A burst pipe safety valve

Abstract

The application provides a burst pipe safety valve, which comprises a main valve, a pressure measuring pipe and a second guide valve. The main valve comprises a flow valve cavity, a main control cavity and a main valve core. The flow valve cavity is provided with a water inlet end and a water outlet end. The main valve core is arranged in the main control cavity and extends into the flow valve cavity. The main valve core has a stop position for closing the flow valve cavity and a flow position for opening the flow valve cavity under the action of the main control cavity. The pressure measuring pipe is connected with the water outlet end. The second guide valve is connected with the water inlet end, the main control cavity and the pressure measuring pipe. The second guide valve has a second valve closing state for connecting the water inlet end and the main control cavity and a second valve opening state for cutting off the connection between the water inlet end and the main control cavity under the interaction of the internal pressure of the water inlet end and the pressure measuring pipe. The first guide valve is connected with the water outlet end and arranged between the water inlet end and the second guide valve. The first guide valve has a first valve closing state for connecting the water inlet end and the second guide valve and a first valve opening state for cutting off the connection between the water inlet end and the second guide valve under the pressure of the water inlet end.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valve structure, and particularly relates to a burst pipe safety valve. BACKGROUND

[0002] The burst pipe safety valve is a device capable of quickly detecting and cutting off fluid delivery after a pressurized pipeline bursts, and is suitable for various water supply pipelines such as urban water supply projects and industrial water supply projects. The burst pipe safety valve controlled by water force does not need electrical control, and can rely on the pressure characteristics and flow rate characteristics of the pipelines before and after the valve as double judgment conditions, and uses the pressure of the pipeline itself to realize valve action, and is suitable for fluid control occasions with large burst pipe influence, fast and accurate closing requirement and high automation degree.

[0003] There is a pilot pressure differential burst pipe cut-off valve in the prior art, which comprises a main valve, a pilot valve, a pressure measuring pipe and a plurality of control pipelines. The pressure measuring pipe is connected with the downstream side of the valve seat of the main valve. One end of the control pipeline one, the control pipeline two and the control pipeline three is connected with the upstream side of the valve seat, the pressure measuring pipe and the main valve upper cavity of the main valve piston respectively. The other end is respectively communicated with the lower communication node, the lower cavity of the pilot valve and the upper communication node. The control pipeline one is also communicated with the space composed of the pilot valve shaft, the pilot valve upper end cover and the pilot valve piston. The main valve spring is located in the main valve lower cavity and is always in a pre-tightening state under pressure. In the normal state, the valve is in a fully open state. In the burst pipe state, the valve is closed.

[0004] However, using only pressure drop as the judgment standard for valve action cannot avoid the possible mis-closing caused by the increase of flow rate due to the pressurization of the upstream valve. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to overcome the defect in the prior art that only using pressure drop as the judgment standard for valve action cannot avoid the possible mis-closing caused by the increase of flow rate due to the pressurization of the upstream valve, so as to provide a burst pipe safety valve.

[0006] The present application provides a burst pipe safety valve, comprising: a main valve, comprising a flow valve cavity and a main control cavity, and a main valve core, the flow valve cavity is provided with a water inlet end and a water outlet end, the main valve core is arranged in the main control cavity and extends into the flow valve cavity, and has a stop position for closing the flow valve cavity under the action of the main control cavity and a flow-through position for opening the flow valve cavity; a pressure measuring tube is arranged in communication with the water outlet end; a second pilot valve is connected with the water inlet end, the main control cavity and the pressure measuring tube, and has a second valve closing state for communicating the water inlet end and the main control cavity under the interaction of the internal pressure of the pressure measuring tube and the water inlet end, and a second valve opening state for isolating the water inlet end and the main control cavity; and a first pilot valve is connected with the water outlet end and arranged between the water inlet end and the second pilot valve, and has a first valve closing state for communicating the water inlet end and the second pilot valve under the action of the pressure of the water inlet end, and a first valve opening state for isolating the water inlet end and the second pilot valve.

[0007] The flow cross-sectional diameter of the pressure measuring tube is smaller than the flow cross-sectional diameter of the flow valve cavity.

[0008] The main control cavity comprises: a main control upper cavity connected with the second pilot valve; a main control lower cavity arranged separately from the main control upper cavity; a main elastic member arranged on the main valve core and adapted to drive the main valve core to stay in the flow-through position; and a main piston member arranged between the main control upper cavity and the main control lower cavity and connected with the main valve core, and adapted to separate the main control upper cavity and the main control lower cavity and drive the main valve core to move or stop between the flow-through position and the stop position under the interaction of the pressure difference between the main control upper cavity and the main control lower cavity and the main elastic member.

[0009] The main control cavity further comprises a main exhaust hole arranged on the main control lower cavity and adapted to communicate with the external environment, and / or the main elastic member is arranged in the main control lower cavity and connected with the main piston member and the inner wall of the main control lower cavity at both ends.

[0010] The flow valve cavity comprises: a flow guide part arranged between the water inlet end and the water outlet end and arranged in a curved manner, at least part of the flow guide part being arranged in the same direction as the main valve core; and a sealing inner protrusion protruding from the inner wall of the flow guide part in the circumferential direction, one end of the main valve core extending into the flow valve cavity is provided with a sealing valve disc, and in the stop position, the sealing valve disc is sealingly abutted with the side of the sealing inner protrusion facing the main control cavity, and adapted to close the flow valve cavity.

[0011] The second pilot valve comprises a second switching chamber connected with the water inlet end and the main control chamber respectively, a second control chamber connected with the water inlet end and the pressure measuring pipe respectively, and a second valve core member arranged in the second switching chamber and extending into the second control chamber, adapted to move under the pressure difference between the second control chamber and the second switching chamber, and connect the water inlet end and the main control chamber in the second closing state, and disconnect the water inlet end and the main control chamber in the second opening state.

[0012] The second control chamber comprises a second control upper chamber connected with the water inlet end, a second control lower chamber arranged separately from the second control upper chamber and connected with the pressure measuring pipe, a second elastic member arranged on the second valve core member and adapted to drive the second valve core member to stay in the second opening state, and a second control piston member arranged between the second control upper chamber and the second control lower chamber and connected with the second valve core member, adapted to separate the second control upper chamber and the second control lower chamber, and drive the second valve core member to switch between the second closing state and the second opening state under the interaction of the pressure difference between the second control upper chamber, the second control lower chamber and the second switching chamber and the second elastic member.

[0013] The second switching chamber comprises a second switching upper chamber connected with the main control upper chamber of the main control chamber, a second switching lower chamber arranged in connection with the first pilot valve, and a second switching piston member arranged between the second switching upper chamber and the second switching lower chamber and connected with the second valve core member, adapted to drive the second valve core member to switch between the second closing state and the second opening state under the interaction of the pressure difference between the second switching upper chamber, the second switching lower chamber and the second control chamber and the second elastic member.

[0014] The first pilot valve comprises a first switching chamber connected with the water inlet end and the second switching lower chamber of the second switching chamber respectively, a first control chamber arranged in connection with the water outlet end, and a first valve core member arranged in the first switching chamber and extending into the first control chamber, adapted to move under the pressure difference between the first control chamber and the first switching chamber, and connect the water inlet end and the second switching lower chamber in the first closing state, and disconnect the water inlet end and the second switching lower chamber in the first opening state.

[0015] The first control cavity comprises: a first control upper cavity in communication with the water outlet end; a first control lower cavity, which is arranged in a spaced manner with the second control upper cavity and is adapted to communicate with the outside; a first elastic member, which is arranged on the first valve core member and is adapted to drive the first valve core member to switch from the first valve closing state to the first valve opening state; and a first control piston member, which is arranged between the first control upper cavity and the first control lower cavity, is arranged in connection with the first valve core member, is adapted to separate the first control upper cavity and the first control lower cavity, and is adapted to drive the first valve core member to switch between the first valve closing state and the first valve opening state under the interaction of the pressure difference between the first control upper cavity and the first control lower cavity, the first switch cavity and the first elastic member.

[0016] The first switch cavity comprises: a first switch upper cavity in communication with the water inlet end; a first switch lower cavity in communication with the second switch lower cavity of the second switch cavity; and a first switch piston member, which is arranged between the first switch upper cavity and the first switch lower cavity, is arranged in connection with the first valve core member, and is adapted to drive the first valve core member to switch between the first valve closing state and the first valve opening state under the interaction of the pressure difference between the first switch upper cavity and the first switch lower cavity, the first control cavity and the first elastic member.

[0017] The first elastic member is arranged in the first control lower cavity, one end of the first elastic member is arranged in connection with the first control piston member, and the other end of the first elastic member is arranged in connection with a first adjusting assembly, the first adjusting assembly is adapted to adjust the elastic force of the first elastic member.

[0018] And / or,

[0019] The second elastic member is arranged in the second control lower cavity, one end of the second elastic member is arranged in connection with the second control piston member, and the other end of the second elastic member is arranged in connection with a second adjusting assembly, the second adjusting assembly is adapted to adjust the elastic force of the second elastic member.

[0020] One end of the second valve core member penetrates out of the second switch cavity and is arranged in connection with the second operating handle.

[0021] One end of the first valve core member penetrates out of the first switch cavity and is arranged in connection with the first operating handle.

[0022] The technical scheme of the present application has the following advantages:

[0023] The application provides a burst pipe safety valve, which comprises a main valve, a pressure measuring pipe and a second pilot valve.

[0024] The main control cavity is arranged to drive the main valve core to move, thereby controlling the opening and closing of the flow valve cavity from the water inlet end to the water outlet end. The first pilot valve and the second pilot valve are arranged on the water path between the main control cavity and the water inlet end. The second pilot valve is further connected with the pressure measuring pipe, and the opening and closing of the second pilot valve can be controlled by the interaction between the pressure measuring pipe and the water inlet end. The first pilot valve is arranged between the main control cavity and the second pilot valve on the water path, and the opening and closing of the first pilot valve can be controlled by the water outlet end and other external forces. The first pilot valve and the second pilot valve are arranged to detect the pressure and flow rate changes at the water inlet end and the water outlet end, and the pressure and flow rate changes at the water inlet end and the pressure measuring pipe. The pressure and flow rate changes at the front of the water inlet end and the rear of the pressure measuring pipe are used as the double judgment standards to select the opening and closing of the flow valve cavity, thereby overcoming the defect that the pressure drop is used as the double judgment standard for valve operation in the prior art, and the valve upstream pressure increase may cause the flow rate to increase, which may cause the valve to be closed. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0026] Figure 1 The structure diagram of the burst pipe safety valve provided in the embodiments of the application is shown in the figure.

[0027] The reference signs are explained as follows:

[0028] 1, overcurrent valve cavity; 11, water outlet end; 12, water inlet end; 13, flow guide part; 14, sealing inner convex; 2, main control cavity; 21, main control upper cavity; 22, main control lower cavity; 23, main elastic member; 24, main piston member; 25, main exhaust hole; 3, main valve core member; 31, sealing valve disc; 4, pressure measuring tube; 5, first pilot valve; 51, first switch cavity; 511, first switch upper cavity; 512, first switch lower cavity; 513, first switch piston member; 52, first control cavity; 521, first control upper cavity; 522, first control lower cavity; 523, first elastic member; 524, first control piston member; 53, first valve core member; 6, second pilot valve; 61, second switch cavity; 611, second switch upper cavity; 612, second switch lower cavity; 613, second switch piston member; 62, second control cavity; 621, second control upper cavity; 622, second control lower cavity; 623, second elastic member; 624, second control piston member; 63, second valve core member; 7, first adjusting assembly; 8, second adjusting assembly; 9, first operation handle; 10, second operation handle. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In addition, the technical features involved in the different embodiments of the application described below can be combined with each other as long as they do not conflict with each other.

[0033] As Figure 1 shown, the present embodiment provides a burst safety valve, comprising a main valve, a pressure measuring pipe 4, a second pilot valve 6 and a first pilot valve 5.

[0034] The main valve comprises a flow valve cavity 1 and a main control cavity 2, and a main valve core 3, wherein the flow valve cavity 1 is provided with a water inlet end 12 and a water outlet end 11 in the form of pipe ends on both sides respectively, and the main control cavity 2 is provided separately from the flow valve cavity 1, and in the present embodiment, the main control cavity 2 is provided on the upper side of the flow valve cavity 1. Further, the main body structure of the main valve core 3 is in the form of a straight rod, the main valve core 3 is arranged in the main control cavity 2, a part of which extends into the flow valve cavity 1, and has a stop position for closing the flow valve cavity 1 under the action of the main control cavity 2, and a flow-through position for opening the flow valve cavity 1;

[0035] The pressure measuring pipe 4 is provided in the form of a straight pipe, one end of which is in communication with the water outlet end 11. In the present embodiment, the flow cross-sectional diameter of the pressure measuring pipe 4 is smaller than the flow cross-sectional diameter of the flow valve cavity 1, and in the present embodiment, the flow cross-sectional size of the flow valve cavity 1 is uniformly arranged from the water inlet end 12 and the water outlet end 11, and as an alternative embodiment, the flow rate of the pressure measuring pipe 4 can be less than or equal to the flow rate of the water flow in the flow valve cavity 1.

[0036] The second pilot valve 6 is connected with the water inlet end 12, the main control cavity 2 and the pressure measuring pipe 4 respectively, and has a second valve closing state for communicating the water inlet end 12 and the main control cavity 2 under the mutual action of the internal pressure of the pressure measuring pipe 4 and the water inlet end 12, and a second valve opening state for cutting off the communication between the water inlet end 12 and the main control cavity 2;

[0037] The first pilot valve 5 is connected with the water outlet end 11 and is arranged between the water inlet end 12 and the second pilot valve 6, and has a first valve closing state for communicating the water inlet end 12 and the second pilot valve 6 under the action of the pressure of the water inlet end 12, and a first valve opening state for cutting off the second pilot valve 6. In the present embodiment, the first pilot valve 5 and the second pilot valve 6 are arranged in the same type. Such arrangement reduces the replacement and production cost, and as an alternative embodiment, the first pilot valve 5 and the second pilot valve 6 can be arranged in different types.

[0038] The main control cavity 2 is arranged to drive the main valve core 3 to move, thereby controlling the opening and closing of the water passage from the water inlet end 12 to the water outlet end 11 of the overflow valve cavity 1. The first pilot valve 5 and the second pilot valve 6 are arranged on the water passage of the main control cavity 2 and the water inlet end 12. The second pilot valve 6 is further connected with the pressure measuring pipe 4, and the opening and closing of the second pilot valve 6 can be controlled by the interaction between the pressure measuring pipe 4 and the water inlet end 12. The first pilot valve 5 is arranged on the water passage between the main control cavity 2 and the second pilot valve 6, and the first pilot valve 5 is further connected with the water outlet end 11, and the opening and closing of the first pilot valve 5 can be controlled by the water outlet end 11 and other external forces. The double pilot valves are arranged to use the pressure characteristics and flow rate characteristics of the front of the water inlet end 12 and the rear of the pressure measuring pipe 4 as double judgment standards to realize the selection of the flow passage and the blocking of the overflow valve cavity 1, and overcome the defect that the pressure drop is used as the double judgment standard of the valve action in the prior art, and the flow rate increase caused by the pressure increase upstream of the valve may lead to misoperation.

[0039] The flow rate of the water flowing through the water inlet end 12 and the water outlet end 11 of the overflow valve cavity 1 is Q, the overflow cross-sectional diameter of the overflow valve cavity 1 is D1, the diameter of the pressure measuring pipe 4 is D2, the water flow rate in the overflow valve cavity 1 is v1, the water flow rate in the pressure measuring pipe 4 is v2, and the diameter ratio k is the ratio of the overflow cross-sectional diameter of the overflow valve cavity 1 to the diameter of the pressure measuring pipe 4. Specifically,

[0040]

[0041] According to Bernoulli's principle, when the water flows,

[0042] The above formulas are associated, and

[0043] Further, when the water flowing through the valve is at a certain flow rate, the overflow cross-sectional diameter of the pressure measuring pipe 4 is smaller than the overflow cross-sectional diameter of the overflow valve cavity 1, so the above formula, the flow rate in the overflow valve cavity 1 is smaller than the flow rate in the pressure measuring pipe 4. According to Bernoulli's principle, the water pressure in the overflow valve cavity 1 is smaller than the water pressure in the pressure measuring pipe 4.

[0044] In this way, the second pilot valve 6 is connected with the water inlet end 12 and the pressure measuring pipe 4, and the water pressure difference between the two and the external force such as the elastic force of the elastic member are used to form a power together to drive the main valve core 3 in the main control cavity 2, thereby controlling the opening and closing of the overflow valve cavity 1.

[0045] In this embodiment, the main control cavity 2 includes a main control upper cavity 21, a main control lower cavity 22, a main elastic member 23, and a main piston member 24.

[0046] The main control cavity 2 is separated into a main control upper cavity 21 and a main control lower cavity 22 by a main piston piece 24, in this embodiment, the main piston piece 24 completely separates the main control upper cavity 21 and the main control lower cavity 22, which are arranged apart from each other, the main control upper cavity 21 is connected with the second pilot valve 6, and further, a first pilot valve 5 is arranged between the main control upper cavity 21 and the second pilot valve 6, and the first pilot valve 5 is used to realize on-off control of the main control upper cavity 21 and the second pilot valve 6.

[0047] The main elastic piece 23 is a spring piece, and can also be other elastic structures, the main elastic piece 23 is sleeved on the main valve core piece 3, in this embodiment, when the burst safety valve works, the main elastic piece 23 applies an elastic force to the main piston piece 24 towards the main control upper cavity 21, and can drive the main valve core piece 3 to stay in the flow-through position, the main piston piece 24 is arranged between the main control upper cavity 21 and the main control lower cavity 22, and is connected with the main valve core piece 3, can separate the main control upper cavity 21 and the main control lower cavity 22, and under the interaction of the pressure difference and the main elastic piece 23, drives the main valve core piece 3 to move or stop between the flow-through position and the stop position.

[0048] Further, the main control cavity 2 further comprises a main exhaust hole 25, the main exhaust hole 25 is arranged on the main control lower cavity 22, and is adapted to communicate with the external environment, and such an arrangement can keep the main control lower cavity 22 at the same pressure as the external environment. In this embodiment, the main elastic piece 23 is arranged in the main control lower cavity 22, and the two ends thereof are connected with the main piston piece 24 and the inner wall of the main control lower cavity 22 respectively.

[0049] As a variable implementation, the main exhaust hole 25 can not be arranged, and as another variable implementation, the main elastic piece 23 is arranged in the main control upper cavity 21, and applies a pulling stress to the main piston piece 24.

[0050] Further, the overflow valve cavity 1 comprises a flow guide part 13 and a sealing inner protrusion 14.

[0051] The flow guide part 13 is arranged between the water inlet end 12 and the water outlet end 11, and at least part of the extension direction of the flow guide part 13 is arranged in the same direction as the extension direction of the main valve core piece 3, and such an arrangement facilitates the on-off control of the overflow valve cavity 1 by the extension and retraction cooperation of the main valve core piece 3 and the sealing inner protrusion 14.

[0052] The sealing inner protrusion 14 protrudes from the inner wall of the flow guide part 13 in the circumferential direction, one end of the main valve core piece 3 extending into the overflow valve cavity 1 is provided with a sealing valve disc 31, the inner diameter of the sealing inner protrusion 14 is smaller than the outer diameter of the sealing valve disc 31, and in the stop position, the sealing valve disc 31 is sealingly abutted against the side of the sealing inner protrusion 14 facing the main control cavity 2, and is adapted to close the overflow valve cavity 1.

[0053] The second pilot valve 6 comprises a second switch cavity 61, a second control cavity 62 and a second valve core piece 63.

[0054] The second switch cavity 61 is connected to the water inlet end 12 and the main control cavity 2 respectively, and the second control cavity 62 is connected to the water inlet end 12 and the pressure pipe 4 respectively; the second valve core member 63 is arranged in the second switch cavity 61 and extends into the second control cavity 62, can move under the pressure difference between the second control cavity 62 and the second switch cavity 61, and in the second valve closing state, the second switch cavity 61 is connected to the water inlet end 12 and the main control cavity 2, and in the second valve opening state, the second switch cavity 61 is separated from the water inlet end 12 and the main control cavity 2.

[0055] Further, the second control cavity 62 comprises a second control upper cavity 621, a second control lower cavity 622 and a second elastic member 623.

[0056] The second control upper cavity 621 is connected to the water inlet end 12, and the second control lower cavity 622 is arranged separately from the second control upper cavity 621 and is connected to the pressure pipe 4; the second elastic member 623 is arranged on the second valve core member 63 and can drive the second valve core member 63 to stay in the second valve opening state; the second control piston member 624 is arranged between the second control upper cavity 621 and the second control lower cavity 622 and is connected to the second valve core member 63, is suitable for separating the second control upper cavity 621 and the second control lower cavity 622, and under the interaction of the pressure difference between the second control upper cavity 621, the second control lower cavity 622 and the second switch cavity 61 and the second elastic member 623, drives the second valve core member 63 to convert between the second valve closing state and the second valve opening state.

[0057] The second switch cavity 61 comprises a second switch upper cavity 611, a second switch lower cavity 612 and a second switch piston member 613.

[0058] Specifically, the second switch upper cavity 611 is connected to the main control upper cavity 21 of the main control cavity 2, the second switch lower cavity 612 is arranged in communication with the first guide valve 5, and the second switch piston member 613 is arranged between the second switch upper cavity 611 and the second switch lower cavity 612 and is connected to the second valve core member 63.

[0059] In this embodiment, in the second valve closing state, the second switch piston member 613 separates the second switch upper cavity 611 and the second switch lower cavity 612, and in the second valve opening state, the second switch piston member 613 connects the second switch upper cavity 611 and the second switch lower cavity 612; the second switch piston member 613 can drive the second valve core member 63 to convert between the second valve closing state and the second valve opening state under the interaction of the pressure difference between the second switch upper cavity 611, the second switch lower cavity 612 and the second control cavity 62 and the second elastic member 623.

[0060] The first guide valve 5 comprises a first switch cavity 51, a first control cavity 52 and a first valve core member 53.

[0061] The first switch cavity 51 is connected with the water inlet end 12 and the second switch lower cavity 612 of the second switch cavity 61 respectively, the first control cavity 52 is arranged at the lower side of the first switch cavity 51 and connected with the water outlet end 11; the first valve core 53 is arranged in the first switch cavity 51 and extends into the first control cavity 52, is adapted to move under the pressure difference of the first control cavity 52 and the first switch cavity 51, and in the first valve closing state, the water inlet end 12 and the second switch lower cavity 612 are communicated, and in the first valve opening state, the water inlet end 12 and the second switch lower cavity 612 are cut off.

[0062] The first control cavity 52 comprises a first control upper cavity 521, a first control lower cavity 522, a first elastic member 523 and a first control piston member 524.

[0063] Specifically, the first control upper cavity 521 is communicated with the water outlet end 11, the first control lower cavity 522 is arranged separately from the second control upper cavity 621 and is adapted to be communicated with the outside, the first elastic member 523 is arranged on the first valve core 53 and is adapted to drive the first valve core 53 to convert from the first valve closing state to the first valve opening state, and the first control piston member 524 is arranged between the first control upper cavity 521 and the first control lower cavity 522 and is connected with the first valve core 53, is adapted to separate the first control upper cavity 521 and the first control lower cavity 522, and under the interaction of the pressure difference, the first switch cavity 51 and the first elastic member 523, drives the first valve core 53 to convert between the first valve closing state and the first valve opening state. In this embodiment, the first elastic member 523 is specifically a spring member.

[0064] The first switch cavity 51 comprises a first switch upper cavity 511, a first switch lower cavity 512 and a first switch piston member 513.

[0065] In this embodiment, the first switch upper cavity 511 is communicated with the water inlet end 12, the first switch lower cavity 512 is communicated with the second switch lower cavity 612 of the second switch cavity 61. The first switch piston member 513 is arranged between the first switch upper cavity 511 and the first switch lower cavity 512 and is connected with the first valve core 53, can separate the first switch upper cavity 511 and the first switch lower cavity 512 in the first valve closing state, communicate the first switch upper cavity 511 and the first switch lower cavity 512 in the first valve opening state, and under the interaction of the pressure difference of the first switch upper cavity 511, the first switch lower cavity 512 and the first control cavity 52 and the first elastic member 523, drives the first valve core 53 to convert between the first valve closing state and the first valve opening state.

[0066] In the embodiment, the first elastic member 523 is arranged in the first control lower cavity 522, one end of which is connected with the first control piston member 524, and the other end of which is connected with the first adjusting assembly 7, which is adapted to adjust the elastic force of the first elastic member 523. The second elastic member 623 is arranged in the second control lower cavity 622, one end of which is connected with the second control piston member 624, and the other end of which is connected with the second adjusting assembly 8, which is adapted to adjust the elastic force of the second elastic member 623.

[0067] As a convertible embodiment, the first adjusting assembly 7 and the second adjusting assembly 8 can be provided only one of them.

[0068] In the embodiment, the first adjusting assembly 7 and the second adjusting assembly 8 are provided in the same type, specifically, the adjusting assembly comprises a locking nut arranged outside the pilot valve, and a locking bolt passing through the locking nut and extending into the control lower cavity of the corresponding pilot valve, the locking bolt is in abutment or fixed connection with the elastic member of the corresponding pilot valve. In this way, the pre-tightening force of the elastic member in the pilot valve can be manually adjusted by screwing the locking bolt, and then the pressure threshold or flow threshold when the overflow valve cavity 1 is closed can be adjusted, and the overall setting is simple and compact.

[0069] As a convertible embodiment, the first adjusting assembly 7 and the second adjusting assembly 8 can be a cover that can be opened and closed, and by opening and closing the cover, the model of the internal elastic member can be replaced, and then the pre-tightening force of the elastic member can be adjusted.

[0070] In the embodiment, one end of the second valve core member 63 penetrates out of the second switch cavity 61 and is provided with the second operating handle 10, and one end of the first valve core member 53 penetrates out of the first switch cavity 51 and is provided with the first operating handle 9. By providing the operating handle, it is convenient for maintenance personnel to manually control the on-off of the burst safety valve, and it is convenient for adjustment.

[0071] Working process:

[0072] I. When the burst safety valve is working normally, the water pressure of the inlet end 12, the water pressure of the outlet end 11 and the water pressure of the pressure measuring pipe 4 are all at stable values. The fluid in the pipeline before and after the burst safety valve has stable pressure and stable flow rate. At this time, the first pilot valve 5 blocks the communication between the second switch cavity 61 of the second pilot valve 6 and the inlet end 12.

[0073] In the first pilot valve 5, since the first control upper cavity 521 is communicated with the water outlet end 11, the first switch upper cavity 511 is communicated with the water inlet end 12, the first control lower cavity 522 is communicated with the outside, and the first switch lower cavity 512 is communicated with the second switch lower cavity 612 of the second pilot valve 6, at this time, the first elastic member 523 is arranged in the first control lower cavity 522 and arranged in a compressed state, the pre-tightening force of which is less than the water pressure of the first control upper cavity 521, the first control piston member 524 and the first switch piston member 513 are at the lower dead point, and the first switch piston member 513 blocks the communication between the water inlet end 12 and the second switch lower cavity 612;

[0074] In the second pilot valve 6, since the second control lower cavity 622 is connected with the pressure measuring tube 4, the second control upper cavity 621 is connected with the water inlet end 12, and the second switch upper cavity 611 is connected with the main control cavity 2 of the main valve core, the second switch lower cavity 612 is blocked from being connected with the water inlet end 12 by the first pilot valve 5, the second elastic member 623 is arranged in the second control lower cavity 622 and exerts a force on the second control piston member 624 towards the second control upper cavity 621, and in this embodiment, the water pressure of the overflow valve cavity 1 is less than the water pressure in the pressure measuring tube 4, and then the upper side pressure received by the second valve core member 63, the second control piston member 624 and the second switch piston member 613 is less than the lower side pressure, and then the second control piston member 624 and the second switch piston member 613 are at the upper dead point, and the second switch piston member 613 blocks the main control cavity 2 from the second switch lower cavity 612.

[0075] Then, the water pressure of the main control upper cavity 21 and the main control lower cavity 22 of the burst pipe safety valve is zero, the main piston member 24 is driven by the pre-tightening force of the main elastic member 23 to drive the main valve core member 3 and the sealing valve disc 31 to move away from the abutment with the sealing inner protrusion 14, the main valve core member 3 is at the flow-through position, and the overflow valve cavity 1 is at the open state.

[0076] II. When the pipe behind the burst pipe safety valve bursts, the water flow passing through the burst pipe safety valve rapidly rises, and the pressure of the pipes before and after the burst pipe safety valve rapidly decreases.

[0077] At this time, the flow rate at the positions of the water inlet end 12 and the water outlet end 11 rises, and the water pressure decreases, and correspondingly, in the first pilot valve 5, the water pressure in the first control upper cavity 521 decreases, the water pressure in the first switch upper cavity 511 decreases, and then under the action of the pre-tightening force of the first elastic member 523, the first valve core member 53 moves towards the upper side, and the first switch piston member 513 moves in the same direction, and then the first switch upper cavity 511 and the second switch upper cavity 611 are communicated, and further, the water inlet end 12 is communicated with the second switch lower cavity 612 of the second pilot valve 6.

[0078] In the second pilot valve 6, the water pressure difference between the inlet 12 and the pressure pipe 4 changes, the second switch piston 613 and the second control piston 624 are driven to move the second valve core 63 downward under the driving of the water pressure overcoming the elastic force, to connect the inlet 12 and the main control upper cavity 21, and then the water pressure of the main control upper cavity 21 balances the water flow impact of the overflow valve cavity 1, the main valve piston overcomes the pre-tightening force of the main valve spring, moves downward, and the main valve starts to close. In the process of closing, the water pressure of the outlet 11 and the pressure of the pressure pipe 4 gradually decrease, so the movement trend of the first valve core 53 upward and the second valve core 63 downward in the first pilot valve 5 does not change until the burst safety valve is fully closed.

[0079] Obviously, the above embodiments are only examples for clearly illustrating, but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A pipe rupture safety valve, characterized in that, include: The main valve includes a flow valve chamber (1), a main control chamber (2), and a main valve core (3). The flow valve chamber (1) is provided with an inlet end (12) and an outlet end (11). The main valve core (3) is located in the main control chamber (2) and extends into the flow valve chamber (1). It has a stop position that closes the flow valve chamber (1) under the action of the main control chamber (2) and a flow position that opens the flow valve chamber (1). The pressure measuring tube (4) is connected to the water outlet (11); The second pilot valve (6) is connected to the water inlet (12), the main control chamber (2), and the pressure measuring pipe (4) respectively. It has a second closed state where, under the interaction of the internal pressures of the pressure measuring pipe (4) and the water inlet (12), it connects the water inlet (12) and the main control chamber (2), and a second open state where it disconnects the water inlet (12) from the main control chamber (2). The second pilot valve (6) includes a second switching chamber (61), a second control chamber (62), and a second valve core (63). The second switching chamber (61) is connected to the... The water inlet (12) and the main control chamber (2) are connected. The second control chamber (62) is connected to the water inlet (12) and the pressure measuring tube (4) respectively. The second valve core (63) extends into the second switching chamber (61) and into the second control chamber (62). It is adapted to move under the pressure difference between the second control chamber (62) and the second switching chamber (61). In the second closed state, it connects the water inlet (12) and the main control chamber (2). In the second open state, it disconnects the water inlet (12) and the main control chamber (2). The second control chamber (62) includes a second upper control chamber (621), a second lower control chamber (622), a second elastic element (623), and a second control piston element (624). The second upper control chamber (621) is connected to the water inlet end (12). The second lower control chamber (622) is separated from the second upper control chamber (621) and communicates with the pressure measuring tube (4). The second elastic element (623) is disposed on the second valve core element (63) and is adapted to drive the second valve core element (63) to stay in the second open valve state. The second control piston (624) is disposed between the second control upper chamber (621) and the second control lower chamber (622), and is connected to the second valve core (63). It is adapted to separate the second control upper chamber (621) and the second control lower chamber (622), and under the interaction of the pressure difference between the second control upper chamber (621), the second control lower chamber (622) and the second switching chamber (61) and the second elastic member (623), it drives the second valve core (63) to switch between the second closed state and the second open state. A first pilot valve (5) is connected to the outlet end (11) and is connected between the inlet end (12) and the second pilot valve (6). It has a first closed state where, under the pressure of the inlet end (12), it connects the inlet end (12) and the second pilot valve (6), and a first open state where it disconnects the inlet end (12) and the second pilot valve (6). The first pilot valve (5) includes: The first switch chamber (51) is connected to the water inlet end (12) and the second switch chamber (612) of the second switch chamber (61), respectively. The first control chamber (52) is connected to the water outlet (11); The first valve core (53) extends into the first switching chamber (51) and into the first control chamber (52), and is adapted to move under the pressure difference between the first control chamber (52) and the first switching chamber (51). In the first closed valve state, it connects the water inlet (12) and the second lower switch chamber (612). In the first open valve state, it disconnects the water inlet (12) and the second lower switch chamber (612). The first control cavity (52) includes: The first control chamber (521) is connected to the water outlet (11); The first lower control chamber (522) is spaced apart from the second upper control chamber (621) and is suitable for communication with the outside world; The first elastic element (523) is disposed on the first valve core element (53) and is adapted to drive the first valve core element (53) to switch from the first closed valve state to the first open valve state. The first control piston (524) is disposed between the first control upper chamber (521) and the first control lower chamber (522) and is connected to the first valve core (53). It is adapted to separate the first control upper chamber (521) and the first control lower chamber (522) and drive the first valve core (53) to switch between the first valve closed state and the first valve open state under the interaction of their pressure difference, the first switching chamber (51) and the first elastic member (523).

2. The pipe rupture safety valve according to claim 1, characterized in that, The diameter of the flow section of the pressure measuring tube (4) is smaller than the diameter of the flow section of the flow valve cavity (1).

3. The pipe rupture safety valve according to claim 1 or 2, characterized in that, The main control cavity (2) includes: The main control chamber (21) is connected to the second pilot valve (6); The lower main control chamber (22) is separated from the upper main control chamber (21); The main elastic element (23) is disposed on the main valve core element (3) and is adapted to drive the main valve core element (3) to stay in the flow position; The main piston (24) is disposed between the main control upper chamber (21) and the main control lower chamber (22) and is connected to the main valve core (3). It is adapted to separate the main control upper chamber (21) and the main control lower chamber (22) and drive the main valve core (3) to move or stop between the flow position and the stop position under the interaction of the pressure difference and the main elastic element (23).

4. The pipe rupture safety valve according to claim 3, characterized in that, The main control chamber (2) also includes a main exhaust port (25), which is disposed on the main control lower chamber (22) and is suitable for connecting to the external environment; And / or, The main elastic element (23) is disposed in the main control lower cavity (22), and its two ends are respectively connected to the main piston element (24) and the inner wall of the main control lower cavity (22).

5. The pipe rupture safety valve according to claim 4, characterized in that, The overflow valve chamber (1) includes: The guide section (13) is disposed between the inlet end (12) and the outlet end (11), and is curved. At least part of the extension direction of the guide section (13) is in the same direction as the extension direction of the main valve core (3). A sealing inner protrusion (14) is provided circumferentially protruding from the inner wall of the guide portion (13). A sealing valve disc (31) is provided on one end of the main valve core (3) extending to the flow valve cavity (1). In the stop position, the sealing valve disc (31) and the sealing inner protrusion (14) are sealed and abutted against the side facing the main control cavity (2), which is suitable for closing the flow valve cavity (1).

6. The pipe rupture safety valve according to claim 1, characterized in that, The second switching cavity (61) includes: The second switch upper cavity (611) is connected to the main control upper cavity (21) of the main control cavity (2); The lower chamber (612) of the second switch is connected to the first pilot valve (5); The second switch piston (613) is disposed between the second switch upper chamber (611) and the second switch lower chamber (612) and is connected to the second valve core (63). It is adapted to drive the second valve core (63) to switch between the second closed state and the second open state under the interaction of the pressure difference between the second switch upper chamber (611), the second switch lower chamber (612) and the second control chamber (62) and the second elastic member (623).

7. The pipe rupture safety valve according to claim 1, characterized in that, The first switching cavity (51) includes: The upper cavity (511) of the first switch is connected to the water inlet (12); The first switch lower cavity (512) is connected to the second switch lower cavity (612) of the second switch cavity (61); The first switch piston (513) is disposed between the first switch upper chamber (511) and the first switch lower chamber (512) and is connected to the first valve core (53). It is adapted to drive the first valve core (53) to switch between the first closed valve state and the first open valve state under the interaction of the pressure difference between the first switch upper chamber (511), the first switch lower chamber (512) and the first control chamber (52) and the first elastic element (523).

8. The pipe rupture safety valve according to claim 7, characterized in that, The first elastic element (523) is disposed in the first control lower cavity (522), one end of which is connected to the first control piston (524), and the other end is connected to the first adjustment component (7). The first adjustment component (7) is adapted to adjust the elastic force of the first elastic element (523). And / or, The second elastic element (623) is disposed in the second control lower cavity (622), one end of which is connected to the second control piston (624), and the other end is connected to the second adjustment component (8). The second adjustment component (8) is adapted to adjust the elastic force of the second elastic element (623).

9. The pipe rupture safety valve according to claim 8, characterized in that, One end of the second valve core (63) extends out of the second switch cavity (61) and is provided with a second operating handle (10). One end of the first valve core (53) extends out of the first switch cavity (51) and is provided with a first operating handle (9).

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