A type of compensated anti-impact butterfly check valve

Abstract

This utility model discloses a compensating, impact-resistant butterfly check valve in the field of check valve technology. It includes a valve body, with a bellows expansion joint connected to the outlet of the valve body via a flange. A valve shaft is fixedly inserted inside the valve body, with pressure sleeves fitted at both ends of the valve shaft. A butterfly plate is rotatably connected to the valve shaft via an outer mounting seat. Springs are fitted at both ends of the outer side of the valve shaft, and the ends of the springs are fixedly connected to the mounting seat and the butterfly plate, respectively. This utility model, by connecting a bellows expansion joint at the outlet of the valve body, allows the bellows expansion joint to absorb water flow impacts during pump shutdown and switching, compensating for the movement of the valve due to changes in the flow field. This achieves a flexible connection with the system, avoiding excessive vibration caused by rigid connections, thus protecting the valve and increasing its service life.

Description

Technical Field

[0001] This utility model relates to the technical field of check valves, and in particular to a compensated anti-impact butterfly check valve. Background Technology

[0002] In large thermal power plants, swing check valves are commonly used at the outlets of both open and closed pumps. However, these traditional check valves typically require a large installation space. Their valve discs rotate around an axis, requiring a certain amount of swing space during opening and closing, resulting in a relatively large overall size.

[0003] Traditional check valves, while opening to a certain angle, still impede fluid flow, resulting in a relatively high flow resistance coefficient. In contrast, butterfly check valves offer less resistance to fluid flow when open, typically exhibiting a lower flow resistance coefficient and thus better reducing pressure loss in piping systems.

[0004] Traditional check valves have a slower closing speed due to the weight of the valve disc and the relatively high friction of the swing shaft. When fluid flows in the opposite direction, they cannot close quickly, easily leading to significant backflow and a relatively high possibility of water hammer. Butterfly check valves, on the other hand, are more sensitive and close quickly, effectively preventing water hammer.

[0005] However, existing butterfly check valves lack compensation capabilities. At the moment the valve closes, the pipeline experiences significant vibration and displacement in both the axial and radial directions, and the lack of axial and radial compensation results in substantial vibration and weak valve impact resistance. Furthermore, the valve flange installation process requires forced alignment with the pipeline flange, increasing internal pipeline stress and creating potential equipment hazards. Utility Model Content

[0006] To address the issue mentioned above where existing butterfly check valves lack compensation capabilities, resulting in significant vibration and displacement in the pipeline in both axial and radial directions at the moment of valve closure, this invention provides a compensating, impact-resistant butterfly check valve.

[0007] This utility model provides a compensated, impact-resistant butterfly check valve, which adopts the following technical solution:

[0008] A compensated anti-impact butterfly check valve includes a valve body, with a bellows expansion joint connected to the outlet of the valve body via a flange. A valve shaft is fixedly inserted inside the valve body, with pressure sleeves fitted at both ends of the valve shaft. A butterfly plate is rotatably connected to the valve shaft via an outer mounting seat. Springs are fitted at both ends of the outer side of the valve shaft, and the two ends of the springs are fixedly connected to the mounting seat and the butterfly plate, respectively.

[0009] By adopting the above technical solution, when the medium flows from right to left, the medium pressure acts on the butterfly plate, generating a torque that causes the butterfly plate to rotate around the valve shaft. When this torque is greater than the resistance torque such as the self-weight of the valve shaft, the elastic force of the spring, and the frictional force between the sealing rings, the butterfly plate opens, and the medium passes through the valve. When the flow direction of the medium changes or stops, the medium pressure decreases or disappears, and the butterfly plate, under the action of its own weight and the elastic force of the spring, rotates around the valve shaft back to the closed position. When the water flow impact is large during the shut-off and switching of the water pump, the bellows expansion joint can absorb the water flow impact, compensate for the movement of the pipeline valve due to changes in the flow field, realize a flexible connection with the system, avoid the problem of excessive vibration caused by rigid connection, protect the valve, and increase the service life of the valve.

[0010] Optionally, a sealing ring is provided at the connection between the valve body and the butterfly plate, and the sealing ring is a polytetrafluoroethylene sealing ring.

[0011] By adopting the above technical solution, when the butterfly plate is closed, the sealing ring can ensure the valve's sealing performance and prevent backflow of the medium.

[0012] Optionally, a sealing ring pressure plate is bolted to the side of the butterfly plate opposite to the valve shaft.

[0013] By adopting the above technical solution, the sealing ring can be fixed on the valve body, ensuring that the sealing ring will not shift during operation, thereby guaranteeing the sealing effect.

[0014] Optionally, the gap between the valve body and the valve shaft is filled with packing material, and the packing material is graphite.

[0015] By adopting the above technical solution, leakage of the medium from the gap between the valve shaft and the valve body is further prevented, thus achieving a sealing effect.

[0016] Optionally, both sets of pressure sleeves are located outside the valve body, and a hexagonal nut is screwed onto the side of both sets of pressure sleeves away from the center of the valve shaft.

[0017] By adopting the above technical solution, the pressure sleeve is fixed by a hexagonal nut, and the pressure sleeve is used to axially position the valve shaft to prevent the valve shaft from moving during operation. At the same time, it also provides a certain support and lubrication for the rotation of the valve shaft.

[0018] Optionally, the valve body, valve shaft, and bellows expansion joint are all made of stainless steel.

[0019] By adopting the above technical solutions, the corrosion resistance of stainless steel can effectively resist the erosion of the medium, ensuring the long-term stable operation of the check valve as a whole.

[0020] In summary, this utility model has at least one of the following beneficial effects:

[0021] By connecting a bellows expansion joint at the outlet of the valve body, when the water pump experiences significant water flow impact during shutdown and switching, the bellows expansion joint can absorb the water flow impact, compensate for the movement of the pipeline valve due to changes in the flow field, achieve a flexible connection with the system, avoid excessive vibration caused by rigid connections, protect the valve, and increase its service life.

[0022] By installing a sealing ring at the connection between the valve body and the butterfly plate, the valve's sealing performance can be guaranteed, preventing backflow of the medium. At the same time, the sealing ring is fixed to the valve body by the sealing ring pressure plate, ensuring that the sealing ring will not shift during operation, thereby guaranteeing the sealing effect. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a cross-sectional structural diagram of the present invention;

[0025] Figure 2 This is a schematic diagram of the left-side structure of this utility model.

[0026] In the diagram: 1. Valve body; 2. Sealing ring; 3. Butterfly plate; 4. Sealing ring pressure plate; 5. Pressure sleeve; 6. Packing; 7. Spring; 8. Valve shaft; 9. Bellows expansion joint. Detailed Implementation

[0027] The following is in conjunction with the appendix Figures 1-2 The present invention will be described in further detail below.

[0028] Please refer to the attached diagram in the instruction manual. Figure 1 and Figure 2 This utility model provides an embodiment of a compensated, impact-resistant butterfly check valve, comprising a valve body 1, a bellows expansion joint 9 bolted to the outlet of the valve body 1 via a flange, a valve shaft 8 fixedly inserted inside the valve body 1, and a packing 6, made of graphite, filling the gap between the valve body 1 and the valve shaft 8. This further prevents leakage of the medium from the gap between the valve shaft 8 and the valve body 1, thus providing a sealing effect. The valve body 1, valve shaft 8, and bellows expansion joint 9 are all made of stainless steel. The corrosion resistance of stainless steel effectively resists the erosion of the medium, ensuring the long-term stable operation of the check valve as a whole.

[0029] Please refer to the attached diagram in the instruction manual. Figure 1 and Figure 2Both ends of the valve shaft 8 are movably fitted with pressure sleeves 5. Both sets of pressure sleeves 5 are located outside the valve body 1, and hexagonal nuts are screwed onto the side of each set of pressure sleeves 5 away from the center of the valve shaft 8. The pressure sleeves 5 are fixed by the hexagonal nuts and are used to axially position the valve shaft 8 to prevent the valve shaft 8 from moving during operation. They also provide some support and lubrication for the rotation of the valve shaft 8.

[0030] Please refer to the attached diagram in the instruction manual. Figure 1 and Figure 2 The valve shaft 8 is rotatably connected to the butterfly plate 3 via an outer mounting seat. A sealing ring 2, which is made of polytetrafluoroethylene, is provided at the connection between the valve body 1 and the butterfly plate 3. When the butterfly plate 3 is closed, the sealing ring 2 ensures the valve's sealing performance and prevents backflow of the medium.

[0031] Please refer to the attached diagram in the instruction manual. Figure 1 and Figure 2 A sealing ring pressure plate 4 is bolted to the side of the butterfly plate 3 away from the valve shaft 8. This secures the sealing ring 2 to the valve body 1, ensuring that the sealing ring 2 will not shift during operation and thus guaranteeing a sealing effect. Springs 7 are fitted at both ends of the outer side of the valve shaft 8, and the two ends of the springs 7 are fixedly connected to the mounting base and the butterfly plate 3, respectively.

[0032] Working principle: When the medium flows from right to left in the specified direction during use, the medium pressure acts on the butterfly plate 3, generating a torque that causes the butterfly plate 3 to rotate around the valve shaft 8. When this torque is greater than the resistance torque such as the weight of the valve shaft 8, the elastic force of the spring 7, and the friction between the sealing rings 2, the butterfly plate 3 opens, and the medium passes through the valve.

[0033] When the flow direction of the medium changes or stops, the medium pressure decreases or disappears. Under the action of its own weight and the elastic force of the spring 7, the butterfly plate 3 rotates around the valve shaft 8 and returns to the closed position. At this time, the butterfly plate 3 and the sealing ring 2 on the valve body 1 are tightly fitted to prevent the medium from flowing back, thereby realizing the check function.

[0034] When valve maintenance is required, the connecting flange on one side of the bellows expansion joint 9 can be removed and the bellows expansion joint 9 can be compressed. The check valve can be inspected and maintained without disassembling the valve. When the water flow impact is large during the shut-off and switching of the water pump, the bellows expansion joint 9 can absorb the water flow impact, compensate for the movement of the pipeline valve due to the change of flow field, realize the flexible connection with the system, avoid the problem of excessive vibration caused by rigid connection, protect the valve, and increase the service life of the valve.

[0035] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A compensated anti-impact butterfly check valve, comprising a valve body (1), characterized in that: The valve body (1) has a bellows expansion joint (9) connected to its outlet via a flange. A valve shaft (8) is fixedly inserted inside the valve body (1). Both ends of the valve shaft (8) are fitted with pressure sleeves (5). The valve shaft (8) is rotatably connected to a butterfly plate (3) via an outer mounting seat. Both ends of the outer side of the valve shaft (8) are fitted with springs (7), and both ends of the springs (7) are fixedly connected to the mounting seat and the butterfly plate (3) respectively.

2. The compensated anti-impact butterfly check valve according to claim 1, characterized in that: A sealing ring (2) is provided at the connection between the valve body (1) and the butterfly plate (3), and the sealing ring (2) is a polytetrafluoroethylene sealing ring.

3. A compensating anti-impact butterfly check valve according to claim 2, characterized in that: The butterfly plate (3) is bolted to a sealing ring pressure plate (4) on the side away from the valve shaft (8).

4. A compensating anti-impact butterfly check valve according to claim 1, characterized in that: The gap between the valve body (1) and the valve shaft (8) is filled with packing material (6), and the packing material (6) is made of graphite.

5. A compensated anti-impact butterfly check valve according to claim 1, characterized in that: Both sets of pressure sleeves (5) are located outside the valve body (1), and both sets of pressure sleeves (5) are screwed with hexagonal nuts on the side away from the center of the valve shaft (8).

6. A compensated anti-impact butterfly check valve according to claim 1, characterized in that: The valve body (1), valve shaft (8) and bellows expansion joint (9) are all made of stainless steel.

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