Claims:We Claim:
1. A liquid cylinder valve, comprising:
• a body 1 mounted with a bonnet 2;
• a Gasket 17 to seal leakage between body 1 and bonnet 2;
• a rotatably operable handwheel 9 to manually open or close the valve;
• an upper spindle 3 connected with the handwheel 9;
• a lower spindle 12 connected below the upper spindle 3;
• a spindle nut 5 connected between upper spindle 3 and bonnet 2;
• a disc 13 located at the bottom of the lower spindle 12;
• a Spring 16 located between lower spindle 12 and bonnet 2;
• a V-Packing to seal the upper spindle 3 and the bonnet 2;
• a packing gland 7 to seal handwheel and V Packing;
• a top washer 8 to seal handwheel 9 and packing gland 7;
• plurality of washers to spread the load of a screwed fastening;
• plurality of nuts for secure fitings; and
• plurality of gaskets as mechanical seals,
wherein,
the disc 13 regulates the flow by controlling the orifice opening;
the spring 16 is incorporated to restrict the backflow of fluid media;
the spring 16 seals the valve when the pressure drops at the inlet side.

2. The liquid cylinder valve as claimed in claim 1 wherein, the valve is non-rising spindle type.

3. The liquid cylinder valve as claimed in claim 1 wherein, the manual torque on the handwheel 9 rotates the upper spindle 3.

4. The liquid cylinder valve as claimed in claim 1 wherein, the rotational motion of the upper spindle 3 is transmitted linearly to the lower spindle 12 through the spindle nut 5.

5. The liquid cylinder valve as claimed in claim 1 wherein, the lower spindle moves linearly in up and down position to move the disc 7 moves in and out along the axis of the orifice.

6. The liquid cylinder valve as claimed in claim 1 wherein, the movement of the disc 7 regulates the fluid flow through the orifice.

7. The liquid cylinder valve as claimed in claim 1 wherein, the plurality of washers are selected from one or more of a top washer, disc washer and flat washer.

8. The liquid cylinder valve as claimed in claim 1 wherein, a Nylon nut 14 is securely fitted with the handwheel 9 to prevent loosening while rotation of the handwheel. , Description:FIELD OF THE INVENTION

[001] The present invention generally relates to a cylinder valve installed in pipelines to control the flow of fluids. More particularly, the present invention relates to a cylinder valve having an in built non-return valve to prevent backflow of fluid.

BACKGROUND OF THE INVENTION

[002] A valve is a device used for controlling the flow of fluids in a pipe or other enclosures. The valve directs or controls the flow of a fluid by opening, closing, or partially obstructing the passages in pipelines. Typical liquid cylinder valve is used for the blocking of the flow path or control of the flow rate in pipelines. When the opening of the valve creates a gap between the valve seat and the valve, and fluid flows through this space. This type of valve allows the fluid flow in both directions when opening is created. In such pipelines, if it is required to have a flow in one direction then a separate non return valve must be installed to prevent backflow.

[003] Further, when these valves are installed in a pipe or system where a cryogenic fluid such as liquid oxygen, liquid nitrogen etc. flows, then there is a possibility that the cryogenic fluid gets entrapped between the liquid cylinder valve and the non-return valve while the liquid cylinder valve is closed which damages the pipeline or system. In this case, an additional valve such as non-return valves, thermal relief valve or safety valves, must be installed to prevent pressure build-up. Addition of multiple valves results in higher manufacturing and installation costs and also makes the system complicated.

[004] Therefore, to overcome the limitations of the prior art., there is required a single valve system which not only controls the flow of fluids but also prevents reverse flow i.e. a valve having in built non-return valve which allows fluid flow in one direction only. Further, there is a need of a valve which can be efficiently work in a pipe or system where a cryogenic fluid is flowing without being damaged.

OBJECTIVES OF THE INVENTION

[005] The primary objective of the present invention is to provide a liquid cylinder valve which prevents backflow of fluid (a non-return valve) alongwith regulating the fluid flow rate.

[006] Another objective of the present invention is to provide a non-return liquid cylinder valve which can be installed in a pipe or system where a cryogenic fluid is flowing.

[007] Yet another objective of the present invention is to provide a non-return liquid cylinder valve which less complicated and demands less pipeline or system manufacturing cost.

[008] Other objectives and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein, by way of illustration and example, the aspects of the present invention are disclosed.

BRIEF DESCRIPTION OF DRAWINGS
[009] The present invention will be better understood after reading the following detailed description of the presently preferred aspects thereof with reference to the appended drawings, in which the features, other aspects and advantages of certain exemplary embodiments of the invention will be more apparent from the accompanying drawing in which:

[0010] Figure 1 illustrates axial section of a conventional liquid cylinder valve.

[0011] Figure 2 illustrates axial section of the non-return liquid cylinder SDNR (Screw Down Non-Return) valve.

SUMMARY OF THE INVENTION

[0012] The present invention relates to a liquid cylinder SDNR shut off valve equipped with a non-return valve having built in reverse flow prevention function and therefore fluid is designed to flow in only one direction. The valve comprises of a body 1, Bonnet 2, Upper Stem 3, Stem Seal Gasket 4, a Spindle Nut 5, `V' Packing 6, Packing Gland 7, Top Washer 8, Handwheel 9, Disc Washer 10, Flat Washer 11, Lower Spindle 12, Disc 13, Nylon Nut 14, Hub Cap 15, Spring 16, and Gasket 17. The valve regulates the required flow and prevents the backflow.

[0013] While, the following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
DETAILED DESCRIPTION OF INVENTION
[0014] The following detailed description and embodiments set forth herein below are merely exemplary out of the wide variety and arrangement of instructions which can be employed with the present invention. The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. All the features disclosed in this specification may be replaced by similar other or alternative features performing similar or same or equivalent purposes. Thus, unless expressly stated otherwise, they all are within the scope of the present invention.

[0015] Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0016] The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention.

[0017] It is to be understood that the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

[0018] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps, or components but does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof.

[0019] The main embodiment of the present invention is a liquid cylinder SDNR (screw down non return) valve equipped with a non-return valve. In accordance with this embodiment, the non-return liquid cylinder SDNR valve allows fluid flow in only one direction and prevent flow from downstream to upstream. The valve constructed in accordance with the embodiment is illustrated in the accompanying drawings, in which figure 2 is an axial section of the non-return liquid cylinder SDNR valve. The illustrated valve comprises a body 1, Bonnet 2, Upper Stem 3, Stem Seal Gasket 4, a Spindle Nut 5, `V' Packing 6, Packing Gland 7, Top Washer 8, Handwheel 9, Disc Washer 10, Flat Washer 11, Lower Spindle 12, Disc 13, Nylon Nut 14, Hub Cap 15, Spring 16, and Gasket 17. Figure 1 depicts axial section of a conventional liquid cylinder valve without non-return functionality.

[0020] The body 1 is the main element of the non-return liquid cylinder SDNR valve assembly that holds all the other elements together. The body 1 is designed to connect the valve to the pipeline and resists the fluid pressure loads from connecting pipeline hence acts as a first pressure boundary of a valve. The body 1 of the non-return liquid cylinder SDNR valve is made of metal or alloy such that but not limited to Brass.

[0021] The body 1 is mounted with a bonnet 2 which acts as a cover on the valve body 1. The attachment of the bonnet 2 to the body 1 is considered as a second pressure boundary. The bonnet 2 allows the spindle to rotate through it to maintain the fluid flow rate. It provides a leakproof closure for the valve body 1. The bonnet 2 is also made of a metal or an alloy such that but not limited to Brass. To prevent the leakage between body 1 and bonnet 2, a gasket 17 is used to seal the space between the two. Hence, the gasket 17 acts as a mechanical seal to prevent leakage between body 1 and bonnet 2. The gasket 17 is made of a metal or an alloy such that but not limited to Copper.

[0022] To open or close the valve, the body 1 is screwed with a spindle that rotates when the torque is applied to the handwheel 9 by the operator. The upper stem or upper spindle 3 passes through the body and attaches the lower spindle 12 with the handwheel 9. The upper stem serves as a connector from the handwheel 9 to the lower spindle 12 and transmits the actuation force inside the valve. The upper spindle 3 has a rotatory motion which is transmitted to the lower spindle through a spindle nut 5 which converts the rotary motion to linear motion. Hence, the lower spindle moves linearly in up and down position. In accordance with this invention, the valve is a non-rising spindle type, hence while rotating i.e. while opening or closing of the valve, the spindle will rise or fall in the valve body itself.

[0023] The upper spindle 3 and the bonnet 2 are sealed with a V-Packing 6 sealing gland to prevent leakage. The V-Packing 6 is mounted with a packing gland 7 which along with top washer 8 further improves the sealing against leakage. The packing gland 7 acts as spacer for handwheel and V Packing while the top washer 8 acts as a sealing between handwheel 9 and packing gland 7.The non-return liquid cylinder SDNR valve further comprises of a plurality of washers such as disc washer 12 and flat washer 13. The disc washer 10, also known as Belleville spring acts as a mechanism for live loading of V packing 8 via handwheel 9. These washers are applied to the gaskets and used to spread the load of a screwed fastening. The valve also comprises a Nylon nut 14 to securely fit the handwheel 9 which prevents loosening of nut while rotation or motion of the handwheel. The flat washer 11 acts as a spacer for nylon nut 14 and disc washer 10. Further, the handwheel 9 is securely fitted with a decorative hubcap 15.

[0024] The non-return liquid cylinder SDNR valve includes an orifice set through which the fluid flows. To regulate the fluid flow through the orifice, a disc 13 is located at the end of the lower spindle 6. The disc 7 moves in and out along the axis of the orifice based on the movement of the spindle 6, stem 5 and handwheel 11. When the disc 13 completely sits on the orifice then it stops the fluid flow, whereas the flow progressively increases when the disc 13 is moved away. To operate the valve smoothly, the spindle is screwed so that rotation of the handle moves the disc in and out.

[0025] The non-return liquid cylinder SDNR valve is installed in pipeline such that the upstream is connected to inlet and outlet connected with downstream. The disc of the valve is opened to its appropriate opening percentage regulating the required flow and prevents the backflow using non return functionality by mean of the spring 16. At any time, if there is a pressure drop at the inlet side of the valve, the spring force assisted along with the pressure at outlet would help in sealing the valve, thus preventing any backflow of the fluid media. Further, the valve includes a valve guide which is mounted between Bonnet, Upper Spindle and Disc Holder assembly to block the back flow.

[0026] In a preferred embodiment of the present invention, the materials for the different elements of the non-return liquid cylinder SDNR valve are selected but not limited to the ones described herein. The body 1 is made of metal or alloy such that but not limited to Brass C37700; the bonnet 2, Upper Stem 3, Lower Spindle 12, and Packing Gland 7 are made of Brass CW614N R360; the Upper Stem or upper spindle 3 is made of Brass CW614N R360; the Stem Seal Gasket 4, `V' Packing 6, and Top Washer 8 are made of Polytetrafluoroethylene (P.T.F.E); the Disc 13 is made of Polychlorotrifluoroethylene (P.C.T.F.E); the Packing Gland 7 is made of Brass CW614N R360; the handwheel 9 is made of Aluminum; the Disc Washer 10, Flat Washer 11, Nylon Nut 14 and Spindle Nut 5 are made of stainless steel such as but not limited to SS304; whereas the Spring 16 is made of stainless steel SS316 and Hub Cap 15 is made of M.Z.S steel.

[0027] In accordance with the present invention, the summarized details of the material used for each elements/components and their functioning is tabulated below:

Component Material Function
Body 1 Brass C37700 Pressure Holding
Gasket 17 Copper Sealing between Body-Bonnet
Bonnet 2 Brass CW614N R360 Pressure Containing, Holding Trim parts
Stem Seal Gasket 4 P.T.F.E Sealing between Upper Spindle-Bonnet
Upper Stem 3 Brass CW614N R360 Connector for Handwheel & Lower Spindle
Lower Spindle 12 Brass CW614N R360 Accommodate Disc
Disc 13 P.C.T.F.E Sealing
`V' Packing 6 P.T.F.E Sealing Gland
Packing Gland 7 Brass CW614N R360 Spacer for handwheel & V Packing
Top Washer 8 P.T.F.E Sealing between Handwheel and Gland
Handwheel 9 Aluminum Rotary motion and torque transfer
Disc Washer 10 SS304 Live Loading
Flat Washer 11 SS304 Spacer for Nylon Nut and Disc Washer
Nylon Nut 14 SS304 Pre-Load application for Disc Washer
Hub Cap 15 M.Z.S Decorative
Spring 16 SS316 Pre-Load for sealing force for Disc and Body
Spindle Nut 5 SS304 Rotary motion to Linear motion transfer

[0028] While the present invention has been described with reference to one or more preferred aspects, which aspects have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, such aspects are merely exemplary and are not intended to be limiting or represent an exhaustive enumeration of all aspects of the invention. The scope of the invention, therefore, shall be defined solely by the following claims. Further, it will be apparent to those of skill in the art that numerous changes may be made in such details without departing from the principles of the invention.