Claims:We Claim,
1. A conservator sequester valve (CSV) comprising of a transformer side flange, conduit or pipe (1), and a conservator side flange, conduit or pipe (3) connected to a rectangular housing (2) with an operating flap (7) mounted on the pivoting bar (5) placed on the transformer side flange (1) with the help of bar holding plate (4);
the said operating flap (7) is provided with a packing or sealing gasket (13) fitted such that during flow of oil due to rupture of electrical transformer tank (16) or bursting of electrical transformer bushing or draining of oil, it swings towards the transformer side flange, conduit or pipe (1) so as to restrict flow of oil from the conservator tank (15) to transformer tank (16);
a stopper plate (6) mounted on the transformer side flange (1) to set the flow rate of oil for triggering the movement of the operating flap (7) during flow of oil due to rupture of electrical transformer tank (16) or bursting of electrical transformer bushing or draining of oil or any other condition causing increase in flow rate of the oil on the transformer side so as to stop the flow of oil from the conservator tank (15) to transformer tank (16);
a rotating bar (8) connected with an external adjustable lever (11) placed inside inner threaded bush (10) to manually fix the position of the operating flap (7) such that in one such position the operating flap (7) does not restrict flow of oil from the conservator tank (15) to transformer tank (16) as needed during filtration or filling or refilling and in another position of the operating flap (7) stops the flow of oil from the conservator tank (15) to transformer tank (16) as needed during servicing or maintenance;
a monitoring means connected to the operating flap (7) for alerting the changes in the position of the operating flap (7) caused due to flow of oil.
2. The conservator sequester valve (26) as recited in claim 1, wherein the monitoring means for monitoring the position of the operating flap (7) can be selected from group of magnetic sensor, proximity sensor, magnetic switch, or combination thereof.
3. The conservator sequester valve (26) as recited in claim 1, wherein the circuit used for monitoring the position of the operating flap (7) is normally close (NC) circuit.
4. The conservator sequester valve (26) as recited in claim 1, wherein the rotating bar (8) is fixed to a position where it does not interfere with the movement of the operating flap (7) thereby allowing the operating flap (7) to move in response to the increase in the flow of the oil.
5. The conservator sequester valve (26) as recited in claim 1, wherein the rotating bar (8) is used to manually fix the position of the operating flap (7) to a point where the flow of the oil from the conservator tank (15) to transformer tank (16) is not restricted.
6. The conservator sequester valve (26) as recited in claim 1, wherein the rotating bar (8) is used to manually fix the position of the operating flap (7) to a point where it closes the flow of the oil from the conservator tank (15) to transformer tank (16).
7. The conservator sequester valve (26) as recited in claim 1, wherein the position of the stopper plate (6) is shifted towards conservator side flange (3) to increase the threshold of the flow rate of oil at which the operating flap (7) shall close the flow of the oil.
8. The conservator sequester valve (26) as recited in claim 1, wherein the position of the stopper plate (6) is shifted towards transformer side flange (1) to decrease the threshold of the flow rate of oil at which the operating flap (7) shall close the flow of the oil. , Description:FIELD OF THE INVENTION
The present invention relates to the field of a Conservator Sequester Valve (CSV) designed for an electrical transformer to stop the oil flow from conservator tank to transformer tank during servicing or maintenance and or emergency situations such as transformer oil leakages due to rupture of electrical transformer and or bushing failure, explosion, fire of electrical transformer; and to keep oil flow open during oil filtration.
BACKGROUND OF THE INVENTION
In electrical transformers, emergency situations arising due to rupture and or bushing failure or explosion, fire leading to the leakage of transformer oil requires a device or a valve to stop the oil flow automatically from conservator tank to transformer tank.
In the cases of malfunctioning of the transformer due to different reasons, the valve has to be manually closed in order to stop the flow of oil. Even in the cases of carrying out servicing or maintenance of the transformer, the valve has to be manually closed to stop the flow of oil. In the case of periodic filtration of the oil, the valve has to be manually opened for maintaining the free flow of oil.
Indian patent 202300, describes the Transformer Conservator Isolation Valve (TCIV) which is being used to isolate the conservator from the transformer in case of emergency and keep oil flow open manually for oil filtration. The Transformer Conservator Isolation Valve (TCIV) helps to stop the flow of oil from the conservator to the transformer but it has a number of drawbacks which has to be addressed and solved.
The prior art describes that the transformer conservator isolation valve (TCIV) which operates in two modes i.e. normal flow and filtration mode. It does not provide any mode which can be opted during servicing activities which has to be carried out during transformer maintenance. The said transformer conservator isolation valve (TCIV) has an operating device suspended from rectangular housing wherein the said operating device closes the flow of oil in response to increase in flow of oil or presence of vacuum. The exerted forces act on the bottom (moving end) of the operating device as the top end is fixed. Due to this situation, the angle of the valve installation becomes a critical factor in maintaining the initial gap between the outlet conduit pipe and the operating device which causes increase or decrease of the set closing flow rate of the valve.
Another main drawback of the transformer conservator isolation valve (TCIV) is that the weight of operating device which is acting against the oil flow direction and resultant weight of the operating pendulum device increases due to the gravitational force when the operating device moves towards the outlet conduit pipe. So the closing force required to move the operating device against outlet conduit pipe increases in proportion with decrease in gap between outlet conduit pipe and operating device.
Another major drawback of the transformer conservator isolation valve (TCIV) is its inability to maintain the free flow of oil during increase in flow rate of oil wherein such increase in flow rate of oil is below the normal threshold limit. This is caused due to gradual increase in resultant weight of the operating device due to gradual increase in the flow rate of the oil. As the valve closes, the gap between the outlet pipe and operating device decreases, thereby causing restriction to the flow of oil to the transformer.
Even though the required closing force gradually increases, the valve restricts the flow of oil. This phenomenon is contradictory in order to fulfil the valve functional requirement of timely conservator tank oil isolation. This will directly affect the oil isolation effectiveness and exhibit delay in terms of time taken for isolation.
Also the switching device present in the transformer conservator isolation valve (TCIV) does not continuously monitor the position of operating device. The switching device generates an alarm in the event of contact of moving end of the operating device to the outlet conduit pipe. Since the alarm is generated only in the event of contact of the operating device to an outlet conduit pipe, the failure of switching device, circuit, sensors or any other component related to the alarm system shall affect the system’s ability to generate an alarm. For example, if the sensors or the circuit is damaged even after establishment of the contact between the operating device and the outlet conduit pipe, the system may not be able to generate an alarm.
Another drawback of the transformer conservator isolation valve (TCIV) is related to its installation requirement. Since the gravitational forces acts in determining the resultant weight of the operating device during the normal flow rate of oil, the angle of installation of the valve plays a very crucial role in the operation of the device. The angle of installation affects the opening gap between operating device and the outlet conduit pipe.
Hence, there is a need to design and develop a valve which can overcome the drawbacks of the prior art. The designed valve must be able to stop the flow of oil from the conservator tank to the transformer tank during service or maintenance of the transformer and also during emergency situations like leakage of transformer oil due to rupture of the transformer or bushing failure of the electrical transformer and facilitate the normal flow of oil during filtration.
OBJECTS OF THE INVENTION
The primary objective of this invention is to provide a conservator sequester valve (CSV) for isolating the electrical transformer conservator during abnormal flow of oil due to rupture of electrical transformer tank or bursting of electrical transformer bushing or any other hazardous conditions resulting into increase in flow rate of the oil.
Another objective of the present invention is to provide a conservator sequester valve (CSV) for permitting the normal flow of oil during non-hazardous conditions.
Another objective of the present invention is to provide a conservator sequester valve (CSV) which provides a means for manually locking the operating flap to the position where it allows the flow of oil from conservator to transformer as needed during the process of filtration of oil.
Another objective of the present invention is to provide a conservator sequester valve (CSV) which provides a means for manually locking the operating flap to the position where it prevents the flow of oil from conservator to transformer as needed during the process of servicing or maintenance of the electrical transformer.
Another objective of the present invention is to provide a conservator sequester valve (CSV) which can be operated in three modes i.e. Normal working mode (Auto Mode), Filtration mode, Service mode.
Another objective of the present invention is to provide a conservator sequester valve (CSV) wherein the response of the operating flap is achieved only after the flow rate of oil has increased beyond the predetermined threshold limit.
Another objective of the present invention is to provide a conservator sequester valve (CSV) wherein the position of the operating flap in response to change in the flow rate of the oil is monitored on a continuous basis thereby providing additional alters related to mechanical or electrical failures like loose contact or wire break.
Another objective of the present invention is to provide a conservator sequester valve (CSV) which provides the flexibility in setting the closing flow rate by means of minor adjustments in position of the stopper plate w.r.to operating flap.
Another objective of the present invention is to continuously monitor the position of operating flap by means of magnetic sensor connected in normally closed (NC) circuit to facilitate the identification of mechanical or electrical failures like loose assembly, loose electrical contact, wire break etc.

SUMMARY OF THE INVENTION
The disadvantages associated with the prior art are addressed in the present invention by designing the conservator sequester valve (CSV) which can be operated in three different modes.
The first mode, referred as an auto mode in which the operating flap is used for isolating the electrical transformer conservator during abnormal flow of oil due to rupture of electrical transformer tank or bursting of electrical transformer bushing or any other hazardous condition involving increase in flow rate of oil. During the normal operation or non-hazardous condition, the conservator sequester valve (CSV) permits the normal flow of oil.
During the filtration mode the operating flap is locked to open position to get the uninterrupted oil flow from conservator tank to transformer tank. For repair or maintenance or service mode, a means for manually locking the operating flap to a position where it prevents the flow of oil from conservator tank to transformer tank is provided.
The present invention describes a Conservator Sequester Valve (CSV) comprising of a transformer side flange (1) and conservator side flange (3) connected to the housing (2). An operating flap (7) is mounted on to a pivoting bar (5) and pivoting bar (5) is mounted on the transformer side flange (1) with the help of bar holding plate (4). A stopper plate (6) is mounted on transformer side flange (1) to facilitate the movement of the operating flap (7) in response to abnormal flow rate of oil and thereby stopping the flow of the oil. This complete assembly could be manually controlled and operated by a rotating bar (8) placed inside inner threaded bush (10) and can be fixed with adjustable lever ring (11) on the housing (2). An adjustable lever ring (11) allows the valve to operate in three modes such as Auto Mode (28), Filtration Mode (29) and Service Mode (30).
In Auto Mode (28), the adjustable lever ring (11) is fixed or locked to ‘Position 1’ (FIG. 3) in such a way that the operating flap (7) is free from rotating bar (8) locking and is ready to operate automatically during emergency situations such as oil leakages due to rupture of electrical transformer, bushing failure, explosion, fire of electrical transformer. During emergency situations, flow rate of oil moving towards the transformer tank (16) increases which causes additional pressure on the operating flap (7). This additional pressure pushes the operating flap (7) against the pipe opening of transformer side flange (1) thereby stopping the flow of the oil to the transformer tank (16).
In Filtration Mode (29), the adjustable lever ring (11) is fixed and or locked to ‘Position 2’ (FIG 4). In the said position the rotating bar (8) pushes the stopper rod (22) to hold the operating flap (7) backwards in a non-operational situation i.e. away from transformer side flange (1). During the process of filtration, the oil flows from conservator tank (15) to transformer tank (16) and the forward movement of operating flap (7) is prevented by rotating bar (8). This allows flow of oil from conservator tank (15) to transformer tank (16) during filtration process.
In Service Mode (30), the adjustable lever ring (11) is fixed or locked to ‘Position 3’ (FIG.5). In the said position, the rotating bar (8) pushes the stopper rod (22) to hold the operating flap (7) forward in a non-operational situation i.e. against the pipe opening of transformer side flange (1). This prevents the flow of oil from conservator tank (15) to transformer tank (16).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG.1 illustrates the conservator sequester valve in open position during normal flow of oil.
FIG.2 illustrates the conservator sequester valve in closed position during hazardous conditions which results in increase in the flow rate of the oil.
FIG.3 illustrates the position of the conservator sequester valve in auto mode.
FIG.4 illustrates the position of the conservator sequester valve in filtration mode.
FIG.5 illustrates the position of the conservator sequester valve in service mode.
FIG 6 illustrates the position of the stopper plate in the conservator sequester valve during installation process.
FIG.7 illustrates the comparison of resultant weight of operating flap of Conservator Sequester Valve (CSV) and Transformer Conservator Isolation Valve (TCIV) in response to oil flow rate.
DETAILED DESCRIPTION OF THE INVENTION
The present invention describes a conservator sequester valve (CSV) which is used to stop the oil flow from the conservator to transformer during hazardous conditions.
REFERENCE NUMBERS USED IN FIGURES:
1) Transformer Side Flange
2) Main Housing
3) Conservator Side Flange
4) Bar Holding Plate
5) Pivoting Bar
6) Stopper Plate
7) Operating Flap
8) Rotating Bar
9) Oil Seal
10) Inner Bush
11) Adjustable Lever Ring
12) Operation View Gauge
13) Packing Gasket
14) Sealing Gaskets
15) Conservator Tank
16) Transformer Tank
17) Force Open Locking
18) Force Close Locking
19) Floating or Resting Lock
20) Inlet Pipe Conservator Side
21) Outlet Pipe Transformer Side
22) Stopper Rod
23) Magnetic Sensor
24) Air Release Bolt
25) Oil Drain Bolt
26) Conservator Sequester Valve (CSV)
27) Buchholz Relay
28) Auto Mode
29) Filtration Mode
30) Service Mode
Conservator Sequester Valve (CSV) comprising of transformer side flange (1) and conservator side flange (3) connected to the main housing (2). An operating flap (7) is mounted on pivoting bar (5) and pivoting bar (5) is mounted on transformer side flange (1) with the help of bar holding plate (4). Stopper plate (6) is mounted on transformer side flange (1) to set the closing oil flow rate to move the operating flange (7) to stop the abnormal oil flow. This complete assembly could be manually controlled and operated by rotating bar (8) placed inside inner threaded bush (10) and fixed with adjustable lever ring (11) on main housing (2). An adjustable lever ring (11) gives flexibility to put the valve in three different operating modes such as Auto Mode (28), Filtration Mode (29) and Service Mode (30).
The present invention describes the conservator sequester valve (CSV) wherein the movement of the conservator sequester valve (26) is monitored by a magnetic sensor (23). The magnetic sensor (23) which is provided with the conservator sequester valve (26) is mounted on the stopper plate (6) and connected through normally closed (NC) circuit. This NC circuit continuously monitors the home position of the operating flap (7) and triggers immediate signal to the transformer protection system if the contact breaks. Thus the conservator sequester valve (26) identifies the operating movement of operating flap (7) in all the modes and also its mechanical or electrical failures like loose assembly, loose electrical contact, wire break etc.
Operating flap (7) is designed to move in an anticlockwise direction to stop the flow of oil from the conservator to transformer in any hazardous conditions which results into increase in flow rate of oil. In this position the rotating bar (8) has kept an operating flap (7) at a position where it can move in response to the increase in the flow rate of the oil. In this position the movement of the operating flap (7) in clockwise direction is prevented by stopper plate (6). The position of the operating flap (7) when it is in contact with stopper plate (6) determines the threshold of the flow rate of oil to which the anticlockwise movement of the operating flap (7) is triggered.
The operating flap (7) of the conservator sequester valve (26) can be manually moved in clockwise direction by moving the rotating bar (8). The operating flap (7) can be locked at this position by moving the adjustable lever ring (11) which is connected to rotating bar (8). This position of the operating flap (7) is desired during the filtration mode for allowing flow of the oil.
The operating flap (7) can be manually moved in anticlockwise direction by using a rotating bar (8) to close the valve. The operating flap (7) can be locked at this position by moving the assembly of adjustable lever ring (11) and rotating bar (8) in anticlockwise direction. This manual operation can be performed during servicing or maintenance of the transformer.
The conservator sequester valve (26) is also provided with an air release bolt (24) and an oil drain bolt (25) for releasing air and oil respectively. The said air release bolt (24) and an oil drain bolt (25) can be used during the installation and maintenance of conservator sequester valve (26).
As illustrated in FIG. 1, conservator sequester valve (26) is mounted between the conservator tank (15) and Buchholz relay (27) with help of an inlet conservator side pipe (20) and outlet transformer side pipe (21). In this figure, the operating flap (7) inside the conservator sequester valve (26) is resting in Auto mode (28) allowing the normal oil flow from conservator tank (15) to transformer tank (16).
As illustrated in FIG.2, the operating flap (7) is pushed in anticlockwise direction to stop the oil flow from conservator tank (15) to transformer tank (16) during hazardous conditions like cracking and or rupture, bushing failure or explosion or fire or any other condition resulting in increase in flow rate of oil.
As illustrated in FIG 3, the conservator sequester valve (26) is in Auto mode locking position. In this mode operating flap (7) is free to open & close as per the condition & requirement.
As illustrated in FIG 4, the conservator sequester valve (26) is in filtration mode locking position. In this mode, the operating flap (7) is forced to move in clockwise direction to maintain the regular & proper flow of oil during the filtration process.
As illustrated in FIG.5, the conservator sequester valve (26) is in service mode locking position. In this mode, the operating flap (7) is forced to move in anticlockwise direction to close the valve to prevent the flow of oil from conservator tank (15) to transformer tank (16).
As illustrated in FIG 6, the conservator sequester valve (CSV) describes the various positions of stopper plate (6) during installation process. The stopper plate (6) can be installed at variable positions i.e. close to the pivot bar (5) or away from the pivot bar (5). When the stopper plate (6) is installed close to pivot bar (5) as described in Position “A” of FIG 6, the resultant weight of the operating flap (7) decreases and when the stopper plate (6) is installed away from the pivot bar (5) as described in Position “B” of FIG 6, the resultant weight of the operating flap (7) increases. The closing flow rate of the operating flap (7) is directly proportional to its resultant weight. Thus closing flow rate can be easily set by varying position of the stopper plate (6). The conservator sequester valve (CSV) (26) of the present invention gives flexibility to set the closing flow rate as per its installation angle or as per the demand of the end user.
As illustrated in FIG 7, the comparison of resultant weight of operating flap or device of Conservator Sequester Valve (CSV) and Transformer Conservator Isolation Valve (TCIV) respectively in response to oil flow rate is shown.
As described in the graph, once the flow rate of oil in the CSV (26) has increased to a point where it can displace the resultant weight of the operating flap (7) of the conservator sequester valve (26), the operating flap (7) is moved to the anticlockwise direction thereby stopping the flow of oil from conservator tank (15) to transformer tank (16).
In TCIV, the gradual increase in the flow rate of the oil causes gradual increase in the resultant weight of the operating device. Once the resultant weight of the operating device of the TCIV reaches the point sufficient to establish contact with the outlet conduit pipe, the valve reaches to the closed position and the flow of oil stops. During this process of gradual movement of the operating device the space available for movement of the oil is gradually decreased thereby causing disturbances to the flow of the oil. This also causes the monitoring system to issue false alters if the said monitoring system is monitoring the flow of incoming oil to the transformer end.
In conservator sequester valve (CSV) (26), the increase in the flow rate of the oil does not affects the resultant weight of the operating flap (7). For the operating flap (7) to move in an anticlockwise direction a force equivalent to more than its weight has to be generated by the incoming flow of the oil. This ensures that the movement of the operating flap (7) is triggered only at the point when the force generated by the incoming flow of oil is sufficient to cause movement of the operating flap (7).
The closing of the conservator sequester valve (26) is immediate and not gradual as seen in TCIV.
ADVANTAGES OF THE INVENTION
The primary advantage of the conservator sequester valve (26) disclosed in the present invention is its ability to operate in three modes. The Auto mode (28) where the valve (26) can remain in open condition in the presence of normal flow rate and to a closed condition in the presence of increased flow rate caused due to hazardous conditions like transformer cracking, rupture, bushing failure, explosion, fire etc.
In the filtration mode, the conservator sequester valve (26) is manually kept at open position to maintain the proper flow of oil allowing filtration of oil or draining of oil.
In the service mode, the conservator sequester valve (26) is manually kept at close position to stop the flow of the oil during the servicing or maintenance operations carried out with transformer.
Yet another advantage of this conservator sequester valve (26) is its precision in the movement which is caused only after the set flow rate of oil is achieved and this allows the normal flow of oil from conservator tank (15) to the transformer tank (16) when the flow rate of the oil is below the threshold limit.
Yet another advantage of the conservator sequester valve (26) is its ability to adjust the threshold limit by adjusting the position of the stopper plate (6) w.r.to the operating flap (7).
Yet another advantage of the conservator sequester valve (26) is related to the continuous monitoring of the position of the operating device (7) which ensures the issuing of alters in the event of abnormal flow rate of oil and also in the event of mechanical or electrical failures like loose assembly, loose electrical contact, wire break etc.
Another advantage of the conservator sequester valve (26) is related to prevention of false trigger or emergency signals caused due to minor increase in the flow rate of the oil wherein such increase in the flow rate is below the threshold limit.
Yet another advantage of the conservator sequester valve (26) is its ability to nullify the effects caused due to variation in the angle of installation. As the operating flap (7) movement is sudden and specific to the threshold flow rate any minor increase in the flow rate of the oil which is below threshold limit does not affect the passage of movement of oil.