CN102384274A - Double-seal butterfly valve with maintenance sealing system - Google Patents

Abstract

The invention provides a double-seal butterfly valve with an inspection sealing system, which includes a sealing butterfly valve, a water inlet control device and a position adjustment device. The sealing butterfly valve includes an inspection sealing plate and a main sealing plate; the main sealing plate is operable to close or open the valve body The valve body also includes a main sealing valve seat and an inspection sealing valve seat that can slide along the inner wall of the main sealing valve seat; a cavity is provided on the inner wall of the main sealing valve seat: the inspection sealing valve seat is installed in the main sealing valve seat, and Seal the chamber and separate the chamber to form a first chamber and a second chamber; the water inflow control device can controlly fill the first chamber and the second chamber with water; wherein, the first chamber and the second chamber The water pressure difference in the cavity pushes the inspection sealing valve seat close to or away from the inspection sealing plate; the position adjustment device includes a threaded rod fixed on the inspection sealing valve seat, a limit sleeve fixed on the threaded rod and an external thread of the threaded rod The nut is rotatably connected, and the side end of the nut is opposed to the limit sleeve.

Description

Double seal butterfly valve with service seal system

technical field

The invention relates to the field of mechanical seals, in particular to a double-sealed butterfly valve with an overhaul sealing system.

Background technique

In the construction of existing small and medium-sized hydropower stations, one-pipe dual-machine or one-pipe multi-machine layout schemes are often adopted: that is, a pressure tunnel or a large-diameter main water inlet pipe is used to introduce the upstream water storage to the front of the power plant, and then divide it into Two or more water diversion branch pipes, and a water inlet butterfly valve is installed on each water diversion branch pipe. A set of hydroelectric generator set is installed on the downstream side of each inlet butterfly valve.

When the water turbine generates electricity, the water inlet butterfly valve is opened, and the upstream pressure water enters the water turbine through the butterfly valve to drive the water turbine to generate electricity. However, when the water inlet butterfly valve on a certain water diversion branch needs to be sealed and overhauled, the pressure water in the main water inlet pipe must be emptied, and the generator sets on all water diversion branches under the main water inlet pipe must be deactivated, so that the water inlet Butterfly valves are overhauled, resulting in the waste of pressure water and the loss of generator sets on other diversion branch pipes being implicated and forced to stop.

Contents of the invention

The purpose of the present invention is to provide a double-sealed butterfly valve with an overhaul sealing system to solve the technical problems in the prior art that cause pressure water to be wasted and generator sets on other water diversion branch pipes to be implicated and forced to stop.

In order to achieve the above object, according to one aspect of the present invention, a double-sealed butterfly valve with an overhaul sealing system is provided, including a sealed butterfly valve and a water inlet control device. The butterfly plate includes an inspection sealing plate and a main sealing plate arranged side by side at intervals; the main sealing plate is operable to close or open the valve body; the valve body also includes a main sealing seat and can slide along the inner wall of the main sealing seat The maintenance sealing valve seat; the inner wall of the main sealing valve seat is provided with a cavity: the maintenance sealing valve seat is installed in the main sealing valve seat, and the cavity is sealed, and the cavity is separated to form a first cavity and a second cavity. chamber; the first chamber is provided with a first water inlet and a first water outlet; the second chamber is provided with a second water inlet and a first water outlet; the water inlet control device is provided with a first water inlet connected to the first A water diversion pipe, the first water diversion pipe is controllable to fill the first chamber with water; the water inlet control device is also provided with a second water diversion pipe connected to the second water inlet, the second water diversion pipe is controllable to fill the second chamber It is filled with water; wherein, the pressure difference generated by the water pressure in the first chamber and the second chamber pushes the maintenance sealing valve seat close to or away from the maintenance sealing plate; the position adjustment device includes a threaded rod fixed on the maintenance sealing valve seat, a fixed The limit sleeve on the threaded pull rod and the nut rotatably connected with the external thread of the threaded pull rod, the side ends of the nut and the limit sleeve against each other.

Further, the limit sleeve is detachably fixed on the threaded pull rod; wherein, the limit sleeve can be selectively located on the first side of the nut facing the inspection sealing valve seat, or on the second side of the nut facing away from the inspection sealing valve seat end.

Further, a connecting valve is connected between the first and second water diversion pipes; the first and second water diversion pipes are respectively provided with manual valves for opening or closing the first and second water diversion pipes.

Further, the double-sealed butterfly valve with maintenance sealing system also includes a water tank or an upstream pipeline; the inlet ends of the first and second water diversion pipes are connected with the water tank or the upstream pipeline; at the inlet ends of the first and second water diversion pipes There is a manual booster pump.

Further, the first water outlet is connected with the first water discharge valve; the second water outlet is connected with the second water discharge valve; the main sealing valve seat is provided with a through hole, the through hole is located between the maintenance sealing plate and the main sealing plate, and the through hole There is a drain valve connected.

Further, the main sealing valve seat is provided with a passage through the cavity, and the butterfly plate is rotatably installed in the passage; the inspection sealing valve seat is slidably installed in the passage, and the periphery of the inspection sealing valve seat facing the passage is provided with There is an inspection sealing ring; a sealing rubber pad is arranged on the periphery of the inspection sealing plate; the inspection sealing ring abuts against the sealing rubber pad or is separated from the sealing rubber pad as the inspection sealing valve seat moves.

Further, the main sealing valve seat includes a first main body, a second main body, a fixing ring and a connecting sleeve; wherein, the fixing ring is fixedly sleeved on the first end of the second main body facing the first main body; the connecting sleeve is fixedly sleeved on the fixed On the outer peripheral edge of the ring, and the connecting sleeve extends toward the direction of the first body, and is fixedly connected to the first end of the first body; the cavity is in the channel, and the cavity is formed by the end face of the first end of the first body , the end face of the fixed ring and its connecting sleeve are surrounded together; the first water inlet, the first water outlet, the second water inlet and the second water outlet are all set on the connecting sleeve, and all of them run through the tube of the connecting sleeve wall.

Further, the inspection and sealing valve seat includes a movable sealing cylinder and a supporting plate that are slidably fitted in the channel and seal the cavity; the supporting plate is formed by extending the outer peripheral edge of the movable sealing cylinder outward along the radial direction of the movable sealing cylinder; wherein , the support plate is located in the cavity and abuts against the inner wall surface of the connecting sleeve to divide the cavity into a first cavity and a second cavity.

Further, the threaded pull rod includes a fixed head and a threaded rod fixed on the support plate, wherein the threaded rod is fixed on one side of the fixed head; the threaded rod passes through the fixed ring along the axial direction of the channel and is exposed Outside the valve body; scales are provided on the part of the threaded rod part exposed outside the valve body; both the limit sleeve and the nut are installed on the part exposed outside the valve body of the threaded rod part.

The invention has the following beneficial effects: the double-seal butterfly valve with inspection sealing system of the present invention is jointly driven by hydraulic and mechanical means to achieve the purpose of reliable movement of the inspection sealing ring, visible position, and adjustable sealing effect with the inspection sealing plate. In addition, through the through hole of the valve body located between the inspection sealing plate and the main sealing plate and the drain valve connected to the through hole, the leakage of the inspection sealing ring is monitored, and the sealing between the inspection sealing ring and the inspection sealing plate is improved. accuracy and precision.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. Hereinafter, the present invention will be described in further detail with reference to the drawings.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

Fig. 1 is a schematic diagram of a double-seal butterfly valve with an overhaul sealing system in a preferred embodiment of the present invention, the sealing system includes a double-seal butterfly valve, but the valve plate of the double-seal butterfly valve is not shown in this schematic diagram;

Fig. 2 is a schematic structural view of the double-sealed butterfly valve in Fig. 1 of the present invention when it enters water;

Fig. 3 is a schematic diagram of the cut-off structure of the double-sealed butterfly valve of Fig. 2;

Fig. 4 is the cut-off structural schematic diagram of the double-sealed butterfly valve in Fig. 1 of the present invention during maintenance; and

Fig. 5 is a schematic diagram of another embodiment of a double-seal butterfly valve with an inspection sealing system according to a preferred embodiment of the present invention.

Detailed ways

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways defined and covered by the claims.

Please refer to Fig. 1 to Fig. 3, the double-seal butterfly valve with maintenance sealing system of the preferred embodiment of the present invention includes a sealing butterfly valve 1 installed in a diversion branch pipe (not shown) and a water inlet control device 2 for supplying water to the sealing butterfly valve 1 .

The sealing butterfly valve 1 includes a valve body 10 , a butterfly plate 20 rotatably installed in the valve body 10 , and a position adjustment device 30 installed in the valve body 10 . Preferably, the sealed butterfly valve 1 further includes an operating mechanism installed outside the valve body 10, and the operating mechanism is connected to the butterfly plate 20 through a valve shaft. At this time, the butterfly plate 20 can be rotated by operating the operating mechanism, so that the butterfly plate 20 can be opened or closed, so as to open or close the sealing butterfly valve 1 .

The position adjusting device 30 includes a threaded pull rod 31 , a limiting sleeve 32 and a nut 33 . The threaded pull rod 31 includes a fixed head portion 311 and a threaded rod portion 312 provided with external threads. The threaded rod portion 312 is formed by extending from one side of the fixing head portion 311 . Preferably, a scale is engraved on the threaded rod part 312 , through the scale on the threaded rod part 312 , it can be determined whether the inspection sealing ring 135 of the valve body 10 has reached the sealing position. Both the limiting sleeve 32 and the nut 33 can be detachably installed on the threaded rod portion 312 , and the nut 33 abuts against the limiting sleeve 32 . When the nut 33 is turned, the threaded shank 312 is forced to move by action and reaction between the nut 33 and the threaded shank 312 .

The valve body 10 includes a main sealing valve seat 11 and an inspection sealing valve seat 13 movably installed in the main sealing valve seat 11 . A channel 111 is provided in the middle of the main sealing valve seat 11 for water flow, and the butterfly plate 20 is installed in the channel 111 . The main sealing valve seat 11 includes a first body 113 located at the water inlet end of the channel 111 , a second body 115 located at the water outlet end of the channel 111 , a fixing ring 117 and a connecting sleeve 119 . There is a gap between the first end of the first body 113 and the first end of the second body 115 . A working sealing ring 118 is fixedly protruding from the inner wall of the second main body 115 near the second end. The second main body 115 has a through hole 12 at the working sealing ring 118 , and a drain valve 14 is installed in the through hole 12 . The fixing ring 117 is fixedly sleeved on the outer peripheral edge of the first end of the second body 115 facing the first body 113 . Preferably, a sealing ring is provided between the outer peripheral edge of the second main body 115 and the inner peripheral edge of the fixing ring 117 to prevent the water in the channel 111 from leaking outward. The connecting sleeve 119 is fixedly fitted on the outer periphery of the fixing ring 117, and the end of the connecting sleeve 119 away from the fixing ring 117 is fixedly connected to the first end of the first main body 113, so that the first main body 113 and the second main body 115 are sealed and connected as a whole. At this time, the connecting sleeve 119 , the end surface of the fixing ring 117 and the first end of the first body 113 jointly enclose a cavity 116 that communicates with the channel 111 . The side wall of the connecting sleeve 119 is provided with the first water inlet 112 and the second water inlet 114 passing through the cavity 116 at intervals, and the first water outlet 15 and the second water inlet 15 opposite to the first water inlet 112 and the second water inlet 114 respectively. Two water outlets 16. The first water outlet 15 and the second water outlet 16 are respectively connected with a first water discharge valve 18 and a second water discharge valve 19 .

The maintenance sealing valve seat 13 includes a moving sealing cylinder 131 and a supporting plate 133 slidably fitted in the channel 111 . Wherein, the support plate is formed by the outer peripheral edge of the movable sealing cylinder 131 extending outward along the radial direction of the movable sealing cylinder 131 . The movable sealing cylinder 131 abuts against the inner peripheral edge of the channel 111 and seals the opening of the cavity 116 facing the channel 111 . The moving sealing cylinder 131 is operable to slide along the inner wall of the channel 111 . Preferably, a sealing ring is provided between the outer peripheral edge of the movable sealing cylinder 131 and the inner peripheral edge of the channel 111 . An inspection sealing ring 135 protrudes from the inner peripheral edge of the moving sealing cylinder 131 . The support plate 133 extends into the cavity 116, and the outer peripheral edge of the support plate 133 is against the inner wall of the connecting sleeve 119, and the support plate 133 is located between the first water inlet 112 and the second water inlet 114, so that the cavity 116 is divided into a first cavity 132 and a second cavity 134 , and the first cavity 132 is close to the first body 113 , and the second cavity 134 is close to the second body 115 . Wherein, the first water inlet 112 and the first water outlet 15 communicate with the first chamber 132 ; the second water inlet 114 and the second water outlet 16 communicate with the second chamber 134 .

The fixed head 311 of the threaded pull rod 31 of the position adjustment device 30 is fixed on the support plate 133 so that the maintenance sealing valve seat 13 moves together with the threaded pull rod 31 . The threaded rod portion 312 of the threaded tie rod 31 passes through the fixing ring 117 along the axial direction of the channel 111 and is exposed outside the cavity 116 . The limit sleeve 32 and the nut 33 are fixed on the threaded rod portion 312 exposed outside the cavity 116 superior. The limit sleeve 32 can be optionally located on the first side end of the nut 33 facing the support plate 133 of the inspection sealing valve seat 13 , or at the second side end of the nut 33 facing away from the support plate 133 of the inspection sealing valve seat 13 .

The butterfly plate 20 includes an inspection sealing plate 201 and a main sealing plate 203 which are connected to each other and arranged at intervals along the axial direction of the butterfly plate 20 . The through hole 12 on the valve body 10 is located between the maintenance sealing plate 201 and the main sealing plate 203 . The main sealing plate 203 can be operatively abutted against and sealed with the working sealing ring 118 of the valve body 10 or opened alternately. There is a gap between the outer peripheral edge of the maintenance sealing plate 201 and the inner wall of the channel 111 , and the maintenance sealing plate 201 is close to the maintenance sealing ring 135 . Preferably, sealing rubber pads 291 and 292 are respectively fixed on the periphery of the first and main sealing plates 201 and 203 .

The water inlet control device 2 includes a water tank 21 , a first water diversion pipe 22 and a second water diversion pipe 23 . Wherein, the inlet end of the first water diversion pipe 22 is connected to the water tank 21 , and the outlet end of the first water diversion pipe 22 is connected to the first water inlet 112 ; and a manual valve 221 is installed on the first water diversion pipe 22 . The inlet end of the second water pipe 23 is connected to the water tank 21 , and the outlet end of the second water pipe 23 is connected to the second water inlet 114 ; and a manual valve 231 is installed on the second water pipe 23 . By operating the manual valves 221 and 231 , the first water diversion pipe 22 and the second water diversion pipe 23 can be controlled to open water intake or close to prevent water intake. A communication valve 27 is also connected between the first water diversion pipe 22 and the second water diversion pipe 23 , and the pressures in the first water diversion pipe 22 and the second water diversion pipe 23 are equalized by opening the communication valve 27 .

When generating electricity, the butterfly plate 20 is operated so that the main sealing plate 203 and the working sealing ring 118 of the valve body 10 are opened alternately. At this time, the sealing butterfly valve 1 is opened, and the upstream pressurized water flows into the water turbine through the passage 111, and drives the water turbine to generate electricity. When the water turbine needs to be overhauled or power generation needs to be stopped, the butterfly plate 20 is operated to make the sealing rubber pad 292 on the main sealing plate 203 and the working sealing ring 118 of the valve body 10 push against and seal each other. At this time, the sealing butterfly valve 1 is closed, thereby sealing the passage 111, so as to prevent upstream pressure water from flowing into the water turbine through the passage 111. During the above-mentioned process of generating electricity, the hydraulic turbine needs to be overhauled or the electricity generation needs to be stopped, the water inflow control device 2 is always in the closing device, and does not discharge water into the first or second chambers 132, 134.

Please refer to Fig. 4. When it is necessary to perform seal inspection on the sealing butterfly valve 1 itself, that is, to inspect the sealing condition between the main sealing plate 203 of the sealing butterfly valve 1 and the working sealing ring 118 of the valve body 10, the specific operation process and method are as follows :

Step 1: Operate the butterfly plate 20 to close the sealing butterfly valve 1 . Both the communication valve 27 and the manual valves 221 and 231 are closed to prevent the water inflow control device 2 from releasing water into the first or second chamber 132 , 134 . Open the second water discharge valve 19 again to make the accumulated water in the second chamber 134 all empty.

Step 2: after the accumulated water in the second cavity 134 is emptied, close the second water discharge valve 19 . At this time, the manual valve 221 is opened, so that the water inlet control device 2 sends high-pressure water into the first chamber 132 through the first water pipe 22 . During the process of filling the first chamber 132 with water, due to the pressure difference between the first chamber 132 and the second chamber 134 , the maintenance sealing valve seat 13 is forced to move toward the second chamber 134 . At this time, the inspection sealing ring 135 of the inspection sealing valve seat 13 approaches the inspection sealing plate 201 along with the inspection sealing valve seat 13 .

Preferably, a pressure gauge 25 is also installed in the first chamber 132 or on the first water diversion pipe 22 to monitor the water pressure sent into the first chamber 132 . More preferably, a manual booster pump 26 is also provided, and the manual booster pump 26 is connected with the first water diversion pipe 22 and the second water diversion pipe 23, so as to increase the second water diversion through the first water diversion pipe 22 or the second water diversion pipe 23. The pressure in either the first chamber 132 or the second chamber 134. More preferably, a double filter device 28 is provided between the water tank 21 and the manual booster pump 26 to ensure that the pressurized water entering the first cavity 132 or the second cavity 134 is clean and free of impurities.

In other embodiments, if the maintenance sealing valve seat 13 does not move during the process of filling the first chamber 132 with water, it means that the water pressure in the first chamber 132 is not enough. At this time, turn on the manual booster pump 26, to pressurize the first chamber 132, thereby forcing the maintenance sealing valve seat 13 to move.

During the whole process of the second step, the moving distance of the maintenance sealing ring 135 can be judged by observing the scale on the threaded rod portion 312 . When it is observed that the inspection sealing ring 135 of the inspection sealing valve seat 13 and the sealing rubber pad 291 of the inspection sealing plate 201 are about to abut against each other, close the manual valve 221 to stop the first water pipe 22 from delivering high-pressure water into the first chamber 132 .

Step 3: By adjusting the position adjusting device 30 , the inspection sealing ring 135 of the inspection sealing valve seat 13 and the sealing rubber pad 291 of the inspection sealing plate 201 are abutted and sealed.

The specific process is: first fix the limit sleeve 32 of the position adjusting device 30 on the threaded rod portion 312; outside. After that, the nut 33 is screwed, thereby forcing the threaded rod portion 312 to approach toward the second cavity 314 . At this time, the inspection sealing ring 135 of the inspection sealing valve seat 13 approaches the inspection sealing plate 201 along with the inspection sealing valve seat 13 until the inspection sealing ring 135 contacts and seals against the sealing rubber pad 291 of the inspection sealing plate 201 . During this process, open the drain valve 14 of the valve body 10. If there is still water flowing out of the through hole 12 of the valve body 10, it means that the inspection sealing ring 135 of the sealing valve seat 13 and the sealing rubber pad 291 of the inspection sealing plate 201 If it is not sealed well, it is necessary to continue to screw the nut 33. If there is no water flowing out in the through hole 12 of the valve body 10, it means that the inspection sealing ring 135 of the inspection sealing valve seat 13 and the sealing rubber pad 291 of the inspection sealing plate 201 have been sealed against each other. At this time, the maintenance personnel can enter the water branch pipe from the manhole (not shown) of the sealing butterfly valve 1 to check the sealing condition between the main sealing plate 203 of the sealing butterfly valve 1 and the working sealing ring 118 of the valve body 10. Overhaul or replace the sealing rubber gasket 292 on the main sealing plate 203, etc. Like this, need not empty the pressurized water in this main water inlet pipe, also need not stop simultaneously the generator set on all diversion branch pipes under this main water inlet pipe, can avoid the waste of pressurized water and stop the loss that all generator sets cause simultaneously.

After the overhaul or replacement is completed, the first water discharge valve 18 is opened to empty the high-pressure water in the first chamber 132 . Open the manual valve 231 to fill the second cavity 134 with high-pressure water, thereby forcing the maintenance sealing valve seat 13 to move toward the first cavity 132 . At this time, the inspection sealing ring 135 of the inspection sealing valve seat 13 moves away from the inspection sealing plate 201 along with the inspection sealing valve seat 13 . Finally, the nut 33 is removed and installed inside the limit sleeve 32, and then the nut 33 is screwed, thereby forcing the threaded rod portion 312 to approach the first chamber 312 until the maintenance sealing ring 135 retreats in place. Now, open the communication valve 27 and close all other valves, that is, close the drain valve 14, the first water discharge valve 18, the second water discharge valve 19, and the manual valves 221 and 231. During this process, it can be judged by the scale on the threaded rod portion 312 whether the maintenance sealing ring 135 has retreated to its position.

From the above, it can be seen that the double-seal butterfly valve with inspection sealing system of the present invention can be jointly driven by hydraulic and mechanical means to achieve the purpose of reliable movement of the inspection sealing ring 135 , visible when in place, and adjustable sealing effect with the inspection sealing plate 201 . In addition, through the through hole 12 between the maintenance sealing plate 201 and the main sealing plate 203 of the valve body 10 and the drain valve 14 connected to the through hole 12, the leakage of the maintenance sealing ring 13 is monitored, which improves the maintenance of the maintenance sealing ring 13. The correctness and accuracy of the seal between the inspection and sealing plate 201.

Please refer to FIG. 5 , in other embodiments, the water inlet control device 2 of the double-sealed butterfly valve with a maintenance sealing system of the present invention is provided in addition to passing through the water tank 21, the first water diversion pipe 22 and the second water diversion pipe 23 to the first chamber 132 or The second chamber 134 conveys high-pressure water outside. It is also possible to draw high-pressure water directly from the upstream pipeline 40 . Between the upstream pipeline 40 and the inlets of the first and second water diversion pipes 22 and 23 , a main water inlet valve 41 , a chamber water inlet valve 43 and double filters 45 are arranged in sequence. The water tank 21 can also be connected to the upstream pipeline 40 through the water tank inlet valve 47, so as to transport high-pressure water from the upstream pipeline 40 to the water tank 21.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. One kind with the maintenance sealing system double seals butterfly valve; Comprise seal butterfly valve and inlet control device; Said seal butterfly valve comprises valve body, position regulator and is installed in the butterfly plate in the said valve body rotationally that said butterfly plate comprises that the maintenance sealing plate that is arranged side by side at interval is with the primary seal plate;

   Said primary seal plate operationally closure is perhaps opened said valve body;

   It is characterized in that,

   Said valve body also comprises primary seal valve seat and the maintenance seal valve seat that can slide along the inwall of said primary seal valve seat;

   The inwall of said primary seal valve seat is provided with a cavity:

   Said maintenance seal valve seat is installed in the said primary seal valve seat, and gets up said cavity airtight, and said cavity is separated to form one first chamber and one second chamber;

   Said first chamber is provided with one first water intake and one first water outlet; Said second chamber is provided with one second water intake and one second water outlet;

   Said inlet control device is provided with first aqueduct that is connected with said first water intake, and said first aqueduct is water-filling in said first chamber controllably;

   Said inlet control device also is provided with second aqueduct that is connected with said second water intake, and said second aqueduct is water-filling in said second chamber controllably; Wherein, the pressure difference that produces of the hydraulic pressure in said first chamber and said second chamber promote said maintenance seal valve seat near or away from said maintenance sealing plate;

   Said position regulator comprises the nut that an end is fixed on thread on the said maintenance seal valve seat, is fixed on the stop collar on the said thread and is connected rotationally with the outside thread of said thread, the side of said nut and said stop collar push up each other to.
2. 2. the double seals butterfly valve of band maintenance sealing system according to claim 1 is characterized in that said stop collar is dismountable to be fixed on the said thread;

   Wherein, said stop collar selectively is positioned at first side towards said maintenance seal valve seat of said nut, perhaps is positioned at second side of the said dorsad maintenance seal valve seat of said nut.
3. 3. the double seals butterfly valve of band maintenance sealing system according to claim 2 is characterized in that, is connected with a coupling cock between said first and second aqueduct;

   Be respectively equipped with the manually operated valve that makes said first and second aqueduct open or close on said first and second aqueduct.
4. 4. the double seals butterfly valve of band maintenance sealing system according to claim 3 is characterized in that, the double seals butterfly valve of said band maintenance sealing system also comprises a water tank or a upstream line;

   The entrance point of said first and second aqueduct is connected with said water tank or said upstream line;

   Also be provided with a hand increasing pressure pump at the entrance point place of said first and second aqueduct.
5. 5. the double seals butterfly valve of band maintenance sealing system according to claim 3 is characterized in that said first water outlet is connected with first discharging valve;

   Said second water outlet is connected with second discharging valve;

   Said primary seal valve seat is provided with a through hole, and said through hole is between said maintenance sealing plate and said primary seal plate, and said through hole is connected with a drain valve.
6. 6. the double seals butterfly valve of band maintenance sealing system according to claim 5 is characterized in that said primary seal valve seat is provided with a passage that connects with said cavity, and said butterfly plate is installed in rotation in the said passage;

   Said maintenance seal valve seat is slidably mounted in the said passage, and said maintenance seal valve seat is provided with a maintenance seal ring towards the periphery of said passage;

   Said maintenance sealing plate periphery be provided with sealing rubber pad;

   Said maintenance seal ring is against on the said sealing rubber pad or with said sealing rubber pad along with said maintenance seal valve seat pushes up movably and separates.
7. 7. the double seals butterfly valve of band maintenance sealing system according to claim 6 is characterized in that said primary seal valve seat comprises first main body, second main body, retaining ring and coupling sleeve;

   Wherein, said retaining ring is fixedly set in first end towards said first main body of said second main body; Said coupling sleeve is fixedly set on the outer periphery of said retaining ring, and said coupling sleeve extends to the direction of said first main body, and is fixedly connected on first end of said first main body;

   Said cavity is in said passage, and said cavity is formed by the end face of the end face of first end of said first main body, said retaining ring and common encirclement of said coupling sleeve thereof;

   Said first water intake, said first water outlet, said second water intake and said second water outlet all are located on the said coupling sleeve, and all run through the barrel of said coupling sleeve.
8. 8. the double seals butterfly valve of band according to claim 7 maintenance sealing system is characterized in that, said maintenance seal valve seat comprises and is sleeved in the said passage slidably and the hydrodynamic reciprocating sealing tube and the dunnage of airtight said cavity;

   Said dunnage is formed along extending radially outwardly of said hydrodynamic reciprocating sealing tube by the outer periphery of said hydrodynamic reciprocating sealing tube;

   Wherein, said dunnage is positioned at said cavity, and the top be against on the internal face of said coupling sleeve, said cavity is divided into said first chamber and said second chamber.
9. 9. the double seals butterfly valve of band maintenance sealing system according to claim 8 is characterized in that said thread comprises fixing head and the thread rod part that is fixed on the said dunnage, and wherein, said thread rod part is fixed on a side of said solid head;

   Said thread rod part is exposed at outside the said valve body after the axial direction of said passage passes said retaining ring;

   The outer position of said valve body that is exposed at of said thread rod part is provided with scale;

   Said stop collar and said nut are installed on the outer position of the said valve body of being exposed at of said thread rod part.

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