KR102589725B1 - Cryogenic valve with check valve function - Google Patents

Abstract

The present invention includes a valve body forming an inlet, an outlet, and a flow path; a bonnet connected to the upper part of the valve body, a gland maintained with a handle on the upper part of the bonnet, and an operating shaft connected to the handle and protruding downward; a valve stem whose lower end extends to the valve body and is connected to the operating shaft; A flow prevention member coupled to the lower side of the valve stem to prevent the valve stem from flowing during the operation process and maintain airtightness; A bellows connected to the valve stem by mounting upper and lower bellows flanges on the upper and lower sides of the valve stem; a jacket mounted on the outside of the valve body and bonnet to maintain a vacuum and prevent heat conduction; It is configured to include a plug coupled to the lower end of the valve stem to open and close a flow path formed in the valve body;
a connection pipe formed integrally with the upper part of the plug body and protruding therefrom, which has a hemispherical plug head at the bottom that selects the distribution of cryogenic fluid through direct connection with and separation from the operating surface of the flow path formed inside the valve body; The connecting protrusion formed at the lower end of the valve stem is combined with the connecting pipe body, so that the plug rises and falls by the valve stem, and when there is a backflow of cryogenic fluid through the discharge port, the pressure of the backflowing cryogenic fluid is applied to the connecting protrusion. It is characterized by having the function of blocking the flow path by lowering the connecting pipe.

Description

Cryogenic valve with check valve function {CRYOGENIC VALVE WITH CHECK VALVE FUNCTION}

The present invention relates to a cryogenic valve having a check valve function. More specifically, the present invention relates to a cryogenic valve that functions as a check valve to prevent or block the backflow of cryogenic fluid, thereby providing ease of installation and maintenance of the valve and minimizing installation space. This relates to the provision of improved cryogenic valves.

Cryogenic valves are mainly used in piping systems used for storage and transportation of cryogenic fluids such as liquefied gases LNG, LPG, LN ₂ , LH ₂ , etc., and are characterized by having a long bonnet on the upper part of the body through which the cryogenic fluid is physically distributed. am.

Various types of cryogenic valves as described above have been developed and used in the past, and a representative example of the prior art through patent documents is as follows.

Patent Document 1 discloses that a first flow path and a second flow path are formed inside, and a partition is formed inside to partition the first flow path and the second flow path, but in which a fluid passage hole is formed, and the upper part is open at the top of the partition. A valve body in which a valve body movement space is formed;

A valve bonnet formed with a female thread for the bonnet in the center and coupled to the upper part of the valve body to close the upper part of the valve body movement space;

an extension pipe whose lower end is coupled to the upper part of the valve bonnet and extends upward;

An extension part disposed along the inside of the extension pipe and having a diameter smaller than the inner diameter of the extension pipe, and a female thread for the bonnet formed directly below the extension part, the outer diameter of the thread being smaller than or equal to the diameter of the extension part. A first male screw portion screwed together with a valve body coupling portion having a snap ring mounting groove formed directly below the first male screw portion and having a diameter smaller than or equal to the inner diameter of the thread of the first male thread portion, and the extension A valve stem including an airtight mounting portion formed directly above the portion and having a diameter smaller than or equal to the diameter of the extension portion, and a handle coupling portion formed on an upper portion of the airtight mounting portion and having a cross section smaller than the cross section of the airtight mounting portion;

an airtight means including an airtight material provided between the airtight material mounting portion of the valve stem and an inner peripheral surface of an upper end of the extension pipe;

A handle coupled to the handle coupling portion of the valve stem;

It includes a valve body that is coupled to the valve body coupling portion of the valve stem and opens and closes the fluid passage hole,

The valve body includes a snap ring mounted on the snap ring mounting groove, an auxiliary mounting device fixed to the valve body coupling portion at the top of the snap ring, an auxiliary male thread formed on a lower portion of the outer circumference, and a polygonal flange portion formed on the upper portion of the outer circumference; A valve seat is provided at the lower part, and a female thread forming part is formed at the upper part in which a female screw part is screwed with the auxiliary male screw part of the auxiliary mounting device. A ring-shaped protrusion is formed on the upper part of the female thread forming part and is deformed to come into close contact with the flange part, so that the valve is formed. It is characterized by including a valve disk on which anti-rotation protrusions are formed to prevent rotation of the disk.

Patent Document 2 states that a flow path is formed inside the lower valve body, a vertical bonnet is formed at the top of the valve body, and a stem having a disk for opening and closing the flow path is formed inside the valve body and the bonnet, In the cryogenic valve having a structure in which a handle is formed that is connected to the top of a stem extending vertically from the top of the bonnet to rotate the stem,

A cylindrical flange connected to the top of the bonnet is formed, and a packing hole with an inner diameter larger than the inner diameter through which the stem passes at a predetermined length inside the center of the top of the bonnet is formed, so that the packing is accommodated in the packing hole. and a pressing means consisting of a lower pressing part and an upper support part internal to the packing hole while pressing the upper part of the packing is formed, and a first through hole is formed that penetrates from the lower part of the pressing part to the upper part of the support part and internalizes the stem. It is coupled to the flange of the bonnet using fastening means in first fastening holes formed on both sides of the upper part of the support part,

Located between the flange of the bonnet and the handle, a second through hole is formed in the center to accommodate the stem, and a horizontal plate-shaped clearance support plate is formed with second fastening holes on both sides, and a second fastening hole of the clearance support plate is used. A support means coupled to the flange of the bonnet is provided as a fastening means,

A hemispherical anti-condensation portion is connected to the bottom of the bonnet and has a plurality of openings penetrating inside the upper outer circumferential surface in a cylindrical shape,

It is located at the bottom of the condensation prevention part and seals the inner center of the fastening part with threads formed on the upper outer circumference and the lower outer circumference based on the step protruding in a circular shape at the center of the outer circumference, and the plurality of first through holes penetrated through the upper surface and the center of the upper surface. A socket portion consisting of a blocking plate with a third through hole formed to allow the stem to pass through is provided,

A casing is provided between the socket part and the valve body, the upper part of which is coupled to the lower fastening part of the socket part, and the lower part is coupled to the valve body to form an internal space,

A cylindrical first heat transfer part accommodated in the space of the casing and having a fourth through hole formed in the center to allow the stem to pass through, a vertical first connection pin connected to the outer peripheral surface of the first heat transfer part and protruding in all directions, and the first heat transfer part. A heat transfer member consisting of a cylindrical second heat transfer portion that surrounds the first connection pin on all sides while the end of the connection pin is connected to the inner peripheral surface, and a plurality of vertical second connection pins that are connected to the outer peripheral surface of the second heat transfer portion and protrude radially. It is characterized by being provided.

Utility model registration No. 20 - 0478984 - 0000 Patent Registration No. 10 - 1736365 - 0000

doesn't exist.

The cryogenic valve to which the prior art is applied is installed in the middle of the cryogenic fluid line to control the distribution of cryogenic fluid and performs the function of completely blocking the flow of cryogenic fluid or controlling the flow rate. There is a gap between the cryogenic valve and the cryogenic valve. A check valve is installed to prevent backflow of cryogenic fluid.

As mentioned above, there may be slight differences in the configuration and shape of the cryogenic valve, but overall, it has a similar configuration, prevents the cryogenic fluid from being vaporized by external heat transfer, and heat conduction of the cryogenic fluid prevents the bonnet and handle from being evaporated. It is designed to provide insulation measures to prevent frost from occurring.

In addition, a check valve is installed between the cryogenic valve and the connection between the cryogenic valve and the fluid line to limit reverse movement of the cryogenic fluid.

In this way, when it is necessary to install additional check valves in addition to the cryogenic valve, there is no difficulty in installation if there is enough space for installation, but if space is insufficient, installation takes a lot of time, and maintenance and management even after installation is difficult. The disadvantage is that separate costs are required.

It takes time and money to install additional check valves, but after installing the check valve, it prevents the fluid from evaporating due to conduction of external air temperature, and the cryogenic fluid conducts to the bonnet and handle of the check valve, causing frost, thereby preventing normal operation. Since insulation measures must be taken to prevent operation from being interrupted, the problem of excessive cost is not avoided.

When attempting to provide insulation for cryogenic valves and check valves, not only must a hatch be installed on the outside of the body and bonnet to maintain a vacuum, but dozens of layers of insulation sheet (film) must be wound around the outer diameter of the body and bonnet to prevent radiant heat. Because the structure and construction are complicated, greater difficulties arise.

Accordingly, the present invention was invented to solve the above problems, and includes a valve body 105 forming an inlet 101, an outlet 102, and a flow path 103;

A long bonnet 106 connected to the upper part of the valve body 105, a gland 108 maintained with a handle 107 on the upper part of the bonnet 106, and connected to the handle 107 an operating shaft (109) protruding downward;

a valve stem (110) whose lower end extends to the valve body (105) and is connected to the operating shaft (109);

A flow prevention member 111 coupled to the lower side of the valve stem 110 to prevent the valve stem 110 from flowing during the operation process and maintain airtightness;

A bellows 115 connecting the upper and lower bellows flanges 112 and 113 to the upper and lower sides of the valve stem 110;

A jacket 116 mounted on the outside of the valve body 105 and the bonnet 106 to maintain a vacuum and prevent heat conduction;

It is configured to include a plug 120 that is coupled to the lower end of the valve stem 110 and opens and closes the flow path 103 formed in the valve body 105;

A plug body (123) having a hemispherical plug head (122) at the bottom that selects the distribution of cryogenic fluid through direct connection and separation from the operating surface (121) of the flow path (103) formed inside the valve body (105). A connection pipe (125) formed integrally and protruding from the upper part of;

The connecting protrusion 126 formed at the lower end of the valve stem 110 is coupled with the connecting pipe 125, so that the plug 120 rises and falls by the valve stem 110, and cryogenic fluid flows through the outlet 102. In the case of backflow, the connection pipe 125 is lowered with respect to the connection protrusion 126 due to the pressure of the backflow cryogenic fluid, thereby blocking the flow path 103;

In the forward direction of the cryogenic fluid, fluid can be supplied by the upward motion of the plug, and when the cryogenic fluid flows back at the outlet location, the pressure of the reversed cryogenic fluid lowers the plug to block the flow path to prevent backflow. Since there is no need to install a check valve, it is possible to achieve the goal of reducing costs and time for installation and maintenance.

The present invention improves the structure of the cryogenic valve so that the plug, which is located inside the body and moves up and down by the valve stem, can also function as a check valve, thereby eliminating the inconvenience of installing a separate check valve, reducing installation cost and time. It has the effect of providing ease of maintenance while reducing

The present invention prevents the plug of a cryogenic valve from rising due to the valve stem and fluid pressure during forward flow, causing disruption to fluid distribution, and lowers due to fluid pressure during reverse flow, thereby fundamentally blocking the reverse flow of cryogenic fluid. By performing the function as a valve, it has the effect of improving the quality and durability of the cryogenic valve.

The present invention improves only the structural relationship between the valve stem and the plug to enable the distribution of cryogenic fluid in the forward direction while blocking the movement of cryogenic fluid in the reverse direction, thereby minimizing structural changes to the cryogenic valve and maintaining the valve and check valve functions. It has the excellent effect of significantly reducing the costs and time for manufacturing, installing, and maintaining cryogenic valves.

Figure 1 is an external perspective view showing a cryogenic valve having a check valve function to which the technology of the present invention is applied.
Figure 2 is a fractured perspective view showing a cryogenic valve having a check valve function to which the technology of the present invention is applied.
Figure 3 is a cross-sectional view showing a cryogenic valve having a check valve function to which the technology of the present invention is applied.
Figure 4 is an exploded perspective view of the plug portion of a cryogenic valve having a check valve function to which the technology of the present invention is applied.
Figure 5 is a fractured perspective view of the plug portion of a cryogenic valve having a check valve function to which the technology of the present invention is applied.
Figure 6 is a cross-sectional view of the plug portion of a cryogenic valve having a check valve function to which the technology of the present invention is applied.
Figure 7 is a diagram illustrating the forward fluid flow operation state of a cryogenic valve having a check valve function to which the technology of the present invention is applied.
Figure 8 is a diagram showing the forward fluid flow blocking state of the cryogenic valve having a check valve function to which the technology of the present invention is applied.

Hereinafter, the preferred configuration and operation of the present invention for achieving the above object will be described in relation to the accompanying drawings.

Figure 1 is an external perspective view showing a cryogenic valve having a check valve function to which the technology of the present invention is applied, Figure 2 is a fractured perspective view showing a cryogenic valve having a check valve function to which the technology of the present invention is applied, and Figure 3 is a fractured perspective view of the cryogenic valve having a check valve function to which the technology of the present invention is applied. A cross-sectional view showing a cryogenic valve with a check valve function to which the technology of the present invention is applied, Figure 4 is an exploded perspective view of the plug portion of a cryogenic valve with a check valve function to which the technology of the present invention is applied, and Figure 5 is a check to which the technology of the present invention is applied. Figure 6 is a fractured perspective view illustrating the plug portion of a cryogenic valve with a valve function, Figure 6 is a cross-sectional view illustrating the plug portion of a cryogenic valve with a check valve function to which the technology of the present invention is applied, and Figure 7 is a check valve to which the technology of the present invention is applied. The forward fluid flow operation state of the cryogenic valve with the function and FIG. 8 are also explained as the forward fluid flow blocking state diagram of the cryogenic valve with the check valve function to which the technology of the present invention is applied.

A typical cryogenic valve 100 has an inlet 101 through which cryogenic fluid can flow on one side, and an outlet 102 on the opposite side of the inlet 101, and the inlet 101 and the outlet 102 ) A valve body 105 forming a flow path 103 is provided between them.

A long bonnet 106 is connected to the upper part of the valve body 105 to reduce temperature conduction of the cryogenic fluid, and the upper part of the bonnet 106 is maintained by a gland 108 having a handle 107. do.

The handle 107 has an operating shaft 109 protruding downward and positioned in the center of the bonnet 106, and the lower end of the operating shaft 109 is formed by a valve stem 110 whose lower end extends to the valve body 105. Connected to the upper end, the operating shaft 109 rises and falls by rotation, and the valve stem 110 rises and falls without rotation.

A flow prevention device 111 made of Teflon is attached to the lower part of the valve stem 110 to prevent the valve stem 110 from flowing during the operation process and maintain airtightness, and the upper side of the valve stem 110 On the lower side, the upper and lower bellows flanges (112, 113) are mounted to connect the bellows (115).

A jacket 116 is installed on the outside of the valve body 105 and the bonnet 106 to maintain a vacuum to prevent heat conduction, and a flow path formed in the valve body 105 at the bottom of the valve stem 110 ( It is configured by combining a plug 120 for opening and closing 103).

In the present invention, the valve stem 110 and the plug 120 are improved to function as a check valve, thereby eliminating the inconvenience of separately providing and installing a check valve, and improving the ease of installation and maintenance of the cryogenic valve 100. It is characterized by being able to provide.

A cylindrical plug body (123) having a hemispherical plug head (122) at the bottom that selects the distribution of cryogenic fluid through direct connection and separation from the operating surface (121) of the flow path (103) formed inside the valve body (105). ) is provided.

A connection pipe 125 is integrally formed on the upper part of the plug body 123 and protrudes, and a connection protrusion 126 formed at the lower end of the valve stem 110 is coupled to the connection pipe 125.

The connection pipe 125 and the connection protrusion 126 are connected to the connection pipe 125 to form a form that can maintain the coupling force by using the dimensional difference without fixing them with a separate fixing means such as a screw or bond. The coupling force of the protrusion 126 is greater than the self-weight of the plug 120 and smaller than the pressure of the cryogenic fluid flowing back through the outlet 102, so that the connection protrusion 125 and the connection pipe body are connected during the lifting operation for opening and closing the flow path 103. (126) is not separated and allows the connection pipe 125 to move downward with respect to the connection protrusion 126 only by the countercurrent pressure of the cryogenic fluid.

The length (L) of the connection pipe 125 and the connection protrusion 126 is longer than the maximum stroke through which the plug 100 opens and closes the flow path 103, so that the connection pipe 125 is connected to the connection protrusion 126 during the operation process. ), it would be desirable to prevent malfunction or inoperability from occurring.

In addition, the upper side of the plug body 123 constituting the flag 120 is positioned at about the middle of the outlet 102 and the flow path 103 to prevent the cryogenic fluid flowing back through the outlet 102 from plug body 123. It is desirable to receive it and quickly descend to block the flow path 103.

The operating state of the cryogenic valve 100 to which the technology of the present invention is applied as described above is as follows.

If you want to distribute cryogenic fluid after installing the cryogenic valve 100 in the line through which you want to distribute cryogenic fluid, operate the handle 107 to raise the valve stem 110 through the operating shaft 109 to open the valve. The plug 120 connected to the stem 110 and connected to the operating surface 121 of the flow path 103 formed inside the valve body 105 is raised.

Then, since the connection pipe 125 formed to protrude from the upper part of the plug body 123 and the connection protrusion 126 formed at the bottom of the valve stem 110 are coupled to each other, the plug body 125 is raised as the valve stem 110 rises. Since (123) also rises, it is possible for the cryogenic fluid to move to the desired location through the inlet 101, the flow path 103, and the outlet 102.

In addition, although the cryogenic fluid must be continuously supplied to the desired location, if backflow of the cryogenic fluid occurs at the outlet 102 location, the plug 120 plays the same role as a check valve and causes the cryogenic temperature at the outlet 102 location. It is possible to block fluid from flowing back into the flow path 103 and the inlet 101.

This is because the coupling force of the connection pipe 125 and the connection protrusion 126 can be maintained by using the dimensional difference without fixing it with a separate fixing means such as a screw or bond, so that the valve stem 110 is usually raised. Alternatively, during the lowering operation, the plug 120 moves up and down together with the valve stem 110.

In addition, when there is a backflow of cryogenic fluid at the location of the outlet 102, the backflowing cryogenic fluid fills the upper part of the outlet 102 and the flow path 103, and the pressure of this cryogenic fluid increases at the top of the plug 120. It acts as a force to lower (120), and when this force becomes greater than the pressure of the fluid supplied through the inlet 101, the plug 120 descends and blocks the operating surface 121 of the flow path 103. This prevents backflow of cryogenic fluid.

This means that the coupling force between the connecting pipe 125 and the connecting protrusion 126 is greater than the self-weight of the plug 120 and smaller than the pressure of the cryogenic fluid flowing back through the outlet 102, so that the lifting operation process for opening and closing the flow path 103 This is possible because the connection pipe 125 and the connection protrusion 126 are not separated but are coupled so that the connection pipe 125 can move downward with respect to the connection protrusion 126 only by the countercurrent pressure of the cryogenic fluid.

For this reason, in normal conditions, the cryogenic fluid flowing in through the inlet 101 is supplied to the desired location through the outlet 102 through the space between the raised plug 120 and the flow path 103. It becomes possible.

Even though the operating surface 121 of the flow path 103 is not blocked by lowering the plug 120, if the cryogenic fluid in the direction of the discharge port 102 flows back, the plug 120 is blocked by the pressure of the counterflowing cryogenic fluid. Since the downward operation blocks the flow path 103, it is possible to perform the function of blocking backflow even if a check valve is not separately installed.

The present invention as described above enables fluid supply by the upward motion of the plug in the forward direction of the cryogenic fluid, and when the cryogenic fluid flows backwards at the outlet location, the plug is lowered by the pressure of the cryogenic fluid flowing backwards to block the flow path to prevent reverse flow. This has the advantage of reducing the cost and time of installation and maintenance by eliminating the need to install a separate check valve.

100; Cryogenic valve
103; Euro
105; valve body
106; bonnet
107; handle
110; valve stem
111; Flow prevention zone
112; Upper bellows flange
113; Lower bellows flange
115; bellows
120; plug
122; plug head
123; plug body
125; connection pipe
126; connection protrusion

Claims (4)

A valve body 105 forming an inlet 101, an outlet 102, and a flow path 103; A long bonnet 106 connected to the upper part of the valve body 105, a gland 108 maintained with a handle 107 on the upper part of the bonnet 106, and connected to the handle 107 an operating shaft (109) protruding downward; A valve stem (110) whose lower end extends to the valve body (105) and is connected to the operating shaft (109); A flow prevention member 111 coupled to the lower side of the valve stem 110 to prevent the valve stem 110 from flowing during the operation process and maintain airtightness; A bellows 115 connecting the upper and lower bellows flanges 112 and 113 to the upper and lower sides of the valve stem 110; A jacket 116 mounted on the outside of the valve body 105 and the bonnet 106 to maintain a vacuum and prevent heat conduction; In the cryogenic valve, which is configured to include a plug 120 coupled to the lower end of the valve stem 110 to open and close the flow path 103 formed in the valve body 105;
A plug body (123) having a hemispherical plug head (122) at the bottom that selects the distribution of cryogenic fluid through direct connection and separation from the operating surface (121) of the flow path (103) formed inside the valve body (105). The connection pipe 125 is protruded from the upper part and combined with the connection protrusion 126 formed at the lower end of the valve stem 110, so that the plug 120 moves up and down by the valve stem 110 to form the outlet 102. When there is a backflow of cryogenic fluid through, the connection pipe 125 is lowered with respect to the connection protrusion 126 by the pressure of the backflowing cryogenic fluid to block the flow path 103;
The coupling force between the connecting pipe 125 and the connecting protrusion 126 is greater than the self-weight of the plug 120 and smaller than the pressure of the cryogenic fluid flowing back through the outlet 102;
The upper side of the plug body 123 is located in the middle of the outlet 102 and the flow path 103, so that the plug body 123 can receive the back-flowing cryogenic fluid and quickly descend to block the flow path 103. A cryogenic valve with a check valve function. delete delete delete

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