The present invention generally relates to sealing application in valves. More particularly, the present invention relates to an improved sealing assembly for use in sealing applications in valves to ensure tight seal having low leakage with sealing surface through media channel and media holes in the sealing unit
BACKGROUND OF THE INVENTION
A valve is a device for regulating or controlling the flow of media such as fluid, gas or slurries by handling the closing, opening operations. The valves have wide range of applications from the agricultural field to industrial area for controlling the flow, pressure of the media. The valves may be controlled or operated manually through a lever or wheel, or the valves may be automatic and semi-automatic, depending upon the requirements. The valves are classified on the actuation feature such as hydraulic valve, pneumatic valve, manual valve, solenoid valve or motor valve.
Generally, a valve comprises of a body, ports, seat, handle or wheel, disc or valve member, valve balls, spring, seal and trim. The valves are also classified according to the operating positions such as two-port valves, three port valves and four port valves. A seal in the valve is considered as one of the critical component which has the potential for enhancing the life and performance of the valve along with reduction in leakage and mean time to repair. The valve seal is used to improve the durability of the valve that meets with the increasing stringent performance related to leakage and in some cases also low emissions of harmful components such as hydrocarbons. The seal is also assembled with other components in the valve for preventing the escape of media.

Several improvements are done on the valves for making more robust and leak proof. As due to leakage issue, in some cases the hydrocarbon and other harmful emission enters into the atmosphere which leads to severe air pollution.
In the currently available valve, there is a sealing for making the valve leak proof. Additionally, in the conventional designs, only the spring force is used to keep the valve in the closed position and control the media leakage between the inlet and outlet.
US2799470 discloses a valve, a casing having a valve chamber and a port, a valve member movably mounted in said chamber, a sealing assembly mounted in said port and having a fluid passage there through in communication with the valve chamber, said sealing assembly comprising an annular carrier having a sealing face at one end thereof and engaging said valve member, an annular, a flexible diaphragm means rigidly attaching said diaphragm at its inner margin to the carrier, non-yielding means attaching the outer margin of said diaphragm within the casing, said diaphragm having a free annular portion between the attached inner and outer margins, the terminal inner and outer marginal portions of said free annular portion lying substantially in a plane which is perpendicular to the axis of the carrier, said non-yielding means including an annular non-yielding surface extending from the one attached margin to the other attached margin of said diaphragm and disposed generally perpendicularly with respect to the axis of the carrier and directly opposed to and closely adjacent one side of said free annular portion of the diaphragm, said free annular portion of the diaphragm being of a width greater than the straight radial line distance between the attached margins of the diaphragm and at least as great as the distance along said annular non-yielding surface opposite said free annular portion whereby the entire free annular portion of the diaphragm may be freely flexed directly against said annular non-yielding surface and supported thereby with the free annular portion of the diaphragm free of tensile stresses tending to move the carrier.

But this invention fails to ensure complete sealing of the valve in the closed position and control the media leakage between the inlet and outlet.
Therefore, there is a need of an improved sealing assembly having a profile that ensures complete sealing of a valve in closed position and achieving high robustness in the sealing performance of the valve.
OBJECT OF THE INVENTION
The main object of the present invention is to provide an improved sealing assembly with an improved profile that ensures complete sealing and enhanced robustness in sealing performance.
Another object of the present invention is to provide an improved sealing assembly in which not only the spring load is used to keep the valve in the closed position but also pressure of media (e.g. gas vapor) is used to keep the valve in closed position.
Yet another object of the present invention is to provide an improved sealing assembly with a sealing unit preferably made of rubber and that comprises a flexible sealing lip and a stopper.
Still another object of the present invention is to provide an improved sealing assembly in which the media enters from the inlet holes for providing uniform pressure on the back side of the flexible sealing lip.
SUMMARY OF THE INVENTION
The present invention relates to an improved sealing assembly for achieving ameliorated sealing performance in valves, in which not only the spring load is used to keep the valve in the closed position but also pressure of media is used to keep the valve in closed position and the media enters from the inlet

holes into a media channel for providing uniform pressure on the back side of the flexible sealing lip.
In an embodiment, the present invention provides an improved sealing assembly comprising of a sealing unit having a flexible sealing lip and a stopper for the flexible sealing lip, a seal that includes a spring resisting surface and a sealing surface, a spring and a seal holder, wherein said sealing unit includes a plurality of media channels, and a plurality of media inlet holes. Said seal is assembled over the sealing unit by attaching the sealing surface with the flexible sealing lip. The seal holder is provided to hold the sealing unit along with the seal and the compression spring. The placement of sealing unit and seal helps to keep the valve in closed position, because not only the compression spring force keep the valve in closed position but also pressure of media (like gas vapor) is used to keep the valve in closed position. Additionally, the valve with improved sealing, controls the media leakage between the inlet and outlet which adds robustness to sealing performance. The media enters from the inlet holes and fills inside the media channel for providing a uniform pressure on the back side of the flexible sealing lip.
The above objects and advantages of the present invention will become apparent from the hereinafter set forth brief description of the drawings, detailed description of the invention, and claims appended herewith.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be described with reference to the following drawing. The drawing and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention:
Fig. 1 shows an exploded view of the improved sealing assembly in accordance with the present invention.

Figs. 2(a) and 2(b) show top and bottom perspective views of the seal of the sealing assembly respectively in accordance with the present invention.
Fig. 3(a) to Fig. 3(e) show a top and cross-sectional views of the sealing unit in accordance with the present invention.
Fig. 4(a) to Fig. 4(c) show top and cross-sectional views of the seal holder in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described hereinafter with reference to the accompanying drawings in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough, and will fully convey the scope of the invention to those skilled in the art.
Many aspects of the invention can be better understood with references made to the drawings below. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed upon clearly illustrating the components of the present invention. Moreover, like reference numerals designate corresponding parts through the several views in the drawings. Before explaining at least one embodiment of the invention, it is to be understood that the embodiments of the invention are not limited in their application to the details of construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The embodiments of the invention are capable of being practiced and carried out in various ways. In addition, the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

The present invention provides an improved sealing assembly which adds robustness to sealing performance as the media (like gas vapor) enters from the inlet holes to keep the valve in closed position in addition to the spring load.
In a main embodiment, the present invention provides an improved sealing assembly comprising of a sealing unit having a flexible sealing lip and a stopper for the flexible sealing lip, a seal that includes a spring resisting surface and a sealing surface, a spring and a seal holder, wherein said sealing unit includes a plurality of media channels, and a plurality of media inlet holes. Said seal is assembled over the sealing unit by attaching the sealing surface with the flexible sealing lip. The seal holder is provided to hold the sealing unit along with the seal and the compression spring. The placement of sealing unit and seal helps to keep the valve in closed position, because not only the compression spring force keep the valve in closed position but also pressure of media (like gas vapor) is used to keep the valve in closed position. Additionally, the valve with improved sealing, controls the media leakage between the inlet and outlet which adds robustness to sealing performance. The media enters from the inlet holes and fills inside the media channel for providing a uniform pressure on the back side of the flexible sealing lip. Said sealing assembly is not limited for applications with positive pressure, but it works in negative pressure (vacuum) application as well in the vice versa manner.
Referring to Fig. 1, an exploded view of the sealing assembly is shown that includes a sealing unit (1) preferably made of rubber having flexible sealing lip and stopper, a seal (16), a seal holder (2) and a compression spring (15). The seal (16) has a spring resisting surface (19) that holds the compression spring (15). For sealing application, not only the spring load from spring (15) is used to keep the valve in closed position and control the media leakage between the inlet and outlet.

Referring to Fig. 2(a) and Fig. 2(b), a top and bottom perspective view of the seal (16) is shown that includes a spring resisting surface (19) and a sealing surface (20) which is assembled over the sealing unit (1) by attaching the sealing surface (20) with the flexible sealing lip (23).
Referring to Fig. 3(a) to Fig. 3(e), a top and cross-sectional view of the sealing unit (1) is shown. The sealing unit (1) preferably made of rubber ensures an improved sealing control of the media leakage between inlet and outlet and has a flexible sealing lip (23) and a media channel (21) on the bottom side of sealing lip (23) which adds robustness to sealing performance. The media enters from the media inlet holes (22) and fills inside the media channel (21) for providing a uniform pressure on the back side of the flexible sealing lip (23). In uninstalled condition, there is no external force on the flexible sealing lip (23). However, in installed condition, an external force acts on flexible sealing lip (23) and a stopper (24) is provided to hold the flexible sealing lip (23) when bent in installed condition. The material of the stopper (24) includes but is not limited to rubber. The sealing unit (1) has media inlet holes (22) at the bottom side of the sealing unit (1). And, the profile of media inlet holes (22) and air channel varies as per requirement and it not essentially as shown in the figure 3(d). The external force acting on flexible sealing lip (23) is not only limited to the force exerted by spring but also can be any other force acting on it.
Referring to Fig. 4(a) to Fig. 4(e), a top, a cross-sectional view and assembled view of the seal holder (2) is provided where the media inlet holes (22), media channel (21) and stopper (24) is alternatively provided in the seal holder (2) itself.
Therefore, the present invention provides an improved sealing assembly in which not only the spring load is used to keep the valve in the closed position but also pressure of media (like gas vapor) is used to keep the valve in closed

position that further enhances robustness in sealing performance. The profile of sealing unit, air/media inlet holes vary according to application.
Many modifications and other embodiments of the invention set forth herein will readily occur to one skilled in the art to which the invention pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
The foregoing description of embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principals of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.

CLAIMS
We claim:

1. An improved sealing assembly for valve comprising:
a sealing unit (1);
a seal (16);
a seal holder (2); and
a compression spring (15);
wherein:
said seal (16) includes a spring resisting surface (19) that holds said compression spring (15) and a sealing surface (20) which is attached with a flexible sealing lip (23) of said sealing unit (1) and said sealing unit (1) is attached to a seal holder (2);
said sealing unit (1) ensures a sealing control of media leakage between an inlet and an outlet having a plurality of media inlet hole (22) at bottom side and said sealing unit (1) includes a media channel (21) and a stopper (24) on bottom of said flexible sealing lip (23) for adding robustness in sealing; and
said media channel (21) is filled with a media entering through said plurality of media inlet hole (22) for providing a uniform pressure on the back side of said flexible sealing lip (23).
2. The improved sealing assembly for valve as claimed in claim 1,
wherein said sealing unit (1) and stopper (24) are made of material that
includes but is not limited to rubber.

3. The improved sealing assembly for valve as claimed in claim 1, wherein said plurality of media inlet hole (22) is alternatively provided in said seal holder (2).
4. The improved sealing assembly for valve as claimed in claim 1, wherein said compression spring (15) keeps the valve in closed position and control media leakage between the inlet and outlet.
5. The improved sealing assembly for valve as claimed in claim 1, wherein said media is gas vapors.
6. The improved sealing assembly for valve as claimed in claim 1, wherein said flexible sealing lip (23) experiences no external force in an uninstalled condition.
7. The improved sealing assembly for valve as claimed in claim 1, wherein said flexible sealing lip (23) experiences external force in an installed condition and said stopper (24) is provided to hold said flexible sealing lip (23) when bent in said installed condition.