JP2010265962A - Check valve incorporated with liquid-sealing prevention mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a collection pipe from being in a liquid-sealed state in an LP gas supply system. <P>SOLUTION: When pressure on the collection pipe 11 side exceeds a first set value, a check valve 17 operates to prevent reverse flow to the side of LP gas containers 3, 5, 7, 9. When the pressure on the collection pipe 11 side exceeds a second set value larger than the first set value, a relief valve 19 operates to allow a predetermined amount of the reverse flow. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention, for example, in an apartment house or the like, from a plurality of LP gas containers to the consuming side (for example, each household) LP gas (LPG: Liquefied Petroleum Gas: liquefied gas) through the collecting pipe and the automatic switching regulator The present invention relates to a check valve with a built-in liquid seal prevention mechanism used in a supplied LP gas supply system.

  Patent Document 1 describes a “safety device for a high-pressure gas container”. This device is implemented with a check valve that prevents back flow of gas into the gas container.

  FIG. 12 shows a check used in an LP gas supply system for supplying LP gas to a consumer side from a plurality of LP gas containers via a collecting pipe and an automatic switching regulator in a business use or an apartment house. A valve 301 is shown. The check valve 301 includes a valve body 303, a valve seat 305, and a spring 307 that biases the valve body 303 in a direction away from the valve seat 305. This check valve 301 is installed between the other end of the high-pressure hose whose one end is connected to the on-off valve provided in each LP gas container and the collecting pipe, and when the on-off valve and the high-pressure hose are not connected. When a predetermined differential pressure is generated on the upstream side and the downstream side of the check valve, the valve body 303 is pressed against the valve seat 305 against the urging force of the spring 307 to prevent the LP gas from being released into the atmosphere.

Japanese Utility Model Publication No. 57-139800

  In the LP gas supply system using the check valve 301 described above, the following problems may occur when the consuming side does not use LP gas.

  For example, if the LP gas supply system is exposed to sunlight during the daytime in fine weather, the temperature and pressure (vapor pressure) of the LP gas container, which has a larger heat collection area than the collecting pipe, rises first, and there is a temperature difference between the collecting pipe and Pressure difference occurs. In the case of LP gas, it is known that if the temperature difference is 3 ° or more, a reliquefaction phenomenon occurs in which the gas liquefies by the amount exceeding the saturated vapor pressure. If LP gas generated by the phenomenon stays in the lower part and this state continues for 30 minutes to 1 hour, the collecting pipe may be filled with LP gas.

  In the LP gas supply system, since the LP gas container is exchanged according to a predetermined delivery plan, the LP gas container may be exchanged with the collecting pipe filled with LP gas as described above. The manual on-off valve 309 is closed, the high-temperature used LP gas container is removed, and after installing a new LP gas container, the on-off valve 309 is opened.

  New LP gas containers that have not been exposed to sunlight for a long time, such as used LP gas containers, are at a lower temperature and lower pressure than the collecting pipe. Generally, the check valve 301 has a pressure difference between the collecting pipe and the LP gas container. Is set to close to 0.01 MPa or more, and the check valve 301 is instantaneously closed by LP gas flowing from the high-pressure side collecting pipe toward the low-pressure side LP gas container. The check valve 301 is attached between the collecting pipe and each LP gas container, and the check valve 301 is closed by all the replaced LP gas containers. It is blocked and enters a liquid seal state filled with LP gas.

  If the collecting pipe that is closed and sealed in liquid is kept exposed to sunlight, the internal pressure (hydraulic pressure) may rise abnormally and reach a high pressure exceeding 5 MPa. The automatic switching regulator connected to the collecting pipe When such a high pressure is applied, the precise adjusting portion is damaged, and the pressure adjusting function or the like is defective.

  The conventional check valve 301 does not have a function of preventing the collecting pipe from being in a liquid-sealed state.

  Therefore, the present invention prevents the collecting pipe from being liquid-sealed in an LP gas supply system that supplies LP gas from a plurality of LP gas containers to the consuming side via the collecting pipe and the automatic switching regulator. The purpose is to provide a check valve with a built-in liquid seal prevention mechanism.

  The check valve with a built-in liquid seal prevention mechanism according to claim 1 includes a plurality of LP gas containers for supplying LP gas, a collecting pipe for collecting gas from the LP gas container, and an LP gas disposed on the collecting pipe. A check valve with a built-in liquid seal prevention mechanism disposed between each LP gas container and a collecting pipe of an LP gas supply system having an automatic switching regulator for supplying to a consumer side, the pressure on the collecting pipe side Is activated when the pressure exceeds the first set value, and a check valve that prevents backflow to the LP gas container side, and when the pressure on the collecting pipe side exceeds the second set value that is greater than the first set value. And a relief valve that operates to allow a predetermined amount of backflow.

  The invention of claim 2 is the check valve with a built-in liquid seal prevention mechanism according to claim 1, wherein the check valve includes a check valve body, a valve seat of the check valve body, and a reverse valve. First urging means for urging the stop valve body in the direction of moving from the valve seat, and when the pressure on the collecting pipe side is equal to or lower than the first set value, the check valve body is first attached. When the pressure on the collecting pipe side exceeds the first set value by the urging force of the urging means, the check valve body is pressed against the urging force of the first urging means against the urging force. The relief valve prevents backflow, and the relief valve is movably disposed in a through hole provided in the check valve body of the check valve, and the relief provided in the check valve body And a second urging means for urging the relief valve body toward the relief valve seat. When the pressure on the collecting pipe side is equal to or lower than the second set value, the relief valve body is Second force When the pressure on the collecting pipe side exceeds the second set value, the relief valve body is relieved against the urging force of the second urging means. It moves from the valve seat and allows a predetermined amount of backflow.

  The invention of claim 3 is the check valve with a built-in liquid seal prevention mechanism according to claim 1, wherein the check valve includes a check valve body, a valve seat of the check valve body, and a reverse valve. First urging means for urging the stop valve body in the direction of moving from the valve seat, and when the pressure on the collecting pipe side is equal to or lower than the first set value, the check valve body is first attached. When the pressure on the collecting pipe side exceeds the first set value by the urging force of the urging means, the check valve body is pressed against the urging force of the first urging means against the urging force. The relief valve includes a relief valve body provided with the valve seat of the check valve, a small-diameter portion that is a valve seat of the relief valve body, and a large-diameter portion that is a backflow allowing portion. And a second urging means for urging the relief valve body toward the small-diameter portion, and when the pressure on the collecting pipe side is equal to or lower than the second set value, the relief valve body is the second urging means. Small due to the urging force of When the pressure on the collecting pipe side exceeds the second set value, the relief valve element moves to the large diameter portion against the urging force of the second urging means and is pressed by a predetermined amount. It is characterized by allowing back flow of the water.

  The invention of claim 4 is the check valve with a built-in liquid seal prevention mechanism according to claim 1, wherein the check valve includes a check valve body, a valve seat of the check valve body, and a reverse valve. First urging means for urging the stop valve body in the direction of moving from the valve seat, and when the pressure on the collecting pipe side is equal to or lower than the first set value, the check valve body is first attached. When the pressure on the collecting pipe side exceeds the first set value by the urging force of the urging means, the check valve body is pressed against the urging force of the first urging means against the urging force. The relief valve prevents the reverse flow, and the relief valve is a relief valve body provided with the valve seat of the check valve, the valve seat of the relief valve body, and the second for urging the relief valve body toward the valve seat side. In the range where the pressure on the collecting pipe side is equal to or lower than the second set value, the relief valve body is pressed against the valve seat by the urging force of the second urging means to prevent backflow, The pressure on the tube side is Exceeds the set value, characterized in that the relief valve body to allow the reverse flow of moving a predetermined amount from the valve seat against the biasing force of the second biasing means.

  The invention according to claim 5 is the check valve with a built-in liquid seal prevention mechanism according to claim 4, wherein the relief valve body is made of resin.

  The invention of claim 6 is the check valve with a built-in liquid seal prevention mechanism according to any one of claims 1 to 5, wherein the check valve and the relief valve are assembled on the same member. Features.

  The check valve with a built-in liquid seal prevention mechanism according to claim 1 is provided with a relief valve that operates when the pressure on the collecting pipe side exceeds a predetermined value (second set value) to allow backflow. When the check valve is closed by the pressure from the collecting pipe when the container is replaced, if the pressure rises further and exceeds the second set value, the relief valve is opened and a predetermined amount of backflow is generated. By allowing, the collecting tube is prevented from being in a liquid-sealed state.

  Therefore, the internal pressure of the collecting pipe does not increase excessively, and the automatic switching regulator is not damaged by the high pressure from the collecting pipe, and the pressure adjusting function, the switching function, etc. are kept normal.

  In addition, by incorporating (adding) a relief valve to a conventional check valve, it can be made compact and lightweight and can be implemented at low cost.

  The check valve with a built-in liquid seal prevention mechanism according to claim 2 is configured such that when the pressure on the collecting pipe side exceeds a predetermined value (second set value), the relief valve is opened to allow a predetermined amount of backflow. Thus, the same effect as that of the structure of claim 1 can be obtained.

  Further, since the relief valve element disposed in the through hole of the check valve element has a small diameter, a small pressure receiving area, and a low pressure received from the LP gas, a small second urging means having a weak urging force should be used. it can.

  Further, by disposing the relief valve body in the check valve body (through hole) and incorporating the relief valve into the check valve, the structure is small and light, and can be implemented at low cost.

  The check valve with a built-in liquid seal prevention mechanism according to claim 3 is configured such that when the pressure on the collecting pipe side exceeds a predetermined value (second set value), the relief valve is opened to allow a predetermined amount of backflow. Thus, the same effect as that of the structure of claim 1 can be obtained.

  The check valve with a built-in liquid seal prevention mechanism according to claim 4 is configured such that when the pressure on the collecting pipe side exceeds a predetermined value (second set value), the relief valve is opened to allow a predetermined amount of backflow. Thus, the same effect as that of the structure of claim 1 can be obtained.

  The liquid seal prevention mechanism built-in check valve according to claim 5 can achieve the same effect as the structure of claim 4.

  Further, since the relief valve body is made of resin, the liquid check prevention mechanism built-in check valve according to claim 4 is light in weight and does not require packing, so that it can be implemented at low cost.

  The check valve with a built-in liquid seal prevention mechanism according to the sixth aspect of the present invention can achieve the same effects as the configurations of the first to fifth aspects.

  Further, by assembling the check valve and the relief valve on the same member, for example, a plug screwed to the case body side, the structure can be reduced in size and weight and the assembling work to the case body can be facilitated.

  In particular, the configuration according to claim 2 in which the relief valve body is arranged in the through hole of the check valve body makes it easy to assemble the check valve and the relief valve on the same member, and the effect of the assembly on the same member. Easy to get.

  Further, by assembling the check valve and the relief valve on the same member, the assembling work for attaching (for example, screwing) the same member to the case main body side becomes extremely easy.

It is drawing which shows the structure of the LP gas supply system 15 in which each Example was used. It is a top view which shows check valve 1,101,201 with a liquid-seal prevention mechanism of each Example. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2, illustrating a state in which a check valve 17 built in the check valve 1 with a built-in liquid seal prevention mechanism according to the first embodiment is opened. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2, illustrating a state in which a check valve 17 built in the check valve 1 with a built-in liquid seal prevention mechanism of Example 1 is closed. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, showing a state in which a relief valve 19 built in the check valve 1 with a built-in liquid seal prevention mechanism of Example 1 is opened. FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 2, illustrating a state in which a check valve 103 built in the check valve 101 with a built-in liquid seal prevention mechanism according to the second embodiment is opened. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, illustrating a state in which a check valve 103 built in a check valve 101 with a built-in liquid seal prevention mechanism according to a second embodiment is closed. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, showing a state in which a relief valve 105 built in the check valve 101 with a built-in liquid seal prevention mechanism of Example 2 is opened. FIG. 4 is a cross-sectional view taken along the line AA of FIG. 2, illustrating a state in which a check valve 203 built in the check valve 201 with a built-in liquid seal prevention mechanism according to the third embodiment is opened. FIG. 4 is a cross-sectional view taken along the line AA of FIG. 2, illustrating a state in which a check valve 203 built in a check valve 201 with a built-in liquid seal prevention mechanism of Example 3 is closed. FIG. 4 is a cross-sectional view taken along the line AA of FIG. 2, illustrating a state in which a relief valve 205 built in the check valve 201 with a built-in liquid seal prevention mechanism according to the third embodiment is opened. It is sectional drawing of a prior art example.

  Hereinafter, embodiments of the check valve with a built-in liquid seal prevention mechanism according to the present invention will be described.

  The check valve 1 (embodiment 1) with a built-in liquid seal prevention mechanism will be described with reference to FIGS.

[Features of check valve 1 with built-in liquid seal prevention mechanism]
The check valve 1 with a built-in liquid seal prevention mechanism includes LP gas containers 3, 5, 7, 9 for supplying LP gas, a collecting pipe 11 for collecting LP gas from the LP gas containers 3, 5, 7, 9, LP gas containers 3, 5, 7, 9 of the LP gas supply system 15, which are arranged on the collecting pipe 11, and have an automatic switching regulator 13 that supplies LP gas to the consuming side (for example, each household); It is arranged between.

  Further, the check valve 1 with a built-in liquid seal prevention mechanism of this embodiment is activated when the pressure on the collecting pipe 11 side exceeds the first set value, and the backflow to the LP gas containers 3, 5, 7, 9 side is performed. And a relief valve 19 that operates when a pressure on the collecting pipe 11 side exceeds a second set value (greater than the first set value) and allows a predetermined amount of backflow. .

  Furthermore, the check valve 1 with a built-in liquid seal prevention mechanism of the present embodiment includes a check valve 17 having a valve body 21 (check valve body), a valve seat 25 provided on a plug 23 (same member), a valve As shown in FIG. 3, the coil spring 27 (first urging means) that urges the valve body 21 in the direction of movement from the seat 25 is provided, and the pressure on the collecting pipe 11 side is within the first set value or less. In addition, when the valve body 21 is moved from the valve seat 25 by the urging force of the coil spring 27 (check valve 17: opened) and the pressure on the collecting pipe 11 side exceeds the first set value, as shown in FIG. The valve element 21 is pressed against the valve seat 25 against the urging force of the coil spring 27 (check valve 17: closed) to prevent backflow.

  The relief valve 19 includes a valve body 31 (relief valve body) movably disposed in a coaxial through hole 29 provided in the valve body 21 of the check valve 17, and a valve seat 33 provided in the valve body 21. (Relief valve seat) and a coil spring 35 (second urging means) that urges the valve body 31 toward the valve seat 33, and the pressure on the collecting pipe 11 side is within a second set value or less. Then, the valve body 31 is pressed against the valve seat 33 by the urging force of the coil spring 35 (relief valve 19: closed) to prevent backflow, and when the pressure on the collecting pipe 11 side exceeds the second set value, FIG. As described above, the valve body 31 moves from the valve seat 33 against the urging force of the coil spring 35 (relief valve 19: opened), and moves from the collecting pipe 11 to the LP gas containers 3, 5, 7, 9 as indicated by arrows. A predetermined amount of backflow is allowed.

  Further, the check valve 17 and the relief valve 19 are assembled on the plug 23.

  As shown in FIG. 1, the LP gas supply system 15 includes a collecting pipe 11 to which the LP gas containers 3 and 5 are connected and a collecting pipe 11 to which the LP gas containers 7 and 9 are connected. Connected to and configured. The LP gas supply system may be configured by connecting three or four or more LP gas containers to the left and right of the automatic switching adjuster 13.

  The LP gas containers 3, 5, 7, and 9 are connected to the collecting pipe 11 through an on-off valve 37, a high-pressure hose 39, and a check valve 1 with a built-in liquid seal prevention mechanism. The automatic switching adjuster 13 is connected to each household side through an outflow port, and switches the left and right collecting pipes 11 (LP gas containers 3 and 5 and LP gas containers 7 and 9) and uses a pressure adjusting function. The pressure of LP gas sent to the home is properly maintained.

  The coil spring 35 of the relief valve 19 is held by the E ring 41 and the valve body 21 of the check valve 17, and the packing 43 that is pressed against the valve seat 25 when the check valve 17 is closed is attached to the valve body 21. It has been. As described above, the check valve 17 and the relief valve 19 are incorporated in the plug 23, and the check valve 17 and the relief valve 19 are assembled by screwing the plug 23 into the case main body 45. The plug 23 is provided with a port 47 for connecting the collecting pipe 11, and the case body 45 is provided with a port 49 for connecting a high-pressure hose 39. A manual on-off valve 51 is assembled to the case body 45, and the on-off valve 51 rotates the valve body 57 via the lever 53 and the stem 55 to communicate with or shut off the ports 47 and 49.

  The first set value is set by adjusting the biasing force of the coil spring 27, the second set value is set by adjusting the biasing force of the coil spring 35, and the first set value is a conventional check. The set value is the same as that of the valve, and the second set value is set to a value moderately larger than the first set value.

  For example, when LP gas is used on the consumption side, the pressure on the collecting pipe 11 side is kept below the first set value. During this time, the check valve 17 is opened by the coil spring 27 and the LP gas container is opened. When LP gas is supplied from 3, 5, 7, 9 to the collecting pipe 11 and the pressure exceeds the first set value, the pressure closes the check valve 17 against the biasing force of the coil spring 27, Prevents backflow of LP gas.

  Even if the pressure on the collecting pipe 11 side exceeds the first set value, the relief valve 19 is closed by the coil spring 35 and the backflow of LP gas is prevented while the pressure is equal to or less than the second set value. However, when the pressure exceeds the second set value, the pressure opens the relief valve 19 against the urging force of the coil spring 35, and from the collecting pipe 11 to the LP gas containers 3, 5, 7, 9 A predetermined amount of backflow is allowed, and the pressure in the collecting pipe 11 and the LP gas containers 3, 5, 7, 9 is equalized.

  Therefore, the temperature of the LP gas containers 3, 5, 7, 9 is higher than that of the collecting pipe 11 due to solar radiation (for example, the temperature difference is 3 ° or more), and the collecting pipe 11 is filled with LP gas. The LP gas containers 3, 5, 7, and 9 are replaced, and the check is caused by the differential pressure (for example, 0.01 MPa or more) generated between the collecting pipe 11 and the new LP gas containers 3, 5, 7, and 9. Even if the valve 17 is closed and the positive pressure continues to hit the collecting pipe 11 and the inside of the collecting pipe 11 becomes a high pressure, the relief valve 19 as described above is caused by this differential pressure (pressure exceeding the second set value). Is opened and moderate backflow from the collecting pipe 11 to the LP gas containers 3, 5, 7, and 9 is allowed, and the collecting pipe 11 is prevented from being in a liquid-sealed state, and the internal pressure becomes abnormal even when exposed to sunlight. The function of the automatic switching adjuster 13 is damaged because it does not rise. It is not.

[Effect of check valve 1 with built-in liquid seal prevention mechanism]
The check valve 1 with a built-in liquid seal prevention mechanism is provided with a relief valve 19 that operates when the pressure on the collecting pipe 11 side exceeds a predetermined value (second set value) and allows backflow. When the check valve 17 is closed by high-pressure LP gas when 3, 5, 7, and 9 are replaced, the relief valve 19 is opened when the pressure further rises and exceeds the second set value. Since a predetermined amount of backflow is allowed, the collecting tube 11 will not be in a liquid-sealed state.

  Accordingly, the internal pressure of the collecting pipe 11 does not rise excessively, and the automatic switching adjuster 13 is released from damage caused by the high pressure, and the pressure adjusting function, the switching function, and the like are kept normal.

  Further, since the valve body 31 disposed in the through hole 29 of the valve body 21 has a small diameter, a small pressure receiving area, and a small pressure received from the LP gas, the coil spring 35 can be used with a small urging force and a small size. In addition, by incorporating the relief valve 19 into the check valve 17, it can be made compact and lightweight and can be implemented at low cost.

  Further, the valve body 31 of the relief valve 19 is disposed in the valve body 21 (through hole 29) of the check valve 17, and the check valve 17 and the relief valve 19 are connected by incorporating the relief valve 19 into the check valve 17. Assembling to the plug 23 is facilitated, and by assembling (assembling) the check valve 17 and the relief valve 19 on the plug 23, the assembling work for screwing the plug 23 to the case main body 45 becomes extremely easy.

  A liquid seal prevention mechanism built-in check valve 101 (Example 2) will be described with reference to FIGS. Hereinafter, the same functional parts and functional members as those in the first embodiment are denoted by the same reference numerals, and duplicate explanations are omitted.

[Features of Check Valve 101 with Built-in Liquid Seal Prevention Mechanism]
The liquid seal prevention mechanism built-in check valve 101 includes LP gas containers 3, 5, 7, 9 for supplying LP gas, a collecting pipe 11 for collecting LP gas from the LP gas containers 3, 5, 7, 9, LP gas containers 3, 5, 7, 9 of the LP gas supply system 15, which are arranged on the collecting pipe 11, and have an automatic switching regulator 13 that supplies LP gas to the consuming side (for example, each household); It is arranged between.

  Further, the check valve 101 with a built-in liquid seal prevention mechanism according to the present embodiment operates when the pressure on the collecting pipe 11 side exceeds the first set value, and causes a back flow to the LP gas containers 3, 5, 7, 9 side. And a relief valve 105 that operates when a pressure on the collecting pipe 11 side exceeds a second set value (greater than the first set value) and allows a predetermined amount of backflow. .

  Further, in the check valve 101 with a built-in liquid seal prevention mechanism of the present embodiment, the check valve 103 moves the valve body 107 (check valve body), the valve seat 109, and the valve body 107 from the valve seat 109. In the range where the pressure on the collecting pipe 11 side is equal to or lower than the first set value, the valve body 107 is coil spring 111 as shown in FIG. When the pressure on the collecting pipe 11 side exceeds the first set value, the valve body 107 is attached to the coil spring 111 as shown in FIG. The valve seat 109 is pressed against the force (check valve 103: closed) to prevent backflow.

  The relief valve 105 includes a valve body 113 (relief valve body) provided with a valve seat 109 of the check valve 103, a small-diameter portion 115 that is a valve seat of the valve body 113, and a large-diameter portion that is a reverse flow allowing portion. 117 and a coil spring 119 (second urging means) that urges the valve body 113 toward the small diameter portion 115, and the valve body 113 is within a range where the pressure on the collecting pipe 11 side is equal to or lower than the second set value. When the coil spring 119 is moved to the small diameter portion 115 side by the urging force of the coil spring 119 (relief valve 105: closed) to prevent backflow and the pressure on the collecting pipe 11 side exceeds the second set value, as shown in FIG. The body 113 moves to the large diameter portion 117 against the urging force of the coil spring 119 (relief valve 105: opened), and a predetermined amount is transferred from the collecting pipe 11 to the LP gas containers 3, 5, 7, 9 as indicated by arrows. Backflow is allowed.

  A small diameter portion 115 and a large diameter portion 117 of the relief valve 105 are provided in a plug 121, and the plug 121 is screwed to the case main body 45. A washer 123 is disposed between the plug 121 and the case main body 45, and a stopper 125 of the valve body 113 is provided on the plug 121, and the coil spring 119 presses the valve body 113 against the stopper 125 on the washer 123. ing. A packing 127 that is pressed against the small diameter portion 115 when the relief valve 105 is closed is attached to the valve body 113, and a LP gas flow path 129 is provided coaxially. The coil spring 111 of the check valve 103 urges the valve element 107 in a direction away from the valve seat 109 (valve element 113) on the valve element 113, and the check valve 103 is closed to the valve element 107. A packing 131 that is pressed against the valve seat 109 is attached.

  The check valve 103 and the relief valve 105 are assembled by screwing the plug 121 onto the case body 45 while pressing the coil spring 119 against the washer 123. The plug 121 is provided with a port 133 for connecting the right collecting pipe 11, and the case body 45 is provided with a port 49 for the left collecting pipe 11.

  The first set value is set by adjusting the biasing force of the coil spring 111, the second set value is set by adjusting the biasing force of the coil spring 119, and the first set value is a conventional check. The set value is the same as that of the valve, and the second set value is set to a value moderately larger than the first set value.

  For example, when LP gas is used on the consumption side, the pressure on the collecting pipe 11 side is kept below the first set value. During this time, the check valve 103 is opened by the coil spring 111 and the LP gas container is opened. When LP gas is supplied from 3, 5, 7, 9 to the collecting pipe 11 and the pressure exceeds the first set value, the pressure closes the check valve 103 against the biasing force of the coil spring 111, Prevents backflow of LP gas.

  Further, even if the pressure on the collecting pipe 11 side exceeds the first set value, the relief valve 105 is closed by the coil spring 119 while the pressure is equal to or less than the second set value, and the backflow of LP gas is prevented. However, when the pressure exceeds the second set value, the pressure opens the relief valve 105 against the urging force of the coil spring 119, and is moved from the collecting pipe 11 to the LP gas containers 3, 5, 7, 9. A fixed amount of backflow is allowed, and the pressure in the collecting pipe 11 and the LP gas containers 3, 5, 7, 9 is equalized.

  Therefore, the temperature of the LP gas containers 3, 5, 7, 9 is higher than that of the collecting pipe 11 due to solar radiation (for example, the temperature difference is 3 ° or more), and the collecting pipe 11 is filled with LP gas. The LP gas containers 3, 5, 7, and 9 are replaced, and the check is caused by the differential pressure (for example, 0.01 MPa or more) generated between the collecting pipe 11 and the new LP gas containers 3, 5, 7, and 9. Even if the valve 103 is closed, this pressure difference (pressure exceeding the second set value) causes the relief valve 105 to be opened as described above, so that the collecting pipe 11 can be appropriately transferred to the LP gas containers 3, 5, 7, 9. Therefore, the collecting tube 11 is prevented from becoming liquid-sealed, and the internal pressure does not increase abnormally even when exposed to sunlight, so that the function of the automatic switching regulator 13 is damaged. There is no.

[Effect of Check Valve 101 with Built-in Liquid Seal Prevention Mechanism]
Since the check valve 101 with a built-in liquid seal prevention mechanism is provided with a relief valve 105 that operates when the pressure on the collecting pipe 11 side exceeds a predetermined value (second set value) and allows backflow, for example, an LP gas container When the check valve 103 is closed by the high-pressure LP gas when 3, 5, 7, and 9 are replaced, the relief valve 105 is opened when the pressure further rises and exceeds the second set value. Since a predetermined amount of backflow is allowed, the collecting tube 11 will not be in a liquid-sealed state.

  Accordingly, the internal pressure of the collecting pipe 11 does not rise excessively, and the automatic switching adjuster 13 is released from damage caused by the high pressure, and the pressure adjusting function, the switching function, and the like are kept normal.

  Further, the check valve 101 with a built-in liquid seal prevention mechanism is configured to be small and light by incorporating the check valve 103 and the relief valve 105 into the plug 121, and can be implemented at low cost.

  A liquid seal prevention mechanism built-in check valve 201 (Example 3) will be described with reference to FIGS. Hereinafter, the same functional parts and functional members as those in the second embodiment will be described with the same reference numerals, and redundant explanations will be omitted.

[Features of Check Valve 201 with Built-in Liquid Seal Prevention Mechanism]
Liquid check prevention mechanism built-in check valve 201 includes LP gas containers 3, 5, 7, 9 for supplying LP gas, collecting pipe 11 for collecting LP gas from LP gas containers 3, 5, 7, 9, LP gas containers 3, 5, 7, 9 of the LP gas supply system 15, which are arranged on the collecting pipe 11, and have an automatic switching regulator 13 that supplies LP gas to the consuming side (for example, each household); It is arranged between.

  Further, the check valve 201 with a built-in liquid seal prevention mechanism operates when the pressure on the collecting pipe 11 side exceeds the first set value to prevent backflow to the LP gas containers 3, 5, 7, 9 side. A valve 203 and a relief valve 205 that operates when a pressure on the collecting pipe 11 side exceeds a second set value (greater than the first set value) and allows a predetermined amount of backflow are provided.

  Further, in the check valve 201 with a built-in liquid seal prevention mechanism of the present embodiment, the check valve 203 moves the valve body 207 (check valve body), the valve seat 209, and the valve body 207 from the valve seat 209. In the range in which the pressure on the collecting pipe 11 side is equal to or lower than the first set value, the valve element 207 is coil spring 211 as shown in FIG. When the pressure on the collecting pipe 11 side exceeds the first set value, the valve body 207 is attached to the coil spring 211 as shown in FIG. The valve seat 209 is pressed against the force (check valve 203: closed) to prevent backflow.

  The relief valve 205 includes a valve body 213 (relief valve body) provided with a valve seat 209 of the check valve 203, a valve seat 215, and a coil spring 217 that biases the valve body 213 toward the valve seat 215 (second And the valve body 213 is pressed against the valve seat 215 by the urging force of the coil spring 217 in the range where the pressure on the collecting pipe 11 side is equal to or lower than the second set value to prevent backflow, and the collecting pipe When the pressure on the 11th side exceeds the second set value, the valve body 213 moves from the valve seat 215 against the urging force of the coil spring 217 (relief valve 205: opened) as shown in FIG. A predetermined amount of backflow is allowed to the LP gas containers 3, 5, 7, and 9, as indicated by arrows, from a slight gap (for example, 0.1 mm to 0.2 mm) generated between 213 and the valve seat 215. .

  The valve body 213 is made of resin.

  A valve seat 215 of the relief valve 205 is provided on the plug 121. The coil spring 217 urges the valve body 213 toward the valve seat 215 on the washer 123, and a LP gas channel 129 is provided in the valve body 213. The coil spring 211 of the check valve 203 biases the valve body 207 on the valve body 213 in a direction away from the valve seat 209 (valve body 213). A packing 219 that is pressed against the valve seat 209 when the check valve 203 is closed is attached to the valve body 207. The check valve 203 and the relief valve 205 are assembled by screwing the plug 121 onto the case body 45 while pressing the coil spring 217 against the washer 123.

  The first set value is set by adjusting the urging force of the coil spring 211, the second set value is set by adjusting the urging force of the coil spring 217, and the first set value is a conventional check. The set value is the same as that of the valve, and the second set value is set to a value moderately larger than the first set value.

  For example, when LP gas is used on the consumption side, the pressure on the collecting pipe 11 side is kept below the first set value. During this time, the check valve 203 is opened by the coil spring 211 and the LP gas container is opened. When LP gas is supplied to the collecting pipe 11 from 3, 5, 7, 9 and the pressure exceeds the first set value, the pressure closes the check valve 203 against the biasing force of the coil spring 211, Prevents backflow of LP gas.

  Even if the pressure on the collecting pipe 11 side exceeds the first set value, the relief valve 205 is closed by the coil spring 217 while the pressure is not more than the second set value, and the backflow of LP gas is prevented. However, when the pressure on the collecting pipe 11 side exceeds the second set value, the pressure opens the relief valve 205 against the urging force of the coil spring 217, and the LP gas containers 3, 5 are discharged from the collecting pipe 11. A predetermined amount of backflow is allowed to 7, 9 and the collecting pipe 11 and the LP gas containers 3, 5, 7, 9 are equalized.

  Therefore, the temperature of the LP gas containers 3, 5, 7, 9 is higher than that of the collecting pipe 11 due to solar radiation (for example, the temperature difference is 3 ° or more), and the collecting pipe 11 is filled with LP gas. The LP gas containers 3, 5, 7, and 9 are replaced, and the check is caused by the differential pressure (for example, 0.01 MPa or more) generated between the collecting pipe 11 and the new LP gas containers 3, 5, 7, and 9. Even when the valve 203 is closed, this pressure difference (pressure exceeding the second set value) causes the relief valve 205 to be opened as described above, so that the collecting pipe 11 can be appropriately transferred to the LP gas containers 3, 5, 7, 9. Therefore, the collecting pipe 11 is prevented from being in a liquid-sealed state, and the internal pressure does not rise abnormally even when exposed to sunlight, so that the function of the automatic switching regulator 13 is damaged. There is no.

[Effect of Check Valve 201 with Built-in Liquid Seal Prevention Mechanism]
The check valve 201 with a built-in liquid seal prevention mechanism is provided with a relief valve 205 that operates when the pressure on the collecting pipe 11 side exceeds a predetermined value (second set value) and allows backflow. When the check valve 203 is closed by high-pressure LP gas when 3, 5, 7, and 9 are replaced, the relief valve 205 is opened when the pressure further increases and exceeds the second set value. Since a predetermined amount of backflow is allowed, the collecting tube 11 will not be in a liquid-sealed state.

  Therefore, the internal pressure of the collecting pipe 11 does not rise excessively, and the automatic switching adjuster 13 is released from damage due to high pressure, and the pressure adjusting function, the switching function, etc. are kept normal.

  Further, since the valve body 213 is made of a resin, the check valve 201 with a built-in liquid seal prevention mechanism is configured so as to be light and can be implemented at low cost.

  Further, by incorporating the check valve 203 and the relief valve 205 into the plug 121, the plug 121 is further reduced in size and weight and can be implemented at low cost.

DESCRIPTION OF SYMBOLS 1 Check valve with built-in liquid seal prevention mechanism 3, 5, 7, 9 LP gas container 11 Collecting pipe 13 Automatic switching regulator 15 LP gas supply system 17 Check valve 19 Relief valve 21 Valve body (Check valve body)
23 Plug (same material)
25 Valve seat 27 Coil spring (first biasing means)
29 Through-hole provided in the valve body 21 31 Valve body (relief valve body)
33 Valve seat (Relief valve seat)
35 Coil spring (second biasing means)
101 Check Valve 103 Built-in Liquid Seal Prevention Mechanism 103 Check Valve 105 Relief Valve 107 Valve Element (Check Valve Element)
109 Valve seat 111 Coil spring (first biasing means)
113 Valve body (Relief valve body)
115 Small diameter part (valve seat)
117 Large-diameter part (allowable part of backflow)
119 Coil spring (second biasing means)
121 plug (same material)
201 Check valve 203 with built-in liquid seal prevention mechanism Check valve 205 Relief valve 207 Valve element (valve element for check)
209 Valve seat 211 coil spring (first biasing means)
213 Disc (Relief disc)
215 Valve seat 217 Coil spring (second biasing means)

Claims (6)

LP gas having a plurality of LP gas containers for supplying LP gas, a collecting pipe for collecting the gas from the LP gas container, and an automatic switching regulator arranged on the collecting pipe for supplying LP gas to a consumer side A check valve with a built-in liquid seal prevention mechanism disposed between each LP gas container and the collecting pipe of the supply system,
A check valve that operates when the pressure on the collecting pipe side exceeds a first set value and prevents backflow to the LP gas container side;
A check valve with a built-in liquid seal prevention mechanism, comprising a relief valve that operates when a pressure on the collecting pipe side exceeds a second set value that is greater than a first set value and allows a predetermined amount of backflow. valve. A check valve with a built-in liquid seal prevention mechanism according to claim 1,
The check valve includes a check valve body, a valve seat of the check valve body, and first biasing means for biasing the check valve body in a direction of moving from the valve seat. When the pressure on the pipe side is equal to or lower than the first set value, the check valve body moves from the valve seat by the urging force of the first urging means, and the pressure on the collecting pipe side exceeds the first set value. The check valve body is pressed against the valve seat against the urging force of the first urging means to prevent backflow,
The relief valve includes a relief valve body movably disposed in a through-hole provided in the check valve body of a check valve, a relief valve seat provided in the check valve body, Second urging means for urging the relief valve body toward the relief valve seat, and when the pressure on the collecting pipe side is equal to or lower than the second set value, the relief valve body is the second urging means. When the pressure on the collecting pipe side exceeds the second set value, the relief valve body is relieved against the urging force of the second urging means. A check valve with a built-in liquid seal prevention mechanism that moves from the valve seat and allows a predetermined amount of backflow. A check valve with a built-in liquid seal prevention mechanism according to claim 1,
The check valve includes a check valve body, a valve seat of the check valve body, and first biasing means for biasing the check valve body in a direction of moving from the valve seat. When the pressure on the pipe side is equal to or lower than the first set value, the check valve body moves from the valve seat by the urging force of the first urging means, and the pressure on the collecting pipe side exceeds the first set value. The check valve body is pressed against the valve seat against the urging force of the first urging means to prevent backflow,
The relief valve includes a relief valve body provided with the valve seat of the check valve, a small diameter portion that is a valve seat of the relief valve body, a large diameter portion that is a reverse flow allowing portion, and a relief valve body In the range where the pressure on the collecting pipe side is equal to or lower than the second set value, the relief valve element has a small diameter due to the urging force of the second urging means. When the pressure on the collecting pipe side exceeds the second set value, the relief valve element moves to the large diameter portion against the urging force of the second urging means and is pressed by a predetermined amount. A check valve with a built-in liquid seal prevention mechanism, characterized by allowing backflow of water. A check valve with a built-in liquid seal prevention mechanism according to claim 1,
The check valve includes a check valve body, a valve seat of the check valve body, and first biasing means for biasing the check valve body in a direction of moving from the valve seat. When the pressure on the pipe side is equal to or lower than the first set value, the check valve body moves from the valve seat by the urging force of the first urging means, and the pressure on the collecting pipe side exceeds the first set value. The check valve body is pressed against the valve seat against the urging force of the first urging means to prevent backflow,
The relief valve includes a relief valve body provided with the valve seat of the check valve, a valve seat of the relief valve body, and second urging means for urging the relief valve body toward the valve seat side. In the range where the pressure on the collecting pipe side is less than or equal to the second set value, the relief valve body is pressed against the valve seat by the urging force of the second urging means to prevent backflow, and the pressure on the collecting pipe side When the second set value is exceeded, the relief valve body moves from the valve seat against the urging force of the second urging means and allows a predetermined amount of backflow, and has a built-in check mechanism with a liquid seal prevention mechanism. valve. A check valve with a built-in liquid seal prevention mechanism according to claim 4,
A check valve with a built-in liquid seal prevention mechanism, wherein the relief valve body is made of resin. A check valve with a built-in liquid seal prevention mechanism according to any one of claims 1 to 5,
A check valve with a built-in liquid seal prevention mechanism, wherein the check valve and the relief valve are assembled on the same member.

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