A minimum flow valve seal

Abstract

This utility model relates to a minimum flow valve sealing structure, comprising: a valve body, the valve body including an inlet at the bottom and a first outlet at the top, a flow channel inside the valve body, and a second outlet on one side of the valve body, the inlet, the first outlet, and the second outlet all communicating with the flow channel; a telescopic column, the telescopic column being vertically disposed within the flow channel, and a main valve disc being disposed on the outer surface of the telescopic column; in this utility model, by setting a limiting column and a protrusion, in conjunction with multiple balls on the protrusion, and the restriction of the inner wall of the connecting pipe, when the secondary valve disc is moved up and down by the main valve disc to open and close, the movement trajectory of the secondary valve disc can be limited by the limiting column and the balls sliding laterally within the connecting pipe, preventing the secondary valve disc from failing to accurately return to its original position for sealing during multiple opening and closing operations.

Description

Technical Field

[0001] This utility model relates to the field of flow valve technology, specifically a sealing structure for a minimum flow valve. Background Technology

[0002] The minimum flow valve is a key component in a pump protection system, primarily used to prevent cavitation, overheating, or severe noise in centrifugal pumps operating at low flow rates. Its core function is to protect internal pump components by maintaining the pump's minimum operating flow rate. This valve is connected to the pump's outlet and, similar to a check valve, relies on the medium pressure to open the valve disc. Existing minimum flow valves typically include an inlet, a main outlet, and a secondary outlet. Each outlet has a valve disc; when the flow rate is high, the main valve disc opens, simultaneously closing the secondary valve disc via a lever. When the flow rate is low, the main valve disc closes, and the secondary valve disc opens via a lever. The secondary outlet is the minimum flow outlet.

[0003] In actual operation, it was found that since the main valve disc moves vertically up and down, but the secondary valve disc moves horizontally back and forth by lever, the secondary valve disc is subjected to the force of the main valve disc moving up and down during the movement. This makes it easy for the secondary valve disc to fall out of the intercepting groove during the movement, resulting in the loss of the seal at the secondary drain port and causing liquid to flow out. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a sealing structure for a minimum flow valve, which solves the technical problem that the secondary valve disc at the secondary drain port of the existing minimum flow valve is easily dislodged from the intercepting groove during movement due to the force of the main valve disc moving up and down, resulting in loss of sealing at the secondary drain port and liquid leakage.

[0005] The present invention provides a minimum flow valve sealing structure, comprising: a valve body, the valve body including an inlet at the bottom and a first outlet at the top, a flow channel inside the valve body, and a second outlet on one side of the valve body, wherein the inlet, the first outlet and the second outlet are all connected to the flow channel; A telescopic column is vertically positioned within the flow channel. A main valve flap is located on the outer surface of the telescopic column. When the telescopic column moves downward, it causes the main valve flap to abut against the inner circumferential wall of the flow channel, thereby sealing the flow channel. A secondary valve flap is laterally positioned at the second drain outlet. The main valve flap and the secondary valve flap are connected by a connecting rod. A limiting post is located on the side of the secondary valve flap away from the main valve flap. The limiting post is movably inserted into the second drain outlet and is used to limit the position of the secondary valve flap.

[0006] As a further improvement of this utility model, the end of the second drain port away from the secondary valve disc is fixedly connected to a connecting pipe, and the limiting post extends from the second drain port into the connecting pipe, the diameter of the limiting post being smaller than the inner diameter of the connecting pipe.

[0007] As a further improvement of this utility model, at least two protrusions protrude outward from the outer peripheral wall of the limiting post, and a plurality of balls are embedded on the side of the protrusions away from the limiting post. The outer surface of the plurality of balls contacts the inner wall of the connecting pipe, and the inner diameter of the connecting pipe is the same as the inner diameter of the second drain port.

[0008] As a further improvement of this utility model, a flow-blocking groove is provided on the side of the second drain port near the flow channel. When the secondary valve disc is inserted into the flow-blocking groove, the second drain port is closed; when the secondary valve disc is disengaged from the flow-blocking groove, the second drain port is opened.

[0009] As a further improvement of this utility model, a sealing ring is provided at the edge of the secondary valve disc near the intercepting groove, and the diameter of the intercepting groove is larger than the diameter of the second drain port.

[0010] As a further improvement of this utility model, the inner wall of the flow channel is provided with cross support plates near the top and bottom ends, and the telescopic column is located between the two cross support plates. The telescopic column includes an outer rod and an inner rod. The bottom end of the outer rod is movably inserted into the cross support plate located below, and the top end of the inner rod is fixedly connected to the cross support plate located above. One end of the connecting rod is connected to the outer rod.

[0011] As a further improvement of this utility model, a telescopic cavity is provided at the top of the outer rod, the inner rod is movably inserted into the telescopic cavity, and a spring is provided between the telescopic cavity and the bottom end face of the inner rod.

[0012] As a further improvement of this utility model, the outer rod body has a horizontal through-hole near the bottom, and a mounting bracket is vertically provided at the bottom of the inner wall of the mounting hole. One end of the connecting rod is mounted between the mounting brackets and rotatably connected to the mounting brackets, and the other end of the connecting rod is rotatably connected to the center position of one side of the auxiliary valve disc.

[0013] As a further improvement of this utility model, the top two sides of the inner wall of the mounting port are provided with oblique openings offset upwards by 45°, and the width of the oblique openings is adapted to the width of the connecting rod.

[0014] As a further improvement of this utility model, a stop cavity is provided in the middle of the flow channel. The diameter of the stop cavity is larger than the diameter of the inlet and the first outlet. A sealing ring is also provided on the bottom end face of the main valve disc. The main valve disc abuts against the bottom of the inner peripheral wall of the stop cavity to close the flow channel between the inlet and the first outlet.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: In this invention, by setting a limiting post and a protrusion, in conjunction with multiple balls on the protrusion, and the restriction of the inner wall of the connecting pipe, when the secondary valve disc is driven to open and close by the up and down movement of the main valve disc, the movement trajectory of the secondary valve disc can be limited by the limiting post and the balls sliding laterally in the connecting pipe. This prevents the secondary valve disc from failing to accurately return to its original position for sealing during multiple opening and closing operations. At the same time, the design of the balls reduces the resistance during sliding and does not affect the discharge of liquid from the second drain port and the connecting pipe. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the overall three-dimensional sectional structure of this utility model; Figure 2 This is a schematic diagram of the overall frontal cross-section of the present invention after the main valve disc is closed; Figure 3 This is a schematic diagram of the overall frontal cross-section of the main valve disc after it is opened, representing the entire structure of this utility model. Figure 4 This is a schematic diagram of the overall three-dimensional front view of the present invention; Figure 5 This is a three-dimensional rear view schematic diagram of the limiting post structure of this utility model; Figure 6 This is a three-dimensional side view of the limiting post structure of this utility model; Figure 7 This utility model Figure 2 A magnified structural diagram at point A.

[0017] In the diagram: 1. Valve body; 11. Liquid inlet; 12. First drain outlet; 13. Second drain outlet; 14. Flow channel; 131. Connecting pipe; 132. Secondary valve disc; 133. Limiting post; 134. Cut-off groove; 133a. Raised bar; 133b. Ball bearing; 141. Cross support plate; 142. Stop chamber; 2. Telescopic post; 21. Outer rod; 22. Inner rod; 211. Telescopic chamber; 212. Spring; 213. Mounting port; 214. Mounting bracket; 215. Connecting rod; 216. Main valve disc. Detailed Implementation

[0018] The following illustrations will reveal several embodiments of the present invention. For clarity, many physical details will be described in the following description. However, it should be understood that these physical details should not be used to limit the present invention. That is, in some embodiments of the present invention, these physical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and components will be shown in a simple schematic manner in the illustrations.

[0019] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0020] In the description of this technology, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this technology based on the specific circumstances.

[0021] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0022] Please see Figure 1-7 The present invention provides a minimum flow valve sealing structure, comprising: a valve body 1, the valve body 1 including an inlet 11 at the bottom and a first outlet 12 at the top, a flow channel 14 inside the valve body 1, and a second outlet 13 on one side of the valve body 1, the inlet 11, the first outlet 12 and the second outlet 13 all being connected to the flow channel 14. Telescopic column 2 is vertically positioned within flow channel 14. A main valve disc 216 is provided on the outer surface of telescopic column 2. When telescopic column 2 moves downward, it causes the main valve disc 216 to abut against the inner circumferential wall of flow channel 14, thereby sealing flow channel 14. A secondary valve disc 132 is provided laterally at the second drain port 13. The main valve disc 216 and the secondary valve disc 132 are connected by a connecting rod 215. A limiting post 133 is provided on the side of the secondary valve disc 132 away from the main valve disc 216. The limiting post 133 is movably inserted into the second drain port 13 and is used to limit the movement of the secondary valve disc 132.

[0023] In this embodiment, the valve body 1 can be a shell structure with an internal flow channel formed by casting or forging, and the material can be carbon steel, stainless steel or special alloy; the main valve disc 216 and the auxiliary valve disc 132 can be metal sealing rings, composite sealing plates or valve plate structures with elastic sealing elements; the connecting rod 215 can be a rigid connecting rod, an adjustable threaded rod or a transmission rod with a spherical bearing; the limiting pin 133 can be a guide pin fixed to the valve body, a detachable limiting bolt or a guide shaft integrally formed with the auxiliary valve disc 132; The main valve disc 216 and the auxiliary valve disc 132 are rigidly linked by a connecting rod 215. The two ends of the connecting rod 215 can be connected to the main valve disc 216 and the auxiliary valve disc 132 respectively by a pin, a ball joint, or a threaded connection. The limiting post 133 is movably inserted into the second drain port 13. Its connection with the auxiliary valve disc 132 can be by interference fit, bolt fixing, or integral machining. The sliding fit between the limiting post 133 and the inner wall of the second drain port 13 achieves precise constraint on the movement trajectory of the auxiliary valve disc 132. The technical feature of the telescopic column 2 moving downward to cause the main valve disc 216 to abut against the inner peripheral wall of the flow channel 14 and close the flow channel 14 is as follows: When the flow rate entering from the inlet 11 is insufficient to push the main valve disc 216 upward, the telescopic column 2 moves downward under the force of the spring 212, pushing the main valve disc 216 to fit tightly against the sealing surface at the inner diameter of the valve body. This sealing surface can be a conical sealing surface, a flat sealing surface, or a composite sealing structure with a sealing ring. The axial displacement of the main valve disc 216 achieves complete closure of the flow channel 14. At this time, the second drain port 13 opens the recirculation passage through the linkage control of the auxiliary valve disc 132.

[0024] This design, through the setting of limiting post 133 and protrusion 133a, in conjunction with multiple balls 133b on the protrusion, and the restriction of the inner wall of the connecting pipe 131, allows the secondary valve disc 132 to be driven to open and close by the up and down movement of the main valve disc 216. It can slide laterally within the connecting pipe 131 through the limiting post 133 and the balls 133b to limit the movement trajectory of the secondary valve disc 132, preventing the secondary valve disc 132 from failing to accurately return to its original position for sealing during multiple opening and closing. At the same time, the design of the balls 133b reduces the resistance during sliding and does not affect the discharge of liquid from the second drain port 13 and the connecting pipe 131.

[0025] Please see Figure 6 and Figure 7 In this embodiment, the end of the second drain port 13 away from the secondary valve disc 132 is fixedly connected to a connecting pipe 131, and the limiting post 133 extends from the second drain port 13 into the connecting pipe 131. The diameter of the limiting post 133 is smaller than the inner diameter of the connecting pipe 131. At least two protrusions 133a protrude outward from the outer peripheral wall of the limiting post 133. Multiple balls 133b are embedded on the side of the protrusions 133a away from the limiting post 133. The outer surface of the multiple balls 133b contacts the inner wall of the connecting pipe 131. The inner diameter of the connecting pipe 131 is the same as the inner diameter of the second drain port 13. The second drain port 13 has a flow-blocking groove 134 on the side near the flow channel 14. When the secondary valve disc 132 is inserted into the flow-blocking groove 134, the second drain port 13 is closed. When the secondary valve disc 132 is disengaged from the flow-blocking groove 134, the second drain port 13 is opened. A sealing ring is provided on the edge of the secondary valve disc 132 near the intercepting groove 134. The diameter of the intercepting groove 134 is larger than the diameter of the second drain port 13.

[0026] The connecting pipe 131 can be a steel pipe, stainless steel pipe, or corrosion-resistant alloy pipe, and it is fixedly connected to the second drain port 13 by welding, threaded connection, or flange connection; the limiting post 133 is a cylindrical guide component, and the material can be high-strength alloy steel or wear-resistant ceramic; the rib 133a is a rib structure that extends radially outward along the limiting post 133, and its material can be the same as the limiting post 133 or a more wear-resistant composite material; the ball 133b is a steel or ceramic rolling element used to reduce friction; the intercepting groove 134 is an annular groove machined on the inner wall of the second drain port 13, and its cross-sectional shape can be rectangular, trapezoidal, or arc-shaped; the sealing ring can be an O-ring, V-ring, or metal sealing ring, and the material can be rubber, polytetrafluoroethylene, or flexible graphite.

[0027] The connecting pipe 131 and the second drain port 13 are fixedly connected by welding. The limiting post 133 extends from the second drain port 13 into the connecting pipe 131, and its fit with the second drain port 13 is a clearance fit. The protrusion 133a and the limiting post 133 are integrally formed or fixed by welding. The ball 133b is embedded in the mounting hole of the protrusion 133a through a retainer or directly, so that the outer surface of the ball 133b forms a rolling contact with the inner wall of the connecting pipe 131. The secondary valve disc 132 closes the second drain port 13 by engaging with the intercepting groove 134. When the secondary valve disc 132 disengages from the intercepting groove 134, the second drain port 13 opens. The sealing ring is fitted on the edge of the secondary valve disc 132 near the intercepting groove 134 and is fixed by interference fit or adhesive. When the secondary valve disc 132 engages with the intercepting groove 134, the sealing ring is deformed by pressure to achieve a seal.

[0028] It is worth noting that the technical feature of the limiting post 133 having a diameter smaller than the inner diameter of the connecting pipe 131 is as follows: This design allows an annular gap to be formed between the limiting post 133 and the inner wall of the connecting pipe 131. Combined with the rolling contact between the ball bearing 133b on the protrusion 133a and the inner wall of the connecting pipe 131, this ensures that the limiting post 133 can move freely along the axial direction, and the rolling friction of the ball bearing 133b replaces the sliding friction, significantly reducing the movement resistance. At the same time, the structural feature of the intercepting groove 134 having a diameter larger than the diameter of the second drain port 13 allows the secondary valve disc 132 to completely cover the opening area of ​​the second drain port 13 when it is inserted into the intercepting groove 134. Combined with the deformation compensation of the sealing ring, this ensures the sealing reliability of the second drain port 13 when it is closed.

[0029] This design incorporates a protruding strip 133a with ball bearings 133b on the outer periphery of the limiting post 133, transforming the movement of the limiting post 133 within the connecting pipe 131 from sliding friction to rolling friction. This significantly reduces motion resistance and improves the sensitivity and service life of the secondary valve disc 132. The snap-fit ​​design between the intercepting groove 134 and the secondary valve disc 132, combined with the sealing effect of the sealing ring, ensures zero leakage when the second drain port 13 is closed. Simultaneously, the design that the inner diameter of the connecting pipe 131 is the same as the inner diameter of the second drain port 13 ensures the stability of the flow field during fluid passage, avoiding pressure loss and cavitation risks caused by sudden changes in pipe diameter. Compared to traditional limiting structures, this design offers the advantages of smoother movement, more reliable sealing, and a more stable flow field.

[0030] Please see Figure 1 and Figure 2 It should be noted that cross support plates 141 are respectively provided on the inner wall of the flow channel 14 near the top and bottom. The telescopic column 2 is located between the two cross support plates. The telescopic column 2 includes an outer rod 21 and an inner rod 22. The bottom end of the outer rod 21 is movably inserted into the cross support plate 141 located below, and the top end of the inner rod 22 is fixedly connected to the cross support plate 141 located above. One end of the connecting rod 215 is connected to the outer rod 21. The outer rod 21 has a telescopic cavity 211 at its top end, and the inner rod 22 is movably inserted into the telescopic cavity 211. A spring 212 is provided between the telescopic cavity 211 and the bottom end face of the inner rod 22. The outer rod 21 has a horizontally penetrating installation port 213 near the bottom end. The bottom of the inner wall of the installation port 213 is vertically provided with a mounting bracket 214. One end of the connecting rod 215 is supported between the mounting brackets 214 and rotatably connected to the mounting brackets 214. The other end of the connecting rod 215 is rotatably connected to the center position of one side of the secondary valve disc 132. The top two sides of the inner wall of the mounting port 213 are provided with oblique openings that are offset upwards by 45°, and the width of the oblique openings is adapted to the width of the connecting rod 215. A stop chamber 142 is provided in the middle of the flow channel 14. The diameter of the stop chamber 142 is larger than the diameter of the inlet 11 and the first outlet 12. A sealing ring is also provided on the bottom end face of the main valve disc 216. The main valve disc 216 abuts against the bottom of the inner peripheral wall of the stop chamber 142 to close the flow channel 14 between the inlet 11 and the first outlet 12.

[0031] The cross support plate 141 can be a support plate with cross-shaped ribs, a fixed plate with guide grooves, or a positioning ring with a central hole, and the material can be stainless steel or wear-resistant alloy steel; the telescopic column 2 is composed of an outer rod 21 and an inner rod 22. The outer rod 21 can be a hollow round tube, a square tube, or a special-shaped tube, and the inner rod 22 can be a solid shaft, a hollow tube, or a stepped shaft; the telescopic cavity 211 is a cylindrical cavity, a rectangular cavity, or a conical guide cavity opened inside the outer rod 21; the spring 212 can be a helical compression spring 212, a butterfly spring 212 group, or a gas spring 212; the mounting bracket 214 can be a U-shaped bracket, an L-shaped fixed seat, or a support structure with a bearing seat; the mounting port 213 is a rectangular opening, a circular through hole, or a special-shaped through hole; the oblique opening is a 45° inclined guide groove, an arc-shaped notch, or a wedge-shaped opening; the stop cavity 142 is an enlarged cavity in the middle of the flow channel 14, and its cross-sectional shape can be cylindrical, conical, or stepped.

[0032] Specifically, the two cross support discs 141 are fixed to the top and bottom of the inner wall of the flow channel 14 by welding, threaded connection or interference fit, respectively; the bottom of the outer rod 21 is movably connected to the lower cross support disc 141 by sliding bearing, linear bearing or clearance fit; the top of the inner rod 22 is fixedly connected to the upper cross support disc 141 by bolts, welding or snap-fit; one end of the connecting rod 215 is connected to the outer rod 21 by a pin, spherical bearing or rotary joint; the inner rod 22 is movably inserted into the telescopic cavity 211 of the outer rod 21, and the spring 212 is set between the bottom of the telescopic cavity 211 and the bottom end face of the inner rod 22, providing elastic force through pre-compression; the mounting bracket 214 is vertically fixed to the bottom of the inner wall of the mounting port 213, and one end of the connecting rod 215 is rotatably connected to the mounting bracket 214 by a rotating shaft, bearing or hinge, and the other end is rotatably connected to the center of the secondary valve disc 132 by a ball joint, universal joint or pin.

[0033] It is worth noting that the top two sides of the inner wall of the mounting port 213 are offset upwards at a 45° angle. These angled openings are symmetrically arranged on both sides of the top of the mounting port 213, with an inclination angle of exactly 45°. The width matches the diameter or width of the connecting rod 215, allowing the connecting rod 215 to move smoothly along the guide trajectory of the angled openings during movement, avoiding jamming. At the same time, the structural feature that the diameter of the shut-off cavity 142 is larger than the diameter of the liquid inlet 11 and the first liquid outlet 12 provides sufficient movement space and sealing contact area for the main valve disc 216, ensuring that the main valve disc 216 can completely cover the flow cross section of the flow channel 14.

[0034] This solution utilizes the dual positioning and guiding function of the cross support disc 141, combined with the inner and outer rod structures 21 of the telescopic column 2 and the spring 212 buffer device, to achieve precise control and impact absorption of the main valve disc 216's movement. The oblique opening design ensures that the connecting rod 215 has a definite guiding trajectory during movement, improving the synchronicity and stability of the secondary valve disc 132's action. The matching design of the stop chamber 142 and the main valve disc 216, along with the sealing effect of the sealing ring, ensures the tightness of the main flow channel 14 when closed. Compared with the traditional single support structure, this solution offers the advantages of smoother movement, more accurate positioning, and longer service life.

[0035] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A minimum flow valve seal structure, characterized by, include: The valve body (1) includes an inlet (11) at the bottom and a first outlet (12) at the top. A flow channel (14) is provided inside the valve body (1). A second outlet (13) is provided on one side of the valve body (1). The inlet (11), the first outlet (12), and the second outlet (13) are all connected to the flow channel (14). A telescopic column (2) is vertically positioned within the flow channel (14). A main valve disc (216) is provided on the outer surface of the telescopic column (2). The telescopic column (2) moves downward, causing the main valve disc (216) to abut against the inner circumferential wall of the flow channel (14) to seal the flow channel (14). A secondary valve disc (132) is provided laterally at the second drain port (13). The main valve disc (216) and the secondary valve disc (132) are connected by a connecting rod (215). A limiting column (133) is provided on the side of the secondary valve disc (132) away from the main valve disc (216). The limiting column (133) is movably inserted into the second drain port (13) and is used to limit the secondary valve disc (132).

2. A minimum flow valve seal structure according to claim 1, wherein: The second drain port (13) is fixedly connected to a connecting pipe (131) at one end away from the secondary valve disc (132). The limiting post (133) extends from the second drain port (13) into the connecting pipe (131). The diameter of the limiting post (133) is smaller than the inner diameter of the connecting pipe (131).

3. A minimum flow valve seal structure according to claim 2, wherein: The outer peripheral wall of the limiting post (133) has at least two protrusions (133a) protruding outward. On the side of the protrusions (133a) away from the limiting post (133), a plurality of balls (133b) are embedded. The outer surface of the plurality of balls (133b) is in contact with the inner wall of the connecting pipe (131). The inner diameter of the connecting pipe (131) is the same as the inner diameter of the second drain port (13).

4. The minimum flow valve seal structure of claim 1, wherein: The second drain port (13) has a flow intercepting groove (134) on the side near the flow channel (14). When the secondary valve disc (132) is inserted into the flow intercepting groove (134), the second drain port (13) is closed. When the secondary valve disc (132) is disengaged from the flow intercepting groove (134), the second drain port (13) is opened.

5. A minimum flow valve seal structure according to claim 4, wherein: The secondary valve disc (132) is provided with a sealing ring at the edge of the intercepting groove (134) on the side near the intercepting groove (134), and the diameter of the intercepting groove (134) is larger than the diameter of the second drain port (13).

6. A minimum flow valve seal structure according to claim 1, wherein: The inner wall of the flow channel (14) is provided with cross support plates (141) near the top and bottom of the channel. The telescopic column (2) is located between the two cross support plates. The telescopic column (2) includes an outer rod (21) and an inner rod (22). The bottom end of the outer rod (21) is movably inserted into the cross support plate (141) located below. The top end of the inner rod (22) is fixedly connected to the cross support plate (141) located above. One end of the connecting rod (215) is connected to the outer rod (21).

7. A minimum flow valve seal structure according to claim 6, wherein: The outer rod (21) has a telescopic cavity (211) at its top end, and the inner rod (22) is movably inserted into the telescopic cavity (211). A spring (212) is provided between the telescopic cavity (211) and the bottom end face of the inner rod (22).

8. A minimum flow valve seal structure according to claim 6, wherein: The outer rod (21) has a horizontally through-hole (213) near the bottom. The bottom of the inner wall of the mounting hole (213) is vertically provided with a mounting bracket (214). One end of the connecting rod (215) is mounted between the mounting brackets (214) and is rotatably connected to the mounting brackets (214). The other end of the connecting rod (215) is rotatably connected to the center position of one side of the secondary valve disc (132).

9. A minimum flow valve seal structure according to claim 8, wherein: The mounting port (213) has oblique openings on both sides of the top of the inner wall, which are offset upwards by 45°. The width of the oblique openings is adapted to the width of the connecting rod (215).

10. A minimum flow valve seal structure according to claim 1, wherein: The flow channel (14) has a stop chamber (142) in the middle. The diameter of the stop chamber (142) is larger than the diameter of the inlet (11) and the first outlet (12). The bottom surface of the main valve disc (216) is also provided with a sealing ring. The main valve disc (216) abuts against the bottom of the inner peripheral wall of the stop chamber (142) to close the flow channel (14) between the inlet (11) and the first outlet (12).

Images