JPH08170739A - Cutoff valve - Google Patents

Abstract

PURPOSE: To provide a cutoff valve which can perfectly cutoff a pipeline and causes no reaction to the pipeline. CONSTITUTION: In such an emergency that fluid flow in a pipe passage is suspended, an air pump is driven, and an opening/closing valve 12 is released. Pressurized gas is introduced from an air pipe 11 into a gas bag 5 through a fixation fitting 9, an installation fitting 8, a piping 7, an elbow 6, and a cap 5a. Proper pressure is kept in the gas bag 5 while confirming by means of a pressure meter. The gas bag 5 is speedily expanded, while its outer peripheral surface is in contact with an inner peripheral surface of a valve box 2 as indicated by a dotted line. Afterward, it is in press contact therewith, so that fluid flow is interrupted without fail. The valve box 2 is formed in a linear tubular form, usually, so that a small amount of fluid passes thereinside. The gas bag 5 is fixed at its two portions, causing little drifting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutoff valve installed in a polyethylene gas conduit or water pipe.

[0002]

2. Description of the Related Art Generally, a shutoff valve for urgently shutting off the flow of fluid in a pipe is installed in a proper place in a gas pipe, a water pipe or the like when a leakage accident occurs.

When the gas conduit or the water pipe is a polyethylene pipe (PE pipe), a general metal valve may be installed as a shutoff valve. In this case, the reaction force of the operating torque when the valve is opened and closed. Acts on the connection pipe, so that 1 m before and after the valve is a steel pipe, and this steel pipe is connected to the PE pipe so as to withstand this reaction force.

Further, Japanese Utility Model Publication No. 6-18772 discloses that
Install a gas bag in the branch pipe of the three-way joint, and store it in the branch pipe in a bent state with the bottom part pulled up with a string-like object in normal times, loosen the string-like object and introduce pressure fluid into the bag in an emergency There is disclosed a shutoff valve in which a gas bag is arranged in a joint body to shut off a pipeline.

[0005]

However, as described above, when a general valve made of metal is used as a shutoff valve, steel pipes must be provided before and after the valve so as to withstand the reaction force of the operating torque when the valve is opened and closed. There is a problem that it must be.

On the other hand, in the case of a shutoff valve equipped with a gas bag, not only is it difficult to completely shut off the pipeline,
There is a problem that the gas bag housed in the branch pipe tends to fluctuate due to the flow of fluid, and the housing is likely to be incomplete because the gas bag is pulled up while bending in the flow.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a shutoff valve which can completely shut off a pipeline and which does not exert a reaction force on the pipeline.

[0008]

In order to solve the above problems, a shut-off valve of the present invention comprises a straight tubular valve box integrally molded of a plastic material and an elastic material mounted in the valve box. A gas bag, and a pair of support members that are disposed in the valve box at an appropriate distance in the axial direction and that support and fix the gas bag at one side portion and the other side portion forming an opening, The gas bag is configured so that a support member that supports and fixes the opening communicates with an air supply unit outside the valve box.

[0009]

With the above structure, in an emergency, gas is introduced into the gas bag by the air supply means to inflate the gas bag,
By pressing the outer peripheral surface of the inflated gas bag against the inner peripheral surface of the straight tubular body, the flow of the fluid in the conduit can be reliably blocked. At this time, the operation torque unlike the conventional case is not generated. Further, since the operation torque is not generated as described above, it is possible to easily connect to an adjacent PE pipe or the like without using a steel pipe that withstands a reaction force of the operation torque.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a shutoff valve according to an embodiment of the present invention, FIG. 2 is a plan view of the shutoff valve, and FIG. 3 is a front view of a main part of the shutoff valve. 1 to 3, a shut-off valve 1 has a straight tubular valve box 2 integrally molded of a plastic material such as polyethylene (PE), and a stiffener inside the valve box 2 with an appropriate distance in the axial direction. 3 and a fixing member 4 are arranged and supported and fixed to the stiffener 3 and the fixing member 4, and a gas bag 5 made of an elastic material such as rubber is provided.

The straight tubular valve box 2 has a uniform inner diameter and is formed so that both ends 2a and 2b have the same dimensions as the adjacent pipes, and the center is larger than the ends 2a and 2b. The part 2c is formed with a somewhat thick tube wall.

In the stiffener 3, a short inner cylinder 3b is arranged inside an outer cylinder 3a which is slidably contacted with the inner peripheral surface of the valve box 2, and a radial plate is equally spaced between the outer cylinder 3a and the inner cylinder 3b. Member 3
c is arranged, the inner cylinder 3b is located at the center of the valve box 2 in the radial direction and closer to the fixing member 4, and is configured to support and fix the gas bag 5.

The fixing member 4 includes an elbow 6, a pipe 7 extending in the radial direction from the elbow 6, a mounting metal fitting 8 for mounting the piping 7 on the valve housing 2, and a mounting metal fitting 8 arranged outside the valve housing to fix the mounting metal fitting 8. And the inner tube 3b of the stiffener 3 at the center of the valve box 2 in the radial direction.
Are arranged so as to face each other, and are configured to support and fix the gas bag 5 at one end thereof. The elbow 6, the pipe 7, the mounting metal fitting 8, and the fixing metal fitting 9 have gas introducing holes communicating with each other.

The gas bag 5 is provided with a base 5a on one side forming an opening and a support fitting 5b on the other side. It is folded with a fold 5c toward the bottom. The gas bag 5 is arranged in the axial direction of the valve box 2 with the mouthpiece 5a attached to one end of the elbow 6 and the support fitting 5b supported by the inner cylinder 3b of the stiffener 3. 10 is a rubber O for preventing gas leakage.
It is a ring.

An air supply pipe 11 connected to an air pump (not shown) for pressure-feeding a gas such as air or nitrogen gas is connected to the fixing metal fitting 9, and the fixing metal fitting 9 is provided inside the valve box. The gas bag 5 and the air supply pipe 11 outside the valve box are in communication with each other. An on-off valve 12 and a pressure gauge (not shown) are provided in the air supply pipe 11.

The stiffener 3, the base 5a, the support fitting 5b, the elbow 6, the pipe 7, the mounting fitting 8, the fixing fitting 9,
The on-off valve 12 is made of SUS304 or the like, and the air supply pipe 11 is made of SUS304 from the fixing fitting 9 to the on-off valve 12.
It is made of vinyl, and so on.

The operation of the above structure will be described below.
In an emergency in which the flow of fluid in the pipeline is interrupted, the air pump is driven and the on-off valve 12 is opened, and the fixing pipe 9, the mounting pipe 8, the pipe 7, and the elbow 6 from the air supply pipe 11 are opened.
A pressurized gas is introduced into the inside of the gas bag 5 through the gas introduction hole inside. Then, the gas pressure in the gas bag 5 is maintained at an appropriate pressure while checking with a pressure gauge. As a result, the gas bag 5 quickly inflates, its outer peripheral surface comes into contact with the inner peripheral surface of the valve box 2 as shown by the dotted line, and then comes into pressure contact, so that the flow of the fluid is surely blocked.

As described above, since the flow is shut off by inflating the gas bag 5, no torsion torque is generated in the shut-off valve 1, and a valve fixing pedestal or the like is not required as a countermeasure. Further, since the valve box 2 is formed in a straight tube shape, the turbulence of the fluid passing through the inside is small, and the gas bag 5 is positioned at two places, so the fluctuation is small. Therefore, the gas bag 5 is properly arranged even in an emergency.

The shut-off valve 1 as described above can be manufactured at a very low cost because of its simple shape, and the two end portions 2
Since a and 2b have the same size and the same material as the adjacent PE pipes, the method of connecting the PE pipes can be applied as it is, and the installation work cost can be reduced.

[0020]

As described above, according to the shutoff valve of the present invention, the straight tubular valve box is formed of the plastic material, and the pair of support members are arranged inside the valve box at an appropriate distance in the axial direction. A gas bag made of an elastic material is provided so as to be supported and fixed to the support member.

Thus, the pressurized gas is introduced into the gas bag to inflate the gas bag, and the outer peripheral surface of the gas bag is brought into pressure contact with the inner peripheral surface of the valve box, whereby the flow of the fluid can be surely shut off. In this shut-off method, no operating torque is generated, and the conventional valve fixing pedestal or the like is unnecessary. Further, since the gas bag is positioned at two places, the fluctuation due to the fluid is small, and the gas bag is properly arranged even in an emergency.

Since such a shut-off valve has a simple shape, it can be manufactured at a very low cost.
If it is formed in the same size as the pipe, the method of connecting the PE pipes can be applied as it is, so the installation work cost will be low.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a shutoff valve according to an embodiment of the present invention.

FIG. 2 is a plan view of the shutoff valve.

FIG. 3 is a front view of a main part of the shutoff valve.

[Explanation of symbols]

 1 shutoff valve 2 valve box 3 stiffener 4 fixing member 5 gas bag 11 air supply pipe

Claims (1)

[Claims] 1. A straight tubular valve box integrally molded of a plastic material, a gas bag made of an elastic material mounted in the valve box, and arranged in the valve box at an appropriate distance in the axial direction. And a pair of supporting members for supporting and fixing the gas bag at one side portion and an other side portion having an opening formed therein, and the gas bag has a support member for supporting and fixing the opening portion. A shut-off valve characterized by being configured to communicate with the means.