JP5635813B2 - Check valve with built-in liquid seal prevention mechanism - Google Patents

Description

  The present invention, for example, in an apartment house or the like, from a plurality of LP gas containers to the consumer side (for example, each household) LP gas (LPG: Liquefied Petroleum Gas: liquefied gas) via a collecting pipe and an 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. 8 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 through a collecting pipe and an automatic switching regulator in business use or in 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, will rise first, and there will be a temperature difference between the collecting pipe and the temperature. 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 when 0.02 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 the present invention 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 on the consumption side. A check valve with a built-in liquid seal prevention mechanism arranged between each LP gas container and a collecting pipe of an LP gas supply system having an automatic switching regulator for supplying the pressure to the collecting pipe side A check valve that operates when the pressure difference between the pressure on the LP gas container side and the pressure on the collecting pipe side exceeds the first set value to prevent backflow to the LP gas container side, A relief valve that operates when the difference exceeds a second set value that is greater than the first set value to allow backflow, the check valve having a through-hole, and the relief valve It has a relief valve element that is movably arranged in the through hole. There were moves in the direction positioned so as to seal one end of the through hole does not exceed the second set value, to open the one end of the through hole when the pressure difference exceeds the second set value, the through-hole Has a small-diameter portion and a large-diameter portion having an inner diameter larger than the small-diameter portion, and the relief valve includes a hollow cylindrical body fixed to the other end side of the through hole, a cylindrical body, and a relief valve body. The relief valve element is pressed against the small-diameter portion by the biasing means when the pressure difference does not exceed the second set value. When the pressure difference exceeds the second set value, it moves from the small diameter part to the large diameter part against the urging force of the urging means to open one end of the through hole and urge means is a metal coil spring, a small diameter portion is made of resin, the relief valve body, characterized in that it is made of metal To.

  According to this check valve with a built-in liquid seal prevention mechanism, the check valve has a through-hole, and the relief valve body has a pressure on the LP gas container side lower than the pressure on the collecting pipe side. If the pressure difference between the pressure and the pressure on the collecting pipe side does not exceed the second set value, it is positioned so as to seal one end of the through hole, and if the pressure difference exceeds the second set value, the through hole It moves in the direction which opens one end of. For this reason, when the pressure difference does not exceed the second set value, the through hole is closed. Therefore, when the pressure difference exceeds the first set value, backflow is prevented by the check valve. On the other hand, when the pressure difference exceeds the second set value, one end of the through hole is opened, so that backflow is allowed through the through hole. From these, while preventing the backflow, the backflow is allowed when the inside of the collecting tube is in a liquid-sealed state and becomes a higher pressure. Therefore, in the LP gas supply system that supplies LP gas to the consumption side from the plurality of LP gas containers via the collecting pipe and the automatic switching regulator, it is possible to prevent the collecting pipe from being in a liquid-sealed state.

Further , when the pressure difference exceeds the second set value, the relief valve body moves from the small diameter portion to the large diameter portion against the urging force of the urging means to open the through hole. For this reason, the LP gas in a liquid-sealed state enters from one end of the through hole and escapes to the other end of the through hole through the large diameter portion and the hollow portion of the cylindrical body. Thereby, it can prevent that a collecting pipe will be in a liquid-sealed state. In addition, since the small-diameter portion is made of resin and the relief valve body is made of metal, the airtightness when closing one end of the through-hole can be improved compared to the case where both are made of metal. In addition, when the coil spring is made of metal, the relief valve element is made of metal, so that the relief valve element can be prevented from being damaged.

In the check valve with a built-in liquid seal prevention mechanism according to the present invention, it is preferable that the relief valve body has a protrusion inserted into the coil of the coil spring.

According to this check valve with a built-in liquid seal prevention mechanism , the relief valve body has a protrusion that is inserted into the coil of the coil spring. For this reason, the relief valve body is fixed by the coil spring, and rotation or the like is prevented. Thereby, it can prevent that a relief valve body is damaged by rotation etc., and the airtightness at the time of plugging up the end of a through-hole falls.

  According to the check valve with a built-in liquid seal prevention mechanism of the present invention, it is possible to prevent the collecting pipe from being in a liquid sealed state.

It is a block diagram of the LP gas supply system containing the check valve with a built-in liquid seal prevention mechanism according to the present embodiment. It is an external view which shows the detail of the check valve 1 with a liquid seal prevention mechanism shown in FIG. It is AA sectional drawing of the check valve 1 with a built-in liquid seal prevention mechanism shown in FIG. It is AA sectional drawing of the check valve 1 with a built-in liquid seal prevention mechanism shown in FIG. 2, Comprising: It is sectional drawing which shows the state by which the check valve 17 was closed. It is AA sectional drawing of the check valve 1 with a liquid seal prevention mechanism shown in FIG. 2, Comprising: It is sectional drawing which shows the state in which the relief valve 19 was open | released. It is an enlarged view which shows the relief valve 19 of the check valve 1 with the liquid seal prevention mechanism which concerns on 2nd Embodiment. It is an enlarged view which shows the relief valve 19 of the check valve 1 with the liquid seal prevention mechanism which concerns on 3rd Embodiment. It is a block diagram which shows a related technique.

  Hereinafter, embodiments of the check valve with a built-in liquid seal prevention mechanism according to the present invention will be described. FIG. 1 is a configuration diagram of an LP gas supply system including a check valve with a built-in liquid seal prevention mechanism according to the present embodiment.

  As shown in FIG. 1, the LP gas supply system 15 includes a plurality of LP gas containers 3, 5, 7, 9, a collecting pipe 11, an automatic switching adjuster 13, a check valve 1 with a built-in liquid seal prevention mechanism, It has.

  The plurality of LP gas containers 3, 5, 7, and 9 are containers in which LP gas is stored, respectively, and supply LP gas to the consumer side (for example, each household). The collecting pipe 11 is a pipe for collecting LP gas from the LP gas containers 3, 5, 7, and 9.

  The automatic switching adjuster 13 is disposed on the collecting pipe 11, and the automatic switching adjuster 13 is connected to each household side through an outflow port. This automatic switching adjuster 13 is disposed at the central portion of the collecting pipe 11 and switches the left and right collecting pipes 11 (LP gas containers 3 and 5 and LP gas containers 7 and 9), and by a pressure adjusting function. Maintain the pressure of LP gas sent to home properly.

  The check valve 1 with a built-in liquid seal prevention mechanism is a valve disposed between each LP gas container 3, 5, 7, 9 and the collecting pipe 11, and more specifically, each LP gas container 3, 5, 7 , 9 and the high pressure hose 39 extending from the on-off valve 37 and the collecting pipe 11. When replacing the LP gas containers 3, 5, 7, 9, etc., the operator operates the check valve 1 with a built-in liquid seal prevention mechanism to prevent backflow, and in this state the LP gas containers 3, 5 , 7 and 9 will be replaced.

  In the example shown in FIG. 1, the LP gas supply system 15 includes four LP gas containers 3, 5, 7, and 9, but is not limited to four, and may be three or less, Five or more may be sufficient.

  FIG. 2 is an external view showing details of the check valve 1 with a built-in liquid seal prevention mechanism shown in FIG. As shown in FIG. 2, the check valve 1 with a built-in liquid seal prevention mechanism includes a plug 23 and a case main body 45. The plug 23 and the case body 45 are separate members, and the check valve 1 with a built-in liquid seal prevention mechanism is configured by combining these separate members.

  The case body 45 includes an on-off valve 51 and a lever 53. The operator or the like operates the lever 53 to close the on-off valve 51 and operate the check valve 1 with a built-in liquid seal prevention mechanism to prevent backflow. In this state, the LP gas containers 3 and 5 , 7 and 9 will be replaced.

  3 is a cross-sectional view taken along line AA of the check valve 1 with a built-in liquid seal prevention mechanism shown in FIG. As shown in FIG. 3, the check valve 1 with a built-in liquid seal prevention mechanism includes a check valve 17 and a relief valve 19. In the check valve 17, the pressure on the LP gas containers 3, 5, 7, 9 side becomes lower than the pressure on the collecting pipe 11 side, and the pressure on the LP gas containers 3, 5, 7, 9 side and the pressure on the collecting pipe 11 side When the pressure difference between and exceeds the first set value, it operates to prevent backflow to the LP gas containers 3, 5, 7, 9 side. The relief valve 19 operates when the pressure difference exceeds a second set value that is larger than the first set value, such as in a liquid-sealed state, and allows backflow.

  Hereinafter, the check valve 17 and the relief valve 19 will be described in detail. The check valve 17 includes a valve body 21, a coil spring 27, and a packing 43. The valve body 21 is a main body portion of the check valve 17 and has a substantially conical shape. The conical tip side of the valve body 21 has a shape that matches a valve seat 25 formed on the plug 23. The coil spring 27 is an urging member disposed between a notch 25 a formed in the valve seat 25 and the valve body 21. The packing 43 is an elastic member such as rubber provided on the distal end side of the valve body 21.

  Since the configuration is as described above, when the pressure difference is equal to or smaller than the first set value, the valve body 21 and the valve seat 25 are separated by the urging force of the coil spring 27 as shown in FIG. For this reason, the gas from the LP gas containers 3, 5, 7, 9 side is supplied to the collecting pipe 11.

  FIG. 4 is a cross-sectional view taken along the line AA of the check valve 1 with a built-in liquid seal prevention mechanism shown in FIG. 2 and shows a state where the check valve 17 is closed. On the other hand, when the pressure difference exceeds the first set value, the valve element 21 moves toward the valve seat 25 against the urging force of the coil spring 27 and closes the flow path. Thereby, the backflow from the collecting pipe 11 side is prevented.

  A through hole 29 is formed in the valve body 21 of the check valve 17, and the relief valve 19 includes a valve body (relief valve body) 31. The valve body 31 is a sphere that is movably disposed in the through hole 29. The valve body 31 is positioned so as to seal one end of the through hole 29 when the pressure difference does not exceed the second set value, and the through hole 29 when the pressure difference exceeds the second set value. It moves in the direction which opens one end of.

  More specifically, the through-hole 29 has a small-diameter portion 29a and a large-diameter portion 29b having an inner diameter larger than that of the small-diameter portion 29a. The relief valve 19 includes a cylindrical body 35, a coil spring (biasing means). 41. The cylindrical body 35 is a hollow member fixed to the other end of the through hole 29. The coil spring 41 is an urging member interposed between the cylindrical body 35 and the valve body 31.

  Due to such a configuration, the valve body 31 is positioned so as to be pressed against the small diameter portion 29a by the coil spring 41 and seal one end of the through hole 29 when the pressure difference does not exceed the second set value. To do.

  FIG. 5 is a cross-sectional view of the check valve 1 with a built-in liquid seal prevention mechanism shown in FIG. 2 taken along line AA, showing a state in which the relief valve 19 is opened. On the other hand, the valve body 31 moves from the small diameter portion 29a to the large diameter portion 29b against the urging force of the coil spring 41 when the pressure difference exceeds the second set value, thereby opening one end of the through hole 29. . As a result, the liquid-sealed LP gas enters from one end of the through-hole 29 and escapes to the other end of the through-hole 29 through the large-diameter portion 29 b and the hollow portion of the cylindrical body 35. Thereby, it can prevent that the collecting pipe 11 will be in a liquid-sealed state.

  In the above, the first set value is set by adjusting the biasing force of the coil spring 27, and the second set value is set by adjusting the biasing force of the coil spring 41. The first set value is the same as the conventional check valve (for example, about 0.01 to 0.02 MPa), and the second set value is a value that is reasonably larger than the first set value ( For example, it is set to about 1.5 to 1.6 MPa.

  Next, the operation of the check valve 1 with a built-in liquid seal prevention mechanism according to this embodiment will be described. First, when the pressure difference is equal to or less than the first set value, such as when LP gas is used on the consumption side, the check valve 17 is opened by the coil spring 27 and the LP gas containers 3, 5, 7, LP gas is supplied from 9 to the collecting pipe 11 (see FIG. 3).

  If the pressure difference exceeds the first set value, the check valve 17 is closed against the biasing force of the coil spring 27, and the collecting pipe 11 is connected to the LP gas containers 3, 5, 7, and 9. Backflow is prevented (see FIG. 4).

  Further, if the pressure difference exceeds the second set value, the relief valve 19 is opened against the biasing force of the coil spring 41, and the backflow from the collecting pipe 11 to the LP gas containers 3, 5, 7, 9 is performed. (See FIG. 5). For this reason, it is avoided that the inside of the collecting pipe 11 is in a liquid-sealed state, and even if the collecting pipe 11 is exposed to sunlight, the internal pressure does not rise abnormally, and the function of the automatic switching adjuster 13 is damaged. There is no.

  Thus, according to the check valve 1 with a built-in liquid seal prevention mechanism according to the present embodiment, the check valve 17 is formed with the through hole 29, and the valve element 31 is formed of the LP gas containers 3, 5, 7, 9. When the pressure on the side becomes lower than the pressure on the collecting pipe 11 side, and the pressure difference between the pressure on the LP gas container 3, 5, 7, 9 side and the pressure on the collecting pipe 11 side does not exceed the second set value, it penetrates It is located so as to seal one end of the hole 29, and moves in a direction to open one end of the through hole 29 when the pressure difference exceeds the second set value. For this reason, when the pressure difference does not exceed the second set value, the through hole 29 is closed. Therefore, when the pressure difference exceeds the first set value, the check valve 17 prevents back flow. On the other hand, when the pressure difference exceeds the second set value, one end of the through hole 29 is opened, and thus backflow is allowed through the through hole 29. From these, while preventing the backflow, the backflow is allowed when the inside of the collecting pipe 11 is in a liquid-sealed state and becomes a higher pressure. Therefore, in the LP gas supply system 15 that supplies LP gas from the plurality of LP gas containers 3, 5, 7, 9 through the collecting pipe 11 and the automatic switching regulator 13, the collecting pipe 11 is liquid-sealed. It is possible to prevent the situation from occurring.

  Further, the valve body 31 moves from the small diameter portion 29a to the large diameter portion 29b against the biasing force of the coil spring 41 when the pressure difference exceeds the second set value, thereby opening the through hole 29. For this reason, the LP gas in a liquid-sealed state enters from one end of the through hole 29 and escapes to the other end of the through hole 29 through the large diameter portion 29 b and the hollow portion of the cylindrical body 35. Thereby, it can prevent that the collecting pipe 11 will be in a liquid-sealed state.

  Next, a second embodiment of the present invention will be described. A check valve 1 with a built-in liquid seal prevention mechanism according to the second embodiment is the same as that of the first embodiment, but a part of the configuration is different.

  FIG. 6 is an enlarged view showing the relief valve 19 of the check valve 1 with a built-in liquid seal prevention mechanism according to the second embodiment. As shown in FIG. 6, in the relief valve 19 according to the second embodiment, the valve body 31 has a shape in which a protrusion 31a is connected to a sphere. The protrusion 31 a extends to the other end side of the through hole 29 and is inserted into the coil spring 41.

  For this reason, it will be in a fixed state by the valve body 31 coil spring 41, and rotation etc. will be prevented. Here, when the valve body 31 is a spherical body, if the valve body 31 is made of resin and the coil spring 41 is made of metal, the valve body 31 is damaged, and the airtightness is lowered due to the damage. However, according to the structure which concerns on 2nd Embodiment, the fall of airtightness can be prevented.

  Thus, according to the check valve 1 with a built-in liquid seal prevention mechanism according to the second embodiment, it is possible to prevent the collecting pipe 11 from being in a liquid sealed state.

  Furthermore, according to the second embodiment, the valve body 31 has the protrusion 31 a that is inserted into the coil of the coil spring 41. For this reason, the valve body 31 is fixed by the coil spring 41, and rotation or the like is prevented. Thereby, it can prevent that the valve body 31 is damaged by rotation etc. and the airtightness at the time of plugging up the end of the through-hole 29 falls.

  Next, a third embodiment of the present invention will be described. The check valve 1 with a built-in liquid seal prevention mechanism according to the third embodiment is the same as that of the first embodiment, but is partially different in configuration.

  FIG. 7 is an enlarged view showing the relief valve 19 of the check valve 1 with a built-in liquid seal prevention mechanism according to the third embodiment. As shown in FIG. 7, the relief valve 19 according to the second embodiment is provided with a resin pedestal 29c at a location corresponding to the small diameter portion 29a of the first embodiment. The pedestal 29c is a hollow cylinder, and has an inner diameter smaller than that of the large-diameter portion 29b.

  In the third embodiment, the valve body 31 is made of metal. For this reason, confidentiality can be improved by the metal valve body 31 and the resin pedestal 29c. Since the coil spring 41 is made of metal, it is preferable that the valve body 31 is made of metal instead of resin because the valve body 31 is not damaged. However, not limited to this, the valve body 31 may be made of resin and the pedestal 29c may be made of metal.

  Thus, according to the check valve 1 with a built-in liquid seal prevention mechanism according to the third embodiment, it is possible to prevent the collecting pipe 11 from being in a liquid sealed state.

  Furthermore, according to the third embodiment, one of the small-diameter portion 29a and the valve body 31 is made of resin, and the other is made of metal, so that one end of the through hole 29 is made as compared with the case where both are made of metal. The airtightness when closing can be improved.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the said embodiment, You may add a change in the range which does not deviate from the meaning of this invention, and combines each embodiment. Also good.

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 switch regulator 15 LP gas supply system 17 Check valve 19 Relief valve 21 Valve body 23 Plug 25 Valve seat 27 Coil spring 29 Through-hole 29a Small diameter part 29b Large diameter part 29c Base 31 Valve body (relief valve body)
31a Protrusion 35 Tubular 41 Coil spring (biasing means)

Claims (2)

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,
When the pressure on the LP gas container side becomes lower than the pressure on the collecting pipe side and the pressure difference between the pressure on the LP gas container side and the pressure on the collecting pipe side exceeds a first set value, the LP gas container side operates. A check valve that prevents backflow to the gas container,
A relief valve that operates when the pressure difference exceeds a second set value that is greater than the first set value to allow backflow;
The check valve is formed with a through hole,
The relief valve has a relief valve body that is movably disposed in the through hole of the check valve;
The relief valve body is positioned so as to seal one end of the through hole when the pressure difference does not exceed the second set value, and when the pressure difference exceeds the second set value. Move in a direction to open one end of the through hole ,
The through hole has a small diameter portion and a large diameter portion having an inner diameter larger than the small diameter portion,
The relief valve further comprises a hollow cylindrical body fixed to the other end side of the through hole, and an urging means interposed between the cylindrical body and the relief valve body,
The relief valve element is positioned so as to seal one end of the through hole by being pressed against the small diameter portion by the biasing means when the pressure difference does not exceed the second set value. When the difference exceeds the second set value, the small diameter portion moves from the large diameter portion against the urging force of the urging means to open one end of the through hole,
The biasing means is a metal coil spring,
The small diameter portion is made of resin, and the relief valve element is made of metal . 2. The check valve with a built-in liquid seal prevention mechanism according to claim 1, wherein the relief valve body has a protrusion inserted into a coil of the coil spring .

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