JPS5819911B2 - gas cutoff valve - Google Patents

Description

[Detailed description of the invention] TECHNICAL FIELD The present invention relates to gas shutoff valves.

For example, such a valve can be installed in a sprinkler piping system, especially in a riser pipe, to prevent so-called dripping (a phenomenon in which liquid drips only in the vicinity of the sprinkler as the injection pressure decreases) and to prevent the liquid from dripping in the vicinity of the sprinkler. Effective for dispersing and finishing most of the liquid.

In other words, when spraying liquid pesticides nears the end, instead of pumping the pesticides, air is sent to disperse most of the pesticides, and when the air reaches the vent valve in the pipe, it is shut off and reaches the sprinkler. I won't force you.

In other words, since air is not blown out from the sprinkler unnecessarily, the capacity and cost of the air blowing equipment can be significantly reduced.

As such a valve, for example, a gas cutoff valve as disclosed in Japanese Patent Publication No. 52-869 is known.

However, this gas cutoff valve has a structure in which the valve is opened and closed by the gravity of the float, which is greater than the pressure of the gas, so the device is large and heavy, making it difficult to handle.

The inventors have already applied for patent application No. 53-31572 (Patent Publication No. 53-31572).
No. 7-55952), a light and easy-to-handle gas cutoff valve that closes by itself with gas pressure is provided with a liquid outlet at the bottom of a float chamber provided in a part of the fluid pipeline. When the liquid flows, the buoyancy of the float and/or the pressure fluid resistance opens the liquid outlet and allows it to flow, while the gas arrives and the float descends.
We applied for a gas shutoff valve that uses gas pressure to close the liquid outlet on its own to cut off gas flow, but after further intensive research, we discovered that the fluid inlet of the float chamber had a convex shape inside the float chamber. By having a water pressure receiver provided at the tip of the protruding fluid inflow pipe and recessed inside the float so as to communicate with the fluid inflow pipe, the operating range is wider than the gas cutoff valve, and the operation range is wider than the gas cutoff valve. We succeeded in developing a gas cutoff valve with good stability.

That is, the present invention provides an automatic release valve that opens at a certain pressure or more, a fluid inlet, a fluid outlet, and a valve for the automatic release valve, inside a container that has a liquid outlet at the top and a liquid introduction at the bottom. It has a float chamber having a seat, and when the liquid is flowing in the float chamber, it floats due to buoyancy and/or pressure fluid resistance to open the fluid outlet and allow the liquid to flow,
In a gas cutoff valve having a weighted float that descends under conditions in which the liquid in the float chamber is replaced with gas and closes the fluid outlet by the pressure of the gas, the fluid inlet of the float chamber has a convex shape inside the float chamber. This gas cutoff valve is provided at the tip of a fluid inflow pipe protruding from the float, and has a water pressure receiver recessed inside the float so as to communicate with the fluid inflow pipe.

The present invention will be explained below with reference to the drawings.

Note that the present invention is not limited to the example shown in FIG.

In FIG. 1, reference numeral 1 denotes a sprinkler riser pipe, the upper end of which is connected to a sprinkler (not shown).

). Reference numeral 2 denotes a main body container of the apparatus of the present invention, which has a liquid outlet part 1a at the upper part and a liquid introduction part 1b at the lower part.

Reference numeral 3 is an automatic release valve, 4 is a float chamber, and 5 is a float, which constitute the operating section of this device.

The float 5 moves up and down inside the float chamber 4.
The flow of liquid and gas is controlled by opening and closing the fluid outlet 4c provided in the.

The fluid direct inlet 4b of the float chamber 4 is provided at the tip of a fluid inflow pipe 4d projecting convexly into the float chamber 4, and the fluid inflow pipe 4d is a concave water pressure receiver provided in the float 5. What are you doing with 5a?

When gas at a pressure lower than the pressure at which the automatic release valve 3 opens rises and enters the float chamber via the riser pipe 1 and the liquid inlet 4b, the float 5 passes through the air vent hole 5c and the pressure of the gas accumulated in the upper part of the float chamber increases. /or descends due to gravity and reaches the outlet 4c
and shut off the gas flow.

Next, when liquid comes at a pressure higher than the pressure at which the automatic release valve 3 opens, the automatic release valve 3 opens and gas and liquid flow out from the automatic release valve valve hole 4a.

The float 5 floats when receiving the buoyant force of the liquid and/or the ejection force due to the pressure fluid resistance by the water pressure receiver 5a, and opens the fluid outlet 4c to allow the liquid to flow.

- In the valve of the present invention, the fluid inflow pipe 4d of the float chamber and the water pressure receiver 5 provided on the float are in contact with each other, so when liquid with a pressure higher than the pressure at which the automatic release valve 3 opens flows in from the fluid inlet 4b, the pressure fluid is released. The float 5 is reliably floated by the ejection force generated by the resistance.

Furthermore, if a gas vent hole 5c is provided in the float 5, when gas with a pressure lower than the pressure at which the automatic release valve 3 opens enters the float chamber from the liquid inlet 4b, it passes through the air vent hole 5c and accumulates in the upper part of the float chamber. The fluid outlet 4 allows the float 5 to descend reliably.
Make sure to close c.

In the device of the present invention, the automatic opening/closing valve 3 may be of any type, such as one using a spring or a heavy object made of metal, synthetic resin, etc., as long as it opens and closes at a predetermined pressure, but it is preferable that the automatic opening/closing valve 3 be installed at a certain time. It is preferable to use a spring that cannot be peeled off.

Automatic on-off valves that use heavy objects can only be installed vertically, but by using springs, they can be installed diagonally or horizontally and still be effective.

The float 5 is provided with a water pressure receiving portion 5a (a recessed portion) so that it is susceptible to pressure fluid resistance.

More preferably, a pressure relief hole is provided so that the gas flows into the upper part of the float chamber when the gas flows into the float chamber.

The weight of the float 5 may be any weight as long as it floats due to pressure fluid resistance and falls due to gravity and/or the pressure of gas remaining in the upper part of the float chamber when gas flows in.

Although any material may be used for the device of the present invention, materials with excellent corrosion resistance such as synthetic resin, rubber, aluminum, and stainless steel are preferred.

In the device of the present invention, the cross-sectional shapes of the fluid inflow pipe 4d and the water pressure receiver 5a may be of any shape as long as they do not pose a problem for mutual operation.

In the device of the present invention, the length of the water pressure receiver 5a and the fluid inflow pipe 4d provided on the float 5 are set to be at least % of the diameter of a circle corresponding to the cross-sectional area of the fluid inlet 4b, and the water pressure receiver 5a and the fluid inflow It is preferable that the clearance of the pipe 4d is less than % of the diameter of a circle corresponding to the cross-sectional area of the fluid inlet 4b.

When the length of the fluid inflow pipe 4d is less than the diameter of a circle corresponding to the cross-sectional area of the fluid inlet 4b, the water pressure receiver 5a and the fluid inflow pipe 4d are connected to each other.
If the clearance is more than % of the diameter of a circle corresponding to the cross-sectional area of the fluid inlet 4b, the water pressure receiver 5a will not be able to receive sufficient water pressure, and the range in which the float will operate will be narrowed.

In the gas cutoff valve of the present invention, the clearance between the side surface of the float chamber and the side surface of the float is % of the outer diameter of a circle corresponding to the cross section of the float.

o-i. It is preferable to set it within the range of . The side of the outer diameter of the circle where the clearance between the side of the float chamber and the side of the float corresponds to the cross section of the float.

In the following cases, when liquid flows in from the fluid inlet 4b and raises the float, the pressure at the top of the float chamber decreases slowly and the float may pulsate, depending on the flow rate used.

When the clearance between the side surface of the float chamber and the float side surface is greater than or equal to the outer diameter of the circle corresponding to the cross section of the float, when gas flows in from the fluid inlet 4b, the pressure not only in the upper part of the float chamber but in the entire float chamber increases, resulting in fluid flow. It takes time to close the outlet 4c and air leakage increases.

In the gas cutoff valve of the present invention, the cross-sectional shape of the gas hole 5c provided in the float may be any shape.

Gas hole 5 made in the float in the gas cutoff valve of the present invention
The cross-sectional area of c is %~a of the cross-sectional area of the float chamber inlet 4b.

. It is preferable to keep it within the range of . If the cross-sectional area of the gas hole 5c is greater than or equal to % of the cross-sectional area of the float chamber inlet 4b, when the liquid flows into the float chamber from the fluid inlet 4b, the liquid passes through the gas hole 5c before the float 5 rises. Valve hole 4 for automatic release valve
Since it flows out from a, the pressure in the upper part of the float chamber increases and the float 5 may not float.

Also, the cross-sectional area of the gas hole 5c is equal to the cross-sectional area of the float chamber inlet 4b.

. In the following cases, when gas flows into the float chamber from the fluid inlet 4b, the gas does not pass through the gas hole and flows out from the fluid outlet 4c, and the float 5 does not descend, making it difficult to block the gas.

In the device of the present invention, a fluid inflow pipe 4d, a fluid outflow port 4c,
The number of gas holes 5c may be any number as long as it is one or more.

The float 50 may have any weight and specific gravity as long as it floats due to buoyancy and/or pressure fluid resistance when fluid flows in, and falls due to gravity when gas flows in.

As is clear from the above description, the device of the present invention allows liquid to flow but blocks gas.

By using the device of the present invention, a small and lightweight gas cutoff valve can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of the main parts of the device of the present invention. In the figure, 1 is a riser pipe, 1a is a liquid outlet,
1b is a liquid introduction part, 2 is a main container, 3 is an automatic release valve,
4 is a float chamber, 4a is a valve hole for an automatic release valve, 4b is a fluid inlet, 4c is a fluid outlet, 4d is a fluid inlet pipe, 5a is a water pressure receiver, 5b is a valve for a fluid outlet, 5c is a gas hole are shown respectively.

Claims (1)

[Claims] 1. A liquid outlet part 1a at the upper part, and a liquid introduction part 1 at the lower part.
The container 2 has a float chamber 4 having an automatic release valve 3 that opens above a certain pressure, a fluid inlet 4b, a fluid outlet 4c, and a valve seat 4a for the automatic release valve. When the liquid is flowing, it floats up due to buoyancy and/or pressure fluid resistance, opens the fluid outlet 4c and allows the liquid to flow, and descends under conditions where the liquid in the float chamber is replaced with gas. In a gas cutoff valve having a weight of a float 5 that closes a fluid outlet 4c by a pressure of A gas cutoff valve characterized in that the float 5 has a water pressure receiver 5a recessed inside the float 5 so as to be in contact with the fluid inflow pipe 4d. 2. The length of the water pressure receiver 5a and fluid inflow pipe 4d provided on the float 5 shall be at least % of the diameter of a circle corresponding to the cross-sectional area of the fluid inlet 4b, and the length of the water pressure receiver 5a and fluid inflow pipe 4d
2. The gas cutoff valve according to claim 1, wherein the clearance of the pipe portion is set to less than % of the diameter of a circle corresponding to the cross-sectional area of the fluid inlet 4b. 3. The gas cutoff valve according to claim 1, characterized in that the float 5 has a gas hole 5c. 4. The outer diameter of the circle where the clearance between the side of the float chamber and the side of the float corresponds to the cross-sectional area of the float. - A patent claim characterized in that the float 5 has a gas hole 5c, and the cross-sectional area of the gas hole 5c is within the range of % to Xoo of the cross-sectional area of the float chamber inlet 4b. The gas cutoff valve according to item 1. 5. The gas cutoff valve according to claim 1, wherein the automatic release valve 3 uses a spring.