The present disclosure relates to a valve for controlling fluid flow, more particularly, relates to an improved right angle valve for use in sugar plants.
BACKGROUND OF THE DISCLOSURE
Generally, sugar plants utilize steam for heating and evaporating juice extracted from sugarcane. Steam valves may be used at one or more places in the sugar plants to control the flow of steam in the sugar plants. The steam valves may include large bore size, for example, up to 1000 mm. The steam valves can be operated either manually by an operator or by an automated mechanism. Typically, force or effort required to operate the steam valves of large sized valves is considerably more than small sized valves irrespective of the mode of operation of the valves, i.e. manually or automatically operated valves.
One kind of steam valve that may be used in sugar industry is shown in FIG. 1. The valve (100) includes a steam inlet (102) at a bottom of the valve (100). The valve (100) includes a steam outlet (104), a closure member (106) and a spindle rod (108) connected to the closure member (106) coaxially. The closure member (106) can be moved vertically up or down to allow or to stop steam to flow into the valve (100) when a handle (110) connected to the spindle rod is rotated. In this valve, the steam exerts a force on the closure member (106) in an upward direction. In an example, when the valve is required to be closed by closure member, a force required for closing the closure member should be equal to or greater than the steam force. This is because, the closure member and the spindle rod are coaxial to each other and the spindle rod is being directly connected to the closure member. For example, as shown in FIG. 1, if the steam exerts a force of 100 kgf on the closure member, the force required to be applied at the handle (110) should be equal to or greater than 100 kgf for keeping the closure member (106) in the closed position.
The valve (100) of FIG. 1 thus requires more force for its operation and may cause strain to the operators and in some time it may be found difficult in

operating the valve. Also, in the valve (100) as discussed above, the steam flow may not be smooth since the possibility of steam path getting disturbed by the closure member (106) as an obstacle is more, causing the high pressurized steam to strike the walls of the closure member (106). This may result in reducing the steam pressure in the valve (100) and thereby decreasing overall efficiency of the plant or sugar production output.
In light of the above and other limitations of the existing valves, it is objectively desired to decrease the force required for valve operation and to increase efficiency by reducing pressure losses in the valve.
SUMMARY OF THE DISCLOSURE
The present disclosure provides a valve for use in a sugarcane plant. The valve comprises a valve body having a first opening, a second opening and a third opening. The first opening and the second opening are in fluid communication. The valve further includes a casing extending from the third opening of the valve body at an angle with the valve body. The casing is adapted to accommodate a stem rod which is movable axially in the casing. The valve further includes a valve disc which is hingedly connected at the first opening via a hinge connection. The valve disc is adapted to be operated for closing and opening of the first opening. The valve further includes a plurality of rigid links having a first rigid link, a second rigid link and a third rigid link, each having a first end and a second end. The first end of the first rigid link is hingedly coupled to the valve disc. The first end of the second rigid link is hingedly coupled to a top cover of the valve body and the first end of the third rigid link is hingedly coupled to the stem rod. The second ends of each of the plurality of rigid links are hingedly coupled with one another, such that the plurality of rigid links are adapted to rotate the valve disc about the hinge connection when the stem rod is displaced axially in the casing for closing or opening of the first opening.

In an embodiment, the valve disc comprises a strut member disposed on a top surface of the valve disc.
In an embodiment, the strut member is adapted to hingedly couple the first end of the first rigid link with the valve disc.
In an embodiment, the top cover of the valve body comprises a strut member disposed on a bottom surface of the top cover.
In an embodiment, the strut member is adapted to hingedly couple the first end of the second rigid link with the valve body.
In an embodiment, the second ends of each of the plurality of rigid links are hingedly coupled with one another through a pin member.
In an embodiment, the hinge connection is disposed proximal to the first opening, axis of the hinge connection being substantially orthogonal to axis of the second opening.
In an embodiment, the stem rod comprises a first end connected to the rigid link and a second end connected to an actuator.
In an embodiment, the actuator is a hand wheel. The hand wheel is adapted to be rotated to displace the stem rod axially in the casing.
In an embodiment, the stem rod is configured to push the third rigid link axially to push the first rigid link and the second rigid link for closing the valve disc at the first opening.
In an embodiment, the stem rod is configured to pull the third rigid link axially to pull the first rigid link and the second rigid link for opening the valve disc at the first opening.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
FIG. 1 shows a schematic diagram of a steam valve, according to the prior art;
FIG. 2 shows a sectional perspective view of a valve, according to an
embodiment of the present disclosure;
FIG. 3 shows a sectional view of the valve shown in FIG. 2, according to an
embodiment of the present disclosure;
FIG. 4 shows a sectional perspective view of the valve shown in FIGS. 2 and 3,
where valve disc of the valve is in open position, according to an embodiment of
the present disclosure;
FIG. 5 shows a sectional view of the valve shown in FIGS. 2-4, where valve disc
of the valve is in closed position, according to an embodiment of the present
disclosure;
FIG. 6 shows a schematic diagram of fluid flow in the valve shown in FIG. 4,
according to an embodiment of the present disclosure;
FIG. 7 shows a schematic diagram of fluid flow in the valve shown in FIG. 1,
according to the prior art; and
FIG. 8 shows a schematic diagram of the valve having bigger section at the valve
housing to compensate for the reduction in flow area at the valve according to an
exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE DISCLOSURE WITH REFERENCE TO ACCOMPANYING DRAWINGS
Provided below is a non-limiting exemplary embodiment of the present invention and a reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts. Moreover, references to various elements described herein, are made collectively or individually when there may be more than one element of the same type. However, such references are merely exemplary in nature. It may be noted that any reference to elements in the singular may also be construed to relate to the plural and vice-versa without

limiting the scope of the disclosure to the exact number or type of such elements unless set forth explicitly in the appended claim.
Referring to FIG. 2, which illustrates a sectional perspective view of a valve (200), according to an embodiment of the present disclosure. The valve (200) illustrated in the figure is a fluid flow regulating device used in plants (not shown) such as for example, sugar industry, steel industry etc. The plants may include multiple piping and duct systems for transporting and delivering the generated fluid (for example steam) from a generated location to a utilization location. The fluid may be transported via the piping and the duct systems may be made to pass via devices such as, but not limited to, pressure monitoring devices, check valves or valves, temperature sensors, viscosity sensors etc. The valve typically can be configured to operate automatically or manually. The term "valve" as used herein in the present disclosure, refers to a device for controlling a passage of fluid through a pipe, duct, tube, etc., which controls fluid flow by allowing or stopping the fluid flow. During manual operation of the valve, an operator may be physically operating a handle or a hand wheel of the valve for operating the valve.
The valve (200) in the illustrated embodiment can be made of material including, but not limited to, carbon steel, stainless steel, nickel alloys and titanium alloys. The valve (200), in the illustrated FIG. 2, includes a valve body (202). The valve body (202) embodies a top cover (216). The top cover (216) is mounted on the valve body (202) using fastening means like, nuts and bolts or welding, for sealing the valve body (202). In another embodiment, the top cover (216) may be an integral component with the valve body (202). The top cover (216) is provided to prevent leakage of fluid from the valve body (202). The top cover (216) includes a strut member (240) on a bottom surface (217) of the top cover (216). The strut member (240) may be offset from the center of the top cover (216).
The valve body (202) further includes a first opening (204) provided at a bottom portion of the valve (202). The terms "first opening", "bottom opening", and

"inlet" are interchangeably used in the present disclosure. The terms "first opening", "bottom opening" and "inlet" are one and the same and they are relating to same "opening". The bottom opening (204) is adapted to receive the fluid from a source (not shown) through a stub pipe (not shown) and to allow the fluid to enter the valve body (202). The fluid from the valve body (202) is allowed to exit through a second opening (206) of the valve body (202).
The second opening (206) of the valve body (202) is disposed on a lateral surface (203) of the valve body (202). The second opening (206) is adapted to allow the fluid to exit from the valve body (202). Thus, the first opening (204) and the second opening (206) of the valve body (202) are in fluid communication. The terms "second opening" and "outlet" are interchangeably used in the disclosure. The terms "second opening" and "outlet" are one and the same and they are relating to same "opening". In the illustrated embodiment, the outlet (206) and the inlet (204) are disposed perpendicular to each other. However, orientation of the inlet (204) and the outlet (206) is not meant to be limiting the scope of the invention disclosed in the present disclosure. In the illustrated embodiment, the inlet (204) and the outlet (206) may have same or different diameters.
The valve body (202) further includes a third opening (208). The third opening (208) is provided on the lateral surface (203) of the valve body (202). In the illustrated embodiment, the third opening (208) is provided opposite to the outlet (206). However, it may be understood that the third opening (208) may be provided at any other orientation with respect to the outlet (206) and onto the lateral surface (203) of the valve body (202). In the illustrated FIG. 2, the third opening (208) is having smaller diameter than the inlet (204) and outlet (206). The third opening (208) of the valve body (202) is provided with a casing (210) extending from the third opening (208).
FIG. 3 illustrates a sectional view of the valve (200) shown in FIG. 2, according to an embodiment of the present disclosure. The valve (200) includes the casing

(210) disposed in the third opening (208) at an angle "A" with respect to the bottom opening (204) of the valve body (202). That is to say, an axis (X-X') of the casing (210) and an axis (Y-Y') the bottom opening (204) can meet at a point (not shown), making the angle "A" between each other. The angle "A" may be ranging between 60°-120°. The casing (210) may be made of material including, but not limited to, carbon steel, stainless steel, nickel alloys and titanium alloys. In the illustrated FIG. 3, the casing (210) is made into two cylindrical parts (210a, 210b) which provides an advantage of accessing parts inside the casing (210) during maintenance and/or repair. The two cylindrical parts (210a, 210b) can be joined together to form a single casing (210). It may be understood that the casing (210) may be made into a single cylindrical part or more than two cylindrical parts based on the design of the casing (210).
The casing (210) in the illustrated embodiment includes a first cylindrical part (210a) and a second cylindrical part (210b). The first cylindrical part (210a) of the casing (210) is joined to an edge (209) of the third opening (208) of the valve body (202) by welding process or any such process as may be known in the art. In the illustrated embodiment, diameter of the third opening (208) is same or less than diameter of the casing (210). The casing (210) is a hollow cylindrical member that is adapted to accommodate a stem rod (212). The stem rod (212) in the casing (210) can be adapted to move inside the casing (210) axially along the axis (X-X').
The stem rod (212) is supported by supporting members (224) that are mounted on the casing (210). The supporting members (224) may further include a bush (232) and a gland packing (234) for sliding movement of the stem rod (212). The stem rod (212) includes a first end (212a) and a second end (212'b) opposite to the first end (212a). The stem rod (212) may be a rigid rod-like structure. The second end (212b) of the stem rod (212) is connected to an actuator (220a), shown in FIG. 4. For example, the actuator (220a) may include, but not limited to, automated actuators like, a piston cylinder arrangement, a hydraulic or pneumatic

cylinders, and a manual actuator like, a hand wheel (220). In the illustrated FIG. 3, the actuator (220a) is the hand wheel (220) that can be operated by an operator (not shown). In another embodiment, the hand wheel (220) may be configured to be driven by a motor (not shown) to rotate the hand wheel (220) automatically.
The hand wheel (220) includes a threaded portion on its inner surface (not shown) and can be adapted to mesh with threads provided at the second end (212b) of the stem rod (212). Thus, forming a threaded connection between the stem rod (212) and the hand wheel (220). When the hand wheel (220) is rotated, the threaded connection converts rotational motion of the hand wheel (220) to an axial motion of the stem rod (212) along the axis (X-X') for displacing a valve disc (214) of the valve (200). It is to be understood that the threaded connection between the stem rod (212) and the hand wheel (220) is not meant to be limiting the scope of the invention described in the present disclosure. In an alternate embodiment, the hand wheel (220) and the stem rod (212) may be connected via a worm & gear or a nut & bolt connection.
FIG. 4 illustrates a sectional perspective view of the valve (200) shown in FIGS. 2-3. In the illustrated FIG. 4, the valve disc (214) is in an open position, according to an embodiment of the present disclosure. The term "valve disc" as used herein refers to a "closure member" having a plate like structure or a flat member. The valve disc (214) can be provided inside a valve body (202) of the valve (200) for closing (shown in FIG. 5) and opening the bottom opening (204) of the valve (200) for fluid flow.
In the illustrated embodiment, the valve disc (214) is connected to the lateral surface (203) of the valve body (202) and above the bottom opening (204) via a hinge connection (218). The valve disc (214) is configured to move hingedly about the hinge connection (218). In the illustrated FIG. 4, an axis (not shown) of the hinge connection (218) is substantially orthogonal to an axis (not shown) of the outlet (206). It is to be understood that the location or position of the hinge

connection (218) is not meant to be limiting the scope of the invention described in the present disclosure. However, the advantage of providing the axis of the hinge connection (218) substantially orthogonally to the axis of the outlet (206) is that the fluid flow inside the valve body (202) is less or not disturbed.
The valve disc (214) is configured to rest on a seat resting member (222) at the bottom opening (204) when the valve (200) is closed (shown in FIG. 5). The seat resting member (222) is fixedly mounted on the lateral surface (203) of the valve body (202). The valve (200) will be in the open position, when the valve disc
(214) is moved away or swung away from the seat resting member (222). The valve disc (214) includes a strut member (242) (shown in FIG. 4) on a top surface
(215) for hingedly coupling the valve disc (214) with a first rigid link (226) of the plurality of rigid links (226, 228, 230).
The first rigid link (226) of the plurality of rigid links (226, 228, 230) includes a first end (226a) and a second end (226b) opposite to the first end (226a). The first end (226a) of the first rigid link is hingedly coupled to the strut member (242) of the valve disc (214) via a pin member (231) such that the movement of the first rigid link (226) enable the movement of the valve disc (214). The second end (226b) of the first rigid link (226) is hingedly coupled to a second end (228b) of a second rigid link (228) and a second end (230b) of a third rigid link (230) through a pin member (232).
The second rigid link (228) includes a first end (228a) opposite to the second end (228b). The first end (228a) of the second rigid link (228) is hingedly coupled to the strut member (240) of the top cover (216) via a pin member (233). The hinged coupling between the second rigid link (228) and the top cover (216) provides a support to the plurality of the rigid links (226, 228, 230). That is to say, the plurality of rigid links (226, 228, 230) is supported on the valve body (202) by the hinged connection between the second rigid link (228) of the plurality of rigid links (226, 228, 230) and the strut member (240) of the top cover (216). This

connection also allows the rotation of the second rigid link (228) about the strut
member (240).
The third rigid link (230) includes a first end (230a) opposite to the second end
(230b). The first end (230a) of the third rigid link (230) is hingedly coupled to the
first end (212a) of the stem rod (212) through a pin member (234) such that the
axial movement of the stem rod (212) enables the movement of the third rigid link
(230).
The first rigid link (226), the second rigid link (228) and the third rigid link (230) are rigid links that transfer movement from one rigid link to another link without a permanent deformation. The first rigid link (226), the second rigid link (228) and the third rigid link (230) have modular structure, i.e. each rigid link (226, 228, 230) can be replaced without replacing other rigid links (226, 228, 230). The first rigid link (226), the second rigid link (228) and the third rigid link (230) are rectangular shaped links having same or different lengths. In the illustrated embodiment the plurality of rigid links (226, 228, 230) have different lengths. However, the length and shape of the plurality of rigid links (226, 228, 230) are not meant to be limiting the scope of the invention disclosed in the present disclosure. In an exemplary embodiment, the links (230, 228, 226) can be round or rolled section or some other section or can be solid or hollow members not defined here, the quantity of the links (230, 228, 226) may be single or double to meet the required strength or easy fitment or maintenance. The second end (226b) of the first rigid link (226), the second end (228b) of the second rigid link (228) and the second end (230b) of the third rigid link (230) are pivotably connected together at one point through the pin member (232). That is to say, the second ends (226b, 228b, 230b) of each of the plurality of rigid links (226, 228, 230) are hingedly coupled with one another, such that the plurality of rigid links (226, 228, 230) are adapted to rotate the valve disc (214) about the hinge connection (218) when the stem rod (212) is displaced axially in the casing (210) for closing or opening of the first opening (204).

In the illustrated embodiment, the connections between the stem rod (212), the first rigid link (226), the second rigid link (228), the third rigid link (230), the valve disc (214) and the top cover (216) may include pin members (231, 232, 233, 234). These connections facilitate the transfer of motion from the stem rod (212) to the valve disc (214) via the first rigid link (226), the second rigid link (228) and the third rigid link (230) for opening or closing (shown in FIG. 5) of the bottom opening (204) by the valve disc (214).
FIG. 5 illustrates a sectional view of the valve (200) shown in FIGS. 2-4, where the valve disc (214) of the valve (200) is in a closed position, according to an embodiment of the present disclosure. When the valve (200) is in the open position (shown in FIGS. 3, 4 and 6), i.e. the valve disc (214) is not seated on the seat resting member (222) and the valve disc (214) is hingedly rotated about the hinge connection (218). The fluid (for example: steam) flows from the inlet (204) to the outlet (206) when the valve is in the open position. During this time, the fluid may exert a force for example "Fl" on the valve disc (214). Typically, the force "Fl" may be a higher force ranging from about 50 kgf to about 100 kgf The force "Fl" is transferred to the plurality of rigid links (226, 228, 230) and only a fraction of the force "Fl" is required to be exerted on the hand wheel (220) connected to the third rigid link (230) via the stem rod (212) to overcome the fluid force "Fl" and to close the valve disc (214).
In order to close the valve disc (214), the valve disc (214) is hingedly rotated from the open position (shown in FIG. 4) by the movement of the first rigid link (226), the third rigid link (230) and the stem rod (212) and by the rotation of the second link member at the strut member (240), when the hand wheel (220) is rotated in a direction "CI". That is to say, for closing the valve (200), the hand wheel (220) is rotated in the direction "CI" by exerting a force "F2" on the hand wheel (220). The rotation of the hand wheel (220) is converted to an axial motion of the stem rod (212). The stem rod (212) pushes the third rigid link (230), which further pushes the first rigid link (226) and rotates the second rigid link (228) about the

strut member (240) at the top cover (216). The first rigid link (226) in turn pushes the valve disc (214) which hingedly rotates for closing the valve (200).
In the illustrated embodiment, a force equal to or greater than the fluid force "Fl", is required to be exerted on the valve disc (214). The force "F2" exerted on the hand wheel stem (212) produces a force on the valve disc (214) for balancing the force "Fl" and closing the valve disc (214). The force "F2" exerted by the hand wheel stem (212) is less in magnitude than the force "Fl" exerted by the fluid, but exerts a force equal in magnitude as "Fl" on the valve disc due to the plurality of rigid links (226, 228, 230). The forces on the links (226 and 228) will almost be equal to force "Fl" but the compression force on the link (230) and the valve stem (212) will be reduced to a fraction of "Fl" only. For example, if the fluid exerts the force "Fl" which is equal to 100 kgf, the force "F2" on the hand wheel stem (212) will be 32 kgf, thereby corresponding hand wheel (220) operating torque is reduced in the ratio of 32/100. Thus, a force requirement is reduced from 100 kgf to 32 kgf, i.e. about 68-70% reduction in the force requirement. Thus, the force required for both closing and opening the valve disc (214) is less in the valve (200) as compared with the existing valve (100).
In order to open the valve disc (214), the valve disc (214) is hingedly rotated from the closed position (shown in FIG. 5) by the movement of the first rigid link (226), the third rigid link (230) and the stem rod (212) and by the rotation of the second link member at the strut member (240), when the hand wheel (220) is rotated in a direction (not shown) opposite to the direction of "CI". That is to say, for opening the valve (200), the hand wheel (220) is rotated in the direction opposite to "CI" by exerting a force "F2" on the hand wheel (220). The rotation of the hand wheel (220) is converted to an axial motion of the stem rod (212). The stem rod (212) pulls the third rigid link (230), which further pulls the first rigid link (226) and rotates the second rigid link (228) about the strut member (240) at the top cover (216). The first rigid link (226) in turn pulls the valve disc (214) which hingedly rotates for opening the valve (200).

FIG. 6 shows a schematic diagram of fluid flow in the valve (200) shown in FIG. 4, according to an embodiment of the present disclosure, when the valve (200) is in the open position. The valve (200) provides a less disturbed flow of fluid inside the valve body (202). The valve disc (214) is configured to open about the hinge connection (218) in such a way that reduces the fluid particle collision with the valve disc (214). The axis (not shown) of the hinge connection (218) is substantially orthogonal to the axis (not shown) of the outlet (206) such that the fluid enters the valve body (202) via the inlet (204), follows a curved path (244) inside the valve body (202) and exits the valve body (202) via the outlet (206). Thus, a smooth and less or no disturbed flow of fluid is obtained, which reduces pressure loss inside the valve (200) as compared with the existing valve (100), illustrated in FIG. 7. Therefore, the overall efficiency is increased by reducing fluid disturbance and the pressure loss.
FIG. 8 shows a schematic diagram of the valve (200) according to an exemplary embodiment of the present disclosure. In this embodiment, the inlet of valve (204) may be of smaller size and the valve housing (203) and the valve seat (214) can be made larger size, to compensate the flow area for the fluid. The valve housing (203) may or may not be made of larger size as per the final calculations and permitted pressure drop for particular application.
Advantages
In an embodiment, the valve requires less force for operating the valve disc, when compared with the existing valves. Thus, effort required manually or automatically for operating valve is less. Therefore, operating the valve is easy and less strenuous. The power consumption in operating the valve is less in the automatically operated valves due to reduction in force requirement.
In an embodiment, the valve provides a less disturbed flow of fluid. The less disturbed flow of fluid inside the valve results in reduction in pressure loss and

increase in overall efficiency. Thus, the valve, according to the present disclosure, is more efficient when compared with the existing valves.
In an embodiment, the valve disc is provided with a strut member for connecting the first link member. The advantage of providing the strut member on the valve disc is that the strut member enables the transfer of motion from plurality of rigid links to the valve disc.
In an embodiment, the top cover is provided with a strut member for connecting the second link member. The advantage of providing the strut member on the top cover is that the strut member supports the plurality of rigid links and at the same time enables rotational motion of the second link.
In an embodiment, the valve seat is provided with a hinge connection proximal to the inlet, and the axis of the hinge connection is substantially orthogonal to the axis of the outlet. The advantage of providing hinge connection orthogonally to the outlet is that the fluid flow inside the valve body becomes less or not disturbed, thus a smooth flow is obtained.
In an embodiment, the valve provides a modular structure of plurality of rigid links, in which each rigid link can be replaced independently without replacing other rigid links. Thus, cost involved in maintenance and repair of the valve is less, when compared with the existing valves.
In an embodiment, the force or effort required for operating the valve disc is reduced by approximately 68-70%. Accordingly, the automatic controlling mechanism can be of smaller device which operates the stem rod. Such automatic actuators constitute a major share of the complete valve cost.
In an embodiment, the inlet of valve (204) may be of smaller size and the valve housing (203) and valve seat (214) can be made larger size as shown in valve

(200) in the FIG.8, to compensate the flow area for the fluid. The valve housing (203) may or may not be made of larger size as per the final calculations and permitted pressure drop for particular application.
Industrial Applicability
The disclosed valve finds its potential application in sugar industries where there is a requirement of controlling the flow of fluid. The valve may be used for controlling flow of any type of liquid or gaseous medium from one location to another. In particular, the valve may be used for controlling the flow of steam in sugar plants. However, the disclosed valve may also find its application apart from the sugar industry, such as, but not limited to, power plants. The valve as disclosed also finds its application where controlling flow of steam through a large sized valve play a vital role in their operation. Further, the valve also finds its application where the force required for operating the valve to be reduced and where the overall efficiency of the fluid flow is required to be increased.
While aspects of the present invention have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by modification of the disclosed device without departing from the scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present invention as determined based upon claims and any equivalents thereof.
List of referral numerals:

100 102 104 106 108 110 200

Valve, according to prior art Steam inlet, at the prior art valve Steam outlet, at the prior art valve Closure member, at the prior art valve Spindle rod, at the prior art valve Handle, at the prior art valve Valve, according to present invention

202: Valve body
203: Lateral surface or side surface of valve body
204: First opening or bottom opening or inlet
206: Second opening or outlet
208: Third opening
209: Edge of third opening
210: Casing
210a: First cylindrical part of the casing
210b: Second cylindrical part of the casing
212: Stem rod
212a: First end of the stem rod
212b: Second end of the stem rod
214: Valve disc
215: Top surface of the valve disc
216: Top cover
217: Bottom surface of the top cover
218: Hinge connection
220a: Actuator
220: Hand wheel
222: Seat resting member
224: Supporting member
226: First rigid link
226a: First end of the first rigid link
226b: Second end of the first rigid link
228: Second rigid link
228a: First end of second rigid link
228b: Second end of the second rigid link
230: Third rigid link
230a: First end of the third rigid link
230b: Second end of the third rigid link
231: Pin member connecting the first rigid link and the valve disc

232: Pin member connecting the first rigid link, the second rigid link
and the third rigid link
233: Pin member connecting the second rigid link and the top cover
234: Pin member connecting the third rigid link and the stem rod
236: Bush
238: Gland packing
240: Strut member of the top cover
242: Strut member of the valve disc
244: Curve path of flow of fluid
X-X': Axis of the casing
Y-Y': Axis of first opening
A: Angle between the axis of the casing and the axis of the first
opening
CI: Direction of rotation of the hand wheel for closing the valve disc
Fl: Force exerted by fluid on the valve disc
F2: Force exerted on the hand wheel

We Claim:

1. A valve (200) comprising:
a valve body (202) comprising a first opening (204), a second opening (206) and a third opening (208), the first opening (204) and the second opening (206) are in fluid communication;
a casing (210) extending from the third opening (208) of the valve body (202) at an angle (A) with the valve body, the casing (210) adapted to accommodate a stem rod (212) movable axially in the casing (210);
a valve disc (214) hingedly connected at the first opening (204) via a hinge connection (218), the valve disc (214) adapted to be operated for closing and opening of the first opening (204); and
characterized by,
a plurality of rigid links (226, 228, 230) having a first rigid link (226), a second rigid link (228) and a third rigid link (230), each having a first end (226a, 228a, 230a) and a second end (226b, 228b, 230b), the first end (226a) of the first rigid link (226) hingedly coupled to the valve disc (214), the first end (228a) of the second rigid link (228) hingedly coupled to a top cover (216) of the valve body (202) and the first end (230a) of the third rigid link (230) hingedly coupled to the stem rod (212), the second ends (226b, 228b, 230b) of each of the plurality of rigid links (226, 228, 230) being hingedly coupled with one another, such that the plurality of rigid links (226, 228, 230) being adapted to rotate the valve disc (214) about the hinge connection (218) when the stem rod (212) is displaced axially in the casing (210) for closing or opening of the first opening (201).
2. The valve (200) as claimed in claim 1, wherein the valve disc (214)
comprises a strut member (242) disposed on a top surface (215) of the valve
disc (214).

3. The valve (200) as claimed in claims 1-2, wherein the strut member (242) is adapted to hingedly couple the first end (226a) of the first rigid link (226) with the valve disc (214).
4. The valve (200) as claimed in claim 1, wherein the top cover (216) of the valve body (202) comprises a strut member (240) disposed on a bottom surface (217) of the top cover (216).
5. The valve (200) as claimed in claims 1 and 4, wherein the strut member (240) is adapted to hingedly couple the first end (228a) of the second rigid link (228) with the valve body (202).
6. The valve (200) as claimed in claim 1, wherein the second ends (226b, 228b, 230b) of each of the plurality of rigid links (226, 228, 230) are hingedly coupled with one another through a pin member (232).
7. The valve (200) as claimed in claim 1, wherein the hinge connection (218) is disposed proximal to the first opening (204), an axis of the hinge connection being substantially orthogonal to an axis of the second opening (206).
8. The valve (200) as claimed in claim 1, wherein the stem rod (212) comprises a first end (212a) connected to the third rigid link (230) and a second end (212b) connected to an actuator (220a).
9. The valve (200) as claimed in claim 8, wherein the actuator (220a) is a hand wheel (220), the hand wheel (220) is adapted to be rotated to displace the stem rod (212) axially in the casing (210).
10. The valve (200) as claimed in claims 1, 8 and 9, wherein the stem rod (212) is configured to push the third rigid link (230) axially to push the second rigid

link (228) and the first rigid link (226) for closing the valve disc (214) at the first opening (204).
11. The valve (200) as claimed in claims 1, 8 and 9, wherein the stem rod (212) is configured to pull the third rigid link (230) axially to pull the second rigid link (228) and the first rigid link (226) for opening the valve disc (214) at the first opening (204).