阅读说明：本技术 一种防气蚀快开缓闭泄压安全阀 (Cavitation-proof quick-opening slow-closing pressure relief safety valve ) 是由 黄燕 于明鑫 白建旺 范志勇 肖俊淼 岑坤旺 朱晓磊 于 2021-09-26 设计创作，主要内容包括：本发明公开一种防气蚀快开缓闭泄压安全阀,包括主阀和导阀,主阀包括主阀阀体、形成于主阀阀体内的进口流道和出口流道以及阀芯活动组件；阀芯活动组件内部形成有与进口流道连通且体积大小可变的阀门控制腔；导阀包括导阀阀体、形成于导阀阀体上且与进口流道连通的第一导阀进口以及形成于导阀阀体上分别与阀门控制腔和出口流道连通的第二导阀进口和导阀出口,导阀通过第二导阀进口集成于阀芯活动组件上；导阀阀体内设有在进口流道压力大于设定压力时开启导阀从而导通第二导阀进口和导阀出口、在进口流道压力小于设定压力时关闭导阀从而隔断第二导阀进口和导阀出口的控制结构。本发明结构设计合理,提高了响应速度,安全阀能够快速泄压。(The invention discloses an anti-cavitation quick-opening slow-closing pressure relief safety valve which comprises a main valve and a pilot valve, wherein the main valve comprises a main valve body, an inlet flow channel and an outlet flow channel which are formed in the main valve body, and a valve core movable assembly; a valve control cavity which is communicated with the inlet flow passage and has variable volume is formed in the valve core movable assembly; the pilot valve comprises a pilot valve body, a first pilot valve inlet which is formed on the pilot valve body and is communicated with the inlet flow channel, and a second pilot valve inlet and a pilot valve outlet which are formed on the pilot valve body and are respectively communicated with the valve control cavity and the outlet flow channel, and the pilot valve is integrated on the valve core movable assembly through the second pilot valve inlet; and a control structure which opens the pilot valve when the pressure of the inlet runner is higher than the set pressure so as to conduct the inlet of the second pilot valve and the outlet of the pilot valve and closes the pilot valve when the pressure of the inlet runner is lower than the set pressure so as to separate the inlet of the second pilot valve and the outlet of the pilot valve is arranged in the valve body of the pilot valve. The invention has reasonable structural design, improves the response speed and can quickly release pressure by the safety valve.)

1. The utility model provides an anti-cavitation fast-opening slow-closing pressure relief safety valve which characterized in that includes:

the main valve (1) comprises a main valve body (11), an inlet flow channel (12) and an outlet flow channel (13) which are formed in the main valve body (11), and a valve core movable assembly (14) which is used for communicating or separating the inlet flow channel (12) and the outlet flow channel (13); a valve control cavity (146) which is communicated with the inlet flow channel (12) and has variable volume is formed in the valve core movable assembly (14); and

the pilot valve (2) comprises a pilot valve body (21), a first pilot valve inlet (22) which is formed on the pilot valve body (21) and communicated with the inlet flow channel (12), and a second pilot valve inlet (23) and a pilot valve outlet (24) which are formed on the pilot valve body (21) and respectively communicated with the valve control cavity (146) and the outlet flow channel (13), and the pilot valve (2) is integrated on the valve core movable component (14) through the second pilot valve inlet (23); and a control structure (25) which opens the pilot valve (2) when the pressure of the inlet channel (12) is greater than the set pressure so as to conduct the second pilot valve inlet (23) and the pilot valve outlet (24) and closes the pilot valve (2) when the pressure of the inlet channel (12) is less than the set pressure so as to isolate the second pilot valve inlet (23) and the pilot valve outlet (24) is arranged in the pilot valve body (21), when the pilot valve (2) is in an opening state, the volume of the valve control cavity (146) is reduced so that the inlet channel (12) and the outlet channel (13) are conducted by the valve core movable component (14), and when the pilot valve (2) is in a closing state, the volume of the valve control cavity (146) is restored so that the inlet channel (12) and the outlet channel (13) are isolated by the valve core movable component (14).

2. The cavitation-preventing quick-opening slow-closing pressure relief safety valve as recited in claim 1, wherein: the valve core movable assembly (14) comprises a valve seat (141) with a conical overflowing hole (1411) formed in the circumferential direction, a valve clack sleeve (142) connected above the valve seat (141) in a sealing mode, a valve cover (143) sealed and closed with the top of the valve clack sleeve (142), a valve rod (144) penetrating through the valve cover (143), and a valve clack (145) connected to the bottom of the valve rod (144) and matched with the valve seat (141); and when the pilot valve (2) is in a closed state, the valve clack (145) is in close contact with the valve seat (141) to block the conical overflowing hole (1411), and when the pilot valve (2) is in an open state, the valve clack (145) moves upwards to open the conical overflowing hole (1411) to conduct the inlet flow channel (12) and the outlet flow channel (13).

3. The cavitation-preventing quick-opening slow-closing pressure relief safety valve as recited in claim 2, wherein: the bottom of the valve seat (141) protrudes towards the axial inner side to form an annular limiting part (1412), and the annular limiting part (1412) and an annular sealing ring (1451) arranged on the edge of the bottom of the valve clack (145) are pressed up and down to form a sealing structure.

4. The cavitation-preventing quick-opening slow-closing pressure relief safety valve as recited in claim 2, wherein: the valve core movable assembly (14) is provided with a slow closing structure (3) for controlling the valve clack (145) to move downwards slowly.

5. The anti-cavitation quick-opening slow-closing pressure relief safety valve according to claim 4, characterized in that: the slow-closing structure (3) comprises a sealing cavity (34) formed between the valve clack (145) and the valve clack sleeve (142), the sealing cavity (34) is communicated with a one-way throttle valve (32) through an oil guide pipe (31), and an oil cup (33) used for oil supply is arranged on the one-way throttle valve (32).

6. The anti-cavitation quick-opening slow-closing pressure relief safety valve according to claim 5, characterized in that: the diameter of the inner cavity of the valve clack sleeve (142) is larger than that of the inner cavity of the valve seat (141), and an annular sealing cavity (34) is formed between the top edge of the valve clack (145) and the valve clack sleeve (142) by extending a certain length along the radial outer side.

7. The cavitation-preventing quick-opening slow-closing pressure relief safety valve as recited in claim 1, wherein: the control structure (25) comprises a pressure setting structure (251) arranged at the upper part of the pilot valve body (21), a piston rod (252) pressed below the pressure setting structure (251) and an elastic sheet (253) used for isolating the movable space of the pressure setting structure (251) and the piston rod (252), a closed pilot valve control cavity (254) is formed by surrounding the elastic sheet (253), the pilot valve body (21) and the piston rod (252), the pilot valve control chamber (254) communicates with the inlet channel (12) through a first pilot valve inlet (22), the pilot valve control chamber (254) is capable of controlling the piston rod (252) to open the second pilot valve inlet (23) and communicate with the pilot valve outlet (24) when the inlet channel (12) pressure is greater than a set pressure and to block the second pilot valve inlet (23) when the inlet channel (12) pressure is less than the set pressure.

8. The cavitation-preventing quick-opening slow-closing pressure relief safety valve as recited in claim 7, wherein: the pressure setting structure (251) comprises an adjusting bolt (2511) which is movably connected to the top of the pilot valve body (21) and can vertically extend and retract, and a spring (2513) of which the upper end and the lower end are connected with spring seats (2512) is compressed below the adjusting bolt (2511).

9. The cavitation-preventing quick-opening slow-closing pressure relief safety valve as recited in claim 7, wherein: the pilot valve control cavity (254) is communicated with the inlet flow channel (12) through a first water inlet pipe (4), the second pilot valve inlet (23) is communicated with the valve control cavity (146) through a through hole formed in the valve cover (143), and the pilot valve outlet (24) is communicated with the outlet flow channel (13) through a water outlet pipe (6); the valve control cavity (146) is communicated with the inlet channel (12) through a second water inlet pipe (5), and the second water inlet pipe (5) is provided with an adjusting needle valve (51).

10. The cavitation-preventing quick-opening slow-closing pressure relief safety valve as recited in claim 9, wherein: the caliber of the second pilot valve inlet (23) and the caliber of the pilot valve outlet (24) are not lower than 1/10 of the caliber of the inlet flow channel (12), and the caliber of the second water inlet pipe (5) is not larger than 1/100 of the caliber of the inlet flow channel (12).

Technical Field

The invention relates to the technical field of pipeline valves, in particular to an anti-cavitation quick-opening slow-closing pressure relief safety valve.

Background

The safety valve is a special valve, wherein the opening and closing part is in a normally closed state under the action of external force, and when the medium pressure in equipment or a pipeline exceeds a specified value, the medium is discharged to the outside of the system to prevent the medium pressure in the pipeline or the equipment from exceeding the specified value. The safety valve belongs to the automatic valve class, is mainly used for boiler, pressure vessel and pipeline, can control pressure and not exceed the specified value to play important protection effect to personal safety and equipment operation.

The pressure of pressure release can not be adjusted to current relief valve when the pressure release, need use different relief valves when adjusting different pressures to increase the cost of use, consequently inconvenient user's use has reduced the practicality of relief valve. In addition, the safety valve has cavitation damage phenomenon, low control precision, slow opening response and incapability of quickly relieving pressure, and high closing speed causes large pressure fluctuation and great destructive power to pipelines and the safety valve.

Based on the situation, the invention provides an anti-cavitation quick-opening slow-closing pressure relief safety valve which can effectively solve the problems.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an anti-cavitation quick-opening slow-closing pressure relief safety valve. The structure of the invention is reasonable in design, the pilot valve control cavity is directly connected with the inlet flow passage of the main valve, so that the pressure of the inlet flow passage directly interacts with the set pressure of the pilot valve control structure to open or close the pilot valve, the response speed is improved, the calibers of the inlet and the outlet of the pilot valve are increased, and the medium in the valve control cavity can be quickly discharged through the pilot valve; in addition, a slow closing structure for delaying closing of the valve clack is additionally arranged, so that pressure fluctuation is reduced.

In order to solve the technical problems, the invention is realized by the following technical scheme:

an anti-cavitation quick-opening slow-closing pressure relief safety valve comprises:

the main valve comprises a main valve body, an inlet flow channel and an outlet flow channel which are formed in the main valve body, and a valve core movable assembly for communicating or separating the inlet flow channel and the outlet flow channel; a valve control cavity which is communicated with the inlet flow passage and has variable volume is formed in the valve core movable assembly; and

the pilot valve comprises a pilot valve body, a first pilot valve inlet which is formed on the pilot valve body and communicated with the inlet flow channel, and a second pilot valve inlet and a pilot valve outlet which are formed on the pilot valve body and respectively communicated with the valve control cavity and the outlet flow channel, and the pilot valve is integrated on the valve core movable assembly through the second pilot valve inlet; and a control structure which opens the pilot valve when the pressure of the inlet channel is higher than the set pressure so as to conduct the inlet and the outlet of the second pilot valve and closes the pilot valve when the pressure of the inlet channel is lower than the set pressure so as to isolate the inlet and the outlet of the second pilot valve is arranged in the valve body of the pilot valve, the volume of the valve control cavity is reduced under the opening state of the pilot valve so that the inlet channel and the outlet channel are conducted by the valve core movable assembly, and the volume of the valve control cavity is restored under the closing state of the pilot valve so that the inlet channel and the outlet channel are isolated by the valve core movable assembly.

Preferably, the valve core movable assembly comprises a valve seat, a valve clack sleeve, a valve cover, a valve rod and a valve clack, wherein the valve seat is circumferentially provided with a conical overflowing hole, the valve clack sleeve is connected above the valve seat in a sealing mode, the valve cover is sealed and closed with the top of the valve clack sleeve, the valve rod penetrates through the valve cover, and the valve clack is connected to the bottom of the valve rod and matched with the valve seat; and in the closing state of the pilot valve, the valve clack is tightly contacted with the valve seat to block the conical overflowing hole, and in the opening state of the pilot valve, the valve clack moves upwards to open the conical overflowing hole to conduct the inlet flow channel and the outlet flow channel.

Further preferably, the bottom of the valve seat protrudes towards the inner side in the axial direction to form an annular limiting part, and the annular limiting part and an annular sealing ring arranged on the edge of the bottom of the valve clack are vertically compressed to form a sealing structure.

Further preferably, the valve core movable assembly is provided with a slow closing structure for controlling the valve clack to move downwards slowly.

Still further preferably, the slow-closing structure comprises a sealing cavity formed between the valve clack and the valve clack sleeve, the sealing cavity is communicated with a one-way throttle valve through an oil guide pipe, and an oil cup for supplying oil is arranged on the one-way throttle valve.

Still further preferably, the diameter of the inner cavity of the valve clack sleeve is larger than that of the inner cavity of the valve seat, and the top edge of the valve clack extends outwards along the radial direction for a certain length to form an annular sealing cavity with the valve clack sleeve.

Preferably, the control structure comprises a pressure setting structure arranged at the upper part of the pilot valve body, a piston rod pressed below the pressure setting structure, and an elastic sheet for isolating the pressure setting structure from the moving space of the piston rod, wherein a closed pilot valve control cavity is formed by the elastic sheet, the pilot valve body and the piston rod in a surrounding manner, the pilot valve control cavity is communicated with the inlet flow channel through the first pilot valve inlet, and the pilot valve control cavity can control the piston rod to open the second pilot valve inlet and communicate with the pilot valve outlet when the pressure of the inlet flow channel is greater than the set pressure and to block the second pilot valve inlet when the pressure of the inlet flow channel is less than the set pressure.

Preferably, the pressure setting structure comprises an adjusting bolt movably connected to the top of the pilot valve body and capable of vertically stretching, and a spring with spring seats connected to the upper end and the lower end is pressed below the adjusting bolt.

It is further preferred that the pilot valve control chamber is communicated with the inlet channel through a first water inlet pipe, the second pilot valve inlet is communicated with the valve control chamber through a through hole formed in the valve cover, and the pilot valve outlet is communicated with the outlet channel through a water outlet pipe; the valve control chamber pass through the second inlet tube with the inlet channel intercommunication, just be equipped with on the second inlet tube and adjust the needle valve.

It is further preferred that neither the second pilot valve inlet nor the pilot valve outlet have a caliber less than 1/10 of the caliber of the inlet flow passage and the caliber of the second inlet tube is not greater than 1/100 of the caliber of the inlet flow passage.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the invention has reasonable structural design, the control cavity of the pilot valve is directly connected with the inlet flow passage of the main valve, so that the pressure of the inlet flow passage directly interacts with the set pressure of the control structure of the pilot valve to open or close the pilot valve, the response speed is improved, the caliber of the inlet and the outlet of the pilot valve is increased, the medium in the control cavity of the valve can be quickly discharged through the pilot valve, and the whole response time is not more than 0.5 s.

The pressure setting structure adopted by the invention can adjust the set pressure of the pilot valve only by rotating the adjusting screw to press or loosen the spring, thereby being suitable for different inlet runner pressure requirements and different pipeline structures.

According to the invention, the valve core movable assembly is additionally provided with the slow closing structure for delaying closing of the valve clack, when the valve is opened, grease in the oil cup can quickly enter the closed cavity through the one-way throttle valve without influencing the opening of the valve, and when the valve is closed, the grease can only slowly flow to the oil cup through the internal gap of the one-way throttle valve, so that the valve can only be closed slowly, and the pressure fluctuation is effectively reduced.

The periphery of the valve seat is provided with the plurality of conical overflowing holes, when the valve is opened to quickly release pressure, water flow is ejected from the interior of the valve seat along the circumferential direction through the conical overflowing holes and is discharged after energy dissipation through ejection, and the valve seat has a better cavitation damage prevention effect.

Drawings

FIG. 1 is a schematic view of a typical cross-sectional structure of a safety valve of the present invention;

FIG. 2 is a detailed view of the pilot valve of the present invention.

FIG. 3 is a schematic view of a main valve and a slow-closing structure according to the present invention;

FIG. 4 is a schematic view of the main valve pressure relief state structure of the present invention.

Reference numerals: 1-a main valve; 11-a main valve body; 12-an inlet channel; 13-an outlet flow channel; 14-a spool movable assembly; 141-valve seat; 142-a valve flap sleeve; 143-valve cover; 144-a valve stem; 145-valve flap; 146-a valve control chamber; 1411-a tapered overflow aperture; 1412-an annular limiting part; 1451-ring seal; 2-a pilot valve; 21-a pilot valve body; 22-a first pilot valve inlet; 23-a second pilot valve inlet; 24-pilot valve outlet; 25-a control structure; 251-a pressure setting structure; 252-a piston rod; 253-a spring sheet; 254-pilot valve control chamber; 2511-adjusting bolt; 2512-spring seat; 2513-a spring; 3-slow closing structure; 31-oil guide pipe; 32-one-way throttle valve; 33-oil cup; 34-a sealed cavity; 4-a first water inlet pipe; 5-a second water inlet pipe; 51-adjusting needle valve; 6-water outlet pipe.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the following description of the preferred embodiments of the present invention is provided in conjunction with specific examples, but it should be understood that the drawings are for illustrative purposes only and should not be construed as limiting the patent; for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted. The positional relationships depicted in the drawings are for illustrative purposes only and are not to be construed as limiting the present patent.

The present invention will be further described with reference to the following examples and figures 1-4, but the invention is not limited thereto.

As shown in fig. 1 to 4, the present embodiment provides an anti-cavitation quick-opening slow-closing pressure relief safety valve, which includes a main valve and a pilot valve for quickly opening the main valve for pressure relief, where the main valve 1 includes a main valve body 11, an inlet flow channel 12 and an outlet flow channel 13 formed in the main valve body 11, and a valve core movable assembly 14 for communicating or blocking the inlet flow channel 12 and the outlet flow channel 13; the valve core movable assembly 14 is formed with a valve control chamber 146 with a variable volume size and communicating with the inlet channel 12. The pilot valve 2 comprises a pilot valve body 21, a first pilot valve inlet 22 formed on the pilot valve body 21 and communicating with the inlet flow passage 12, and a second pilot valve inlet 23 and a pilot valve outlet 24 formed on the pilot valve body 21 and communicating with the valve control chamber 146 and the outlet flow passage 13, respectively, the pilot valve 2 being integrated on the valve core movable assembly 14 through the second pilot valve inlet 23; a control structure 25 is arranged in the pilot valve body 21, which opens the pilot valve 2 when the pressure in the inlet channel 12 is higher than a set pressure so as to conduct the second pilot valve inlet 23 and the pilot valve outlet 24, and closes the pilot valve 2 when the pressure in the inlet channel 12 is lower than the set pressure so as to block the second pilot valve inlet 23 and the pilot valve outlet 24, when the pilot valve 2 is in an open state, the volume of the valve control chamber 146 is reduced so that the inlet channel 12 and the outlet channel 13 are conducted by the valve element movable component 14, and when the pilot valve 2 is in a closed state, the volume of the valve control chamber 146 is restored so that the inlet channel 12 and the outlet channel 13 are blocked by the valve element movable component 14.

In this embodiment, the control structure 25 includes a pressure setting structure 251 disposed on the upper portion of the pilot valve body 21, a piston rod 252 tightly pressed below the pressure setting structure 251, and an elastic sheet 253 for isolating the moving space between the pressure setting structure 251 and the piston rod 252, the elastic sheet 253, the pilot valve body 21, and the piston rod 252 surround to form a sealed pilot valve control chamber 254, the pilot valve control chamber 254 is communicated with the inlet channel 12 through the first pilot valve inlet, the pilot valve control chamber 254 can control the piston rod 252 to open the second pilot valve inlet 23 and communicate with the pilot valve outlet 24 when the pressure in the inlet channel 12 is greater than the set pressure, and block the second pilot valve inlet 23 when the pressure in the inlet channel 12 is less than the set pressure. The pilot valve control cavity 254 is communicated with the inlet flow channel 12 through a first water inlet pipe 4, the second pilot valve inlet 23 is communicated with the valve control cavity 146 through a through hole formed in the valve cover 143, and the pilot valve outlet 24 is communicated with the outlet flow channel 13 through a water outlet pipe 6;

in order to increase the response speed and shorten the response time to increase the force-bearing area of the spring plate 253, the pilot valve control chamber 254 is communicated with the inlet channel 12 through the first water inlet pipe 4, so that the inlet channel pressure directly interacts with the set pressure of the pilot valve control structure to open or close the pilot valve, and the response speed is increased; the calibers of the second pilot valve inlet 23 and the pilot valve outlet 24 are not lower than 1/10 of the calibre of the inlet flow channel 12, the calibre of the second water inlet pipe 5 is not larger than 1/100 of the calibre of the inlet flow channel 12, so that the calibers of the pilot valve inlet and outlet are increased, the calibre of the second water inlet pipe 5 is reduced, the medium in the valve control cavity can be quickly discharged through the pilot valve, and the whole response time is not more than 0.5 s. Secondly, the pilot valve is directly integrated on the valve cover through the second pilot valve inlet 23, the length of a pipeline between the valve control valve and an outlet flow channel is shortened, the medium in the valve control valve is rapidly discharged, and the effect of rapid pressure relief is achieved.

Furthermore, the force bearing area of the said spring plate 253 on the side of the pilot valve control chamber is larger than the cross-sectional area of the pressure setting structure and the piston rod active space, and the force bearing area is at least 10 times of the cross-sectional area of the second pilot valve inlet 23, so that the opening response speed of the pilot valve can be further improved.

Further, the pressure setting structure 251 includes an adjusting bolt 2511 movably connected to the top of the pilot valve body 21 and capable of extending vertically, and a spring 2513 with spring seats 2512 connected to the upper and lower ends is pressed below the adjusting bolt 2511. The set pressure of the pilot valve can be adjusted only by rotating the adjusting screw to compress or loosen the spring, so that the pressure requirements of different inlet runners are met, and different pipeline structures are met.

In this embodiment, the valve core moving assembly 14 includes a valve seat 141 circumferentially provided with a tapered overflow hole 1411, a valve clack sleeve 142 hermetically connected above the valve seat 141, a valve cover 143 hermetically closed with the top of the valve clack sleeve 142, a valve rod 144 penetrating through the valve cover 143, and a valve clack 145 connected to the bottom of the valve rod 144 and adapted to the valve seat 141; in the closed state of the pilot valve 2, the valve clack 145 is in close contact with the valve seat 141 to block the tapered overflowing hole 1411, and in the open state of the pilot valve 2, the valve clack 145 moves upwards to open the tapered overflowing hole 1411 to conduct the inlet flow passage 12 and the outlet flow passage 13.

Wherein, the toper discharge orifice has been seted up to circumference on the disk seat, and when the valve opened quick pressure release, rivers were sprayed along the circumferencial direction through toper discharge orifice by the disk seat is inside, discharges after spraying the energy dissipation, has better anti-cavitation damage effect.

Further, the bottom of the valve seat 141 protrudes toward the inside in the axial direction to form an annular stopper 1412, and the annular stopper 1412 and an annular seal 1451 provided at the bottom edge of the valve flap 145 are pressed up and down to form a sealing structure.

In order to reduce the pressure fluctuation when the valve is closed, the valve core movable assembly 14 is provided with a slow closing structure 3 for controlling the valve clack 145 to move downwards slowly. The slow closing structure 3 comprises a sealing cavity 34 formed between the valve clack 145 and the valve clack sleeve 142, the sealing cavity 34 is communicated with a one-way throttle valve 32 through an oil guide pipe 31, and an oil cup 33 for supplying oil is arranged on the one-way throttle valve 32. The diameter of the inner cavity of the valve clack sleeve 142 is larger than that of the inner cavity of the valve seat 141, the top edge of the valve clack 145 extends outwards along the radial direction for a certain length, an annular sealing cavity 34 is formed between the valve clack sleeve 142 and the top edge of the valve clack 145, and a sealing ring for sealing the contact surface of the valve clack and the valve clack sleeve is arranged on one side, close to the valve clack sleeve, of the extending part of the valve clack.

Further, in order to ensure that the main valve blocks the connection of the inlet flow passage to the outlet flow passage before the pilot valve opens, the valve control chamber 146 communicates with the inlet flow passage 12 through a second inlet pipe 5, and the second inlet pipe 5 is provided with a regulating needle valve 51. The water pressure in the inlet channel and the water pressure in the valve control cavity 146 are kept equal to each other to be P through the second water inlet pipe 5, the stress area acting on the valve clack in the valve control cavity 146 is the sum S2 of the extension part of the top valve clack and the end head of the bottom valve clack, the stress area acting on the valve clack in the inlet channel is only the end head S1 of the bottom valve clack, and therefore the valve clack is wholly stressed by downward force, the valve clack is kept downward, and the valve is in a closed state.

The working principle of the embodiment is as follows:

the pilot valve is in a closed state when the inlet channel pressure is below the spring set pressure of the pilot valve. At the moment, the pressure in the valve control cavity is equal to the pressure of the inlet channel, and because S2 is greater than S1, the whole valve clack is acted by downward force, the valve clack keeps downward, and the valve is in a closed state;

when the pressure of the inlet runner exceeds the set pressure of the spring of the pilot valve, the pilot valve is opened, and the water inlet of the second pilot valve is communicated with the water outlet of the pilot valve; the valve control cavity is communicated with the outlet channel through a guide valve, the pressure of the valve control cavity is rapidly reduced, the water flow in the inlet channel pushes the valve clack to move upwards, and the valve is opened;

when the valve is opened, grease in the oil cup flows into the sealing cavity through the one-way throttle valve, and the pilot valve is closed when the pressure of the inlet runner becomes lower than the set pressure of the spring of the pilot valve after pressure relief; at the moment, the pressure of the valve control cavity slowly rises under the action of the second water inlet pipe (inlet runner pressure), the valve clack moves downwards, and the valve is gradually closed; the valve clack moves downwards, grease in a closed cavity between the valve clack sleeve and the valve clack needs to flow to the oil cup, the one-way throttle valve is closed at the moment, the grease can only flow to the oil cup slowly through the inner gap of the one-way throttle valve, and therefore the valve can only be closed slowly.

According to the description and the drawings of the invention, a person skilled in the art can easily manufacture or use the anti-cavitation quick-opening slow-closing pressure relief safety valve and can produce the positive effects recorded in the invention.

Unless otherwise specified, in the present invention, if there is an orientation or positional relationship indicated by terms of "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, rather than to indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore, the terms describing orientation or positional relationship in the present invention are for illustrative purposes only, and should not be construed as limiting the present patent, specific meanings of the above terms can be understood by those of ordinary skill in the art in light of the specific circumstances in conjunction with the accompanying drawings. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

Unless expressly stated or limited otherwise, the terms "disposed," "connected," and "connected" are used broadly and encompass, for example, being fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications and equivalent variations of the above embodiments according to the technical spirit of the present invention are included in the scope of the present invention.