A large-diameter butterfly valve with anti-sinking butterfly plate

Abstract

This utility model discloses a large-diameter butterfly valve with anti-dip valve plate sinking design. It comprises a valve body, with a butterfly plate mounted within the valve body via upper and lower valve shafts. An end cap is attached to the bottom of the valve body via fastening bolts. A copper alloy friction pad is provided on the end cap located within the valve body. The lower valve shaft can slide upwards, thereby causing the butterfly plate to move upwards accordingly. When butterfly plate sinking causes leakage in the butterfly valve, the leakage caused by the sinking can be eliminated by sliding the lower valve shaft upwards, thereby causing the butterfly plate to move upwards.

Description

Technical Field

[0001] This utility model relates to a large-diameter butterfly valve, specifically a large-diameter butterfly valve that can prevent the butterfly plate from sinking. Background Technology

[0002] A butterfly valve is a control element connected to pipeline equipment and is widely used in industries such as petroleum, chemical, urban gas, urban heating, and water treatment to cut off or regulate the flow of media in pipelines. Currently, after a period of use, users have reported internal leakage in large-diameter butterfly valves (DN≥1000mm) installed vertically. After collecting on-site maintenance information, the root cause is that after the butterfly valve is installed vertically, the butterfly plate sinks, and gaps appear in the sealing surface, resulting in internal leakage. The specific situation is as follows: The butterfly valve is installed vertically, and the weight of the upper valve shaft and the butterfly plate acts on the lower valve shaft. During the valve opening and closing process, the lower valve shaft and the end cover generate relative rotational friction. Since both the lower valve shaft and the end cover are steel parts, their contact surfaces may mesh, increasing the valve's opening and closing torque and potentially causing the valve to jam. To avoid direct contact between the lower valve shaft and the end cover, a friction pad is added between their contact surfaces. The friction pad is made of copper alloy material, which has a low coefficient of friction and can effectively reduce the frictional torque at the end cover. However, as the valve is frequently opened and closed, the drawbacks of using the friction pad gradually become apparent. The friction pad is made of copper alloy material, which is not wear-resistant and has low hardness, making it easy to be deformed under pressure. Eventually, the lower valve shaft, the butterfly plate, and the upper valve shaft all fall downwards simultaneously. After falling to a certain height, a gap appears at the highest point of the butterfly valve's sealing surface, resulting in internal leakage of the valve.

[0003] Furthermore, in existing butterfly valves, the valve shaft and disc are connected as a single unit using cylindrical or tapered pins, with the pins transmitting the torque required to open and close the valve. The pin holes on the disc and valve shaft are machined to fit together during valve assembly, with a tight fit where external force presses the pin into the hole. If there is a gap between the pin hole and the pin, vibration during valve operation can cause the pin to dislodge, leading to valve failure. Additionally, the machined pin holes on the valve shaft and disc significantly weaken their strength. Moreover, because the pin holes are custom-made, the valve shaft and disc are one-to-one, preventing interchangeability of valve components, increasing manufacturing costs, and hindering valve maintenance. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a large-diameter butterfly valve that can prevent the butterfly plate from sinking. When the butterfly plate sinks and causes leakage in the butterfly valve, the lower valve shaft can be slid upward to drive the butterfly plate to move upward and eliminate the leakage caused by the sinking of the butterfly plate.

[0005] To solve the above-mentioned technical problems, this utility model provides a large-diameter butterfly valve with anti-butterfly plate sinking, which has a valve body, a butterfly plate is mounted in the valve body through upper and lower valve shafts, and an end cap is mounted on the bottom of the valve body through fastening bolts. A copper alloy friction pad is provided on the end cap located in the valve body. The feature is that the lower valve shaft can slide upward, thereby driving the butterfly plate to move upward accordingly.

[0006] As an improvement of this utility model, a circumferential groove is provided at the lower part of the lower valve shaft, and a split ring is installed in the groove. The copper alloy friction pad is annular in shape and is disposed between the end cover and the split ring. A gap is left between the end cover and the bottom of the valve body. Adjusting the fastening bolt can shorten the distance of the gap between the end cover and the bottom of the valve body, thereby allowing the copper alloy friction pad to push the split ring to move upward. In turn, the upward sliding of the lower valve shaft can drive the butterfly plate to move upward accordingly.

[0007] The large-diameter butterfly valve with the above-described structure that prevents butterfly plate sinking can reduce the distance between the end cover and the bottom of the valve body by adjusting the fastening bolts when the butterfly plate sinks and causes leakage. This allows the copper alloy friction pad to push the split ring upward, and the lower valve axis to slide upward, which in turn drives the butterfly plate to move upward accordingly, thereby eliminating the leakage caused by the butterfly plate sinking.

[0008] As another improvement of this utility model, the copper alloy friction pad is a disc-shaped friction pad, with a friction pad stud at the center and friction pad screw holes evenly distributed along the circumference; the bottom center of the lower valve shaft has a valve shaft center screw hole that mates with the friction pad stud, and the bottom of the lower valve shaft has a valve shaft screw hole that mates with the friction pad screw hole along the circumference; the friction pad stud is screwed into the valve shaft center screw hole, and a positioning screw is screwed into both the friction pad screw hole and the valve shaft screw hole.

[0009] The large-diameter butterfly valve with the above-described structure that prevents butterfly plate sinking can prevent leakage when the butterfly plate sinks. The disc-shaped friction pad can be rotated, and after the required adjustment is reached, the friction pad and the lower valve shaft can be fixed with positioning screws. Then, the end cover is installed, and the fastening bolts on the end cover are tightened. At this time, the friction pad stud can push against the lower valve shaft and slide upward, thereby driving the butterfly plate to move upward accordingly to eliminate leakage caused by the butterfly plate sinking.

[0010] As a further improvement of this utility model, valve shaft sleeves are fixedly connected to the upper and lower parts of the back of the butterfly plate, and the upper and lower valve shafts are respectively provided with corresponding valve shaft mounting sections. The inner wall of the valve shaft sleeve is machined with an internal spline, and the outer wall of the valve shaft mounting section is machined with an external spline that mates with the internal spline. The valve shaft mounting sections of the upper and lower valve shafts extend into the corresponding valve shaft sleeves, and the ends of the valve shaft mounting sections are fitted with positioning baffles by fastening screws to prevent the butterfly plate from moving up and down along the axis of the upper and lower valve shafts.

[0011] The large-diameter butterfly valve with anti-sinking design, employing the above structure, changes the traditional pin-and-hole connection between the butterfly plate and valve shaft. It eliminates the need for machining pin holes on the valve shaft and butterfly plate; instead, matching internal and external splines are machined on the valve shaft mounting section at one end of the valve shaft and the valve shaft sleeve on the back of the butterfly plate. Because the internal and external splines can have numerous teeth and grooves, the alignment between the valve shaft and butterfly plate is excellent, allowing for the transmission of larger torques and more even force distribution. Furthermore, the spline grooves can be machined shallower, resulting in less stress concentration at the tooth roots and minimal weakening of the strength of the valve shaft and butterfly plate. Simultaneously, the machining of the internal and external splines does not need to be performed during the assembly of the butterfly plate and valve shaft; they can be machined separately according to standard dimensions, making machining convenient and facilitating replacement when the valve shaft or butterfly plate is damaged. The positioning baffle at the bottom of the valve shaft section also effectively prevents the butterfly plate from moving up and down along the valve shaft axis. Attached Figure Description

[0012] The present invention will now be described in further detail with reference to the accompanying drawings.

[0013] Figure 1 This is a schematic diagram of the main cross-sectional structure of a large-diameter butterfly valve with anti-butterfly plate sinking according to the first embodiment of this utility model.

[0014] Figure 2 This is a front view schematic diagram of the lower valve shaft in this utility model.

[0015] Figure 3 yes Figure 1 Enlarged schematic diagram of the structure at point I.

[0016] Figure 4 yes Figure 2 A-direction view.

[0017] Figure 5 This is a schematic diagram of the main cross-sectional structure of the valve plate described in this utility model.

[0018] Figure 6 yes Figure 5 The partial view from direction B.

[0019] Figure 7 yes Figure 1 Enlarged schematic diagram of the structure at point II.

[0020] Figure 8 This is a schematic diagram of the main cross-sectional structure of a large-diameter butterfly valve with anti-butterfly plate sinking according to the second embodiment of this utility model.

[0021] Figure 9 yes Figure 8 Enlarged schematic diagram of structure III in the diagram.

[0022] Figure 10 yes Figure 9 A schematic diagram of the main cross-sectional structure of the disc-shaped friction pad in the diagram.

[0023] Figure 11 yes Figure 10 A top-down view.

[0024] Figure 12 yes Figure 9 A partial structural diagram of the lower valve shaft.

[0025] Figure 13 It is along Figure 12 A schematic diagram of the C-direction structure. Detailed Implementation

[0026] See first Figure 1 - Figure 7 This utility model discloses a large-diameter butterfly valve with anti-sinking butterfly plate, comprising a valve body 1, a butterfly plate 2 mounted inside the valve body 1 via upper and lower valve shafts 3 and 4, an end cap 6 mounted on the bottom of the valve body via fastening bolts 5, and a copper alloy friction pad 7 disposed on the end cap located inside the valve body. The lower valve shaft 4 is slidable upwards, thereby driving the butterfly plate 2 to move upwards accordingly. A circumferential groove 8 is formed at the lower part of the lower valve shaft 4, and a split ring 9 is installed in the groove. The copper alloy friction pad 7 is annular in shape and is disposed between the end cap 6 and the split ring 9. A gap 10 is left between the end cap and the bottom of the valve body. Adjusting the fastening bolts 5 can shorten the distance 9 between the end cap 6 and the bottom of the valve body, thereby allowing the copper alloy friction pad 7 to push the split ring 9 upwards, and thus the upward sliding of the lower valve shaft 4 can drive the butterfly plate 2 to move upwards accordingly. Valve shaft sleeves 11 are fixedly connected to the upper and lower parts of the back of the butterfly plate 2, respectively. The upper and lower valve shafts each have corresponding valve shaft mounting sections 12. The inner wall of the valve shaft sleeve is machined with an internal spline 13, and the outer wall of the valve shaft mounting section is machined with an external spline 14 that mates with the internal spline. The valve shaft mounting sections of the upper and lower valve shafts extend into the corresponding valve shaft sleeves. The end of the valve shaft mounting section 12 is fitted with a positioning baffle 16 by a fastening screw 15 to prevent the butterfly plate from moving up and down along the axis of the upper and lower valve shafts. The end cover 6 is also circumferentially fitted with a tightening bolt 17, one end of which abuts against the bottom of the valve body. The tightening bolt is screwed with an anti-loosening nut 18.

[0027] Figure 8 - Figure 13 The diagram shows the main cross-sectional structure of a large-diameter butterfly valve with anti-butterfly plate sinking according to the second embodiment of this utility model. The copper alloy friction pad 7 is a disc-shaped friction pad with a friction pad stud 19 at its center and friction pad screw holes 20 evenly distributed along the circumference. The lower valve shaft 4 has a valve shaft center screw hole 21 at its bottom center that mates with the friction pad stud, and a valve shaft screw hole 22 at its bottom circumference that mates with the friction pad screw hole. The friction pad stud 19 is screwed into the valve shaft center screw hole 21, and a positioning screw 23 is screwed into the friction pad screw hole 20 and the valve shaft screw hole 22.

[0028] It is understood that the above specific description of the present utility model is only used to illustrate the present utility model and is not limited to the technical solutions described in the embodiments of the present utility model. Any modifications or equivalent substitutions to the present utility model to achieve the same technical effect are within the protection scope of the present utility model.

Claims

1. A large-diameter butterfly valve with anti-butterfly plate sinking design, comprising a valve body, a butterfly plate mounted in the valve body via upper and lower valve shafts, an end cap mounted on the bottom of the valve body via fastening bolts, and a copper alloy friction pad provided on the end cap located inside the valve body, characterized in that: The lower valve shaft can slide upward, thereby driving the butterfly plate to move upward accordingly.

2. The large-diameter butterfly valve with anti-butterfly plate sinking as described in claim 1, characterized in that: The lower valve shaft has a circumferential groove at its lower part, and a split ring is installed in the groove. The copper alloy friction pad is annular in shape and is located between the end cover and the split ring. There is a gap between the end cover and the bottom of the valve body. Adjusting the fastening bolt can shorten the distance of the gap between the end cover and the bottom of the valve body, thereby allowing the copper alloy friction pad to push the split ring to move upward. In turn, the lower valve shaft slides upward, which can drive the butterfly plate to move upward accordingly.

3. The large-diameter butterfly valve with anti-butterfly plate sinking as described in claim 1, characterized in that: The copper alloy friction pad is a disc-shaped friction pad with a friction pad stud at its center and friction pad screw holes evenly distributed along its circumference. The bottom center of the lower valve shaft has a valve shaft center screw hole that mates with the friction pad stud, and the bottom of the lower valve shaft has a valve shaft screw hole that mates with the friction pad screw hole along its circumference. The friction pad stud is screwed into the valve shaft center screw hole, and a positioning screw is screwed into both the friction pad screw hole and the valve shaft screw hole.

4. The large-diameter butterfly valve with anti-butterfly plate sinking as described in claim 2 or 3, characterized in that: Valve shaft sleeves are fixedly connected to the upper and lower parts of the back of the butterfly plate. The upper and lower valve shafts each have corresponding valve shaft mounting sections. The inner wall of the valve shaft sleeve is machined with an internal spline, and the outer wall of the valve shaft mounting section is machined with an external spline that mates with the internal spline. The valve shaft mounting sections of the upper and lower valve shafts extend into the corresponding valve shaft sleeves. The ends of the valve shaft mounting sections are fitted with positioning baffles by fastening screws to prevent the butterfly plate from moving up and down along the axis of the upper and lower valve shafts.

5. The large-diameter butterfly valve with anti-butterfly plate sinking as described in claim 2, characterized in that: The end cap is also circumferentially fitted with a tightening bolt, one end of which abuts against the bottom of the valve body, and the tightening bolt is screwed with an anti-loosening nut.

Images