Pressure reducing valve with pressure relief function

Abstract

The utility model relates to the technical field of valve manufacturing, in particular to a pressure reducing valve with a pressure relief function, which comprises a main valve and a pilot valve connected with the main valve, the pilot valve comprises a valve body and a lower valve cover arranged on the lower portion of the valve body, and a pressure relief valve is arranged in a lower cavity formed between the lower valve cover and the valve body. The pressure relief valve comprises a piston arranged below a valve element of the pilot valve, a pressure relief valve port is formed between the valve element and the piston, a through-flow hole is formed in the center of the piston, the lower end of the piston abuts against a lower valve deck through a spring, and a pressure relief pipe is arranged on the side wall below the lower valve deck. The stop valve solves the problems that after a device in the prior art is rapidly closed, a water hammer effect can be generated when the stop valve stops supplying water, or leakage is generated due to sealing failure of a valve port of a main valve after water supply is stopped, then the pressure behind the valve is greatly increased, and the valve behind the valve and a pipeline are leaked or even damaged.

Description

Technical Field

[0001] The utility model relates to the technical field of valve manufacturing, in particular to a pressure reducing valve with a pressure relief function. Background Art

[0002] In the pipeline system for conveying liquids, a pressure reducing valve is generally used to reduce the high pressure before the valve to the required low pressure after the valve, and when the input pressure or output flow fluctuates, the output pressure is kept basically unchanged by utilizing its own structure. However, there is a disadvantage of the common pressure reducing valve, that is, when the stop valve stops supplying water after being quickly closed, water hammer will occur, or after the water supply is stopped, leakage will occur due to a sealing failure of the main valve orifice, etc., resulting in a significant increase in the pressure after the valve, causing the valve and pipeline after the valve to leak or even be damaged. This patent is designed to solve the above technical deficiencies of the existing common pressure reducing valves. Its innovation is that a pressure relief valve is set in the pressure reducing valve or the pilot valve. When the pressure after the valve exceeds the set value, the pressure relief valve opens to release the high-pressure medium to prevent the downstream valves and pipelines from being damaged or leaking due to water hammer impact or high pressure. Utility Model Content

[0003] The utility model provides a pressure reducing valve with a pressure relief function, which solves the problem that the prior art device will produce a water hammer effect when the stop valve stops supplying water after being quickly closed, or leakage occurs due to a sealing failure of the main valve port after the water supply is stopped, thereby causing a significant increase in the pressure behind the valve, causing the valve and pipeline behind the valve to leak, or even be damaged.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A pressure reducing valve with a pressure relief function comprises a main valve and a pilot valve connected to the main valve, the pilot valve comprises a valve body, a lower valve cover arranged at the lower part of the valve body, and a valve core arranged inside the pilot valve, a pressure relief valve is arranged in a lower cavity formed between the lower valve cover and the valve body, the pressure relief valve comprises a piston arranged below the valve core, a valve port of the pressure relief valve is formed between the valve core and the piston, a flow hole is arranged at the center of the piston, a spring is arranged below the piston to abut against the lower valve cover, and a pressure relief pipe is arranged on the side wall below the lower valve cover cylinder.

[0006] Preferably, there is a pit on the lower end surface of the valve core, a sealing gasket is installed in the pit, and the upper end surface of the piston is provided with an upwardly protruding annular edge, and a pressure relief valve port is formed between the annular edge and the sealing gasket.

[0007] Preferably, a spring seat is installed on the bottom surface of the inner hole of the lower valve cover, and a tapered hole is provided on the bottom surface of the spring seat. The lower end surface of the spring abuts against the surface of the spring seat. A screw hole is provided in the center of the bottom of the lower valve cover, and an adjusting screw is threaded in the screw hole. The upper end of the adjusting screw has a cone, and the cone abuts against the tapered hole on the bottom surface of the spring seat.

[0008] Preferably, the lower end surface of the piston and the upper end surface of the spring seat are both annular step surfaces, and the upper and lower end surfaces of the spring are respectively in contact with the step surfaces provided on the lower end surface of the piston and the upper end surface of the spring seat.

[0009] Preferably, the lower valve cover is cylindrical and has an inner hole therein, the piston is arranged in the inner hole, and the outer diameter of the piston is movably matched with the inner hole, and an O-ring is provided between the outer circumference of the piston and the inner hole.

[0010] Preferably, the upper end of the lower valve cover is threadedly connected to the valve body, and a sealing ring is provided between the lower valve cover and the valve body. The pressure relief pipe is arranged on the side wall below the lower valve cover cylinder. The pressure relief pipe is hollow and has a relief hole inside. The pressure relief pipe is connected to the cavity below the piston through the relief hole.

[0011] Preferably, the pilot valve also includes a water inlet and a pressure feedback port, a pilot valve port is formed between the valve body and the valve core of the pilot valve, an inclined through hole is provided on the valve body on one side of the pilot valve port, and the water inlet is connected to the pressure feedback port through the pilot valve port and the through hole.

[0012] Preferably, the through hole communicates with the pressure feedback port and the valve port of the pressure relief valve.

[0013] Preferably, the pressure reducing valve used in the utility model is a 200X pilot pressure reducing valve. This type of pressure reducing valve is commonly used in water supply systems. The utility model only improves the structure of its pilot valve to achieve its invention purpose, which is convenient for modifying the existing water supply system without replacing the main valve of the pressure reducing valve.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The utility model effectively solves the problem that an ordinary pressure reducing valve will produce a water hammer effect when the stop valve stops supplying water after being quickly closed, or that leakage occurs due to a sealing failure of the main valve port after the water supply is stopped, thereby causing a significant increase in the pressure behind the valve, causing the valve and pipeline behind the valve to leak or even be damaged. The utility model provides a pressure reducing valve with a pressure relief function. When the pressure behind the valve exceeds a set value, the pressure relief valve opens to release the high-pressure medium, thereby preventing the downstream valves and pipelines from being damaged or reducing leakage, thereby avoiding damage to the valves or pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The utility model is a schematic cross-sectional view of the overall structure of an embodiment.

[0017] Figure 2 The present invention is a schematic cross-sectional view of the overall structure of a pressure reducing valve in the prior art.

[0018] Figure 3 The present invention is a schematic cross-sectional view of the overall structure of a pilot valve in the prior art.

[0019] Figure 4 It is a cross-sectional view of the overall structure of the device of the utility model, in which the valve port of the pilot valve is open and the valve port of the pressure relief valve is closed.

[0020] Figure 5 It is a cross-sectional view of the overall structure of the device of the utility model, in which the valve port of the pilot valve is closed and the valve port of the pressure relief valve is open.

[0021] In the figure: 1. main valve, 2. main valve core, 3. needle valve, 4. pressure sensing chamber, 5. pilot valve, 6. stop valve, 7. valve core, 8. sealing gasket, 9. piston, 10. O-ring, 11. spring, 12. lower valve cover, 13. spring seat, 14. tightening nut, 15. adjusting screw, 16. prior art pilot valve, A. pressure feedback port, B. water inlet, C. front stop valve, D. rear stop valve, L. pressure relief pipe, V1. main valve port, V2. pilot valve port, V3. pressure relief valve port, a. discharge hole, b. flow hole, c. inner hole, e. through hole. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] In the pipeline system for conveying liquids, pressure reducing valves are generally used to reduce the high pressure before the valve to the required low pressure after the valve, and when the input pressure or output flow fluctuates, the output pressure is kept basically unchanged by using its own structure. Figure 2 ) is used as an example to illustrate the structure of the utility model. This valve mainly includes a main valve 1, a main valve core 2 and a pressure sensing chamber 4 arranged in the main valve, a needle valve 3 connected by several pipelines, a prior art pilot valve 16 and a stop valve 6, and the inlet and outlet of the main valve are also provided with a front stop valve C and a rear stop valve D respectively. The basic structure and working principle of the valve are well-known in the art and will not be described in detail here. The pilot valve of the 200X type pressure reducing valve in the prior art is as follows Figure 3 As shown, the pilot valve has a water inlet B and a pressure feedback port A. The water inlet B is connected to the pressure sensing chamber 4 of the main valve, and is connected to the pressure feedback port A through the valve port V2 and the through hole e. The pressure feedback port A is connected to the lower cavity of the diaphragm at the top of the pilot valve, so that the pressure of the pilot valve port A will be directly transmitted to the bottom of the diaphragm, thereby controlling the rise and fall of the valve core 7. However, the prior art adopts Figure 3 The common type pressure reducing valve of the pilot valve shown has a shortcoming, that is, when the stop valve stops supplying water after rapid closure, a water hammer effect will occur, or leakage will occur due to a sealing failure of the main valve port after the water supply is stopped, resulting in a significant increase in the pressure behind the valve, causing leakage of the valve and pipeline behind the valve, or even damage and other serious problems.

[0024] In order to solve the problem that the ordinary pressure reducing valve in the above-mentioned prior art will produce a water hammer effect when the stop valve stops supplying water after being quickly closed, or leakage will occur due to a sealing failure of the main valve port after the water supply is stopped, thereby causing a significant increase in the pressure behind the valve, causing the valve and pipeline behind the valve to leak or even be damaged, the utility model is improved and optimized on the basis of the existing 200X type pressure reducing valve structure to achieve the purpose of the utility model, and thus the present embodiment is provided.

[0025] Reference Figure 1 , Figure 4 , Figure 5 This embodiment is a pressure reducing valve with a pressure relief function. Its innovation lies in that a pressure relief valve is arranged in the pilot valve. When the pressure after the valve exceeds the set value, the pressure relief valve opens to release the high-pressure medium, thereby preventing the downstream valves and pipelines from being damaged or leaking due to water hammer impact or high pressure.

[0026] Reference Figure 1 The present embodiment comprises a main valve 1, a main valve core 2 and a pressure sensing chamber 4 arranged in the main valve, a needle valve 3, a pilot valve 5 and a stop valve 6 connected by a plurality of pipelines, and a front stop valve C and a rear stop valve D are respectively arranged at the inlet and outlet of the main valve. Different from the prior art, the pilot valve of the present embodiment is as follows Figure 4 Figure 5 The difference is that a pressure relief valve is provided in the lower chamber of the pilot valve (see Figure 4The pressure relief valve is composed of a valve core 7, a sealing gasket 8, a piston 9, an O-ring 10, a spring 11, a lower valve cover 12, a spring seat 13, a tightening nut 14 and an adjusting screw 15. The sealing gasket 8 is arranged in the pit at the bottom of the valve core 7. The body of the lower valve cover 12 is a cylinder with a bottom. The stud at the upper part thereof is screwed with the corresponding screw hole at the lower end of the pilot valve body, and an O-ring is provided to prevent leakage. The inner hole c of the cylinder is connected to the interface A of the pilot valve through the through hole e. The side wall of the lower part of the cylinder is provided with a discharge pipe L extending radially outward. The center of the discharge pipe L is provided with a discharge hole a, and the discharge hole a is connected with the inner hole c of the cylinder. The center of the bottom of the lower valve cover 12 is provided with a screw hole, and an adjusting screw 15 is screwed into the screw hole. The outer diameter of the piston 9 is dynamically matched with the inner hole c of the cylinder of the lower valve cover 12, and is provided with an O-ring 10. A flow hole b is provided in the center, a cone is provided at the top, and a boss is provided at the lower end. The cone and the hole b form an annular edge and form a valve port V3 of the pressure relief valve with the sealing gasket 8. The spring 11 is arranged between the boss at the lower end of the piston 9 and the spring seat 13. The opening pressure of the pressure relief valve can be adjusted by turning the adjusting screw 15. After the adjustment meets the requirements, it is locked with the tightening nut 14. The center line of the above parts is consistent with the vertical center line of the pilot valve.

[0027] The working process of this embodiment is as follows: before water supply, under the action of their respective springs, the main valve port V1 and the pressure relief valve port V3 are closed, while the pilot valve port V2 is fully open; after water supply, under the action of the water inlet pressure P1, the main valve port V1 is opened, and the output pressure P2 increases. Since the output pressure P2 is connected to the output pressure feedback port A of the pilot valve, the opening of the pilot valve port V2 gradually decreases as the output pressure P2 increases. When the pressure of the output pressure P2 acting on the bottom of the pilot valve diaphragm is balanced with the pressure of the pressure regulating spring, the pilot valve port V2 is fully opened. 2 no longer changes, and the opening of the pilot valve port V2 depends on the regulating pressure of the pressure regulating spring; since the water inlet B of the pilot valve is connected to the pressure sensing chamber 4 of the main valve, the opening of the pilot valve port V2 determines the pressure in the pressure sensing chamber 4, and also determines the opening of the main valve port V1. When the opening of the pilot valve port V2 increases, the flow discharged from the pressure sensing chamber 4 to the downstream increases, the pressure in the pressure sensing chamber 4 decreases, and the opening of the main valve port V1 increases; conversely, when the opening of the pilot valve port V2 decreases, the opening of the main valve port V1 increases. The reason is that the opening of the main valve port V1 is less than the maximum opening when supplying water. Due to the throttling and pressure-reducing effect, the output pressure P2 is lower than the input pressure P1, thus achieving pressure reduction. During the water supply process, the input pressure P1 and the output flow rate fluctuate from time to time, which causes the output pressure P2 to change accordingly. Since this force acts on the bottom of the pilot valve diaphragm, the valve core 7 is lifted and lowered appropriately, causing the opening of the pilot valve port V2 to change appropriately, thereby ensuring that the output pressure P2 is basically maintained at the set value. During the lifting and lowering process of the valve core 7, due to the spring Due to the effect of 11, the piston 9 always moves synchronously with the valve core 7, so the valve port V3 of the pressure relief valve is always closed; when the rear stop valve D is closed to stop water supply, no water flows in the pipeline, the water pressure in the downstream pipeline increases, the valve port V2 of the pilot valve is closed, and since there is no medium flowing in the pilot valve, the valve port V1 of the main valve is then closed. Since the downstream water pressure does not increase much, the valve port V3 of the pressure relief valve is also closed. When the rear stop valve D is opened to continue water supply, the water pressure behind the valve decreases, the valve port V2 of the pilot valve is opened, and the medium flows in the pilot valve. As mentioned above, the pressure reducing valve reduces pressure.

[0028] When the water pressure in the downstream pipeline increases significantly due to some reasons, such as water hammer caused by rapid closing of the rear stop valve D, or leakage caused by poor sealing of the main valve port V1, when the water pressure exceeds the set pressure of the spring 11, the piston 9 is pushed downward, and the pressure relief valve port V3 opens ( Figure 4), high-pressure water is discharged outward through the upper chamber of the piston 9, the flow hole b, the lower chamber of the piston 9 and the discharge hole a through the hole e. When the water pressure in the downstream pipeline drops to the set value, the piston 9 moves upward under the push of the spring 11, and the pressure relief valve port V3 is closed. The high pressure generated by water hammer is generally only discharged once, while the high pressure generated by the main valve port V1 failure (such as damage to the seal or foreign matter in the sealing part, etc.) will be repeatedly discharged. In the latter case, the main valve should be repaired in time.

[0029] The beneficial effect of this embodiment is that a pressure relief valve is provided in the lower chamber of the pilot valve. Thus, when the water pressure in the downstream pipeline increases significantly due to some reason, such as water hammer generated when the stop valve is quickly closed, or leakage caused by poor sealing of the main valve port, when the water pressure exceeds the set pressure of the spring, the piston will be pushed downward. At this time, the valve port of the pressure relief valve opens, and high-pressure water is discharged outward through the upper chamber of the piston, the flow hole, the lower chamber of the piston and the discharge pipe, thereby releasing the pressure. In this way, the device of this embodiment solves the problem that the ordinary pressure reducing valve in the prior art will generate water hammer when the stop valve stops supplying water after being quickly closed, or leakage occurs due to a sealing failure of the main valve port after the water supply stops, resulting in a significant increase in the pressure behind the valve, causing leakage or even damage to the valve and pipeline behind the valve. The device of this embodiment is also suitable for overpressure protection of various other types of pressure reducing valves.

[0030] In addition to the above-mentioned embodiments, within the scope disclosed in the claims and the specification of the utility model, the technical features or technical data of the utility model can be reselected and combined to form new embodiments, which should also be regarded as specific embodiments of the utility model and within the protection scope of the utility model.

Claims

1. A pressure reducing valve with a pressure relief function, characterized in that: It includes a main valve and a pilot valve connected to the main valve, the pilot valve includes a valve body, a lower valve cover arranged at the lower part of the valve body, and a valve core arranged inside the pilot valve, a pressure relief valve is arranged in the lower cavity formed between the lower valve cover and the valve body, the pressure relief valve includes a piston arranged below the valve core, a valve port of the pressure relief valve is formed between the valve core and the piston, a flow hole is arranged at the center of the piston, the lower end of the piston is in abutment with the lower valve cover by a spring, and a pressure relief pipe is arranged on the side wall below the lower valve cover.

2. The pressure reducing valve with pressure relief function according to claim 1, characterized in that: There is a pit on the lower end surface of the valve core, and a sealing gasket is installed in the pit. The upper end surface of the piston is provided with an annular edge that protrudes upward, and the pressure relief valve port is formed between the annular edge and the sealing gasket.

3. The pressure reducing valve with pressure relief function according to claim 2, characterized in that: A spring seat is installed on the bottom surface of the inner hole of the lower valve cover, and a tapered hole is provided on the bottom surface of the spring seat. The lower end surface of the spring abuts against the surface of the spring seat. A screw hole is provided at the center of the bottom of the lower valve cover, and an adjusting screw is threaded in the screw hole. The upper end of the adjusting screw has a cone, and the cone abuts against the tapered hole on the bottom surface of the spring seat.

4. The pressure reducing valve with pressure relief function according to claim 3, characterized in that: The lower end surface of the piston and the upper end surface of the spring seat are both annular step surfaces, and the upper and lower end surfaces of the spring are respectively in contact with the step surfaces provided on the lower end surface of the piston and the upper end surface of the spring seat.

5. The pressure reducing valve with pressure relief function according to claim 1, characterized in that: The lower valve cover is cylindrical and has an inner hole inside. The piston is arranged in the inner hole, and the outer diameter of the piston is matched with the inner hole. An O-type sealing ring is arranged between the outer peripheral surface of the piston and the inner hole.

6. The pressure reducing valve with pressure relief function according to claim 1, 3 or 5, characterized in that: The upper end of the lower valve cover is threadedly connected to the valve body, and a sealing ring is provided between the lower valve cover and the valve body. The pressure relief pipe is arranged on the side wall below the lower valve cover cylinder. The pressure relief pipe is hollow and its interior is a relief hole. The pressure relief pipe is connected to the cavity below the piston through the relief hole.

7. The pressure reducing valve with pressure relief function according to claim 1, characterized in that: The pilot valve also includes a water inlet and a pressure feedback port. A pilot valve port is formed between the valve body and the valve core of the pilot valve. An inclined through hole is provided on the valve body on one side of the pilot valve port. The water inlet is connected to the pressure feedback port through the pilot valve port and the through hole.

8. The pressure reducing valve with pressure relief function according to claim 7, characterized in that: The through hole is in communication with the pressure feedback port and the valve port of the pressure relief valve.

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