A pressure reducing type backflow preventer

Abstract

The utility model relates to valve technical field, and disclose a kind of pressure reducing type backflow preventer, including valve body, drain valve seat, drain valve flap, long valve rod, fixed screw, valve cover, the valve body is provided with drain valve seat, the drain valve seat inside is provided with drain valve flap, the drain valve flap upper side is provided with long valve rod, the valve body upper side is provided with valve cover.The pressure reducing type backflow preventer, by first valve seat, first valve flap, first main valve rod, first spring seat, first spring and first hexagon nut are assembled to it before being loaded into valve body, subsequent and present an integral loading into valve body inside, greatly shorten assembly time, also suitable for the assembly in the valve body of smaller volume, the unique flow passage design of two-stage check valve, small flow resistance, open and close speed is fast, can effectively prevent the damage of sudden back pressure rise to valve and pipeline, limit pressure water backflow or siphon backflow, with mute function, effectively prolong the service life of valve.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, specifically a pressure-reducing backflow preventer. Background Technology

[0002] The backflow preventer is a hydraulic control device developed to strictly limit the flow of water in the pipeline to one direction only, given the serious backflow pollution in tap water supply equipment, especially domestic drinking water pipelines, and the lack of effective devices to prevent backflow pollution. Its function is to prevent the backflow of the medium in the pipeline under any operating conditions, so as to avoid backflow pollution. Existing backflow preventers are basically too large, have complex internal structures, and are very cumbersome and difficult to assemble. At the same time, the check valve has poor sealing performance.

[0003] To solve the above problems, we urgently need a pressure-reducing backflow preventer. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a pressure-reducing backflow preventer, which solves the problems mentioned in the background art, such as the existing backflow preventers being too large, having complex internal structures that are cumbersome and difficult to assemble, and having poor check valve sealing.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a pressure-reducing backflow preventer, comprising a valve body, a drain valve seat, a drain valve disc, a long valve stem, a fixing screw, and a valve cover. The valve body is provided with a drain valve seat, the drain valve seat is provided with a drain valve disc inside, the drain valve disc is provided with a long valve stem on its upper side, the valve body is provided with a valve cover on its upper side, and the valve cover is internally threaded with a fixing screw.

[0006] The valve body further includes a first valve seat, a first valve disc, a first main valve stem, a first spring seat, a first spring, a second main valve stem, a second valve disc, a second spring seat, and a second spring. The first valve seat is disposed between the valve body and the valve cover. The first main valve stem is inserted into the first valve seat. The first valve disc is disposed on the right side of the first main valve stem. The first spring seat is disposed on the left side of the first main valve stem. The first spring is sleeved on the outer surface of the first main valve stem. The second main valve stem is inserted into the valve body. The second valve disc is disposed on the right side of the second main valve stem. The second spring seat is disposed on the left side of the second main valve stem. The second spring is sleeved on the outer surface of the second main valve stem.

[0007] Preferably, it further includes a piston sleeve, a piston, a diaphragm pressure plate, a diaphragm, a thin nut, and a set screw, characterized in that: a piston sleeve is provided under the valve cover, a piston is provided under the piston sleeve, a set screw is provided on the upper side of the piston sleeve, a diaphragm pressure plate is provided under the piston, the diaphragm pressure plate wraps around the diaphragm from top to bottom, and a thin nut is provided on the upper side of the diaphragm pressure plate.

[0008] Preferably, a first O-ring is provided between the drain valve seat and the valve body.

[0009] Preferably, a sealing ring is provided between the drain valve disc and the drain valve seat.

[0010] Preferably, a second O-ring is provided between the piston and the piston sleeve.

[0011] Preferably, the fixing screw passes through the valve cover and the interior of the valve body.

[0012] Preferably, a first hexagonal nut is provided on the left side of the first spring seat, and a second hexagonal nut is provided on the left side of the second spring seat.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] This pressure-reducing backflow preventer features a drain valve seat on the valve body, a drain valve disc inside the drain valve seat, a long valve stem on the upper side of the drain valve disc, and a valve cover on the upper side of the valve body. The valve cover has a threaded fixing screw inside. A first valve seat is positioned between the valve body and the valve cover, with a first main valve stem inserted inside. A first valve disc is located to the right of the first main valve stem, and a first spring seat is located to the left of the first valve. A first spring is fitted onto the outer surface of the first main valve stem. A second main valve stem is inserted into the valve body, with a second valve disc to the right of the second main valve stem, and a second spring seat to the left of the second valve. A second spring is fitted onto the outer surface of the second main valve stem. The first valve seat, first valve disc, first main valve stem, first spring seat, first spring, and first hexagonal nut are assembled before being installed into the valve body, and are subsequently installed as a single unit. This design significantly shortens assembly time and is also suitable for assembly within smaller valve bodies. The second main valve stem, second valve disc, second spring seat, and second spring on the right side form a check valve that is directly fixed inside the valve body. Sealing is achieved through the valve body itself and the check valve, providing better sealing compared to a separate valve seat. Furthermore, the valve body, valve disc, and valve stem on both sides are installed using parts of the same specifications, greatly facilitating product manufacturing. The drain valve's accuracy and drain pressure are adjustable, minimizing interference from pipeline pressure fluctuations. It ensures safe and reliable opening and closing, preventing abnormal drainage. The unique flow channel design of the two-stage check valve results in low flow resistance and fast opening and closing speeds, effectively preventing damage to the valve and pipeline from sudden back pressure increases, limiting pressurized water backflow or siphon backflow, and providing a silent operation, effectively extending the valve's service life. Attached Figure Description

[0015] Figure 1 This is a side sectional view of the present invention.

[0016] In the diagram: 1. Valve body; 2. Drain valve seat; 3. First O-ring; 4. Sealing ring; 5. Drain valve disc; 6. Long valve stem; 7. First hexagonal nut; 8. First main valve stem; 9. First spring seat; 10. First spring; 11. First valve seat; 12. First valve disc; 13. Diaphragm pressure plate; 14. Diaphragm; 15. Thin nut; 16. Fixing screw; 17. Piston; 18. Piston sleeve; 19. Second O-ring; 20. Set screw; 21. Valve cover; 22. Second hexagonal nut; 23. Second main valve stem; 24. Second spring seat; 25. Second spring; 26. Second valve disc. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Referring to Figure 1, in order to solve the problems of existing backflow preventers being too large, having complex internal structures and being very cumbersome and difficult to assemble, and having poor sealing performance of check valves, this utility model is provided with a drain valve seat 2 on the valve body 1, a drain valve disc 5 inside the drain valve seat 2, a long valve stem 6 on the upper side of the drain valve disc 5, and a valve cover 21 on the upper side of the valve body 1, with a fixing screw 16 threaded inside the valve cover 21;

[0019] The valve body 1 also includes a first valve seat 11, a first valve disc 12, a first main valve stem 8, a first spring seat 9, a first spring 10, a second main valve stem 23, a second valve disc 26, a second spring seat 24, and a second spring 25. The first valve seat 11 is disposed between the valve body 1 and the valve cover 21. The first main valve stem is inserted into the first valve seat 11. The first valve disc 12 is disposed on the right side of the first main valve stem. The first spring seat 9 is disposed on the left side of the first valve stem. The first spring 10 is sleeved on the outer surface of the first main valve stem. The second main valve stem 23 is inserted into the valve body 1. The second valve disc 26 is disposed on the right side of the second main valve stem. The second spring seat 24 is disposed on the left side of the second valve stem. The second spring 25 is sleeved on the outer surface of the second main valve stem.

[0020] The first valve seat 11, first valve disc 12, first main valve stem 8, first spring seat 9, first spring 10, and first hexagonal nut 7 are assembled before being installed into the valve body 1, and are subsequently installed as a single unit inside the valve body 1, greatly shortening the assembly time. This also allows for assembly within the smaller valve body 1. The second main valve stem 23, second valve disc 26, second spring seat 24, and second spring 25 on the right side form a check valve that is directly fixed inside the valve body 1, using the valve body 1 itself and the check valve for sealing. Compared to a single valve seat, this provides better sealing. The valve boasts excellent sealing performance, and the valve body, valve disc, and valve stem on both sides are installed using parts of the same specifications, which greatly facilitates product manufacturing. Furthermore, the accuracy and drainage pressure of the drain valve are adjustable, minimizing interference from pipeline pressure fluctuations. It ensures safe and reliable opening and closing, preventing abnormal drainage. The unique flow channel design of the two-stage check valve results in low flow resistance and fast opening and closing speed, effectively preventing damage to the valve and pipeline from sudden increases in back pressure, limiting backflow of pressurized water or siphon backflow, and providing a silent operation, effectively extending the valve's service life.

[0021] Compared with related technologies, the pressure-reducing backflow preventer provided by this utility model has the following beneficial effects: it is easier to assemble, and the check valve has better sealing performance. It adopts a unique flow channel design of two-stage check valve, with low flow resistance, fast opening and closing speed, restricts backflow of pressurized water or siphon backflow, has a silent function, and effectively extends the service life of the valve.

[0022] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pressure-reducing backflow preventer, comprising a valve body (1), a drain valve seat (2), a drain valve disc (5), a long valve stem (6), a fixing screw (16), and a valve cover (21), characterized in that: The valve body (1) is provided with a drain valve seat (2), the drain valve seat (2) is provided with a drain valve disc (5), the drain valve disc (5) is provided with a long valve stem (6) on the upper side, the valve body (1) is provided with a valve cover (21), and the valve cover (21) is threaded with a fixing screw (16). The valve body (1) further includes a first valve seat (11), a first valve disc (12), a first main valve stem (8), a first spring seat (9), a first spring (10), a second main valve stem (23), a second valve disc (26), a second spring seat (24), and a second spring (25). The first valve seat (11) is located between the valve body (1) and the valve cover (21). The first main valve stem (8) is inserted inside the first valve seat (11). The first valve disc (12) is located on the right side of the first main valve stem (8). The first spring seat (9) is located on the left side of the first valve. The first spring (10) is sleeved on the outer surface of the first main valve stem (8). The second main valve stem (23) is inserted inside the valve body (1). The second valve disc (26) is located on the right side of the second main valve stem (23). The second spring seat (24) is located on the left side of the second valve. The second spring (25) is sleeved on the outer surface of the second main valve stem (23).

2. The pressure-reducing backflow preventer according to claim 1, characterized in that: The valve body (1) also includes a piston sleeve (18), a piston (17), a diaphragm pressure plate (13), a diaphragm (14), a thin nut (15), and a set screw (20). The valve body (1) is characterized in that: a piston sleeve (18) is provided under the valve cover (21), a piston (17) is provided under the piston sleeve (18), a set screw (20) is provided on the upper side of the piston sleeve (18), a diaphragm pressure plate (13) is provided under the piston (17), the diaphragm pressure plate (13) wraps around the diaphragm (14) from top to bottom, and a thin nut (15) is provided on the upper side of the diaphragm pressure plate (13).

3. The pressure-reducing backflow preventer according to claim 1, characterized in that: A first O-ring (3) is provided between the drain valve seat (2) and the valve body (1).

4. A pressure-reducing backflow preventer according to claim 1, characterized in that: A sealing ring (4) is provided between the drain valve disc (5) and the drain valve seat (2).

5. A pressure-reducing backflow preventer according to claim 2, characterized in that: A second O-ring (19) is provided between the piston (17) and the piston sleeve (18).

6. A pressure-reducing backflow preventer according to claim 1, characterized in that: The fixing screw (16) passes through the valve cover (21) and the valve body (1).

7. A pressure-reducing backflow preventer according to claim 1, characterized in that: The first spring seat (9) is provided with a first hexagonal nut (7) on the left side, and the second spring seat (24) is provided with a second hexagonal nut (22) on the left side.

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