A pressure reducing valve whose output pressure fluctuates positively with output flow fluctuations

Abstract

The application discloses a pressure reducing valve with positive fluctuation of output pressure with output flow, comprising a pressure reducing valve and a pilot valve, wherein a pressure regulating spring and a stiffness adjustable spring are arranged in the pilot valve, the action of the valve rod of the pressure reducing valve directly pushes the stiffness adjustable spring in the pilot valve, and the stiffness of the stiffness adjustable spring is smaller than that of the pressure regulating spring; the input port of the pressure reducing valve is connected with the control cavity and the inlet of the pilot valve through a connecting pipeline and an adjustable throttle valve, and the output port is connected with the output pressure feedback interface of the pilot valve through a connecting pipeline and a stop valve. The output pressure of the pressure reducing valve positively fluctuates with the output flow, the output pressure is large when the water flow is large, and the output pressure is small when the water flow is small, so that the pressure borne by the whole pipeline system in the water low period is reduced, the pipe leakage and pipe explosion rate are reduced, the reliability of the water supply system is improved, and the maintenance cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of valve technology, and specifically relates to a pressure reducing valve whose output pressure fluctuates positively with the output flow rate. Background Technology

[0002] When fluid flows through a standard pressure reducing valve, the output pressure remains constant regardless of flow fluctuations. This is necessary in most cases, but undesirable in certain situations. For example, when water pressure in the water supply network is too high, pressure reduction is necessary when supplying water to buildings. When using a standard pressure reducing valve, the output pressure after pressure reduction must be equal to or greater than the water pressure during peak water usage. In reality, such high water pressure is not needed during off-peak water usage. However, since the output pressure of the pressure reducing valve does not change with flow fluctuations, the entire pipeline system bears this high pressure during off-peak water usage. This increases the rate of leakage and pipe bursts in the pipeline, especially in lower-level pipelines, wasting energy and resources and increasing maintenance costs. Summary of the Invention

[0003] This invention is designed to address the shortcomings of ordinary pressure reducing valves. Its innovation lies in connecting a pilot valve in series at the top of an ordinary 200X pressure reducing valve. By utilizing the change in the opening degree of the main valve port when the flow rate changes, the opening degree of the pilot valve port is controlled, so that the output pressure of the pressure reducing valve fluctuates positively with the output flow rate and achieves matching.

[0004] The technical solution adopted by this invention to solve the above-mentioned technical problems is a pressure reducing valve whose output pressure fluctuates positively with the output flow rate. The valve includes a pressure reducing valve and a pilot valve. The internal thread of the boss at the top of the upper valve cover of the pressure reducing valve is screwed to the external thread at the lower end of the lower valve body of the pilot valve. After screwing, the vertical center lines of the two valves are aligned. The pilot valve is equipped with a pressure regulating spring and a stiffness adjustable spring. The movement of the pressure reducing valve stem pushes the stiffness adjustable spring in the pilot valve via a push rod, which in turn pushes the pressure regulating spring. The stiffness of the stiffness adjustable spring is less than that of the pressure regulating spring. The structure of the pressure reducing valve is basically the same as that of the 200X type pressure reducing valve. The main difference is that a push rod is provided above the top of the valve stem. An O-ring is provided on the outer diameter of the push rod. The upper end of the push rod is a stepped small shaft with a gasket and a retaining ring for positioning. The pressure reducing valve's input port (pressure P1) is connected to the control chamber and the inlet of the pilot valve via a corresponding connecting pipe and an adjustable throttle valve; the output port (pressure P2) is connected to the pilot valve's output pressure feedback interface via a corresponding connecting pipe and a shut-off valve.

[0005] Furthermore, the structure of the pilot valve is basically the same as that of a common adjustable pressure reducing valve. The main difference is that a sleeve with an outwardly protruding ring at the lower end is provided in the valve cavity of the lower valve body. The top plate of the sleeve has a through hole, and one side of the lower part has a long groove. An adjustable stiffness spring is installed in the inner cavity of the sleeve. The width of the long groove is equivalent to the wire diameter of the adjustable stiffness spring. The lower end of the adjustable stiffness spring is supported on the washer at the top of the push rod, and the spring head is inserted into the long groove on the lower side of the sleeve to prevent the adjustable stiffness spring from rotating. Several spring coils on the upper part of the adjustable stiffness spring are screwed into a spiral groove on the surface of the plunger above the inner hole of the sleeve. The pitch and depth of the spiral groove are adapted to the adjustable stiffness spring.

[0006] Furthermore, the top of the plunger abuts against the top surface of the sleeve. The top of the plunger is provided with an internal hexagonal hole. By rotating the plunger, the number of turns of the stiffness-adjustable spring can be changed, thereby changing the effective number of working turns of the stiffness-adjustable spring and changing its stiffness. The lower end of the pressure regulating spring of the pilot valve is supported on the outer convex ring of the sleeve.

[0007] The working principle of this invention is as follows: When the flow rate through the pressure reducing valve increases, the kinetic energy of the medium itself causes the opening of the main valve port to tend to increase. This causes the main valve core to push the valve stem and push rod upwards. The gasket at the upper end of the push rod compresses the adjustable spring, and through the outer convex ring of the sleeve, it applies force to the pressure regulating spring, increasing the opening of the pilot valve port. This results in an increase in the flow rate of the medium exiting the pilot valve, releasing some pressure in the control chamber. The pressure decreases, and under the action of the pressure difference, the main valve core rises, increasing the opening of the main valve port, and the output pressure P2 increases accordingly. Conversely, when the flow rate through the pressure reducing valve decreases, the opening of the main valve port decreases. The output pressure P2 decreases accordingly; the shut-off valve is closed, no medium flows in the pilot valve port, the pressure in the control chamber increases, and the main valve port is closed, stopping the water supply downstream; as can be seen from the above, the output pressure P2 of the pressure reducing valve of the present invention fluctuates positively with the output flow rate. Therefore, when used in situations where the water supply flow rate changes greatly, the output pressure is high when the water flow rate is high (peak water usage) and low when the water flow rate is low (low water usage), thereby reducing the pressure borne by the entire pipeline system during low water usage, reducing the leakage and burst rate of pipelines, especially low-rise pipelines, improving the reliability of the water supply system, and reducing maintenance costs.

[0008] The output pressure and output flow rate of each specification of pressure reducing valve are matched and correspond one-to-one, and a small change in the pilot valve opening will cause a large change in output pressure. If the push rod directly pushes the pressure regulating spring, the change in the pilot valve opening will inevitably be the same as the change in the main valve opening, causing a large fluctuation in output pressure P2, resulting in a mismatch between output pressure P2 and output flow rate. To achieve matching, the present invention employs the following measure: the movement of the push rod first acts on the stiffness adjustable spring through the shim, and then acts on the pressure regulating spring through the outer convex ring of the sleeve. Since the stiffness of the stiffness adjustable spring is smaller than that of the pressure regulating spring, the force acting on the pressure regulating spring is smaller, resulting in a smaller change in the pilot valve opening. To achieve precise matching, the stiffness of the stiffness adjustable spring can be adjusted to regulate the force acting on the pressure regulating spring. Rotating the plunger causes a portion of the stiffness adjustable spring's coils to enter or exit the plunger's spiral groove, thereby increasing or decreasing the effective working number of the stiffness adjustable spring, thus changing the stiffness of the stiffness adjustable spring.

[0009] The formula for spring stiffness is as follows:

[0010]

[0011] Where: P—Spring stiffness (N / mm)

[0012] d—Spring wire diameter (mm)

[0013] D—Mean diameter of the spring (mm)

[0014] n—Number of effective working turns of the spring

[0015] As can be seen from formula (1), when the effective number of working coils n of the spring increases, the spring stiffness decreases, and when the effective number of working coils of the spring decreases, the spring stiffness increases.

[0016] The beneficial effects of this invention are: it effectively solves the problem that the output pressure of existing pressure reducing valves does not change with flow rate fluctuations. When applied to water supply systems, the entire pipeline system is subjected to high pressure during peak water usage periods, especially during off-peak hours, increasing the leakage and burst rates of pipes, particularly lower-level pipes, wasting energy and resources, and increasing maintenance costs. In contrast, the output pressure of this invention fluctuates positively with the output flow rate. Therefore, it can reduce the pressure of the entire pipeline system during off-peak hours, reducing the leakage and burst rates of pipes, especially lower-level pipes, improving the reliability of the water supply system, and saving maintenance costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of one structure of the pressure reducing valve of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of the pilot valve above the pressure reducing valve of the present invention.

[0019] In the diagram: 1. Pressure reducing valve, 2. Main valve core, 3. Valve stem, 4. Push rod, 5. Pilot valve, 6. Adjustable flow valve, 7. O-ring seal, 8. Boss, 9. Nut, 10. Lower valve body, 11. Sleeve, 12. Piston, 13. Pressure adjusting spring, 14. Stiffness adjustable spring, 15. Retaining ring, 16. Gasket, 17. Shut-off valve, a. Spring head, b. Long groove, A. Inlet, B. Output pressure feedback interface, G. Control chamber, V. Main valve port, V0. Pilot valve port. Detailed Implementation

[0020] The specific implementation of the technical solution of the present invention will be further described below through examples and in conjunction with the accompanying drawings.

[0021] Example 1

[0022] In such Figure 1 In Embodiment 1 shown, a pressure reducing valve whose output pressure fluctuates positively with the output flow rate includes a pressure reducing valve 1, a pilot valve 5, an adjustable flow valve 6, a shut-off valve 17, and several connecting pipes. The external thread at the lower end of the lower valve body 10 of the pilot valve 5 is screwed into the internal thread of the top boss 8 of the upper valve cover of the pressure reducing valve 1. After screwing, the vertical center line of the pressure reducing valve 1 is consistent with the vertical center line of the pilot valve 5. The structure of the pressure reducing valve 1 of this invention is basically the same as that of the 200X type pressure reducing valve. The main difference is that a push rod 4 is provided above the top of the valve stem 3 connecting the main valve core 2. An O-ring seal 7 is provided on the outer diameter of the push rod 4. The upper end of the push rod 4 is a stepped small shaft, on which a gasket 16 is fitted and a retaining ring 15 is used for positioning. The structure of the pilot valve 5 is shown in the figure. Figure 2 As shown, the structure is basically the same as that of a common adjustable pressure reducing valve. The main difference is that a sleeve 11 with an outwardly protruding ring at the lower end is provided in the valve cavity of the lower valve body 10. The top plate of the sleeve 11 has a through hole, and one side of the lower part has a long groove b. The width of the long groove b is equivalent to the wire diameter of the stiffness adjustable spring 14. The stiffness adjustable spring 14 is installed in the inner cavity of the sleeve 11. The lower end of the stiffness adjustable spring 14 is supported on the washer 16 at the top of the push rod 4, and the spring head a is inserted into the long groove b at the lower part of the sleeve 11 to prevent the stiffness adjustable spring 14 from rotating. Several spring coils on the upper part of the stiffness adjustable spring 14 are screwed into the spiral groove on the surface of the plunger 12, which is dynamically matched with the inner hole of the sleeve 11 and located above the inner hole. The pitch and depth of the spiral groove are basically the same as the pitch and wire spacing of the stiffness adjustable spring 14. The top end of the plunger 12 abuts against the top surface of the sleeve 11. Its top end is provided with an internal hexagon blind hole. By rotating the plunger 12, a portion of the turns of the stiffness-adjustable spring 14 can enter or exit the spiral groove, thereby changing the effective working number of turns of the stiffness-adjustable spring 14 and changing its stiffness. The lower end of the pressure regulating spring 13 of the pilot valve 5 is supported on the outer convex ring of the sleeve 11. By rotating the lower valve body 10, the output pressure of the pressure reducing valve 1 at the rated flow can be adjusted. After the requirement is met, it is locked with the nut 9.

[0023] The input port (pressure P1) of the pressure reducing valve 1 is connected to the control chamber G and the inlet A of the pilot valve 5 via the corresponding connecting pipe and the adjustable throttle valve 6; the output port (pressure P2) is connected to the output pressure feedback interface B of the pilot valve 5 via the corresponding connecting pipe and the shut-off valve 17.

[0024] When the pressure reducing valve of the present invention is working, when the flow rate through the pressure reducing valve 1 increases, the kinetic energy of the medium itself causes the opening of the main valve port V to tend to increase. As a result, the main valve core 2 pushes the valve stem 3 and the push rod 4 to move upward. The gasket 16 at the upper end of the push rod 4 compresses the adjustable stiffness spring 14, and the outer convex ring of the sleeve 11 applies force to the pressure regulating spring 13, which increases the opening of the pilot valve port V0, resulting in an increase in the flow rate discharged from the pilot valve 5. The pressure in the control chamber G is released and the pressure drops. Under the action of the pressure difference, the main valve core 2 rises, the opening of the main valve port V increases, and the output pressure P2 increases accordingly. Conversely, when the flow rate through the pressure reducing valve 1 decreases, the opening of the main valve port V decreases, and the output pressure P2 decreases accordingly. As can be seen from the above, the output pressure P2 of the pressure reducing valve of the present invention fluctuates positively with the output flow rate. Therefore, when used in situations with large flow rate changes, such as water supply, the output pressure is high when the water flow is high (peak water usage) and low when the water flow is low (low water usage). This reduces the pressure on the entire pipeline system during low water usage, reduces the leakage and burst rate of pipelines, especially low-rise pipelines, improves the reliability of the water supply system, and reduces maintenance costs.

[0025] The output pressure and output flow of each type of pressure reducing valve are matched and correspond one-to-one. A small change in the opening degree of the pilot valve port V0 will cause a large change in the output pressure. If the push rod 4 directly pushes the pressure regulating spring 13, the change value of the pilot valve port V0 opening will inevitably be consistent with the change value of the main valve port V opening, causing a large fluctuation in the output pressure P2, resulting in a mismatch between the output pressure P2 and the output flow. To achieve a proper match, the present invention employs the following measures: the movement of the push rod 4 first acts on the stiffness-adjustable spring 14 through the washer 16, and then acts on the pressure-adjusting spring 13 through the outer convex ring of the sleeve 11. Since the stiffness of the stiffness-adjustable spring 14 is smaller than that of the pressure-adjusting spring 13, the force acting on the pressure-adjusting spring 13 is relatively small, resulting in a smaller change in the opening degree of the pilot valve port V0. To achieve precise matching, the stiffness of the stiffness-adjustable spring 14 can be adjusted to regulate the force acting on the pressure-adjusting spring 13. Rotating the plunger 12 causes a portion of the turns of the stiffness-adjustable spring 14 to enter or exit the spiral groove of the plunger 12, thereby increasing or decreasing the effective number of working turns of the stiffness-adjustable spring 14 and changing its stiffness.

Claims

1. A pressure reducing valve in which the output pressure fluctuates positively with fluctuations in the output flow, characterized by The pressure reducing valve (1) and the pilot valve (5) are connected by the inner thread of the upper valve cover top end boss (8) of the pressure reducing valve (1) and the outer thread of the lower end of the lower valve body (10) of the pilot valve (5), and the vertical center lines of the two are consistent after the connection, the pilot valve (5) is provided with a pressure regulating spring (13) and a stiffness adjustable spring (14), the action of the valve rod (3) of the pressure reducing valve (1) directly pushes the stiffness adjustable spring (14) in the pilot valve (5), and the stiffness of the stiffness adjustable spring (14) is smaller than the stiffness of the pressure regulating spring (13) of the pilot valve (5); The upper end of the push rod is a stepped small shaft, the stepped small shaft is sleeved with a gasket, and a retaining ring is positioned, the valve cavity of the lower valve body of the pilot valve is provided with a sleeve with an outer convex ring at the lower end, the inner cavity of the sleeve is provided with a stiffness adjustable spring, the lower end of the stiffness adjustable spring is supported on the gasket at the top end of the push rod, and the lower end of the pressure regulating spring of the pilot valve is supported on the outer convex ring of the sleeve.

2. The pressure reducing valve according to claim 1, wherein the output pressure is positively fluctuated in accordance with fluctuation of the output flow rate. An O-shaped sealing ring (7) is arranged on the outer diameter of the push rod (4).

3. The pressure reducing valve according to claim 2, wherein A through hole is arranged on the top plate of the sleeve (11), one side of the lower part has a long slot (b), the width of the long slot (b) is equivalent to the diameter of the stiffness adjustable spring (14), and the spring head (a) is inserted into the long slot (b) on one side of the lower part of the sleeve (11) to prevent the stiffness adjustable spring (14) from rotating; a plurality of spring coils on the upper part of the stiffness adjustable spring (14) are screwed in the spiral groove on the surface of the plunger (12) which is movably arranged in the inner hole of the sleeve (11) and located above the inner hole, and the pitch and depth of the spiral groove are matched with the stiffness adjustable spring (14).

4. The pressure reducing valve according to claim 3, wherein The top end of the plunger (12) abuts against the top surface of the sleeve (11), the top end of the plunger (12) is provided with an inner hexagonal hole, and rotating the plunger (12) can change the number of turns of the stiffness adjustable spring (14), so as to change the effective working turns of the stiffness adjustable spring (14) and change the stiffness of the stiffness adjustable spring (14).

5. The pressure reducing valve according to claim 1, wherein The input port of the pressure reducing valve (1) is connected with the control cavity (G) and the inlet (A) of the pilot valve (5) through the corresponding connecting pipelines and the adjustable throttle valve (6); and the output port is connected with the output pressure feedback interface (B) of the pilot valve (5) through the corresponding connecting pipelines and the stop valve (17).

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