Pressure reducing valve for a fire hydrant

Abstract

The utility model provides a pressure reducing valve for fire hydrant belongs to valve technical field, including valve body, the valve body top fixedly connected with lower bonnet and upper bonnet, upper bonnet is fixed in lower bonnet top, the lower bonnet is slidably connected with piston rod, has been seted up on the lower bonnet bottom surface and has opened the movable slot, the piston rod upper portion is provided with the piston, the piston is located in movable slot, control chamber is formed between the piston and movable slot top surface, the piston rod inside is provided with liquid passage, one end of liquid passage is linked together with valve body inside, other end is linked together with control chamber. The utility model can guarantee that pressure reducing valve realizes effective pressure reduction, avoids the overpressure or low pressure situation of fire hydrant outlet pressure when extinguishing fire, ensures that the water flow keeps stable in the fire extinguishing process.

Description

Technical Field

[0001] This utility model belongs to the field of valve technology, and in particular relates to a pressure reducing valve for fire hydrants. Background Technology

[0002] Fire hydrants are fire-fighting facilities that supply water to fire scenes. They are used in buildings, industrial and mining enterprises, public places, and other fire-fighting water supply systems. In fire protection systems, the fire hydrant pressure reducing valve is a crucial component. Its working principle involves automatically adjusting the water pressure within the pipe through an internal regulating mechanism, maintaining it within a set safe range.

[0003] A stable water flow is crucial during firefighting. Excessively high or low water pressure will affect the stability of the water flow, thus impacting the firefighting effectiveness. Fire hydrant pressure reducing valves can adjust the water pressure in the pipeline in real time, ensuring a stable water flow throughout the firefighting process.

[0004] Existing fire hydrant pressure reducing valves are equipped with pressure reducing devices that achieve pressure reduction through the cooperation of a piston, piston sleeve, and spring. These devices are typically located along the valve stem or at the valve outlet. The spring is a key component for pressure reduction adjustment. However, over time, the spring may experience fatigue fracture, plastic deformation, or other elasticity failures, leading to the fire hydrant pressure reducing valve failing to effectively reduce pressure during a fire. This results in overpressure or low pressure at the fire hydrant outlet, making it impossible to ensure a stable water flow during firefighting and impacting fire safety. Utility Model Content

[0005] In view of the defects or deficiencies in the existing technology, this utility model provides a pressure reducing valve for fire hydrants, which can ensure that the pressure reducing valve can effectively reduce pressure, avoid overpressure or low pressure at the fire hydrant outlet during fire extinguishing, and ensure that the water flow remains stable during the fire extinguishing process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: An embodiment of this utility model provides a pressure reducing valve for a fire hydrant, including a valve body, a lower valve cover and an upper valve cover fixedly connected to the top of the valve body, the upper valve cover being fixed above the lower valve cover, a piston rod slidably connected to the lower valve cover, a movable groove being provided on the bottom surface of the lower valve cover, a piston being provided on the upper part of the piston rod, and the piston being located in the movable groove; A control chamber is formed between the piston and the top surface of the movable groove. A liquid channel is provided inside the piston rod. One end of the liquid channel is connected to the inside of the valve body, and the other end is connected to the control chamber.

[0007] Furthermore, the valve body is hollow inside, with a valve body inlet at the bottom, a valve body outlet on the side wall, and an opening at the top. The lower valve cover is fixed to the opening at the top of the valve body.

[0008] Furthermore, a sealing ring is provided at the junction of the outer wall of the lower valve cover and the inner wall of the valve body.

[0009] Furthermore, a valve disc is provided at the bottom end of the piston rod, and a bolt hole is provided at the axis of the valve disc, and the valve disc is fixed to the bottom end of the piston rod by bolts.

[0010] Furthermore, a sealing plate is fixed on the bottom surface of the valve disc.

[0011] Furthermore, a valve stem hole is provided at the top axis of the upper valve cover, and the valve stem hole is connected to the movable groove.

[0012] Furthermore, a valve stem is threaded into the valve stem hole, and a connecting groove is provided at the bottom end of the valve stem, which is adapted to the top end of the piston rod.

[0013] Furthermore, sealing rings are provided between the piston and the inner wall of the movable groove, and between the piston rod and the inner wall of the piston hole.

[0014] Furthermore, a sealing ring is provided between the top of the upper valve cover and the valve stem, and a packing gland is provided at the top of the upper valve cover.

[0015] Furthermore, a handwheel is fixedly connected to the top of the valve stem.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention features a liquid channel within the piston rod, with both ends connecting to the control chamber and the valve body. Water within the valve body flows from the liquid channel to the control chamber and acts on the upper surface of the piston. Under different working pressures and flow rates, different liquid pressures are generated within the control chamber, causing the piston to reciprocate within the control chamber. This stabilizes the outlet pressure of the pressure-reducing valve, reducing the uncertainty of the pressure-reducing performance of the pressure-stabilizing fire hydrant after prolonged use of the spring components. It also prevents overpressure or low pressure at the fire hydrant outlet during firefighting, ensuring a stable water flow during the firefighting process. Attached Figure Description

[0017] Figure 1 This is a diagram showing the internal structure of the pressure reducing valve in an embodiment of this utility model; The components are as follows: 1. Valve body; 2. Valve body inlet; 3. Valve body outlet; 4. Lower valve cover; 5. Sealing ring; 6. Upper valve cover; 7. Piston rod; 8. Piston; 9. Control chamber; 10. Liquid passage; 11. Valve disc; 12. Sealing plate; 13. Locking bolt; 14. Gasket; 15. Valve stem; 16. Connecting groove; 17. Packing gland; 18. Handwheel. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] A typical embodiment of this utility model is as follows: Figure 1 As shown, a pressure reducing valve for a fire hydrant includes a valve body 1, which is hollow inside. A valve body inlet 2 is located at the bottom of the valve body 1, a valve body outlet 3 is located on the side wall of the valve body 1, and an opening is located at the top of the valve body 1. A lower valve cover 4 is fixedly connected to the opening at the top of the valve body 1. A sealing ring 5 is provided at the junction of the outer wall of the lower valve cover 4 and the inner wall of the valve body 1 to ensure the sealing performance of the valve body 1. An upper valve cover 6 is fixedly connected above the lower valve cover 4. A movable groove is provided at the bottom of the upper valve cover 6, and a piston hole is provided at the axis of the lower valve cover 4. A piston rod 7 is slidably connected inside the piston hole. A piston 8 is provided on the upper part of the piston rod 7. The piston 8 and the piston rod 7 are integrally formed. The piston 8 is located in the movable groove and is adapted to the movable groove. Sealing rings 5 ​​are provided between the piston 8 and the inner wall of the movable groove, and between the piston rod 7 and the inner wall of the piston hole, to ensure the sealing performance between the piston 8 and the movable groove, and between the piston rod 7 and the piston hole.

[0020] A control chamber 9 is formed between the piston 8 and the top surface of the movable groove. A liquid channel 10 is provided inside the piston rod 7. One end of the liquid channel 10 is connected to the control chamber 9, and the other end is connected to the inside of the valve body 1. The liquid inside the valve body 1 can flow into the control chamber 9 through the liquid channel 10.

[0021] A valve disc 11 is fixedly connected to the bottom end of the piston rod 7. The valve disc 11 can cover the valve body inlet 2. A sealing plate 12 is provided on the bottom surface of the valve disc 11. The sealing plate 12 can contact the valve body inlet 2, thereby sealing the valve body inlet 2. A bolt hole is provided at the axis of the valve disc 11. The valve disc 11 is fixed to the bottom end of the piston rod 7 by a locking bolt 13.

[0022] A gasket 14 is also fitted on the outside of the locking bolt 13. The gasket 14 is located below the valve disc 11. When the locking bolt 13 is tightened, the gasket 14 is used to fix the sealing plate 12 to the bottom surface of the valve disc 11.

[0023] A valve stem hole is provided at the top axis of the upper valve cover 6. The valve stem hole is connected to the movable groove. The axis of the valve stem hole coincides with the axis of the piston hole. A valve stem 15 is threaded into the valve stem hole. A connecting groove 16 is provided at the bottom of the valve stem 15. The connecting groove 16 is adapted to the top of the piston rod 7. The top of the piston rod 7 can be inserted into the connecting groove 16, thereby realizing the movable connection between the piston rod 7 and the valve stem 15.

[0024] A sealing ring 5 is provided between the top of the upper valve cover 6 and the valve stem 15, and a packing gland 17 is provided at the top of the upper valve cover 6, thereby ensuring the sealing between the upper valve cover 6 and the valve stem 15.

[0025] A handwheel 18 is fixedly connected to the top of the valve stem 15 by bolts. The valve stem 15 can be rotated by the handwheel 18, thereby opening and closing the valve.

[0026] Working principle When opening the valve, turn the handwheel to raise the valve stem to the highest position, so that the bottom of the valve stem is away from the top of the piston rod, releasing the piston's movement space. At this time, the valve disc, piston rod, and piston all move upward under the action of water pressure, and the pressure reducing valve gradually opens, allowing water to enter the valve body.

[0027] At the same time, water quickly fills the control chamber formed between the upper valve cover and the piston through the liquid channel inside the piston rod. The water exerts pressure on the upper surface of the piston, which stops the valve disc in the appropriate position through the piston rod, achieving pressure balance.

[0028] When the pressure at the valve inlet increases, the pressure in the control chamber also increases. Under the hydraulic action of the control chamber, the piston moves downward, reducing the passage between the valve disc and the valve body inlet, thereby increasing the resistance to water flow and reducing the pressure at the valve outlet.

[0029] When the pressure at the valve inlet decreases, the pressure in the control chamber decreases. Under the hydraulic action of the control chamber, the piston moves upward, increasing the passage between the valve disc and the valve body inlet, thereby reducing the resistance to backflow of water and increasing the pressure at the valve outlet.

[0030] By setting a liquid channel inside the piston rod, with the two ends of the liquid channel connecting the control chamber and the inside of the valve body respectively, water in the valve body flows from the liquid channel to the control chamber and acts on the upper surface of the piston. Under different working pressures and flow rates, different liquid pressures are formed in the control chamber. The control piston reciprocates in the control chamber, thereby keeping the outlet pressure of the pressure reducing valve stable. This reduces the uncertainty of the pressure reducing performance of the pressure reducing fire hydrant after long-term use of the spring component, avoids overpressure or low pressure at the fire hydrant outlet during fire extinguishing, and ensures that the water flow remains stable during the fire extinguishing process.

[0031] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A pressure reducing valve for fire hydrants, characterized in that, The valve body includes a lower valve cover and an upper valve cover fixedly connected to the top of the valve body. The upper valve cover is fixed above the lower valve cover. A piston rod is slidably connected to the lower valve cover. A movable groove is opened on the bottom surface of the lower valve cover. A piston is provided on the upper part of the piston rod. The piston is located in the movable groove. A control chamber is formed between the piston and the top surface of the movable groove. A liquid channel is provided inside the piston rod. One end of the liquid channel is connected to the inside of the valve body, and the other end is connected to the control chamber.

2. A pressure reducing valve for a fire hydrant as described in claim 1, characterized in that, The valve body is hollow inside, with a valve body inlet at the bottom, a valve body outlet on the side wall, and an opening at the top. The lower valve cover is fixed to the opening at the top of the valve body.

3. A pressure reducing valve for a fire hydrant as described in claim 2, characterized in that, A sealing ring is provided at the junction of the outer wall of the lower valve cover and the inner wall of the valve body.

4. A pressure reducing valve for a fire hydrant as described in claim 1, characterized in that, A valve disc is provided at the bottom end of the piston rod, and a bolt hole is provided at the axis of the valve disc. The valve disc is fixed to the bottom end of the piston rod by bolts.

5. A pressure reducing valve for a fire hydrant as described in claim 4, characterized in that, A sealing plate is fixed on the bottom surface of the valve disc.

6. A pressure reducing valve for a fire hydrant as described in claim 1, characterized in that, A valve stem hole is provided at the top axis of the upper valve cover, and the valve stem hole is connected to the movable groove.

7. A pressure reducing valve for a fire hydrant as described in claim 6, characterized in that, A valve stem is threaded into the valve stem hole, and a connecting groove is provided at the bottom end of the valve stem, which is adapted to the top end of the piston rod.

8. A pressure reducing valve for a fire hydrant as described in claim 7, characterized in that, Sealing rings are provided between the piston and the inner wall of the movable groove, and between the piston rod and the inner wall of the piston hole.

9. A pressure reducing valve for a fire hydrant as described in claim 7, characterized in that, A sealing ring is provided between the top of the upper valve cover and the valve stem, and a packing gland is provided at the top of the upper valve cover.

10. A pressure reducing valve for a fire hydrant as described in claim 7, characterized in that, A handwheel is fixedly connected to the top of the valve stem.

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