Pressure reduction type backflow preventer

Abstract

The utility model relates to a pressure reduction type backflow preventer which comprises a valve body, an inlet and an outlet of the valve body are respectively provided with a check valve, a water escape valve is arranged between the two check valves at the lower end of the valve body, each check valve comprises a sealing plate, a valve rod, a spring, a valve seat and a guide seat, and the sealing plate is arranged at one end of the valve rod and located on the right side of the valve seat. The guide seat is arranged on the left side of the valve seat, the other end of the valve rod penetrates through the guide seat to be located on the left side of the guide seat, the spring sleeves the portion, located on the left side of the guide seat, of the valve rod, a magnetic ring is arranged on the periphery of the valve seat, and a magnet attracted with the magnetic ring is arranged on the sealing plate. The check valve can be rapidly and reliably closed through the arrangement of the spring when a medium stops flowing or reversely flows, meanwhile, through the cooperation of the magnetic ring and the magnet, the sealing plate can be further pressed on the valve seat under the action of extra magnetic force when the sealing plate is close to the valve seat, tighter sealing is formed, and the sealing effect of the check valve is improved. And the sealing performance of the check valve is greatly improved.

Description

Technical Field

[0001] The utility model relates to a backflow preventer, in particular to a pressure-reducing type backflow preventer. Background Art

[0002] At present, in water supply systems, water treatment facilities, and various fluid transmission networks, preventing the backflow of media is a crucial safety requirement. The backflow of media may not only contaminate the water quality but also cause damage to the pipeline system and even trigger safety accidents. Therefore, as a key safety device, the pressure-reducing type backflow preventer has been widely used in the field of fluid control.

[0003] Traditional backflow preventers usually adopt a single check valve structure, which drives the opening and closing of the valve flap through the flow pressure of the medium to achieve the function of preventing backflow. However, this structure exposes some problems in practical applications, such as insufficient sealing performance, easy wear, slow response speed, etc., and it is difficult to meet the high requirements of modern water supply systems for safety and reliability.

[0004] To overcome the deficiencies of traditional backflow preventers, improve the sealing performance and response speed, and reduce the maintenance cost, those skilled in the art have conducted a large number of studies and improvements. Among them, an effective solution is to set two independent check valves in the valve body and set a drain valve between the two check valves to form a pressure-reducing type backflow preventer. This structure can not only effectively prevent the backflow of media but also discharge the accumulated water or impurities in the valve body through the drain valve when needed to keep the inside of the valve body clean and dry.

[0005] However, the existing pressure-reducing type backflow preventers still need to be further improved in terms of sealing performance. Summary of the Utility Model

[0006] Therefore, in view of the above problems, the utility model proposes a pressure-reducing type backflow preventer.

[0007] To achieve the above object, the utility model adopts the following technical solutions: A pressure-reducing type backflow preventer, comprising a valve body, check valves are respectively arranged at the inlet and outlet of the valve body, a drain valve is arranged at the lower end of the valve body between the two check valves, the check valve includes a sealing plate, a valve stem, a spring, a valve seat, and a guide seat, the sealing plate is arranged at one end of the valve stem and is located on the right side of the valve seat, the guide seat is arranged on the left side of the valve seat, the other end of the valve stem passes through the guide seat and is located on the left side of the guide seat, the spring is sleeved on the part of the valve stem located on the left side of the guide seat, a magnetic ring is arranged around the valve seat, and a magnet that attracts the magnetic ring is arranged on the sealing plate.

[0008] Further improvement, the contact surface of the valve seat in contact with the sealing plate is a sealing surface, and the sealing surface is a conical surface.

[0009] Further improvement: A sealing piece is sleeved on the left side of the valve stem, and an arc-shaped protrusion is arranged on the outer periphery of the sealing piece.

[0010] Further improvement: The sealing piece is fixed on the valve stem through a pressing plate, and the magnetic ring is arranged on the valve stem.

[0011] Further improvement: The upper end of the valve body is detachably provided with an end cover.

[0012] By adopting the foregoing technical solutions, the beneficial effects of the present utility model are as follows: When the check valve of the present utility model is closed, due to the arrangement of the spring, the check valve can be quickly and reliably closed when the medium stops flowing or flows reversely. At the same time, through the cooperation of the magnetic ring and the magnet, when the sealing plate approaches the valve seat, it can be subjected to an additional magnetic force, further pressing tightly on the valve seat to form a more compact seal, greatly improving the sealing performance of the check valve; further, through the arranged conical sealing surface, the sealing effect between the sealing plate and the valve seat is further improved; further, the arc-shaped protrusion arranged on the outer periphery of the sealing piece increases the local thickness of the sealing piece, improves the deformation force at this place, enables it to better fit the sealing surface when subjected to pressure, and further enhances the sealing effect; further, by arranging a detachable end cover, it is convenient to open the end cover when needed to maintain and repair the internal components, reducing the maintenance cost and time. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of the present utility model;

[0014] Figure 2 is Figure 1 the enlarged schematic view at A of

[0015] Figure 3 is a schematic structural diagram of the check valve of the present utility model.

[0016] ICON:

[0017] 1. Valve body; 11. End cover; 2. Check valve; 21. Sealing plate; 211. Sealing piece; 2111. Arc-shaped protrusion; 212. Pressing plate; 213. Magnet; 22. Valve stem; 23. Spring; 24. Valve seat; 241. Sealing surface; 242. Magnetic ring; 25. Guide seat; 3. Drain valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0019] Refer to Figures 1-3, this embodiment provides a pressure-reducing type backflow preventer, which includes a valve body 1. Check valves 2 are respectively provided at the inlet and outlet of the valve body 1. A drain valve 3 is provided at the lower end of the valve body 1 between the two check valves 2. An end cover 11 is detachably arranged at the upper end of the valve body 1. The check valve 2 includes a sealing plate 21, a valve rod 22, a spring 23, a valve seat 24 and a guide seat 25. The guide seat 25 is detachably connected to the valve body 1. The sealing plate 21 is arranged at one end of the valve rod 22 and is located on the right side of the valve seat 24. The guide seat 25 is arranged on the left side of the valve seat 24. The other end of the valve rod 22 passes through the guide seat 25 and is located on the left side of the guide seat 25. The spring 23 is sleeved on the left side part of the valve rod 22 located on the guide seat 25. A magnetic ring 242 is arranged around the valve seat 24. A magnet 213 that attracts the magnetic ring 242 is provided on the sealing plate 21.

[0020] In this embodiment, the contact surface of the valve seat 24 in contact with the sealing plate 21 is a sealing surface 241. The sealing surface 241 is a conical surface. A sealing piece 211 is sleeved on the left side of the valve rod 22. The sealing piece 211 is fixed on the valve rod 22 through a pressing plate 212. An arc-shaped protrusion 2111 is arranged on the outer periphery of the sealing piece 211. The magnetic ring 242 is arranged on the valve rod 22. By setting the conical sealing surface 241, the sealing effect between the sealing plate 21 and the valve seat 24 is further improved. At the same time, the arc-shaped protrusion 2111 arranged on the outer periphery of the sealing piece 211 increases the local thickness of the sealing piece 211, improves the deformation force at this place, enables it to better fit the sealing surface 241 when being pressured, and further enhances the sealing effect.

[0021] In this embodiment, the drain valve 3 is a well-known structure in the market, such as the drain valve 3 structure disclosed in the application number 201310381712.8.

[0022] When the check valve 2 of the present utility model is closed, through the setting of the spring 23, the check valve 2 can quickly and reliably close when the medium stops flowing or flows reversely. At the same time, through the cooperation of setting the magnetic ring 242 and the magnet 213, when the sealing plate 21 approaches the valve seat 24, it can be subjected to an additional magnetic force, and is further pressed tightly on the valve seat 24 to form a more tight seal, greatly improving the sealing performance of the check valve 2.

[0023] It should be noted that the specific pressure value required for the check valve 2 of the present utility model to open depends on its specific design parameters, material selection and manufacturing process. Usually, the opening pressure of the check valve 2 will be precisely calculated and tested to ensure that it can work normally under the predetermined flow rate and pressure conditions.

[0024] Although the present utility model has been specifically shown and described in connection with preferred embodiments, those skilled in the art should understand that various changes may be made to the present utility model in form and detail without departing from the spirit and scope of the present utility model as defined by the appended claims, and all such changes are within the scope of protection of the present utility model.

Claims

1. A pressure-reducing type backflow preventer, comprising a valve body, check valves are respectively arranged at the inlet and outlet of the valve body, a drain valve is arranged at the lower end of the valve body between the two check valves, and it is characterized in that: The check valve includes a sealing plate, a valve stem, a spring, a valve seat and a guide seat. The sealing plate is arranged at one end of the valve stem and on the right side of the valve seat. The guide seat is arranged on the left side of the valve seat. The other end of the valve stem passes through the guide seat and is located on the left side of the guide seat. The spring is sleeved on the part of the valve stem on the left side of the guide seat. A magnetic ring is arranged around the valve seat, and a magnet that attracts the magnetic ring is arranged on the sealing plate.

2. The pressure-reducing type backflow preventer according to claim 1, characterized in that: The contact surface of the valve seat in contact with the sealing plate is a sealing surface, and the sealing surface is a conical surface.

3. The pressure reducing type backflow preventer according to claim 1, characterized in that: A sealing piece is sleeved on the left side of the valve stem, and an arc-shaped protrusion is arranged on the outer periphery of the sealing piece.

4. A pressure-reducing type backflow preventer according to claim 3, characterized in that: The sealing piece is fixed on the valve stem through a pressing plate, and the magnetic ring is arranged on the valve stem.

5. A pressure-reducing type backflow preventer according to claim 1, characterized in that: An end cover is detachably arranged at the upper end of the valve body.

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