Special pressure reducing valve for fire fighting

Abstract

The pressure reducing valve comprises a valve body, an adjusting block is arranged in one end of the valve body, the adjusting block is in threaded connection with the valve body, the adjusting block and the valve body jointly form a valve cavity, an input port is formed in the end portion of the other end of the valve body, and an output port is formed in the side wall of the other end of the valve body; one end of the valve element divides the valve cavity into a first cavity and a second cavity, the other end of the valve element penetrates through the side wall of the second cavity and then is located in the input port, the outer diameter of the part, penetrating through the second cavity, of the valve element shrinks inwards to form a groove, an input channel is formed between the groove and the second cavity, and the input port sequentially passes through the input channel and the second cavity and then is communicated with the output port; the valve is detachably connected to the input port; the pressure spring is positioned in the chamber I, and one end of the pressure spring is connected with the end part of the valve core; the thrust block is located in the first cavity, and the centers of the upper surface and the lower surface of the thrust block protrude outwards to form hemispheres which are embedded into the center of the other end of the compression spring and make contact with the adjusting block respectively. The air pressure adjusting device has the beneficial effects that the purposes that labor is saved during air pressure adjusting, and the structure is simple are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field related to pressure reducing valves, and in particular to a special pressure reducing valve for fire fighting. Background Art

[0002] Among various disasters, fire is one of the most frequent and common major disasters that threaten public safety and social development. As people's awareness of fire protection continues to increase, fire extinguishing systems are not only installed in large engineering buildings, but also in closed and narrow electrical equipment and distribution cabinets to protect electrical equipment. The standby pressure fire extinguishing device is a common fire extinguishing device in real production and life.

[0003] The standby pressure fire extinguishing device stores the liquid fire extinguishing agent in one container, and the propulsion gas is stored in another high-pressure container in a gaseous state. The two containers are connected by a power gas container valve, a fire extinguishing agent start valve, a fire extinguishing agent container valve and a connecting pipe. When a fire occurs, the control center sends a start signal to open the power gas container valve to release the power gas, which is then filled into the fire extinguishing agent container after being decompressed by the fire extinguishing agent start valve, so that the pressure in the fire extinguishing agent container increases, and the fire extinguishing agent is pushed out of the container, and then gasified through the delivery pipeline to the nozzle and sprayed to the protected place to achieve the purpose of extinguishing the fire.

[0004] The pressure reducing valves currently on the market are valves that reduce the inlet pressure to a certain required outlet pressure through regulation, and rely on the energy of the medium itself to automatically keep the outlet pressure stable. From the perspective of fluid mechanics, the pressure reducing valve is a throttling element with variable local resistance, that is, by changing the throttling area, the flow rate and the kinetic energy of the fluid are changed, resulting in different pressure losses, thereby achieving the purpose of reducing pressure. Then, relying on the regulation of the control and regulation system, the fluctuation of the pressure behind the valve is balanced with the spring force, so that the pressure behind the valve remains constant within a certain error range.

[0005] The pressure reducing valve in the prior art usually adjusts the output air pressure by manually rotating the adjusting handle so that the adjusting handle directly acts on the compression spring and changes the deformation of the compression spring. Through the above operation, when the adjusting handle rotates relative to the compression spring, on the one hand, it is easy to cause wear on the surface of the compression spring, which can easily affect the accuracy of air pressure regulation. On the other hand, due to the large contact area between the adjusting handle and the compression spring, it is necessary to overcome a large friction force when rotating the adjusting handle, which makes the operation laborious. In addition, the pressure reducing valve in the prior art often has a complex structure and is inconvenient to use, which will bring great difficulties to the installation and maintenance of the pressure reducing valve, and at the same time, it also brings great manufacturing costs to the enterprise. Summary of the invention

[0006] The present invention aims to overcome the shortcomings of the prior art that the regulating handle is laborious to operate and has a complex structure when regulating air pressure, and provides a fire-fighting special pressure reducing valve that is labor-saving to operate and has a simple structure when regulating air pressure.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A fire-fighting special pressure reducing valve, comprising: A valve body, one end of which is provided with an adjusting block, the adjusting block is threadedly connected to the valve body and forms a valve cavity together with the valve body, the other end of which is provided with an input port, and the other end of which is provided with an output port on the side wall; A valve core, one end of which divides the valve cavity into chamber one and chamber two, and the other end of which penetrates the side wall of chamber two and is located in the input port, the outer diameter of the portion of the valve core that penetrates chamber two is shrunk to form a groove, an input channel is formed between the groove and the portion of chamber two penetrated by the valve core, and the input port is connected to the output port after passing through the input channel and chamber two in sequence: A connecting nut, detachably connected to the input port; A compression spring, located in the chamber 1, one end of which is connected to the end of the valve core; The thrust block is located in the chamber 1, and the centers of the upper and lower surfaces thereof are both protruded outward to form a hemisphere respectively embedded in the center of the other end of the compression spring and in contact with the adjustment block. High-pressure gas is input from the input port, and then enters the chamber 2 through the input channel, so that the valve core compresses the compression spring to move upward until the gas pressure and the force of the compression spring reach a balance, and finally the decompressed gas is output from the output port. The output gas pressure is adjusted by adjusting the tightness of the compression spring. Therefore, when adjusting the output air pressure before use, the operator rotates the adjusting block clockwise or counterclockwise, and the adjusting block acts on the compression spring through the thrust block to control the tightness of the compression spring, which is simple and convenient to operate; in the above-mentioned adjustment process, since the centers of the upper and lower surfaces of the thrust block are both protruding outward to form hemispherical bodies respectively embedded in the center of the other end of the compression spring and in contact with the adjusting block, on the one hand, it is beneficial for the adjusting block to always be in close contact with the compression spring through the thrust block, thereby preventing the adjusting block from loosening freely and ensuring the position stability of the compression spring; on the other hand, the adjusting block is in contact with the hemispherical body on the upper surface of the thrust block, avoiding the adjusting block from directly contacting the end face of the compression spring, preventing the surface wear of the compression spring, and extending the service life of the compression spring while reducing the influence on the air pressure adjustment accuracy, and also reducing the contact area between the adjusting block and the thrust block, reducing the friction resistance when the adjusting block rotates, and saving effort in operation; compared with the traditional pressure reducing valve, the pressure reducing valve involves relatively fewer components, which is convenient for the installation and maintenance of the pressure reducing valve, and is conducive to cost saving, achieving the purpose of labor-saving operation and simple structure when adjusting the air pressure.

[0008] Preferably, the valve core includes a valve stem and a valve block, one end of the valve stem is detachably connected to the center of the valve block, the other end of the valve stem penetrates the side wall of chamber two and is located in the input port, the groove is located on the side wall of the other end of the valve stem, the caliber of chamber one is larger than the caliber of chamber two, and the junction of chamber one and chamber two forms an annular step surface, and the valve block fits with the step surface under the action of the compression spring. The valve block fits with the step surface under the action of the compression spring, so that in the initial state, the valve block, the compression spring, the thrust block and the adjustment block can fit closely with each other, improve the connection strength and position stability of the structure, so as to ensure the pressure adjustment accuracy and smoothly carry out the pressure reduction work.

[0009] Preferably, the outer circumferential side wall of the valve block fits with the side wall of chamber 1, and the valve block is slidably connected to chamber 1. The outer circumferential side wall of the valve block fits with the side wall of chamber 1, which is conducive to the valve block being able to always move along the length direction of chamber 1 under the driving action of high-pressure gas, avoiding radial deviation of the position of the valve block, thereby indirectly ensuring the normal expansion and contraction of the compression spring, preventing the compression spring from deformation, and helping to extend the service life of the compression spring.

[0010] Preferably, one side of the valve block is fitted with the step surface and its center is detachably connected to the valve stem, and the other side of the valve block corresponding to the valve block is provided with a clamping block matching the inside of the compression spring, and the clamping block is fixedly connected to the center of the valve block. The clamping block is embedded in one end of the compression spring, and at the same time, the hemispherical body protruding outward from the center of the lower surface of the thrust block is embedded in the other end of the compression spring, which further improves the position stability and connection strength of the compression spring, prevents the compression spring from positional deviation, ensures the normal expansion and contraction of the compression spring, prevents the compression spring from deformation, and helps to extend the service life of the compression spring.

[0011] Preferably, the step surface is located at one end of chamber two, and a through hole one connected to the input port is provided at the center of the other end of chamber two, and both ends of through hole one are provided with bell mouths open to the outside of through hole one, and the other end of the valve stem passes through through hole one and is located in the input port, and the input channel is formed by the groove and through hole one.

[0012] Preferably, a thread groove is provided at the center of the valve block, one end of the valve stem is threadedly connected to the thread groove and a stopper is provided on the outer side wall thereof, the stopper is fixedly connected to the valve stem and is located outside the thread groove, the stopper covers the thread groove and contacts the surface of the valve block, and a cross groove is provided at the other end of the valve stem. The cross groove facilitates the operator to screw the valve stem into the thread groove on the valve block with a screwdriver, and at the same time, the stopper is limited to indicate that the valve stem has been rotated and assembled in place, and installation and disassembly are simple and convenient.

[0013] Preferably, a connecting sleeve is provided at the input port, one end of the connecting sleeve is threadedly connected to the input port, the other end of the connecting sleeve is provided with a polygonal groove 1, the bottom of the polygonal groove 1 is provided with a through hole 2, the polygonal groove 1 is connected to the cross groove through the through hole 2, the outer wall of the other end of the connecting sleeve is fixed with a flange edge, the flange edge is located outside the input port, the outer wall of the input port and the flange edge together form a mounting groove, the end of the connecting nut is fixed with a mounting ring matching the mounting groove, the connecting nut is detachably fixedly connected to the input port through the mounting ring matching the mounting groove. When assembling the connecting nut, firstly, the connecting nut is set on the outer wall of the input port through the mounting ring sleeve, and then the connecting sleeve is screwed into the input port from the inside of the connecting nut by using the corresponding screwdriver head matching the polygonal groove 1, so that the mounting ring on the connecting nut is limited to be located in the mounting groove, so as to facilitate the threaded docking of the connecting nut with the external component, the structure is simple, and the installation and disassembly are convenient and quick; the polygonal groove 1 is connected to the cross groove through the through hole 2, which is convenient for the assembly and disassembly of the valve stem and the valve body.

[0014] Preferably, the inner diameter of the second through hole is larger than the maximum diameter of the valve stem, so as to facilitate the assembly and disassembly of the valve stem and the valve body, which is convenient and quick.

[0015] Preferably, a screw sleeve is provided at one end of the valve body, the inner diameter of the screw sleeve is larger than the inner diameter of the compression spring and smaller than the outer diameter of the compression spring, an L-shaped limit groove is provided on the outer side wall of one end of the screw sleeve, the limit groove is connected to the inner thread of one end of the valve body, the adjustment block is threadedly connected to one end of the screw sleeve, the thrust block is located in the other end of the screw sleeve, one side of the adjustment block is in contact with the thrust block, and the other side of the adjustment block corresponding to the adjustment block is provided with a second polygonal groove. The inner diameter of the screw sleeve is larger than the inner diameter of the compression spring and smaller than the outer diameter of the compression spring, which is convenient for preliminary limiting of the compression spring; the thrust block is located in the other end of the screw sleeve, which is convenient for radial limiting of the thrust block, and further ensures the matching accuracy of the thrust block and the compression spring; the operator rotates the adjustment block by matching the corresponding screwdriver head with the second polygonal groove, which is convenient for adjusting the size of the output air pressure, and the operation is convenient and quick.

[0016] Preferably, the inner side wall of the connecting nut and the inner side wall of the output port are both provided with connecting threads, which facilitate threaded connection with corresponding external components, and are easy and quick to operate.

[0017] The beneficial effects of the present invention are as follows: the operator rotates the adjusting block clockwise or counterclockwise, and the adjusting block acts on the compression spring through the thrust block to control the tightness of the compression spring, and the operation is simple and convenient; the structural design of the thrust block, on the one hand, is conducive to the adjusting block always being in close contact with the compression spring through the thrust block, thereby preventing the adjusting block from loosening freely and ensuring the position stability of the compression spring; on the other hand, the adjusting block is in contact with the hemispherical body on the upper surface of the thrust block, avoiding the adjusting block from directly contacting the end face of the compression spring, preventing the surface wear of the compression spring, and helping to extend the service life of the compression spring while reducing the influence on the air pressure regulation accuracy. , and also reduces the contact area between the regulating block and the thrust block, reduces the friction resistance when the regulating block rotates, and saves effort in operation; compared with the traditional pressure reducing valve, the pressure reducing valve involves relatively fewer parts, which is convenient for the installation and maintenance of the pressure reducing valve, and is conducive to cost saving, achieving the purpose of labor-saving operation and simple structure when adjusting the air pressure; it is convenient for the valve block, the compression spring, the thrust block and the regulating block to fit closely with each other, improves the connection strength and position stability of the structure, so as to ensure the pressure adjustment accuracy and smoothly carry out the pressure reducing work; compared with the traditional pressure reducing valve, the structure is simple, which is conducive to cost saving, and the installation and disassembly are convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a front view of the present invention; Figure 3 yes Figure 2 Sectional view of AA.

[0019] In the figure: 1. valve body, 2. adjusting block, 3. input port, 4. output port, 5. valve core, 6. chamber 1, 7. chamber 2, 8. groove, 9. connecting nut, 10. compression spring, 11. thrust block, 12. hemispherical body, 13. valve stem, 14. valve block, 15. step surface, 16. clamping block, 17. through hole 1, 18. bell mouth, 19. threaded groove, 20. stopper, 21. cross groove, 22. connecting sleeve, 23. polygonal groove 1, 24. through hole 2, 25. flange edge, 26. mounting groove, 27. mounting ring, 28. screw sleeve, 29. limit groove, 30. polygonal groove 2. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] Unless otherwise specified, the relative arrangement of the components, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present application. For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right" are used in the embodiments to illustrate the relationship between an element or feature shown in the figure and another element or feature. It should be understood that, in addition to the orientation shown in the figure, the spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be fixed "on" other elements or features. Therefore, the exemplary term "lower" can include both upper and lower orientations. The device can be fixed in other ways (rotated 90 degrees or located in other orientations), and the spatial relative description used here can be interpreted accordingly. At the same time, it should be understood that for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, process and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, process and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.It should be noted that similar reference numerals and letters denote similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0023] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0024] like Figure 1 , Figure 2 and Figure 3 In the embodiment described, a fire-fighting pressure reducing valve is provided, which includes a valve body 1, one end of which is provided with an adjusting block 2, the adjusting block 2 is threadedly connected to the valve body 1 and forms a valve cavity together with the valve body 1, the other end of which is provided with an input port 3, and the other end of which is provided with an output port 4 on the side wall; a valve core 5, one end of which divides the valve cavity into chamber 1 6 and chamber 2 7, and the other end of which penetrates the side wall of chamber 2 7 and is located in the input port 3, the outer diameter of the part of the valve core 5 penetrating the chamber 2 7 is contracted to form a groove 8, and an input channel is formed between the groove 8 and the part of the chamber 2 7 penetrated by the valve core 5, and the input port 3 is connected to the output port 4 after passing through the input channel and chamber 2 7 in turn; a connecting nut 9, which is detachably connected to the input port 3; a compression spring 10, which is located in chamber 1 6, and one end of which is connected to the end of the valve core 5; a thrust block 11, which is located in chamber 1 6, and the centers of its upper and lower surfaces are both protruding outward to form a hemispherical body 12 respectively embedded in the center of the other end of the compression spring 10 and in contact with the adjusting block 2.

[0025] The valve core 5 includes a valve stem 13 and a valve block 14. One end of the valve stem 13 is detachably connected to the center of the valve block 14. The other end of the valve stem 13 passes through the side wall of chamber 2 7 and is located in the input port 3. The groove 8 is located on the side wall of the other end of the valve stem 13. The diameter of chamber 1 6 is larger than the diameter of chamber 2 7. An annular step surface 15 is formed at the connection between chamber 1 6 and chamber 2 7. The valve block 14 fits with the step surface 15 under the action of the compression spring 10.

[0026] The outer circumferential side wall of the valve block 14 fits with the side wall of the chamber 16, and the valve block 14 is slidably connected to the chamber 16. One side of the valve block 14 fits with the step surface 15 and its center is detachably connected to the valve stem 13. The other side of the valve block 14 corresponding to the valve block 14 is provided with a block 16 matching the inside of the compression spring 10, and the block 16 is fixedly connected to the center of the valve block 14. The step surface 15 is located at one end of the chamber 2 7, and the center of the other end of the chamber 2 7 is provided with a through hole 17 connected to the input port 3. Both ends of the through hole 17 are provided with a bell mouth 18 open to the outside of the through hole 17. The other end of the valve stem 13 passes through the through hole 17 and is located in the input port 3. The input channel is formed by the groove 8 and the through hole 17.

[0027] A thread groove 19 is provided at the center of the valve block 14, one end of the valve stem 13 is threadedly connected to the thread groove 19 and a stopper 20 is provided on its outer side wall, the stopper 20 is fixedly connected to the valve stem 13 and is located outside the thread groove 19, the stopper 20 covers the thread groove 19 and contacts the surface of the valve block 14, and a cross groove 21 is provided at the other end of the valve stem 13.

[0028] A connecting sleeve 22 is provided at the input port 3, one end of the connecting sleeve 22 is threadedly connected to the input port 3, the other end of the connecting sleeve 22 is provided with a polygonal groove 1 23, the bottom of the polygonal groove 1 23 is provided with a through hole 24, the polygonal groove 1 23 is connected to the cross groove 21 through the through hole 24, the other end of the connecting sleeve 22 is fixed with a flange edge 25 on the outer side wall, the flange edge 25 is located outside the input port 3, the outer side wall of the input port 3 and the flange edge 25 together form a mounting groove 26, the end of the connecting nut 9 is fixed with a mounting ring 27 matching the mounting groove 26, the connecting nut 9 is matched with the mounting groove 26 through the mounting ring 27 and can be detachably fixedly connected to the input port 3. The inner diameter of the through hole 24 is larger than the maximum diameter of the valve stem 13.

[0029] One end of the valve body 1 is provided with a screw sleeve 28, the inner diameter of which is larger than the inner diameter of the compression spring 10 and smaller than the outer diameter of the compression spring 10, an L-shaped limit groove 29 is provided on the outer wall of one end of the screw sleeve 28, the limit groove 29 is connected with the inner thread of one end of the valve body 1, the adjustment block 2 is threadedly connected in one end of the screw sleeve 28, the thrust block 11 is located in the other end of the screw sleeve 28, one side of the adjustment block 2 is in contact with the thrust block 11, and the other side of the adjustment block 2 corresponding to the adjustment block 2 is provided with a polygonal groove 2 30. The inner side wall of the connecting nut 9 and the inner side wall of the output port 4 are both provided with connecting threads.

[0030] High-pressure gas is input from the input port 3, and then enters the chamber 2 7 through the input channel. The high-pressure gas acts on the valve core 5, so that the valve core 5 compresses the compression spring 10 to move upward until the gas pressure and the force of the compression spring 10 reach a balance, and finally the decompressed gas is output from the output port 4. In the above process, the output air pressure is adjusted by adjusting the tightness of the compression spring 10. Therefore, when adjusting the output air pressure before use, the operator rotates the adjustment block 2 clockwise or counterclockwise by matching the corresponding screwdriver head with the polygonal groove 2 30. The adjustment block 2 acts on the compression spring 10 through the thrust block 11 to control the tightness of the compression spring 10, which is simple and convenient to operate. In the above-mentioned adjustment process, since the centers of the upper and lower surfaces of the thrust block 11 both protrude outward to form a hemispherical body 12 respectively embedded in the center of the other end of the compression spring 10 and in contact with the adjustment block 2, on the one hand, it is beneficial for the adjustment block 2 to always be in close contact with the compression spring 10 through the thrust block 11, thereby preventing the adjustment block 2 from loosening freely and ensuring the position stability of the compression spring 10; on the other hand, the adjustment block 2 is in contact with the hemispherical body 12 on the upper surface of the thrust block 11, avoiding direct contact between the adjustment block 2 and the end face of the compression spring 10, preventing the surface wear of the compression spring 10, and extending the service life of the compression spring 10 while reducing the influence on the air pressure adjustment accuracy, and also reducing the contact area between the adjustment block 2 and the thrust block 11, reducing the friction resistance when the adjustment block 2 rotates, and having a simple structure and labor-saving operation.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fire-fighting pressure reducing valve, characterized in that it includes: A valve body (1) having an adjusting block (2) disposed in one end thereof, the adjusting block (2) being threadedly connected to the valve body (1) and forming a valve cavity together with the valve body (1), an input port (3) disposed at the other end thereof, and an output port (4) disposed on the side wall of the other end thereof; A valve core (5), one end of which divides the valve cavity into chamber one (6) and chamber two (7), and the other end of which penetrates the side wall of chamber two (7) and is located in the input port (3); the outer diameter of the portion of the valve core (5) that penetrates chamber two (7) is inwardly contracted to form a groove (8); an input channel is formed between the groove (8) and the portion of chamber two (7) penetrated by the valve core (5); the input port (3) is connected to the output port (4) through the input channel and chamber two (7) in sequence; A connecting nut (9) detachably connected to the input port (3); A compression spring (10), located in the chamber 1 (6), one end of which is connected to the end of the valve core (5); The thrust block (11) is located in the chamber 1 (6), and the centers of the upper and lower surfaces thereof are both protruded outward to form a hemispherical body (12) which is respectively embedded in the center of the other end of the compression spring (10) and in contact with the adjustment block (2).

2. A fire-fighting pressure reducing valve according to claim 1, characterized in that: The valve core (5) comprises a valve stem (13) and a valve block (14); one end of the valve stem (13) is detachably connected to the center of the valve block (14); the other end of the valve stem (13) passes through the side wall of chamber two (7) and is located in the input port (3); the groove (8) is located on the side wall of the other end of the valve stem (13); the caliber of chamber one (6) is larger than the caliber of chamber two (7); an annular step surface (15) is formed at the connection between chamber one (6) and chamber two (7); and the valve block (14) fits the step surface (15) under the action of the compression spring (10).

3. A fire-fighting pressure reducing valve according to claim 2, characterized in that: The outer circumferential side wall of the valve block (14) fits the side wall of the chamber one (6), and the valve block (14) is slidably connected to the chamber one (6).

4. A fire-fighting pressure reducing valve according to claim 2, characterized in that: One side of the valve block (14) is in contact with the step surface (15) and its center is detachably connected to the valve stem (13); the other side of the valve block (14) corresponding to the valve block (14) is provided with a clamping block (16) matching the inside of the compression spring (10); the clamping block (16) is fixedly connected to the center of the valve block (14).

5. A fire-fighting pressure reducing valve according to claim 2, characterized in that: The step surface (15) is located at one end of the second chamber (7); a through hole (17) communicating with the input port (3) is provided at the center of the other end of the second chamber (7); both ends of the through hole (17) are provided with bell mouths (18) open toward the outside of the through hole (17); the other end of the valve stem (13) passes through the through hole (17) and is located in the input port (3); the input channel is formed by the groove (8) and the through hole (17).

6. A fire-fighting pressure reducing valve according to claim 2, characterized in that: A thread groove (19) is provided at the center of the valve block (14); one end of the valve stem (13) is threadedly connected to the thread groove (19) and a stopper (20) is provided on its outer wall; the stopper (20) is fixedly connected to the valve stem (13) and is located outside the thread groove (19); the stopper (20) covers the thread groove (19) and contacts the surface of the valve block (14); and the other end of the valve stem (13) is provided with a cross groove (21).

7. A fire-fighting pressure reducing valve according to claim 6, characterized in that: The input port (3) is provided with a connecting sleeve (22), one end of the connecting sleeve (22) is threadedly connected to the input port (3), the other end of the connecting sleeve (22) is provided with a polygonal groove (23), the bottom of the polygonal groove (23) is provided with a second through hole (24), the polygonal groove (23) is connected to the cross groove (21) through the second through hole (24), the other end of the connecting sleeve (22) is fixed with a flange edge (25) on the outer side wall, the flange edge (25) is located outside the input port (3), the outer side wall of the input port (3) and the flange edge (25) together form a mounting groove (26), the end of the connecting nut (9) is fixed with a mounting ring (27) matching the mounting groove (26), the connecting nut (9) is detachably fixedly connected to the input port (3) through the mounting ring (27) matching the mounting groove (26).

8. A fire-fighting pressure reducing valve according to claim 7, characterized in that: The inner diameter of the second through hole (24) is greater than the maximum diameter of the valve stem (13).

9. A fire-fighting pressure reducing valve according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8, characterized in that: A screw sleeve (28) is provided at one end of the valve body (1), the inner diameter of the screw sleeve (28) is larger than the inner diameter of the compression spring (10) and smaller than the outer diameter of the compression spring (10), an L-shaped limiting groove (29) is provided on the outer wall of one end of the screw sleeve (28), the limiting groove (29) is threadedly connected to the inner part of one end of the valve body (1), the adjusting block (2) is threadedly connected to the inner part of one end of the screw sleeve (28), the thrust block (11) is located in the inner part of the other end of the screw sleeve (28), one side of the adjusting block (2) is in contact with the thrust block (11), and the other side of the adjusting block (2) corresponding to the adjusting block (2) is provided with a polygonal groove 2 (30).

10. A fire-fighting pressure reducing valve according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8, characterized in that: The inner side wall of the connecting nut (9) and the inner side wall of the output port (4) are both provided with connecting threads.

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