve rod.

[0009] Further, one end of the slow closing valve plate plug is welded and fixed on the slow closing valve plate. Alternatively, the slow closing valve plate plug and the slow closing valve plate are integrated.

[0010] Further, the outer diameter of the slow closing valve plate plug is smaller than the diameter of the valve plate central hole. One end of the slow closing valve plate plug is fixed on the slow closing valve plate. When the slow closing valve plate is closed, the other end of the slow closing valve plate plug extends into the valve plate central hole.

[0011] Further, the length of the slow closing valve plate plug is longer than the opening of the valve, so that when the valve plate is closed and the slow closing valve plate is not closed, the end of the slow closing valve plate plug that is not fixed on the slow closing valve plate is still located in the valve plate central hole. The opening of the valve refers to the stroke of the valve plate when the valve is opened. During the opening and use of the valve, the valve plate and the slow closing valve plate are always attached together due to the pressure of the inlet water flow. Only the valve plate is instantaneously separated from the slow closing valve plate (the slow closing valve plate is slowly closed after the valve plate is closed).

[0012] Further, the slow closing valve plate central hole is a three-layer stepped hole, which includes a hole one, a hole two and a hole three with decreasing inner diameters. The plane outside the hole one is used to cooperate with the convex sealing surface on the valve plate. The hole two is used to cooperate with the slow closing valve plate plug, and the inner diameter of the hole two is equal to the outer diameter of the slow closing valve plate plug. The hole three is used for the valve rod to pass through and is connected with the valve rod by screw threads. After the pump is stopped, the valve plate is closed first, and then the slow closing valve plate is slowly closed. The prior art is provided with a convex sealing surface on the end of the valve plate facing the slow closing valve plate, and a plane on the slow closing valve plate is adapted to the convex sealing surface. When the slow closing valve plate is completely closed, the convex sealing surface cooperates with the plane on the slow closing valve plate to seal.

[0013] Further, the through hole is a tapered hole, and the smaller end of the tapered hole is located at the inner side of the slow closing valve plate plug. Cavitation is mainly caused by water vaporization. When water flows from a small area to a large area, the water pressure gradually decreases, and when it decreases to a critical point, it will vaporize, which produces a certain amount of energy and damages the surface of the contacted object. On the contrary, when water flows from a large area to a small area, the water pressure gradually increases, so that the formation of cavitation is reduced. Therefore, the through hole on the slow closing valve plate plug of the application adopts a tapered hole, and the smaller end of the hole is located at the inner side of the slow closing valve plate plug, so that when the water flows through the through hole, not only a water column can be formed, but also the formation of cavitation can be reduced. That is, the anti-cavitation ability of the tapered hole is stronger than that of the cylindrical hole.

[0014] Further, the through hole is connected with the slow closing valve plate plug in a circular arc transition mode.

[0015] Further, the diameter of the through hole is 6-12mm.

[0016] The valve plate center hole in the application refers to the hole through the center of the valve plate and the valve rod. The slow closing valve plate center hole refers to the hole through the center of the slow closing valve plate and the valve rod.

[0017] The utility model has the following beneficial effects:

[0018] The anti-cavitation multifunctional water pump control valve has a slow closing valve plate plug arranged at the water flow passing between the slow closing valve plate and the valve plate, so that the water flow at the outlet of the water pump control valve passes through the slow closing valve plate plug and then enters the inlet of the water pump control valve. Specifically, a slow closing valve plate plug is fixed on the slow closing valve plate, and the through hole on the slow closing valve plate plug guides the external water to enter the lower valve plate in a standardized manner, changes the sheet-shaped water flow in the later stage of valve closing into small columnar water flow, reduces turbulence, and thus reduces cavitation. Moreover, the slow closing valve plate plug can block the direct scouring of the water flow on the valve rod, reduce cavitation damage, and block the direct friction of particles such as silt on the valve rod. The technical problems of damage to the valve plate, the slow closing valve plate and the valve rod caused by cavitation due to the large water flow speed and large pressure drop gradient when the valve plate is closed and the slow closing valve plate is not closed are solved. The technical problem of wear of the valve rod caused by high-pressure water carrying silt is also solved. Compared with the traditional multifunctional water pump control valve, the application range of the multifunctional water pump control valve is expanded, and the service life of the multifunctional water pump control valve under the condition of high pressure and poor water quality is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0020] Figure 1 Existing structural diagram of a multi-functional water pump control valve;

[0021] Figure 2 This is a structural diagram of the anti-cavitation multifunctional water pump control valve of this application;

[0022] Figure 3 This is a structural diagram of the slow-closing valve plate plug;

[0023] Figure 4 Diagram showing the fit between the slow-closing valve plate plug and the slow-closing valve plate;

[0024] Figure 5 This is a cross-sectional view of the slow-closing valve plate plug.

[0025] The serial numbers are: 1-valve body, 2-valve seat, 3-valve stem, 4-valve plate, 5-slow-closing valve plate, 6-slow-closing valve plate plug, 6a-through hole, 6b-one end of slow-closing valve plate plug, 6c-the other end of slow-closing valve plate plug, 7-hole one, 8-hole two, 9-hole three, 10-outlet, 11-inlet. Detailed Implementation

[0026] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0027] Example 1

[0028] A multi-functional water pump control valve resistant to cavitation, such as Figure 2 As shown, the valve includes a valve body 1 and a valve seat 2, valve stem 3, valve plate 4, and slow-closing valve plate 5 disposed within the valve body 1. The valve seat 2 is fixed to the valve body 1. The valve plate 4 and slow-closing valve plate 5 are sequentially disposed above the valve seat 2. The slow-closing valve plate 5 is fixed to the valve stem 3, and the valve stem 3 passes through the valve plate 4. A slow-closing valve plate plug 6 is disposed at the water flow passage between the slow-closing valve plate 5 and the valve plate 4, so that the water flow from the outlet 10 of the water pump control valve passes through the slow-closing valve plate plug 6 before entering the inlet 11 of the water pump control valve. Figure 3 As shown, the slow-closing valve plate plug 6 has mesh-like through holes 6a for water flow. The slow-closing valve plate plug 6 is cylindrical, and the through holes 6a are cylindrical. The slow-closing valve plate plug 6 is fixed to the slow-closing valve plate 5 by welding and is sleeved on the valve stem 3, with a gap between the slow-closing valve plate plug 6 and the valve stem 3.

[0029] like Figure 2The outer diameter of the slow closing valve plate plug 6 is smaller than the diameter of the central hole of the valve plate 4. One end 6b of the slow closing valve plate plug is fixed to the slow closing valve plate 5. When the slow closing valve plate 5 is closed, the other end 6c of the slow closing valve plate plug extends into the central hole of the valve plate 4. The length of the slow closing valve plate plug 6 is longer than the opening of the valve. When the valve plate 4 is closed and the slow closing valve plate 5 is not closed, the end of the slow closing valve plate plug 6 that is not fixed to the slow closing valve plate 5 is still in the central hole of the valve plate 4.

[0030] As shown in Figure 4 The central hole of the slow closing valve plate 5 is a three-layer stepped hole, which includes hole one 7, hole two 8 and hole three 9 with decreasing inner diameters. The flat surface outside hole one 7 is used to cooperate with the protruding sealing surface on the valve plate 4. Hole two 8 is used to cooperate and connect with the slow closing valve plate plug 6. The inner diameter of hole two 8 is equal to the outer diameter of the slow closing valve plate plug 6. Hole three 9 is used for the valve stem 3 to pass through and is connected with the valve stem 3 by threads.

[0031] As shown in Figure 1 The valve plate 4 and the slow closing valve plate 5 in the figure are in the closed state. In actual application, when the water pump is closed, the valve plate 4 is immediately closed and the slow closing valve plate 5 is slowly closed. The water at the valve outlet 10 enters the valve inlet 11 below the valve plate 4 through the space between the slow closing valve plate 5 and the valve plate 4 and the central hole of the valve plate 4. The cavitation effect directly acts on the slow closing valve plate 5, the valve plate 4 and the valve stem 3 through which the water flows. The present application sets a slow closing valve plate plug 6 at the water flow passage of the existing multifunctional water pump control valve. The water first passes through the slow closing valve plate plug 6 with a mesh-shaped arrangement of through holes 6a and then enters the inlet 11 of the water pump control valve. The slow closing valve plate plug 6 has a mesh-shaped distribution of through holes 6a. The through holes 6a on the slow closing valve plate plug 6 guide the water at the outlet 10 to enter below the valve plate 4, changing the sheet-shaped water flow in the later stage of valve closing into small columnar water flow, reducing turbulence and thus reducing cavitation. The slow closing valve plate plug 6 is sleeved on the valve stem 3, and the length of the slow closing valve plate plug 6 is longer than the opening of the valve (as long as it is slightly longer). The positions of the valve stem 3 that are originally directly contacted by the cavitation effect are all wrapped by the slow closing valve plate plug 6. The water flow that washes on the valve stem 3 has become columnar water flow, not only reducing the influence of the cavitation effect on the valve stem 3, but also blocking the high-pressure washing of mud and sand on the valve stem 3. The service life and application range of the multifunctional water pump control valve are improved.

[0032] Example 2

[0033] As shown in Figure 2As shown, a multi-functional water pump control valve with anti-cavitation properties includes a valve body 1 and a valve seat 2, a valve stem 3, a valve plate 4, and a slow-closing valve plate 5 disposed within the valve body 1. The valve seat 2 is fixed to the valve body 1. The valve plate 4 and the slow-closing valve plate 5 are sequentially disposed above the valve seat 2. The slow-closing valve plate 5 is fixed to the valve stem 3, and the valve stem 3 passes through the valve plate 4. A slow-closing valve plate plug 6 is disposed at the water flow passage between the slow-closing valve plate 5 and the valve plate 4, so that the water flow from the outlet 10 of the water pump control valve passes through the slow-closing valve plate plug 6 before entering the inlet 11 of the water pump control valve. The slow-closing valve plate plug 6 has mesh-arranged through holes 6a for water flow. The slow-closing valve plate plug 6 is cylindrical and is fixed to the slow-closing valve plate 5 and sleeved on the valve stem 3, with a gap between the slow-closing valve plate plug 6 and the valve stem 3. The slow-closing valve plate 5 and the slow-closing valve plate plug 6 are an integrated structure.

[0034] like Figure 2 As shown, the outer diameter of the slow-closing valve plug 6 is smaller than the diameter of the central hole of the valve plate 4. One end 6b of the slow-closing valve plug is fixed to the slow-closing valve plate 5. After the slow-closing valve plate 5 is closed, the other end 6c of the slow-closing valve plug extends into the central hole of the valve plate 4. The length of the slow-closing valve plug 6 is longer than the opening of the valve, so that when the valve plate 4 is closed and the slow-closing valve plate 5 is not closed, the end of the slow-closing valve plug 6 that is not fixed to the slow-closing valve plate 5 is still located in the central hole of the valve plate 4. This arrangement ensures that the water flow from the outlet 10 to the inlet 11 is completely surrounded and covered by the slow-closing valve plug 6.

[0035] like Figure 4 As shown, the central hole of the slow-closing valve plate 5 is a three-tiered stepped hole, which includes three holes with inner diameters decreasing from large to small: hole 7, hole 8, and hole 9. The outer surface of hole 7 is used to mate with the raised sealing surface on the valve plate 4. Hole 8 is used to mate with the slow-closing valve plate plug 6, and the inner diameter of hole 8 is equal to the outer diameter of the slow-closing valve plate plug 6. Hole 9 is used for the valve stem 3 to pass through, and is connected to the valve stem 3 by a thread.

[0036] The difference between Example 2 and Example 1 is that in Example 2, the slow-closing valve plate plug 6 and the slow-closing valve plate 5 are an integrated structure, while in Example 1, the slow-closing valve plate plug 6 and the slow-closing valve plate 5 are welded and fixed.

[0037] Example 3

[0038] A multi-functional water pump control valve resistant to cavitation, such as Figure 2As shown, it comprises a valve body 1, a valve seat 2 arranged in the valve body 1, a valve stem 3, a valve plate 4 and a slow closing valve plate 5, the valve seat 2 is fixed with the valve body 1, the valve plate 4 and the slow closing valve plate 5 are arranged in sequence above the valve seat 2, the slow closing valve plate 5 is fixed on the valve stem 3, and the valve stem 3 passes through the valve plate 4; A slow closing valve plate plug 6 is arranged between the slow closing valve plate 5 and the valve plate 4 to make the water flow through the slow closing valve plate plug 6 before entering the inlet 11 of the water pump control valve from the outlet 10 of the water pump control valve; The slow closing valve plate plug 6 has a mesh arranged through hole 6a for water flow. The slow closing valve plate plug 6 is conical, the slow closing valve plate plug 6 is fixed with the slow closing valve plate 5 and is sleeved on the valve stem 3, and the slow closing valve plate plug 6 has a gap with the valve stem 3. One end of the slow closing valve plate plug 6 is welded and fixed with the slow closing valve plate 5.

[0039] As shown in Figure 2 The outer diameter of the slow closing valve plate plug 6 is smaller than the diameter of the center hole of the valve plate 4, one end 6b of the slow closing valve plate plug is fixed with the slow closing valve plate 5, and the other end 6c of the slow closing valve plate plug extends into the center hole of the valve plate 4 after the slow closing valve plate 5 is closed. The length of the slow closing valve plate plug 6 is longer than the opening of the valve, so that when the valve plate 4 is closed and the slow closing valve plate 5 is not closed, the end of the slow closing valve plate plug 6 which is not fixed with the slow closing valve plate 5 is still located in the center hole of the valve plate 4.

[0040] As shown in Figure 4 The center hole of the slow closing valve plate 5 is a three-layer stepped hole, which comprises a hole one 7, a hole two 8 and a hole three 9 with decreasing inner diameters, a flat surface outside the hole one 7 is used to cooperate with the sealing surface of the convex on the valve plate 4, the hole two 8 is used to cooperate and connect with the slow closing valve plate plug 6, and the inner diameter of the hole two 8 is equal to the outer diameter of the slow closing valve plate plug 6; The hole three 9 is used for the valve stem 3 to pass through and is connected with the valve stem 3 by screw thread.

[0041] The through hole 6a is a conical hole, and the smaller end of the conical hole is located on the inner side of the slow closing valve plate plug 6. The diameter of the through hole 6a is 6-12mm.

[0042] The difference between the embodiment 3 and the embodiment 1 is that the through hole 6a on the slow closing valve plate plug 6 in the embodiment 3 is a tapered hole, and the through hole 6a in the embodiment 1 is a cylindrical hole. The tapered hole has stronger anti-cavitation ability than the cylindrical hole, and the specific principle is as follows: cavitation is mainly caused by water vaporization. When water flows from a small area to a large area, the water pressure will gradually decrease, and when it decreases to a critical point, it will vaporize, which produces a certain amount of energy to damage the surface of the object contacted. On the contrary, when water flows from a large area to a small area, the water pressure will gradually increase, so that the formation of vaporization can be reduced. Therefore, the through hole 6a on the slow closing valve plate plug 6 adopts a tapered hole, and the smaller end of the hole diameter is located on the inner side of the slow closing valve plate plug 6, so that when the water flows through the through hole 6a, not only a water column can be formed, but also the formation of vaporization can be reduced.

[0043] When the water pump is closed, the valve plate 4 is immediately closed, and the slow closing valve plate 5 has not been closed, the water flow through the valve plate 4, the slow closing valve plate 5 and the valve rod 3, the water flow speed is large, the pressure drop gradient is large, the water flow through the tapered hole on the slow closing valve plate plug 6, the water flow becomes many columnar water flows and flows into the slow closing valve plate plug 6, the water flow through the valve plate 4, the slow closing valve plate 5, the valve rod 3 are all covered in the slow closing valve plate plug 6, the slow closing valve plate plug 6 reduces the influence of cavitation on the valve plate 4, the slow closing valve plate plug 6 and the valve rod 3, further optimizes that the through hole 6a is a tapered hole, further reduces the influence of cavitation. At the same time, when the valve is in the working condition of poor water quality and large amount of mud, a large amount of mud is also blocked outside the slow closing valve plate plug 6, avoiding the direct friction of the mud and other particles on the valve rod 3, expanding the application range of the multifunctional water pump control valve, and improving the service life of the multifunctional water pump control valve in the case of high pressure and poor water quality. The water flow of the outlet 10 flows into the inlet 11 of the valve from the slow closing valve plate plug 6.

[0044] The above only describes the preferred embodiments of the utility model, and is not used to limit the utility model. For those skilled in the art, the utility model can have various changes and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be included in the scope of the utility model.

Claims

1. A multifunctional anti-cavitation water pump control valve, comprising a valve body and a valve seat, a valve rod, a valve plate and a slow closing valve plate arranged in the valve body, the valve seat is fixed with the valve body, the valve plate and the slow closing valve plate are arranged in sequence above the valve seat, the slow closing valve plate is fixed on the valve rod, and the valve rod passes through the valve plate; characterized in that, The water flow between the slow closing valve plate and the valve plate is provided with a slow closing valve plate plug, so that the water flow at the outlet of the water pump control valve passes through the slow closing valve plate plug and then enters the inlet of the water pump control valve; the slow closing valve plate plug is provided with a mesh arranged through hole for water flow.

2. The multifunctional gas-etching resistant water pump control valve according to claim 1, characterized by, The slow closing valve plate plug is fixed with the slow closing valve plate and is sleeved on the valve rod, and a gap is formed between the slow closing valve plate plug and the valve rod.

3. The multifunctional gas-etching resistant water pump control valve according to claim 2, characterized by, One end of the slow closing valve plate plug is welded and fixed with the slow closing valve plate.

4. The multifunctional gas-etching resistant water pump control valve according to claim 2, characterized by, The slow closing valve plate plug and the slow closing valve plate are integrated.

5. The multifunctional, cavitation-resistant water pump control valve according to claim 3 or 4, characterized in that The outer diameter of the slow closing valve plate plug is smaller than the diameter of the central hole of the valve plate, one end of the slow closing valve plate plug is fixed with the slow closing valve plate, and the other end of the slow closing valve plate plug extends into the central hole of the valve plate when the slow closing valve plate is closed.

6. The multifunctional gas-etching resistant water pump control valve according to claim 5, characterized by, The length of the slow closing valve plate plug is longer than the opening of the valve, so that when the valve plate is closed and the slow closing valve plate is not closed, the end of the slow closing valve plate plug which is not fixed with the slow closing valve plate is still located in the central hole of the valve plate.

7. The multifunctional, cavitation-resistant water pump control valve according to claim 3 or 4, characterized in that The central hole of the slow closing valve plate is a three-layer stepped hole, which includes hole one, hole two and hole three with the inner diameter from large to small, the plane outside hole one is used for cooperating with the convex sealing surface on the valve plate, hole two is used for cooperating with the slow closing valve plate plug, and the inner diameter of hole two is equal to the outer diameter of the slow closing valve plate plug; hole three is used for the valve rod to pass through and is connected with the valve rod by screw thread.

8. The multifunctional gas-etching resistant water pump control valve according to claim 1, wherein The through hole is a tapered hole, and the smaller end of the tapered hole is located on the inner side of the slow closing valve plate plug.

9. The multifunctional gas-etching resistant water pump control valve according to claim 1, wherein The through hole is connected with the slow closing valve plate plug in a circular arc transition mode.

10. The multifunctional gas-etching resistant water pump control valve according to claim 1, characterized by, The diameter of the through hole is 6-12mm.

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