Disclosure of Invention
The invention aims to provide an automatic switching method for ball valve seat sealing, which can realize full-automatic switching of two groups of valve seat sealing, can prevent incorrect sealing components from being started, and is reliable and efficient as a whole.
The invention provides an automatic switching method of a ball valve seat seal, the ball valve comprises a main valve body and a control module, a ball core is arranged in a main valve cavity of the main valve body, a first valve body and a second valve body are arranged on two sides of the main valve body, the first valve body is positioned on a first side, the second valve body is positioned on a second side, the valve seat seal comprises a first valve seat component and a second valve seat component, the first valve seat component is arranged in the first valve body, the second valve seat component is arranged in the second valve body, the first valve seat component is provided with a first valve seat support, a first lip-shaped sealing ring is arranged on the first side of the first valve seat support, a first valve seat is arranged on the second side of the second valve seat support, a second lip-shaped sealing ring is arranged on the second side of the second valve seat support, and the first valve seat and the second valve seat are in sealing contact with the ball core, one side of the ball core is provided with a sealing switching hole which is communicated with the ball core channel; a second side of the first valve seat support is provided with a pressure-bearing retainer ring, and the excircle of the pressure-bearing retainer ring is in sliding contact with the inner wall of the main valve cavity; the upper end of the ball core is connected with a valve rod, the valve rod is connected with an electric driving device, a sealing cavity is formed between the second side of the second lip-shaped sealing ring and the second valve body, and a pressure sensor for detecting the pressure of the sealing cavity is arranged on the second valve body; the control module controls the electric driving device to drive the valve rod to adjust the position of the sealing switching hole according to the signal of the pressure sensor.
The automatic switching method comprises the following steps:
the method comprises the following steps: before formal use, the sealing performance of the ball valve is detected, the pressure drop of the first side when the sealing switching hole is positioned at the first side is detected, and the pressure drop of the first side when the sealing switching hole is positioned at the second side is detected.
Step two: and the sealing switching hole is rotated to the first side, the electric driving device is disconnected from the valve rod, at the moment, the valve rod is driven by the hand wheel, the second valve seat assembly plays a role in sealing the ball valve, and the first valve seat assembly does not play a sealing role.
Step three: when the second valve seat component leaks, the pressure sensor detects the pressure of the sealing cavity, and whether the second valve seat component really fails or not is judged according to the detection signal.
Step four: when judging the second valve holder subassembly is for inefficacy, control module sends and reveals the alarm, simultaneously pressure sensor is with signal transmission to control module, control module control electricity drives the device and is connected with the valve rod transmission, drives the valve rod and drives the rotation of ball core until sealed switching hole towards the second side, first valve holder subassembly plays sealed effect.
Step five: when the first valve seat assembly works, the electric driving device limits the rotation angle of the valve rod, and the sealing switching hole is prevented from rotating to the first side when the valve rod is rotated by the hand wheel.
Step six: the control module issues a replacement seat seal alert when the first seat assembly fails.
Preferably, in the third step, when the pressure sensor detects a discontinuous overpressure signal, it is determined that the second valve seat assembly is not really failed, and when the pressure sensor detects a continuous overpressure signal, it is determined that the second valve seat assembly is sealed to fail.
Preferably, the second valve seat assembly is determined to be sealed and failed when the pressure sensor detects an overpressure signal for more than 5 consecutive seconds.
Preferably, in the fifth step, the control module includes an angle detection device, the valve rod is arranged in the upper valve body, the angle detection device includes a plurality of sensing blocks arranged at equal intervals on the valve rod, and a sensing probe arranged on the inner wall of the upper valve body, the sensing probe sends a signal to the electric drive device when detecting that the rotation angle of the valve rod exceeds a preset angle, and the electric drive device limits the valve rod to continue rotating.
Preferably, in the fifth step, the electric driving device is always connected with the valve rod, when the sensing probe detects that the rotation angle of the valve rod exceeds 90 degrees, a signal is sent to the electric driving device, and the electric driving device realizes the limitation of the rotation of the valve rod by self-locking the driving motor.
Preferably, in the fifth step, the electric driving device comprises a limiting device, and the limiting device is matched with a limiting baffle plate on the valve rod, so that the rotation range of the valve rod is limited within 0-95 degrees.
Preferably, the limiting device is a limiting rod, and the limiting rod extends out when the first valve seat assembly works and is matched with a limiting baffle on the valve rod.
Preferably, the pressure-bearing retaining ring is provided with a one-way drain hole, and the one-way drain hole realizes the conduction from the first side to the second side.
Preferably, in the sixth step, when the first valve seat assembly fails, the pressure medium enters the main valve cavity on the second side through the one-way drain hole, and the pressure sensor detects a pressure signal when the medium enters the seal cavity, and then the control module gives a leakage alarm.
Preferably, in the first step, the seal switching hole of the ball core is rotated to the first side, the pressure testing machine applies the testing fluid pressure from the first side of the ball valve, and whether leakage occurs or not is detected from the second side; subsequently, the ball core is rotated by 180 degrees, the seal switching hole of the ball core is positioned at the second side, the pressure tester applies test fluid pressure from the first side of the ball valve, and whether leakage occurs or not is detected from the second side.
Compared with the prior art, the invention has the following technical effects:
1. the ball valve used by the method of the invention is provided with two groups of sealing components, lip-shaped sealing rings of the two groups of sealing components are arranged in the same direction, and one side of the ball core is provided with the sealing switching hole, so that the downstream sealing component can work in normal use, the upstream sealing component does not work, the upstream sealing component cannot be abraded, the upstream sealing component is in a standby state, and after the downstream sealing component fails, the ball core is rotated, so that the sealing switching hole rotates to the downstream side, and the upstream sealing component is in a working state.
2. The upstream valve seat support in the method is provided with the pressure-bearing retainer ring close to the downstream side, and the arrangement of the pressure-bearing retainer ring can ensure that when the downstream sealing assembly works, the pressure on the downstream side acts on the pressure-bearing retainer ring, so that the pressure on the upstream sealing assembly is partially offset, the stress on the upstream sealing assembly is reduced, and the contact part of the upstream sealing assembly and the ball core is not abraded as far as possible in a standby state.
3. The ball valve of the method of the invention has an electric drive device, which realizes automatic drive of the valve rod through the electric drive device, and can realize transmission connection or disconnection between the electric drive device and the valve rod when receiving signals of a control module, and meanwhile, the electric drive device has a valve rod rotation range limiting function (including using a limiting device or adopting a motor for self-locking) and limits the rotation of the sealing switching hole to a non-preset position possibly caused in a manual operation mode, thereby ensuring that two groups of valve seat sealing assemblies are in preset working requirements, particularly avoiding starting a failed downstream sealing assembly, and further ensuring the correct use of the sealing assembly.
4. The method comprises the step of judging failure signals of the sealing assembly, judging instantaneous overpressure signals such as flash explosion and the like in a valve cavity of the ball valve, and determining whether the sealing assembly really fails or not through judgment to avoid the situation that an electric driving device automatically switches upstream and downstream sealing when the sealing assembly does not really fail.
5. The control module of the method of the invention is provided with an angle detection device, and judges whether the sealing switching hole of the ball core is rotated to an incorrect working position by judging the rotating angle of the valve rod, thereby avoiding using a spare valve seat assembly or reusing a failed sealing assembly and ensuring the sealing reliability.
6. The control module of the method can send out leakage alarm and valve seat seal replacement alarm according to the detection signal, so that an operator can conveniently master the working state of the ball valve in time, meanwhile, the valve body is provided with a flow direction indicator for indicating the flow direction of a medium, and the upper part of the valve rod is provided with a seal working position mark and a ball core switch position mark to help the operator to identify the current working state of the ball valve and the working position of the seal assembly.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments.
Thus, the following detailed description of the embodiments of the invention is not intended to limit the scope of the invention as claimed, but is merely representative of some embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the embodiments of the present invention and the features and technical solutions thereof may be combined with each other without conflict.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the present invention, it should be noted that the terms "upper", "lower", and the like refer to orientations or positional relationships based on those shown in the drawings, or orientations or positional relationships that are conventionally arranged when the products of the present invention are used, or orientations or positional relationships that are conventionally understood by those skilled in the art, and such terms are used for convenience of description and simplification of the description, and do not refer to or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used solely to distinguish one from another, and are not to be construed as indicating or implying relative importance.
The invention provides an automatic switching method of ball valve seat sealing, as shown in fig. 1 to 7, wherein a one-way arrow in the figure represents the flow direction of a pressure medium, a two-way continuous arrow represents the pressure action direction of the pressure medium, and a two-way intermittent arrow represents the spring force action direction; the ball valve comprises a main valve body 101, a first valve body 102, a second valve body 103, an upper valve body 104, a ball core 105, a valve rod 106, a lower fixed shaft 107, a packing press ring 108, a sealing switching hole 109, a sealing working position mark 111, a ball core switch position mark 112, a first valve seat assembly 120 and a second valve seat assembly 130; the ball valve applicable to the automatic switching method includes a main valve body 101 and a control module, a ball 105 is disposed in a main valve chamber 110 of the main valve body 101, a first valve body 102 and a second valve body 103 are disposed on two sides of the main valve body 101, the first valve body 102 is disposed on a first side, the first side is a medium transmission upstream side, the second valve body 103 is disposed on a second side, the second valve body 103 has a second valve chamber 1031, the second side is a medium transmission downstream side, the valve seat seal includes a first valve seat assembly 120 and a second valve seat assembly 130, the first valve seat assembly 120 is disposed in the first valve body 102, the second valve seat assembly 130 is disposed in the second valve body 103, the first valve seat assembly 120 has a first valve seat support 121, a first lip seal 124 is disposed on the first side of the first valve seat support 121, and a first valve seat 122 is disposed on the second side, the second valve seat assembly 130 has a second valve seat support 131, a second valve seat 132 is provided on a first side of the second valve seat support 131, a second lip-shaped seal 134 is provided on a second side, the first valve seat 122 and the second valve seat 132 are in sealing contact with the ball core 105, a seal switching hole 109 is provided on one side of the ball core 105, and the seal switching hole 109 is communicated with the ball core channel; a pressure-bearing retainer ring 1211 is arranged on the second side of the first valve seat support 121, an outer circle of the pressure-bearing retainer ring 1211 is in sliding contact with an inner wall of the main valve cavity 110, preferably, the outer diameter of the pressure-bearing retainer ring 1211 is the same as the inner diameter of the main valve cavity 110, that is, the pressure-bearing retainer ring 1211 is in sliding connection with the main valve cavity 110, and a small gap still exists when the outer diameter of the pressure-bearing retainer ring 1211 is in contact with the main valve cavity 110 through tolerance control in actual machining, so that a small part of pressure medium can be allowed to pass through; the upper end of the ball core 105 is connected with a valve rod 106, the valve rod 106 is connected with an electric driving device, a sealing cavity 1033 is formed between the second side of the second lip-shaped sealing ring 134 and the second valve body 103, and a pressure sensor 1032 for detecting the pressure of the sealing cavity 1033 is arranged on the second valve body 103; the control module controls the electric driver to drive the valve stem 106 to adjust the orientation of the sealing switch orifice 109 based on the signal detected by the pressure sensor 1032.
Preferably, the first valve seat support 121 and the second valve seat support 131 both have a first cylinder, a second cylinder and a third cylinder, the diameter of the second cylinder is greater than the diameter of the first cylinder, the diameter of the third cylinder is greater than the diameter of the second cylinder, the first lip-shaped sealing ring 124 and the second lip-shaped sealing ring 134 are disposed on the first cylinder, the downstream end of the first valve seat support 121 is provided with a first annular groove, the first valve seat 122 is disposed in the first annular groove, the upstream end of the second valve seat support 131 is provided with a second annular groove, the second valve seat 132 is disposed in the second annular groove, and the first valve seat 122 and the second valve seat 132 are in contact with the ball core 105 and mainly play a role in sealing.
Preferably, the open end of the first lip-shaped sealing ring 124 faces the first side and abuts against the step four of the first valve body 102, the other end of the first lip-shaped sealing ring 124 abuts against the end surface of the second cylinder, a first energy storage spring 125 is arranged in the first lip-shaped sealing ring 124, and the open edge of the first lip-shaped sealing ring 124 abuts against the inner walls of the first cylinder and the first valve body 102; the open end of the second lip-shaped sealing ring 134 faces the first side, the other end of the second lip-shaped sealing ring 134 abuts against a first step 1034 of the second valve body 103, a second energy storage spring 135 is arranged in the second lip-shaped sealing ring 134, and the opening edge of the second lip-shaped sealing ring 134 abuts against the inner walls of the first cylinder and the second valve body 103.
Preferably, a plurality of spring holes are circumferentially formed in the end surface of the third cylinder, a first pre-tightening spring 123 is arranged in the spring hole of the first valve seat support 121, the protruding end of the first pre-tightening spring 123 abuts against the third step of the first valve body 102, a second pre-tightening spring 133 is arranged in the spring hole of the second valve seat support 131, and the protruding end of the second pre-tightening spring 133 abuts against the second step 1035 of the second valve body 103.
Preferably, the second end of the first seat support 121 and the first end of the second seat support 131 are provided with inclined surfaces, and a gap is formed between the inclined surfaces and the ball core 105, so that the sealing contact between the seat and the ball core 105 is not affected by the arrangement of the seat supports.
The function of the seal switch orifice 109 is to introduce upstream media pressure into the main valve chamber 110, preventing the first seat assembly 120 from sealing.
The automatic switching method specifically comprises the following steps:
the method comprises the following steps: detecting the sealing performance of the ball valve before formal use, wherein the detection comprises detecting the pressure drop of a first side when the sealing switching hole 109 is positioned at the first side and detecting the pressure drop of the first side when the sealing switching hole 109 is positioned at the second side; specifically, pressure is applied to the valve body by a pressure tester, and then the pressure on the upstream side is maintained, and the valve seat sealing performance is judged by detecting whether the pressure on the upstream side is reduced.
Step two: when the sealing switch hole 109 is rotated to the first side, the electric driving device is disconnected from the valve rod 106, at this time, the valve rod 106 is driven by the handwheel, the second valve seat assembly 130 plays a sealing role, and the first valve seat assembly 120 does not play a sealing role.
Step three: when the second valve seat assembly 130 leaks, pressure medium enters the sealed chamber 1033, and the pressure sensor 1032 detects the pressure in the sealed chamber 1033, and determines whether the second valve seat assembly 130 is actually out of order according to the detection signal.
Step four: when the second valve seat assembly 130 is determined to be failed, the control module issues a leakage alarm, and at the same time, the pressure sensor 1032 transmits a signal to the control module, the control module controls the electric driving device to be in transmission connection with the valve rod 106, the valve rod 106 is driven to drive the ball core 105 to rotate until the sealing switching hole 109 faces the second side, and at this time, the first valve seat assembly 120 plays a sealing role.
Step five: when the first valve seat assembly 120 works, the electric driving device limits the rotation angle of the valve rod 106, and ensures that the sealing switching hole 109 does not rotate to the first side when the valve rod 106 is rotated by a hand wheel; activation of the failed second valve seat assembly 130 is avoided, thereby ensuring proper use of the seal assembly.
Step six: when the first seat assembly 120 also fails, the control module issues a replacement seat seal alarm.
Preferably, in step three, when pressure sensor 1032 detects a discontinuous overpressure signal, it is determined that second seat assembly 130 is not actually failed, and when pressure sensor 1032 detects a continuous overpressure signal, it is determined that second seat assembly 130 is sealed to fail.
Preferably, when the pressure sensor 1032 detects an overpressure signal of more than 5 seconds continuously, it is determined that the second valve seat assembly 130 is sealed and failed, and the purpose of this setting is mainly to avoid overpressure in the main valve chamber 110 due to flash explosion of media and the like, and then to prevent a part of pressure media from entering the seal chamber 1033 instantaneously and being detected by the pressure sensor 1032, so as to signal that the second valve seat assembly 130 is sealed and leaked, actually, only when a continuous overpressure signal is detected, it is considered that the seal is actually leaked, and not because of flash explosion and the like but the second valve seat assembly 130 is not actually failed, it is mistaken by an operator that the second valve seat assembly 130 is failed. The judging method can avoid false alarm caused by medium flash explosion and the like, and ensures the correctness of failure judgment of the second valve seat component 130.
Preferably, in the fifth step, the control module includes an angle detection device, the valve rod 106 is disposed in the upper valve body 104, the angle detection device includes a plurality of sensing blocks disposed at equal intervals on the valve rod 106, and the sensing probe disposed on the inner wall of the upper valve body 104 sends a signal to the electric driving device when the sensing probe detects that the rotation angle of the valve rod 106 exceeds the preset angle, and the electric driving device limits the valve rod 106 from continuing to rotate.
Preferably, in the fifth step, the electric driving device is always connected with the valve rod 106, the sensing probe sends a signal to the electric driving device when detecting that the rotation angle of the valve rod 106 exceeds 90 degrees, and the electric driving device performs self-locking control on the driving motor to prevent the output shaft of the motor connected with the valve rod 106 from rotating, so as to limit the valve rod 106 from continuing to rotate; because the motor is adopted for self-locking, the contact of a mechanical structure is avoided, and the limitation of the rotation angle can be accurately controlled.
Preferably, the top of the valve rod 106 is provided with a sealing working position mark 111 for identifying the position of a pressure release hole of a ball in the valve cavity, the top of the valve rod 106 is provided with a ball core switch position mark 112 for identifying the on/off position of the ball core 105 in the valve cavity, and the outer side of the main valve body 101 is provided with a flow direction indicator for indicating that the medium flow direction is clear when the ball valve is installed and used, which indicates that the valve is in one-way sealing.
Preferably, in the fifth step, the electric driving device comprises a limit device, and the limit device is matched with a limit baffle on the valve rod 106, so that the rotation range of the valve rod 106 is limited to 0-95 degrees. The setting of above-mentioned angle can avoid sealed switching hole 109 to be rotated to the upstream side again because of the maloperation, indicate the ball core passageway to be in the open mode if 0 degree, pressure medium flows through from the ball core passageway, when closing the ball valve, valve rod 106 can rotate 95 degrees at most, can guarantee that the ball valve is in the off-state this moment, and can not further rotate, prevent exactly that operating personnel maloperation, will seal again and switch hole 109 and rotate to the upstream side to start the second valve seat subassembly 130 that has become invalid again, lead to the ball valve to appear revealing.
Preferably, the limiting device is a limiting rod, and the limiting rod extends out when the first valve seat assembly 120 works and is matched with a limiting baffle on the valve rod 106. Because the specific adoption is the gag lever post, and the gag lever post self has certain size, in order to guarantee to be in complete sealing state or conducting state after ball core 105 rotates, when adopting machinery spacing, the angle of rotation that allows is 95 degrees, and the rotation range that adopts motor auto-lock mode 5 degrees more than, mainly offsets the ball core rotation insufficient condition that the structural dimension of gag lever post brought.
Preferably, the pressure-bearing retainer 1211 is provided with a one-way drain hole (not shown in the drawings), which realizes the communication from the first side to the second side, i.e. only when the upstream sealing assembly fails, the pressure medium can enter the main valve cavity 110 formed between the ball element 105 and the main valve body 101 through the one-way drain hole from the upstream side.
Preferably, in the sixth step, when the first valve seat assembly 120 fails, the pressure medium enters the main valve cavity 110 on the second side through the one-way drain hole, specifically, when the first valve seat assembly 120 fails, the first lip-shaped sealing ring 124 deforms, the pressure medium enters the gap between the first valve seat support 121 and the first valve body 102 from the gap between the first lip-shaped sealing ring 124 and the first valve body 102, so as to enter the gap between the pressure-bearing retainer 1211 of the first valve seat support 121 and the first valve body 102, the pressure medium further enters the gap between the ball core 105 and the main valve cavity 110 through the one-way drain hole, and the pressure medium further enters the seal cavity 1033, and the pressure sensor 1032 detects the pressure signal, and the control module issues the leakage alarm, and simultaneously indicates that both the first valve seat assembly 120 and the second valve seat assembly 130 have failed, so as to issue the replacement valve seat seal alarm.
Preferably, the first step further includes rotating the seal switching hole 109 of the core 105 to a first side, applying a test fluid pressure from the first side of the ball valve by a pressure tester, and detecting whether leakage occurs from a second side; subsequently, when the ball core 105 is rotated by 180 degrees and the seal switching hole 109 of the ball core 105 is positioned at the second side, the pressure tester applies test fluid pressure from the first side of the ball valve and detects whether leakage occurs from the second side; then, the valve rod 106 is driven to drive the ball core 105 to rotate 180 degrees, the sealing switching hole 109 of the ball core 105 is located at the upstream end and is restored to the initial position, and the valve seat sealing performance test at the two ends is completed.
Specifically, when the fixed ball valve of the present invention is used, as shown in fig. 2-7, in the normal use state of the ball valve, the seal switching hole 109 of the ball 105 faces the first side, the pressure medium on the first side flows into the ball passage through the seal switching hole 109 and enters the main valve cavity 110 between the ball 105 and the main valve body 101, part of the pressure medium flows to the pressure-bearing retainer 1211 of the first valve seat support 121, the first valve seat support 121 is further pushed to move to the first side, the first valve seat assembly 120 does not perform the sealing function, part of the pressure medium enters the second lip-shaped seal 134 along the gap between the second valve seat support 131 and the second valve body 103, the second lip-shaped seal 134 of the second valve seat assembly 130 is subjected to the medium pressure to perform the sealing function, and at the same time, the second energy storage spring 135 in the second lip-shaped seal 134 applies the spring force upwards and downwards to further increase the sealing effect, the second seat assembly 130 achieves sealing while the electrical drive provided on the upper valve body 104 is disconnected from the valve stem 106 without restricting rotation of the valve stem 106; of course, the rotation of the valve stem 106 may also be limited by an electric drive if to prevent the operator from inadvertently rotating the seal switch bore 109 downstream while the second valve seat assembly 130 is functioning.
As shown in fig. 4, when the second seat assembly 130 fails to seal, part of the pressure medium enters the seal chamber 1033, and after the second seat assembly 130 is judged to be a true seal failure, the control module issues a leak alarm, and the electric drive automatically rotates the valve rod 106 180 degrees to make the seal switching hole 109 face the second side, and the pressure medium on the first side cannot enter the main valve chamber 110 between the ball 105 and the main valve body 101, and at this time, the pressure medium in the first valve chamber 1021 acts on the first seat assembly 120, and the first lip seal 124 of the first seat assembly 120 is sealed by the medium pressure, and pushes the first seat support 121 to move to the second side, so as to seal the first seat assembly 120, and at the same time, the first energy storage spring 125 in the first lip seal 124 exerts a spring force upwards and downwards to further increase the sealing effect; then, a limiting device or a motor self-locking mode is adopted to limit the rotation angle of the valve rod 106, so that the sealing switching hole 109 on the ball core 105 cannot rotate to the first side.
The ball valve used by the method of the invention is provided with two groups of sealing components, lip-shaped sealing rings of the two groups of sealing components are arranged in the same direction, and one side of the ball core is provided with the sealing switching hole, so that the downstream sealing component can work in normal use, the upstream sealing component does not work, and sealing abrasion can not be caused, so that the upstream sealing component is in a standby state, and after the downstream sealing component fails, the ball core is rotated, so that the sealing switching hole rotates to the downstream, the upstream sealing component is in a working state, the downstream sealing component and the upstream sealing component can be used in sequence, the effect that the two groups of sealing components participate in sealing successively can be achieved, the service life of the valve seat sealing is prolonged, and the manufacturing and using cost is reduced; in addition, the upstream valve seat support is provided with a pressure-bearing retainer ring close to the downstream side, and the pressure-bearing retainer ring is arranged to ensure that when the downstream sealing assembly works, the pressure on the downstream side acts on the pressure-bearing retainer ring, so that the pressure on the upstream sealing assembly is partially offset, the stress on the upstream sealing assembly is reduced, and the contact part of the upstream sealing assembly and the ball core is ensured not to be abraded as far as possible in a standby state.
The ball valve is provided with an electric driving device, the valve rod is automatically driven through the electric driving device, the electric driving device can be connected with or disconnected from the transmission of the valve rod when a control module signals, meanwhile, the electric driving device has a valve rod rotation range limiting function (including using a limiting device or adopting a motor for self-locking), the situation that an operator rotates the sealing switching hole to a non-working position by mistake when in a manual operation mode is limited, if the sealing switching hole is rotated to an upstream side by mistake when facing to a downstream side, therefore, two groups of valve seat sealing assemblies are ensured to be in preset working positions, particularly, the downstream sealing assembly which fails is prevented from being started, and therefore, the sealing assembly is ensured to be correctly used.
According to the automatic switching method for the sealing of the ball valve seat, in the process that the ball valve is opened and closed by the ball core, the rotation of the ball core is mainly realized by manually operating the rotary valve rod, and when the sealing assemblies at the upstream and downstream are switched, the electric driving device is involved, the valve rod is automatically rotated in time under the cooperation of the control module, so that the automatic switching of the two groups of sealing assemblies is realized, and when the sealing assemblies are switched, the rotary valve rod is still manually operated to realize the opening and closing of the ball valve; specifically when using seal assembly, need reveal the signal to seal assembly and judge, to the superpressure signal in the twinkling of an eye that the phenomenon such as the flash explosion that appears in the present ball valve caused, confirm whether really became invalid seal assembly through judging to avoid when not really becoming invalid electric drive device to carry out the sealed action of automatic switch upstream and downstream. The control module is provided with an angle detection device, and whether the sealing switching hole of the ball core is rotated to an incorrect working position is judged by judging the rotating angle of the valve rod, so that the use of a spare valve seat assembly or the reuse of a failed sealing assembly is avoided, and the sealing reliability is ensured. Control module can send out according to the detected signal and reveal the alarm and the sealed alarm of changing of disk seat, makes things convenient for operating personnel in time to master ball valve operating condition, simultaneously, sets up the flow direction sign on the valve body for instruct the medium flow direction, set up sealed operating position mark and ball core switch position mark on valve rod upper portion simultaneously, help operating personnel discernment current ball valve's operating condition and seal assembly's operating position.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.