Claims:1. A pneumatic actuation system (100) for a quarter turn valve having a fixed element and a moving element movable with respect to said fixed element in a first open position, a second intermediate partially closed position, and a final fully closed position, said system (100) comprising:
a pneumatic triggering circuit (104B) configured to sense angular displacement of said moving element in said second intermediate partially closed position; and
a pneumatic auxiliary circuit (104A) coupled with said pneumatic triggering circuit (104B) and said quarter turn valve, said pneumatic auxiliary circuit (104A) configured to provide a braking effect to the displacement of said moving element as said moving element approaches said final fully closed position from said second intermediate partially closed position, thereby providing a cushioning effect to said moving element of said quarter turn valve during fast closing thereof.
2. The system (100) as claimed in claim 1, which includes:
a compressed air source (106);
an actuator (108) fluidly coupled with said compressed air source (106) and mechanically coupled with said moving element of said quarter turn valve, said actuator configured to control the actuation of said moving element; and
a first valve (116) in fluid communication with said compressed air source (106) and said actuator (108), wherein said first valve (116) is configured to selectively allow compressed air to be supplied to said actuator for facilitating an opening stroke of said quarter turn valve to displace said moving element in said first open position.
3. The system as claimed in claim 2, wherein said pneumatic auxiliary circuit (104A) comprises:
a second valve (122) fluidly coupled with said first valve (116) and said actuator (108), said second valve (122) disposed downstream of said first valve (116); and
a third valve (124) disposed downstream of said second valve (122) and in fluid communication with said second valve (122), wherein said third valve (124) is configured to selectively regulate the flow of said compressed air therethrough, so as to decelerate said actuator (108) to provide a braking effect to said moving element of said quarter turn valve prior to the completion of said closing stroke in said final fully closed position.
4. The system (100) as claimed in claim 3, wherein said pneumatic triggering circuit (104B) further comprises:
a stroke length sensing means (126, 128, 136) configured to sense the stroke length travelled by said actuator (108), wherein on travel of a first predetermined stroke length by said actuator (108), said stroke length sensing means (126, 128, 136) being further configured to trigger said second valve (122) to redirect the flow of compressed air from an exhaust port of said second valve (122) to said third valve (124) so as to decelerate said actuator (108) to provide a braking effect to said moving element of said quarter turn valve prior to the completion of said closing stroke in said final fully closed position.
5. The system (100) as claimed in claim 4, wherein said first valve (116) is a solenoid valve and said second valve (122) is a pilot operated valve, and wherein in an energized state, said first valve (116) facilitates flow of compressed air from said compressed air source (106) to said actuator (108) to facilitate actuation of said moving element of said quarter turn valve.
6. The system (100) as claimed in claim 5, wherein in a de-energized state of said first valve:
said first valve (116) restricts the flow of compressed air to said actuator (108), thereby causing said actuator (108) to exhaust the compressed air therefrom under the biasing action of a spring of said actuator (108), wherein the exhausted compressed air is routed to said first valve (116), and from said first to an exhaust port of said second valve (122); and
on travel of said first predetermined stroke length by said actuator (108), said stroke length sensing means (126, 128, 136) triggers said second valve (122) to switch ports, thereby routing the supply of the exhausted compressed air from said exhaust port of said second valve (122) to said third valve (124), said third valve (124) being configured to regulate the flow of said exhausted compressed air therethrough, so as to decelerate said actuator to provide a braking effect to said moving element of said quarter turn valve prior to the completion of said closing stroke in said final fully closed position.
7. The system (100) as claimed in claim 6, wherein said second valve (122) is a pilot operated valve and said stroke length sensing means (126, 128, 136) include a cam (126) and a roller operated valve (128).
8. The system (100) as claimed in claim 6, wherein said second valve (122) is a solenoid valve and said stroke length sensing means (126, 128, 136) are proximity sensors (136).
9. The system (100) as claimed in claim 4, which includes:
a fourth valve (118) disposed downstream of said first valve (116) and in fluid communication with said second valve (122) and said actuator (108); and
a partial stroking device (110) coupled with said compressed air source (106) and said actuator (108), said partial stroking device (110) being in fluid communication with said fourth valve (118), wherein said first valve (116) and said partial stroking device (110) facilitate supply of compressed air to said fourth valve (118) to facilitate actuation of said actuator (108).
10. The system (100) as claimed in claim 9, wherein said stroke length sensing means (126, 128, 136) include a cam (126) and a roller operated valve (128).
11. The system (100) as claimed in claim 10, wherein, on travel of said first predetermined stroke length by said actuator (108), said cam (126) displaces a roller of said roller operated valve (128) and facilitates compressed air flow therethrough from said compressed air source (106) to said second valve (122), thereby switching compressed air flow from said exhaust port of said second valve (122) to said third valve (124) which regulates the exhaust so as to decelerate said actuator to provide braking effect to said moving element of said quarter turn valve prior to the completion of said closing stroke in said final fully closed position.
12. The system (100) as claimed in claim 11, wherein said fourth valve (118) is one selected from a pilot operated valve and a solenoid valve.
13. The system (100) as claimed in claim 3, wherein said third valve (124) is one selected from a flow control valve, a needle valve, and an exhaust port flow regulator.
14. The system (100) as claimed in claim 4, wherein said first pre-determined stroke-length ranges from 75% to 90% of the entire stroke-length of said actuator.
15. The system (100) as claimed in claim 1, wherein said quarter turn valve is a butterfly valve.

16. The system (100) as claimed in claim 4, wherein said stroke length sensing means is at least one selected from a group consisting of a position transmitter, an electronic, and a mechanical switch. , Description:
FIELD
[0001] The present disclosure relates to field of mechanical engineering.
BACKGROUND
[0002] A typical butterfly valve comprises a body which has a stem disposed centrally within the body. A disc is mounted on the stem and disposed within the body. When a flow of a fluid is to be regulated by the butterfly valve, it is essentially the disc which needs to be displaced (rotated) within the body to allow or restrict the passage of the fluid therethrough.
[0003] An exemplary application of the butterfly valve is its use as an emergency shutdown valve. In emergency shutdown applications, quick closing action of the valve is desired that in turn will stop the process flow. During such an emergency shutdown application, typically during the closing stroke, the disc of the butterfly valve tends to collide and impact the seat of the butterfly valve. This causes deformation of the seat and results in a reduced service life of the seal, which is not desired.
[0004] Hence, there is need of an actuation circuit for a butterfly valve operating in quick closing mode, which prevents the collision of the disc of the butterfly valve with the seat at the end of the closing stroke of the butterfly valve.
OBJECTS
[0005] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
[0006] An object of the present disclosure is to provide an actuation circuit for a butterfly valve that operates in quick closing mode.
[0007] Another object of the present disclosure is to provide an actuation circuit for a butterfly valve that operates in quick closing mode and prevents the collision of the disc of the butterfly valve with the seat at the end of the closing stroke of the butterfly valve.
[0008] Yet another object of the present disclosure is to provide an actuation circuit for a butterfly valve that prevents the deformation of the seat used in the butterfly valve.
[0009] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
[0010] The present disclosure envisages a pneumatic actuation system for a quarter turn valve to be used in fast closing applications, wherein the quarter turn valve has a fixed element and a moving element movable with respect to the fixed element in a first open position, a second intermediate partially closed position, and a final fully closed position. The system comprises a pneumatic triggering circuit and a pneumatic auxiliary circuit. The pneumatic triggering circuit is configured to sense angular displacement of the moving element at the second intermediate partially closed position. The pneumatic auxiliary circuit is coupled with the pneumatic triggering circuit and the quarter turn valve and configured to provide a braking effect to the displacement of the moving element as the moving element approaches the final fully closed position from the second intermediate partially closed position, thereby providing a cushioning effect to the moving element of the quarter turn valve during fast closing thereof.
[0011] In an embodiment, the system further comprises a compressed air source, an actuator, and a first valve. The actuator is fluidly coupled with the compressed air source and mechanically coupled with the moving element of the quarter turn valve. The actuator configured to control the actuation of the moving element. The first valve is in fluid communication with the compressed air source and the actuator, wherein the first valve is configured to selectively allow compressed air to be supplied to the actuator for facilitating an opening stroke of the quarter turn valve by displacing the moving element in the first open position.
[0012] In another embodiment, the pneumatic auxiliary circuit comprises a second valve fluidly coupled with the first valve and the actuator, wherein the second valve is disposed downstream of the compressed air source and the first valve. The pneumatic auxiliary circuit further includes a third valve disposed downstream of the second valve and in fluid communication with the second valve, wherein the third valve is configured to selectively regulate the flow of the compressed air therethrough, so as to decelerate the actuator to provide a braking effect to the moving element of the quarter turn valve prior to the completion of the closing stroke in the final fully closed position.
[0013] In another embodiment, the pneumatic triggering circuit further comprises a stroke length sensing means configured to sense the stroke length travelled by the actuator, wherein on travel of a first predetermined stroke length by the actuator, the stroke length sensing means is further configured to trigger the second valve to redirect the flow of compressed air from an exhaust port of the second valve to the third valve so as to decelerate the actuator to provide a braking effect to the moving element of the quarter turn valve prior to the completion of the closing stroke in the final fully closed position.
[0014] In another embodiment, the first valve is a solenoid valve and the second valve is a pilot operated valve, and wherein in an energized state, the first valve facilitates the flow of compressed air from the compressed air source to the actuator to facilitate actuation of the moving element of the quarter turn valve.
[0015] In a de-energized state of the first valve, the first valve restricts the flow of compressed air to the actuator, thereby causing the actuator to exhaust the compressed air therefrom under the biasing action of a spring of the actuator, wherein the exhausted compressed air is routed to the first valve, and from the first to an exhaust port of the second valve. On travel of the first predetermined stroke length by the actuator, the stroke length sensing means triggers the second valve to switch ports, thereby routing the supply of the exhausted compressed air from the exhaust port of the second valve to the third valve. The third valve is configured to regulate the flow of the exhausted compressed air therethrough, so as to decelerate the actuator to provide a braking effect to the moving element of the quarter turn valve prior to the completion of the closing stroke in the final fully closed position.
[0016] In another embodiment, the second valve is a pilot operated valve and the stroke length sensing means include a cam and a roller operated valve.
[0017] In another embodiment, the second valve is a solenoid valve and the stroke length sensing means are proximity sensors.
[0018] In another embodiment, the system further includes a fourth valve disposed downstream of the first valve and in fluid communication with the second valve and the actuator. A partial stroking device is coupled with the compressed air source and the actuator. The partial stroking device is in fluid communication with the fourth valve, wherein the first valve and the partial stroking device facilitate supply of compressed air to the fourth valve to facilitate actuation of the actuator.
[0019] In another embodiment, the stroke length sensing means include a cam and a roller operated valve. On travel of the first predetermined stroke length by the actuator, the cam displaces a roller of the roller operated valve and facilitates compressed air flow therethrough from the compressed air source to the second valve, thereby switching compressed air flow from the exhaust port of the second valve to the third valve which regulates the exhaust so as to decelerate the actuator to provide braking effect to the moving element of the quarter turn valve prior to the completion of the closing stroke in the final fully closed position.
[0020] In another embodiment, the fourth valve is one selected from a pilot operated valve and a solenoid valve.
[0021] In another embodiment, the third valve is one selected from a flow control valve, a needle valve, and an exhaust port flow regulator.
[0022] In another embodiment, the first pre-determined stroke-length ranges from 75% to 90% of the entire stroke-length of the actuator. In another embodiment, the quarter turn valve is a butterfly valve.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
[0023] A pneumatic actuation system for a butterfly valve of the present disclosure will now be described with the help of the accompanying drawing, in which:
[0024] Fig. 1 illustrates a schematic view of the pneumatic actuation system for a butterfly valve, in accordance with an embodiment of the present disclosure.
[0025] Fig. 2 illustrates a schematic view of the pneumatic actuation system for a butterfly valve, in accordance with another embodiment of the present disclosure.
[0026] Fig. 3 illustrates a schematic view of the pneumatic actuation system for a butterfly valve, in accordance with yet another embodiment of the present disclosure.
[0027] Fig. 4 illustrates a schematic view of the pneumatic actuation system for a butterfly valve, in accordance with still another embodiment of the present disclosure.
[0028] Fig. 5 illustrates a general arrangement of the pneumatic actuation system of Fig. 1.
LIST AND DETAILS OF REFERENCE NUMERALS USED IN THE DESCRIPTION AND DRAWING:
Reference Numeral Reference
100 Actuation System
104B Pneumatic triggering circuit
104A Pneumatic auxiliary circuit
106 Compressed Air Source
108 Actuator
108A Shaft
110 Partial Stroking Device
112 Air Filter Regulator
114 Pressure Relief Valve
116 First Valve
118 Fourth Valve
120 Volume Booster
122 Second Valve
124 Third Valve
126 Cam
128 Roller Operated Valve
130 Butterfly Valve
132 Quick Exhaust Valve
134 Second Valve
136 Proximity Sensors

DETAILED DESCRIPTION
[0029] An actuation system 100 for a quarter turn valve (hereinafter also referred to as system 100) to be used in fast closing applications is now described with reference to Fig. 1. The quarter turn valve has a fixed element and a moving element movable with respect to the fixed element in a first open position, a second intermediate partially closed position, and a final fully closed position. The system 100 comprises a pneumatic triggering circuit 104B. The pneumatic triggering circuit 104B is configured to sense the angular displacement of the moving element of the quarter in the second intermediate partially closed. The pneumatic auxiliary circuit 104A is coupled with the pneumatic triggering circuit 104B and the quarter turn valve and configured to provide a braking effect to the displacement of the moving element as the moving element approaches the final fully closed position from the second intermediate partially closed position, thereby providing a cushioning effect to the moving element of the quarter turn valve during fast closing thereof. The system 100 further includes an air filter regulator 112 disposed upstream of the pneumatic triggering circuit 104B and the pneumatic auxiliary circuit 104A. In an embodiment, the quarter turn valve is a butterfly valve, the moving element is the disc of the butterfly valve, and the fixed element is the frame of the butterfly valve in which the disc is mounted. It is to be noted that throughout the specification, the terms disc and moving element, and the terms quarter turn valve and butterfly valve are used interchangeably for the sake of simplistically describing the embodiments disclosed hereinafter.
[0030] In accordance with an embodiment of the present disclosure, the system 100 comprises a compressed air source 106 and an actuator 108 fluidly coupled the compressed air source 106 and mechanically coupled with the moving element of the quarter turn valve, which is disc of the butterfly valve in accordance with one embodiment (not shown in Fig. 1). The actuator 108 is configured to control the actuation of the disc. More specifically, the actuator 108 is mechanically coupled with the disc such that during an actuation stroke, the actuator 108 rotates the disc to either allow or restrict the passage of a fluid therethrough. The system 100 further comprises a first valve 116, which in the present embodiment, is a solenoid valve. The first valve 116 is in fluid communication with the compressed air source 106 and the actuator 108, wherein the first valve 116 is configured to selectively allow the compressed air to be supplied to the actuator 108 for facilitating an opening stroke of the quarter turn valve/butterfly valve by displace the moving element/disc of the quarter turn valve in the first position.
[0031] In an actuation stroke of the butterfly valve, the first valve 116, which is a solenoid valve, is energized. In an energized state, the first valve 116 allows the compressed air to be supplied from the compressed air source 106 to the actuator 108. As the compressed air is supplied to the actuator 108, the compressed air displaces the actuator shaft 108A, thereby causing the displacement of the moving element/disc to the first position of the butterfly valve/quarter turn valve into an open configuration.
[0032] In an embodiment, the auxiliary circuit 104A comprises a second valve 122 fluidly coupled with the first valve 116, and a third valve 124 disposed downstream of the second valve 122 and in fluid communication with the actuator 108. For closing the butterfly valve, the first valve 116, which is a solenoid valve, is de-energized. This causes the switching of the ports of the first valve 116, which cuts off the supply of the compressed air to the actuator 108. In absence of the supply of compressed air, the actuator 108 pushes the compressed air towards the first valve 116, under the biasing action of the spring of the actuator 108. In the initial stages of the closing stroke, the compressed air is exhausted via the first valve 116 and the second valve 122, which is disposed downstream of the first valve 116.
[0033] In accordance with the present disclosure, the pneumatic triggering circuit 104B further comprises a stroke length sensing means 126 configured to sense the stroke length travelled by the actuator 108, wherein on travel of a first predetermined stroke length by the actuator 108, the stroke length sensing means 126 is further configured to trigger the second valve 122 to redirect flow of compressed air from an exhaust port of the second valve 122 to the third valve so as to decelerate the actuator to provide a braking effect to the movement of the disc of the butterfly valve prior to the completion of the closing stroke in the final fully closed position. In the present embodiment, the stroke length sensing means 126 is a cam which operates in conjunction with a roller operated valve 128. When the actuator has travelled the first predetermined stroke length, the cam 126 displaces the roller of the roller operated valve 128, which then allows the flow of compressed air therethrough to the second valve 122. In an embodiment, the second valve is a pilot operated valve, and the compressed air from the roller operated valve 128 is supplied to the pilot port of the second valve 122, causing the second valve 122 to switch ports and route the supply of the compressed air from the first valve 116 to the third valve 124. The third valve 124 is a flow control valve configured to selectively regulate the flow of the compressed air therethrough, to provide braking effect to the movement of the disc during fast closing of said disc by decelerating the movement of the actuator 108. In another embodiment, the third valve is a needle valve or an exhaust port flow regulator.
[0034] It is to be noted that the pneumatic triggering circuit 104B, in accordance with the present disclosure, is operational when the moving element of the quarter turn valve is approaching from the second intermediate partially closed position to the final fully closed position and vice versa. The pneumatic triggering circuit 104B is operational when the moving element of the quarter turn valve is moving from the first open position to the second intermediate partially closed position and vice versa.
[0035] The system 100 further includes a partial stroking device 110 that is coupled with the compressed air source 106 and the actuator 108 and is configured to control displacement of the actuator 108, thereby controlling the actuation of the disc of the butterfly valve. The system 100 includes an air filter regulator 112 disposed downstream of the compressed air source 106 and upstream of the pneumatic triggering circuit 104B and the pneumatic auxiliary circuit 104A. The system 100 also includes a pressure relief valve 114 disposed downstream of the air filter regulator 112 and upstream of the pneumatic triggering circuit 104B and the pneumatic auxiliary circuit 104A. More specifically, the air filter regulator 112 and the pressure relief valve 114 are disposed upstream of the actuator 108 and the partial stroking device 110 and facilitate the coupling of the partial stroking device 110 with the compressed air source 106.
[0036] The pneumatic actuation system 100 for a butterfly valve (hereinafter also referred to as system 100) to be used in fast closing applications, in accordance with another embodiment of the present disclosure, is hereinafter described with reference to Fig. 2. Like components in Fig. 1 and Fig. 2 are referenced by like numerals for sake of simplicity. Furthermore, the construction and the connections of all the components illustrated in Fig. 2 is the same as that explained above, with reference to the working of the actuation system 100 illustrated in Fig. 1, barring the incorporation of a quick exhaust valve 132, which is described hereinafter. Hence, the same is not explained again for the sake of brevity of the present disclosure.
[0037] In accordance with the embodiment illustrated in Fig. 2, the quick exhaust valve 132 is disposed downstream of the first valve 116 and upstream of the second valve 122. During the opening stroke of the butterfly valve, the first valve 116, which is a solenoid valve, is energized, thereby allowing the flow of compressed air therethrough to the quick exhaust valve 132. The compressed air is supplied to the actuator 108 via the quick exhaust valve 132. The supply of the compressed air to the actuator 108 causes the opening of the butterfly valve.
[0038] For closing the butterfly valve, the first valve 116, which is a solenoid valve, is de-energized. This causes the switching of ports, which restricts the supply of the compressed air to the actuator 108. In absence of the compressed air supply, the actuator 108 pushes out the compressed air to the quick exhaust valve 132, which routes the compressed air to the exhaust port of the second valve 122. After the actuator 108 has travelled the first pre-determined stroke length, the cam 126 displaces the roller of the roller operated valve 128, thereby facilitating compressed air flow therethrough from the compressed air source 106. The compressed air it supplied to the second valve 122, thereby triggering the second valve 122 to switch ports and allow the compressed air being exhausted from the actuator 108 to be routed to the third valve 124, thereby regulating the flow of compressed air and providing a cushioning effect to the disc of the butterfly valve prior to the completion of the closing stroke.
[0039] The pneumatic actuation system 100 for a butterfly valve (hereinafter also referred to as system 100) to be used in fast closing applications, in accordance with yet another embodiment of the present disclosure, is hereinafter described with reference to Fig. 3. Like components in Fig. 1 and Fig. 3 are referenced by like numerals for sake of simplicity. Furthermore, the construction and the connections of all the components illustrated in Fig. 3 is the same as that explained above, with reference to the working of the actuation system 100 illustrated in Fig. 1, barring the replacement of the stroke length sensing means 126, which was a cam, with at least one proximity sensor 136, which is described hereinafter. Hence, the same is not explained again for the sake of brevity of the present disclosure.
[0040] In accordance with the present disclosure, the stroke length sensing means are proximity sensors 136. The proximity sensors 136 sense the travel of the actuator 108 upto the first predetermined stroke length, and then triggers a second valve 134, which is solenoid valve in the present embodiment, to switch ports. Once the ports are switched, the third valve 124 regulates the exhaust of the compressed air from the actuator 108 to provide cushioning action to the disc of the butterfly valve. In another embodiment, the system 100 further includes a logic solver unit that is communicatively coupled with the proximity sensors 136 and configured to receive signals from the proximity sensors 136 and accordingly trigger the second valve 134, which is a solenoid valve. In accordance with another embodiment, the stroke length sensing means includes a position transmitter which is communicatively coupled with the logic solver unit. In still another embodiment, the stroke length sensing means includes electronic switches and mechanical switches which include all types of contact and non-contact switches.
[0041] The pneumatic actuation system 100 for a butterfly valve (hereinafter also referred to as system 100) to be used in fast closing applications, in accordance with yet another embodiment of the present disclosure, is hereinafter described with reference to Fig. 4. Like components in Fig. 1 and Fig. 4 are referenced by like numerals for sake of simplicity. Furthermore, the construction and the connections of all the components illustrated in Fig. 3 is the same as that explained above, with reference to the working of the actuation system 100 illustrated in Fig. 1, barring the inclusion of a fourth valve 118, which is described hereinafter. Hence, the same is not explained again for the sake of brevity of the present disclosure.
[0042] In an embodiment, the system 100 further comprises the fourth valve 118 disposed downstream of the first valve 116 and in fluid communication with the actuator 108 and the second valve 122. The pneumatic actuation system 100 of the present disclosure facilitates the fast closing of the butterfly valve in two stages, viz., a fast closing action and a cushioning action. In the fast closing action, the first valve 116, which is a solenoid valve, is de-energized by cutting off the electric supply thereto. This causes switching of ports within the first valve 116 which cuts off the supply of compressed air to the pilot port of the fourth valve 118, which is a pilot operated valve in accordance with the present embodiment, thereby facilitating the exhaust of the compressed air from the actuator 108 via the exhaust ports of the fourth valve 118 and the second valve 122. This causes the cam 126 and the actuator 108 to be displaced by a first pre-determined stroke-length. In an embodiment, the first pre-determined stroke-length ranges from 75% to 90% of the entire stroke-length of the actuator 108. In another embodiment, the actuator is adjustable at any predefined position to achieve the cushioning effect. After completion of the first pre-determined stroke-length, the closing stroke continues in the cushioning action. In the cushioning action, when the first pre-determined stroke-length has been travelled by the cam 126 and the actuator 108, the cam 126 displaces a roller of the roller operated valve 128 and facilitates compressed air flow therethrough from the compressed air source 106 to a pilot port of the second valve 122, thereby switching compressed air flow from the exhaust port of the second valve 122 to the third valve 124 which regulates the exhaust so as to decelerate the actuator 108 to provide cushioning effect to the disc of the butterfly valve prior to the completion of the closing stroke.
[0043] In an embodiment, a volume booster 120 is disposed downstream of the partial stroking device 110 and upstream of the fourth valve 118. The output of the volume booster 120 is supplied to the fourth valve 118, which is in fluid communication with the actuator 108 after receiving the pilot signal by the first valve 116. Thus, the compressed air is supplied to the actuator 108, thereby displacing the actuator 108 and displacing the disc of the butterfly valve in an open configuration.
[0044] Fig. 5 illustrates a schematic view of the pneumatic actuation system 100. Like components in Fig. 1 and Fig. 2 are referenced by like numerals for sake of simplicity. Furthermore, the construction and the connections of all the components illustrated in Fig. 2 is the same as that explained above, with reference to the working of the actuation system 100 illustrated in Fig. 1. Hence, the same is not explained again for the sake of brevity of the present disclosure. Referring to Fig. 2, during a valve opening stroke, the solenoid valve 116 gets energized by an electric supply. An electric supply is also given to the partial stroking device 110. As soon as electrical supply given to both the solenoid valve 116 and the partial stroking device 110, compressed, filtered, and regulated air from the air filter regulator 112 flows through both, the solenoid valve 116 and the partial stroking device 110. Compressed air flowing through outlet of partial stroking device 110 gives pneumatic signal to a signal port of the volume booster 120. This pneumatic signal to the volume booster 120 causes compressed air to flow through it. Also, solenoid valve 116 gives a pneumatic signal to the pilot port of the first pilot operated valve 118. The pilot signal operates the first pilot operated valve 118 allowing the compressed air from volume booster 120 to flow therethrough, whereafter the compressed air enters into the actuator 108, thereby causing the opening of the butterfly valve 130.
[0045] To close off the butterfly valve 130, the electrical signal to solenoid valve 116 is cut-off. So pilot signal to the first pilot operated valve 118 also gets cut-off, and the outlet port of the first pilot operated valve 118 gets connected to the exhaust port thereof. Then the compressed air from actuator chamber starts exhausting through the exhaust port of the first pilot operated valve 118. The second pilot operated valve 122 is connected to the exhaust port of the first pilot operated valve 118. During the fast closing application, the air which is exhausting through exhaust port of the first pilot operated valve 118 also gets exhausted through the exhaust port of the second pilot operated valve 122. After 90% of the actuator travel, the cam 126 which is mounted on the actuator shaft presses the roller operated valve 128. This action changes the position of roller operated valve 128, thereby causing the air from air filter regulator to flow through it. That in turn gives signal to pilot port of the second pilot operated valve 122. Due to this, the second pilot operated valve 122 shifts the exhaust to the port connected with the flow control valve 124. As exhaust flow is restricted by flow control valve 124, air exhausts slowly to the atmosphere during the remaining 10% travel of the closing stroke. This reduces velocity of valve disk while closing, and the valve 130 closes slowly without causing any impact of disk on seat. In the present embodiment, the fourth valve 118 is a pilot operated valve. However, the fourth valve 118 is not limited to being a pilot operated valve, and can be any other suitable valve, as can be understood by a person skilled in the art. For example, in another embodiment, the fourth valve 118 is a volume booster valve.
[0046] The present disclosure is further described in light of the following experiment which is set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure.
[0047] Experimental trials were conducted on a fast closing butterfly valve with the conventional method of quick closing, i.e., using quick exhaust valve in a pneumatic circuit without the use of any kind of cushioning mechanism. The tests were conducted on a 20” butterfly valve of ASME class #150. The minimum air supply pressure to the actuator was 4 bars. The butterfly valve was tested with differential hydro seat test pressure of 10 bars for 100 cycles. It was observed that the closing time of the valve was 2.5 seconds. It was further observed that there was a rubbing action between the body seat and disc of the butterfly valve. After 100 cycles, dimensional variation was observed in the internal diameter of seat. Leakage of air was also during the pneumatic seat test.
[0048] Experimental trials were conducted on a fast closing butterfly valve with pneumatic circuit being used to provide cushioning effect. The trials were conducted on a 18” butterfly valve of ASME class #150. The minimum air supply pressure to the actuator was 4 bars. The timing set for valve closing was 4.5 seconds. The butterfly valve was tested with differential hydro seat test pressure of 11 bar for 4500 cycles with the condition that after every 100 cycles it would be tested for seat leakage. It was observed that the closing time for the valve was 4.5 seconds. No leakage was observed during pneumatic and hydro seat leakage test. Furthermore, no dimensional variation observed in the seat.
[0049] Thus, it can be inferred from the above data that the cushioning effect provided by the pneumatic actuation circuit of the present disclosure prevents the collision of the disc of the butterfly valve with the seat of the valve in fast closing applications, thereby preventing the deformation of the seat and preventing the leakage caused due to such deformed seat.
[0050] It is to be noted that the conventional actuators are available in the market which are configured to slow down prior to the end of the closing stroke by using different means such as use of a hydraulic fuel, or stopper plugs, and the like. However, such conventional actuators are very costly. The actuation system, envisaged in the present disclosure, can be retro used with the existing actuators that have no means slow down the actuation prior to the closing stroke, at minimal costs.
[0051] Although the system 100 envisaged in the present disclosure has been described as being used for the actuation of butterfly valve, it is to be noted that the application of the system 100 is not limited to a butterfly valve. The system 100 can be used for the actuation of the moving element of any other variety of the quarter turn valve.
TECHNICAL ADVANCEMENTS
[0052] The present disclosure described herein above has several technical advantages including, but not limited to, the realization of an actuation circuit for a quarter turn valve that:
• operates in quick exhaust mode;
• prevents the collision of the disc of the butterfly valve with the seat at the end of the closing stroke of the butterfly valve;
• prevents the deformation of the seat used in the butterfly valve; and
• can be retro used with existing actuators at minimal costs.
[0053] The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0054] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
[0055] Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
[0056] The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
[0057] Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
[0058] While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.