JP2008189338A - Exhaust valve structure - Google Patents

Abstract

The exhaust valve structure can be installed at an arbitrary position in the vertical portion of the vent pipe, and the exhaust of the valve mechanism can always be maintained normally without being restricted by the space capacity for the installation. Providing a valve structure.
An exhaust valve structure C for attaching an exhaust valve to a vent pipe A that communicates between a tank for storing a volatile liquid and outside air. The exhaust valve structure C includes an exhaust valve body portion C1 having an exhaust port 2 for discharging gas in the tank to the outside and an exhaust valve body 3 for opening and closing the exhaust port 2, and the exhaust valve body portion C1. Mounting means C2 and C2 for vertically mounting on the straight line of the vertical portion of the vent pipe A.
[Selection] Figure 1

Description

  The present invention relates to an exhaust valve structure for attaching an exhaust valve to a vent pipe drawn out from an underground tank for storing petroleum.

  A vent pipe communicating with the outside air was drawn out from an underground storage tank of a gas station that handles petroleum, and a fire mesh of about 40 mesh was attached to the vent at the tip.

  This fire net prevented flames from entering the tank through the vents even if an external fire occurred, but oil vapor continues to be released from the vents to the outside air via the fire net. Was in a situation.

  In recent years, due to the increasing awareness of environmental issues, the oil vapor pressure in the tank has become more than a certain permissible pressure due to the increasing awareness of environmental issues. An exhaust valve that only discharges to the outside air is now attached to the vent at the tip of the vent pipe.

  The applicant of the present application previously described in Patent Document 1 below, as shown in FIG. 4, in the exhaust valve provided at the vent at the tip of the vertical vent pipe A, on the lower side of the exhaust valve main body 3 that closes the exhaust port 2 from above, A structure in which the weight 5 is attached so as to be positioned below the exhaust port 2 is disclosed. In this exhaust valve, the center of gravity of the exhaust valve main body 3 is lowered, and the center of gravity can be set lower than the exhaust outlet 2, so that the exhaust valve main body 3 can move up and down smoothly. The chattering phenomenon due to the exhaust valve is eliminated, no noise is generated in the vicinity, and the life of the valve is extended.

  However, in the case of a vent pipe having a vent hole in the vertical direction, petroleum vapor from the tank discharged from the vent hole is scattered in the vicinity of the vent hole, which has become a new environmental problem. Therefore, in recent years, as shown in FIG. 5, a vent pipe having the vent B oriented in a specific horizontal direction has been installed so that petroleum vapor does not scatter.

  However, an exhaust valve cannot be installed in a vent pipe whose vent is oriented in a specific horizontal direction because of problems in the valve structure, and it must be installed in the vertical part of the vent pipe. I don't get it. For example, in Patent Document 2 below, a vertical part is provided in a bypass manner in the middle of a vent pipe leading to a vent, a dedicated space for installing a valve structure is provided therein, and an intake port communicating with the atmosphere is provided in this dedicated space. And a valve structure having an exhaust port opened to the atmosphere is described.

However, in the case where the vertical bypass is provided by bending the vent pipe as described above and arranged in a dedicated space for installing the valve structure, the valve structure portion is subject to pressure loss due to bending of the gas flow in the vent pipe. As a result, the valve mechanism may not operate properly, and the dedicated space provided in the bypass protrudes from the vent pipe, which may cause contact with people and vehicles depending on the installation position. Depending on the situation, there is also a problem that the installation space cannot be secured.
Japanese Patent Application No. 2005-224484 JP 2001-163400 A

  The problem to be solved by the present invention is to install an exhaust valve in the vent pipe even when the oil vapor discharged from the underground tank through the vent pipe is effectively discharged in a specific horizontal direction without being scattered. An object of the present invention is to provide an exhaust valve structure.

  Specifically, according to the present invention, the exhaust valve structure can be installed at an arbitrary position in the vertical portion of the vent pipe, and the operation of the valve mechanism can be performed without being restricted by the space capacity for the installation. Provide an exhaust valve structure that can always be maintained normally.

  The exhaust valve structure of the present invention is an exhaust valve structure for attaching an exhaust valve to a vent pipe that communicates between a tank storing volatile liquid and outside air, and is for exhausting gas in the tank to the outside air side. An exhaust valve main body portion having an exhaust port and an exhaust valve main body for opening and closing the exhaust port, and an attachment means for vertically mounting the exhaust valve main body portion on a straight line of a vertical portion of the vent pipe To do.

  That is, since the exhaust valve structure of the present invention has the above-mentioned attachment means, it can be installed at an arbitrary position in the vertical portion of the vent pipe, and the exhaust valve main body portion is mounted vertically on a straight line of the vertical portion of the vent pipe. Therefore, pressure loss does not occur in the vent pipe, and the operation of the valve mechanism can be maintained normally.

  Specifically, the attaching means can be flanges or pipe joints provided above and below the exhaust valve main body.

  The exhaust valve structure of the present invention has the following effects.

1. It can be installed at any position in the vertical part of the vent pipe. Therefore, even when oil vapor discharged from the underground tank through the vent pipe is effectively discharged in a specific horizontal direction without being scattered, an exhaust valve can be installed in the vent pipe. Furthermore, the existing vents can be used as they are and are economical, and the types of vents in which exhaust valves can be installed are not limited.

2. Since it can be installed at an arbitrary position in the vertical portion of the vent pipe, it can be installed at a lower position of the vent pipe, so that work at a high place in maintenance and inspection of the exhaust valve is not required, and work safety is improved.

3. Since the exhaust valve is installed on the straight line of the vertical portion of the vent pipe, pressure loss does not occur in the vent pipe, and the operation of the valve mechanism can be maintained normally. Moreover, since the exhaust valve is installed in the pipe line of the ventilation pipe, a dedicated space for installation is not required, and the installation space is not limited.

4). Since it is installed in the ventilation pipe by a flange or a pipe joint, its installation and replacement can be easily performed, and the maintainability is improved.

  Embodiments of the present invention will be described below based on examples shown in the drawings.

  FIG. 1 is a sectional view showing a vent pipe to which an exhaust valve structure of the present invention is applied.

  The proximal end of the vent pipe A communicates with a gas phase portion of an underground tank (not shown), and a vent fitting B is installed at the distal end as a vent that communicates with outside air. And the exhaust valve structure C of this invention is installed in the middle of the vertical part of the vent pipe A. As shown in FIG. The exhaust valve structure C has flanges C2 above and below the exhaust valve main body C1, and is connected to and installed in the vent pipe A via the flanges C2. Thus, the exhaust valve main body portion C1 is vertically attached on a straight line along the vertical portion of the pipe line of the vent pipe A.

  FIG. 2 shows the structure of the exhaust valve structure of the present invention in cross section.

  The exhaust valve structure C is configured by fitting an upper body fitting 1a and a lower body fitting 1b, and flanges C2 are formed at the upper end of the upper body fitting 1a and the lower end of the lower body fitting 1b, respectively.

  A circular exhaust port 2 is formed at the upper end of the upper body fitting 1a, and an exhaust valve body 3 for closing the exhaust port 2 from above is disposed. In other words, the exhaust valve body 3 normally closes the exhaust port 2 from above, and when the pressure in the tank rises, the pressure rises due to the pressure and opens the exhaust port 2. An O-ring 4 is provided between the exhaust valve body 3 and the exhaust port 2 in order to ensure that the exhaust port 2 is closed by the exhaust valve body 3.

  Further, a weight 5 is integrally provided below the exhaust valve body 3. The weight 5 is extended so as to be positioned below the exhaust port 2. As a result, the center of gravity of the exhaust valve main body 3 is lower than the exhaust port 2, and the balance of the exhaust valve main body 3 is improved so that the exhaust valve main body 3 can move up and down smoothly. Further, by adjusting the weight of the weight 5, the exhaust set pressure (pressure when the exhaust valve main body 3 just rises) can be adjusted.

  The weight 5 also functions as the guide portion 6. The guide portions 6 are provided at four locations at equal intervals along the outer periphery of the exhaust valve body 3, and each guide portion 6 is provided so as to be inscribed in the inner peripheral edge of the exhaust port 2. As a result, when the exhaust valve main body 3 moves up and down, it is guided by the guide portion 5, so that the vertical movement of the exhaust valve main body 3 becomes smoother. In addition, in the Example, although the guide part 6 was provided in four places, what is necessary is just to provide in at least three places or more. However, it is preferable to provide each guide part at equal intervals in which the weight is balanced.

  The exhaust valve structure C of this embodiment includes an intake valve mechanism in addition to the above-described exhaust valve mechanism. In this intake valve mechanism, when the intake valve body 7 is normally closed, the intake port 8 provided in the exhaust valve body 3 is closed from the lower side, and when the pressure in the tank is lowered, the intake valve mechanism is lowered by the pressure difference from the external pressure. The mouth 8 is configured to be opened. The intake valve body 7 is normally urged upward by a coil spring 9 so as to close the intake port 8. Adjustment of the intake set pressure (pressure when the intake valve body 7 is just lowered) is adjusted by a coil spring. This is done by adjusting the strength of 9.

  In the present embodiment, an inspection port 10 with a lid is provided on the side surface of the upper body fitting 1a so that the exhaust valve body C1 can be easily inspected.

  In the above configuration, during normal times when the pressure in the tank is substantially equal to the outside air pressure, the exhaust valve body 3 and the intake valve body 7 close the exhaust port 2 and the intake port 8, respectively, and the tank is shut off from the outside air, The gas in the tank is not released to the outside air. When the pressure in the tank rises above the set exhaust pressure, the exhaust valve body 3 rises due to the pressure and opens the exhaust port 2, and the gas in the tank is discharged from the exhaust port 2 to the outside air side from the vent fitting B. Released. When the pressure in the tank becomes lower than the exhaust set pressure due to this gas release, the exhaust valve body 3 descends due to its own weight and closes the exhaust port 2 again. As described above, the vertical movement of the exhaust valve main body 3 is very stable and smooth by providing the weight 5 and the guide portion 6 on the lower side of the exhaust valve main body 3, so that a chattering phenomenon occurs. There is no.

  On the other hand, when the pressure in the tank drops below the intake set pressure, the intake valve body 7 is lowered by the pressure difference from the external pressure to open the intake port 8, and the outside air passes through the vent fitting B and the intake port 8. It flows into the tank. When the pressure in the tank exceeds the intake set pressure due to the outside air inflow, the intake valve body 7 is raised by the urging force of the coil spring 9 and closes the intake port 2 again.

  Thus, even if the pressure in the tank fluctuates, the pressure in the tank returns to a state substantially equal to the external air pressure by the operation of the exhaust valve body 3 and the intake valve body 7.

  FIG. 3 shows another embodiment of the exhaust valve structure of the present invention. In this embodiment, the upper body fitting 1a and the lower body fitting 1a are used as pipe joints, and the exhaust valve body portion C1 is vertically attached on a straight line along the vertical portion of the pipe line of the ventilation pipe A. This embodiment also has the same effect as the previous embodiment. In this embodiment, the upper body fitting 1a is bent at a right angle, and an inspection port 10 with a lid is provided on the upper surface thereof.

The vent pipe to which the exhaust valve structure of the present invention is applied is shown by a cross section. The structure of the exhaust valve structure of this invention is shown with a cross section. Another embodiment of the exhaust valve structure of the present invention is shown. The structure of the conventional exhaust valve is shown by a cross section. An example of a vent is shown.

Explanation of symbols

A Vent B B Vent (vent fitting)
C Exhaust valve structure C1 Exhaust valve body part C2 Flange 1a Upper body bracket 1b Lower body bracket 2 Exhaust port 3 Exhaust valve body 4 O-ring 5 Weight 6 Guide part 7 Intake valve body 8 Inlet 9 Coil spring 10 Inspection port

Claims (4)

An exhaust valve structure for attaching an exhaust valve to a vent pipe that communicates between a tank that stores volatile liquid and outside air,
An exhaust valve main body portion having an exhaust port for discharging the gas in the tank to the outside and an exhaust valve main body for opening and closing the exhaust port, and the exhaust valve main body portion vertically on a straight line of a vertical portion of the vent pipe An exhaust valve structure having attachment means for attachment.   The exhaust valve structure according to claim 1, wherein the attachment means is a flange provided above and below the exhaust valve main body.   The exhaust valve structure according to claim 1, wherein the attachment means is a pipe joint provided above and below the exhaust valve main body. In the exhaust valve body part, the exhaust valve body is arranged so that the exhaust port is closed from above, and when the pressure in the tank rises, the pressure rises due to the pressure and the exhaust port is opened.
The exhaust valve structure according to any one of claims 1 to 3, wherein a weight is attached to the lower side of the exhaust valve main body so as to be positioned below the exhaust port.

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