A low resistance backflow preventer

Abstract

The present invention relates to a low resistance backflow preventer, comprising a valve body consisting of an inlet valve body and an outlet valve body, a first-stage check valve located at the valve inlet of the inlet valve body, and a second-stage check valve located at the valve outlet of the outlet valve body, wherein an intermediate chamber is provided between the first-stage check valve and the second-stage check valve. The structure enables the water flow of the backflow preventer to flow out of the valve body after only one turn inside the valve, thereby reducing the total flow resistance of the backflow preventer, and the entire device has a simple structure and is convenient for disassembly, assembly and maintenance.

Description

Technical Field

[0001] The invention relates to the field of valve devices, in particular to a low-resistance backflow preventer. Background Art

[0002] As a control valve, the main function of the check valve is to prevent the backflow of fluid in the pipeline. Various check valves are disclosed in the prior art. For example, Chinese utility model patent CN205534421U discloses an improved check valve, in which a primary valve flap and a secondary valve flap are respectively installed between the water inlet end and the water outlet end, and the water inlet end and the water outlet end are both provided with a fixing frame, a spring is provided between the primary valve flap and the fixing frame, and a spring is also provided between the primary valve flap and the secondary valve flap. The double valve flap design forms a double check function, can quickly and effectively prevent the backflow of the medium, and can also extend the service life of the valve and the connecting pipeline, but still has the following disadvantages: since the double valve flap backflow preventer uses two identical valve flaps, the water flow must flip twice when passing through the valve body before it can flow out of the valve body. The structure of the entire device is complicated, it is easy to be damaged under the impact of backflow, and it is inconvenient to disassemble and repair. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a low-resistance backflow preventer to solve the defects existing in the prior art.

[0004] The technical solution of the present invention to solve the above technical problems is as follows:

[0005] A low-resistance backflow preventer comprises a valve body consisting of an inlet valve body and an outlet valve body, a first-stage check valve located at the valve inlet of the inlet valve body, and a second-stage check valve located at the valve outlet of the outlet valve body, wherein an intermediate chamber is provided between the first-stage check valve and the second-stage check valve, wherein the first-stage check valve comprises an inlet check valve seat, an inlet check valve flap, and an inlet check spring, wherein the inlet check valve flap contacts the inlet check valve seat under the pulling force of the inlet check spring and blocks the passage of fluid; wherein the second-stage check valve comprises an outlet check spring, an outlet check valve flap, and an outlet check valve seat, wherein the outlet check valve flap contacts the outlet check valve seat under the pressure of the outlet check spring and blocks the passage of fluid; wherein the inlet check valve flap is located at an intermediate position, and the inlet check valve seat is fixed to the inlet valve body; wherein the outlet check valve seat is located at an intermediate position of the valve outlet of the outlet valve body, and is fixedly connected to the outlet valve body, and the outlet check valve flap is an annular valve flap,

[0006] Furthermore, the inlet check spring is fixed on the spring lock block through a spring pressure head;

[0007] Furthermore, a drain valve is provided below the intermediate chamber, the drain valve is connected to pipe joint 1, the valve body is connected to pipe joint 2, a stainless steel pipe is provided between pipe joint 1 and pipe joint 2; pipe joint 2 is fixedly connected to the valve body by a hexagonal bolt; a spring washer for buffering is provided under the hexagonal bolt;

[0008] Furthermore, an O-ring 2 is provided at the connection between the outlet check valve seat and the valve body;

[0009] Furthermore, an O-ring 1 is provided at the connection between the inlet check valve seat and the valve body, and an elastic retaining ring for a hole is provided at the contact between the inlet check valve seat and the inlet check valve disc;

[0010] Furthermore, a stainless steel ball valve with inner and outer threads is arranged above the water inlet valve body.

[0011] The beneficial effects of the present invention are as follows: the structure enables the water flow of the backflow preventer to flow out of the valve body after only one flip inside the valve, thereby reducing the total flow resistance of the backflow preventer. The entire device has a simple structure and is easy to disassemble and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of the present invention;

[0013] The following are the descriptions of the reference numerals:

[0014] 1. Drain valve, 2. Pipe joint 1, 3. Stainless steel pipe, 4. Pipe joint 2, 5. Hexagonal bolt, 6. Spring washer, 7. Outlet check spring, 8. Outlet check valve disc, 9. Outlet check valve seat, 10. Outlet valve body, 11. O-ring 1, 12. Elastic retaining ring for hole, 13. O-ring 2, 14. Inlet check valve seat, 15. Inlet check valve disc, 16. Inlet check spring, 17. Spring pressure head, 18. Spring lock block, 19. Inlet valve body, 20. Stainless steel ball valve with internal and external threads; DETAILED DESCRIPTION

[0015] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0016] like Figure 1As shown, a low-resistance backflow preventer comprises a valve body consisting of an inlet valve body and an outlet valve body, a first-stage check valve located at the valve inlet of the inlet valve body, and a second-stage check valve located at the valve outlet of the outlet valve body, wherein an intermediate chamber is provided between the first-stage check valve and the second-stage check valve, wherein the first-stage check valve comprises an inlet check valve seat, an inlet check valve flap, and an inlet check spring, wherein the inlet check valve flap contacts the inlet check valve seat under the pulling force of the inlet check spring and blocks the passage of fluid; wherein the second-stage check valve comprises an outlet check spring, an outlet check valve flap, and an outlet check valve seat, wherein the outlet check valve flap contacts the outlet check valve seat under the pressure of the outlet check spring and blocks the passage of fluid; wherein the inlet check valve flap is located at a middle position, and the inlet check valve seat is fixed to the inlet valve body; wherein the outlet check valve seat is located at a middle position of the valve outlet of the outlet valve body, and is fixedly connected to the outlet valve body, and the outlet check valve flap is an annular valve flap,

[0017] More specifically, the inlet check spring is fixed to the spring lock block via a spring pressure head;

[0018] More specifically, a drain valve is provided below the intermediate chamber, the drain valve is connected to the first pipe joint, the valve body is connected to the second pipe joint, a stainless steel pipe is provided between the first pipe joint and the second pipe joint; the second pipe joint is fixedly connected to the valve body by a hexagonal bolt; a spring washer for buffering is provided under the hexagonal bolt;

[0019] In order to improve the sealing performance, an O-ring 2 is provided at the connection between the outlet check valve seat and the valve body;

[0020] In order to improve the sealing performance, an O-ring is provided at the connection between the inlet check valve seat and the valve body, and an elastic retaining ring for a hole is provided at the contact between the inlet check valve seat and the inlet check valve disc;

[0021] More specifically, a stainless steel ball valve with inner and outer threads is arranged above the water inlet valve body.

[0022] Working principle: The valve inlet is a first-stage check valve, which consists of an inlet check valve seat 14, an inlet check valve disc 15, an inlet check spring 16, a spring pressure head 17, and a spring lock block 18. Water flows into the middle chamber through the inlet check valve disc 15. Due to the action of the inlet check spring 16, water cannot flow back to the inlet. The second-stage check valve consists of an outlet check spring 7, an outlet check valve disc 8, and an outlet check valve seat 9. Water can flow out of the valve through the outlet check valve disc 8. Due to the action of the outlet check spring 7, water cannot flow back to the middle chamber. The outlet check valve disc 8 is an annular valve disc, and the water flow channel is the annular core of the valve disc. The advantage of this technical solution is that the water flow of the backflow preventer only needs to be turned over once inside the valve to flow out of the valve body, thereby reducing the total flow resistance of the backflow preventer.

[0023] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A low resistance backflow preventer, characterized in that: It comprises a valve body consisting of an inlet valve body and an outlet valve body, a first-stage check valve located at the valve inlet of the inlet valve body, and a second-stage check valve located at the valve outlet of the outlet valve body, wherein an intermediate chamber is formed between the first-stage check valve and the second-stage check valve, and the first-stage check valve comprises an inlet check valve seat, an inlet check valve flap, and an inlet check spring, wherein the inlet check valve flap contacts the inlet check valve seat under the pulling force of the inlet check spring and blocks the passage of fluid; the second-stage check valve comprises an outlet check spring, an outlet check valve flap, and an outlet check valve seat, wherein the outlet check valve flap contacts the outlet check valve seat under the pressure of the outlet check spring and blocks the passage of fluid; the inlet check valve flap is located at a middle position, and the inlet check valve seat is fixed to the inlet valve body; the outlet check valve seat is located at a middle position of the valve outlet of the outlet valve body, and is fixedly connected to the outlet valve body, and the outlet check valve flap is an annular valve flap; The water flow channel is the annular core of the valve disc.

2. A low resistance backflow preventer according to claim 1, characterized in that: The inlet check spring is fixed on the spring locking block through a spring pressure head.

3. A low resistance backflow preventer according to claim 2, characterized in that: A drain valve is arranged below the intermediate chamber, the drain valve is connected to pipe joint 1, the valve body is connected to pipe joint 2, a stainless steel pipe is arranged between pipe joint 1 and pipe joint 2; pipe joint 2 is fixedly connected to the valve body by a hexagonal bolt; a buffer spring washer is arranged under the hexagonal bolt.

4. A low resistance backflow preventer according to claim 3, characterized in that: An O-ring 2 is provided at the connection between the outlet check valve seat and the valve body.

5. A low resistance backflow preventer according to claim 4, characterized in that: An O-ring 1 is provided at the connection between the inlet check valve seat and the valve body, and an elastic retaining ring for a hole is provided at the contact between the inlet check valve seat and the inlet check valve disc.

6. A low resistance backflow preventer according to claim 5, characterized in that: A stainless steel ball valve with inner and outer threads is arranged above the water inlet valve body.

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