JP2001065715A - Ball valve and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new ball valve and control method thereof which can prevent the leak of a fluid by one valve surely. SOLUTION: In a ball valve storing a ball valve element 5 rotatably in a valve main body 3 provided in a piping system and communicating/blocking between the fluid inlet 1 and fluid outlet 2, a seal fluid supply port P for pressing in the higher pressure fluid for sealing than the pressure of inside fluid flowing in the piping system is connected to the valve main body 3. Therefore, as the inside pressure of the valve main body 3 can be maintained higher than the fluid inlet 1 side, the leak of the inside fluid from the fluid inlet 1 side to the fluid outlet 3 side can be prevented surely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve for controlling the flow of a fluid such as gas or liquid flowing in a piping system, and more particularly to a ball valve using a ball-shaped valve.

[0002]

2. Description of the Related Art In general, various piping systems provided in a chemical plant, a power plant, and the like include a large number of valves for controlling the flow of gas, liquid, and the like in the piping. A ball valve A having a structure as shown in FIG. 6 is often used in a portion where a high responsiveness is particularly required.

As shown in the figure, the ball valve A has a valve body 3 having a communication hole 4 rotatably housed in a valve body 3 having a fluid inlet 1 and a fluid outlet 2 formed in a straight line. When the ball valve element 5 is driven to rotate in the horizontal direction by a valve driving unit 7 provided outside the valve body 3 via a rotation shaft 6, the inside of the valve is opened and closed instantaneously, and the flow of fluid is performed. It is intended to be controlled.

Incidentally, in the conventional ball valve A having such a structure, when closed, the structure is
It is difficult to completely stop the flow of the internal fluid, and it is generally known that a small amount of leaks continuously occur.

Therefore, conventionally, when such a ball valve A is used, as shown in FIG.
, Two ball valves A, A are arranged in series, and a sealing gas supply port P is connected between them, and the ball valves A, A are closed. By injecting a sealing fluid (clean gas or the like), leakage of fluid from the ball valves A, A is prevented.

However, in the method using two ball valves A, A as described above, the ball valve A to be used is considered in view of the whole plant that requires a large number of valves.
However, there is a drawback that the cost required for the installation is enormous because the number of devices becomes extremely large.

Accordingly, the present invention has been devised to effectively solve such a problem, and an object of the present invention is to provide a novel ball valve capable of reliably preventing fluid leakage with a single valve. And a control method thereof.

[0008]

According to the present invention, a ball valve is rotatably housed in a valve body provided in a piping system so that a fluid inlet and a fluid outlet are communicated and closed. In the above-mentioned ball valve, a sealing fluid supply port for press-fitting a sealing fluid having a pressure higher than a pressure of an internal fluid flowing in the piping system is connected to the valve body.

At the same time or immediately before the ball valve element is rotated in the closing direction from the communicating state, a sealing fluid having a higher pressure than the internal fluid is injected into the valve body from the sealing gas supply line. Since the inside of the valve body, that is, the gap between the valve body and the ball valve body is filled with the high-pressure seal fluid, the internal fluid cannot pass from the fluid inlet side to the fluid outlet, and the leak is reliably prevented.

As a result, it is not necessary to use two ball valves as in the prior art, so that the amount of valves used is greatly reduced, and a significant cost reduction is achieved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of a ball valve A according to the present invention, and FIG. 2 is a sectional view taken along line XX in FIG.

As shown, this ball valve A is
A ball valve body 5 is rotatably accommodated in a valve body 3 having a fluid inlet 1 and a fluid outlet 2 so as to communicate and close the fluid inlet 1 and the fluid outlet 2.

The ball valve element 5 is formed from a metal sphere having a high sphericity and precision processing. As shown in FIG.
A communication hole 4 is formed at the center thereof to penetrate it horizontally and linearly. In addition, the communication hole 4
A pair of guide grooves 8, 8 are formed horizontally so as to communicate from both sides between both ends of the guide groove.

A rotating shaft 6 extending vertically upward from the ball valve body 5 is integrally connected to the top of the ball valve body 5, and its upper end is mounted on the valve body 3 as shown in FIG. Connected to the valve driving unit 7 side.

Accordingly, the ball valve element 5 is rotatable left and right about the rotation axis 6 as a rotation axis, and the communication hole 4 rotates in the horizontal direction with the rotation of the ball valve element 5. It has become.

The valve drive unit 7 is a combination of an electric actuator, a pneumatic actuator and the like and a gear operating device, as in the prior art, and is driven remotely or manually. Further, flanges 9 and 9 are provided at ends of the fluid inlet 1 and the fluid outlet 2, respectively, and are connected to flanges on a piping system (not shown).

A sealing fluid supply port P for press-fitting a sealing fluid therein is connected to a side portion of the valve body 3, and the sealing fluid supply port P is a ball valve body as shown in FIG. 5 is connected to a position communicating with the guide groove 8. In addition, as this sealing fluid,
Although not particularly limited, for example, when the internal fluid flowing through the piping system is an odorous gas, an odorless gas such as air, an inert gas, or a nitrogen gas, or this piping system is attached to a deodorizing furnace. If it is present, a part of the combustion exhaust gas (processed gas) generated from the deodorizing furnace is used, and if the internal fluid is a chemical solution, distilled water or the like is used.

Next, a method of controlling the ball valve A having the above-described structure according to the present invention will be described.

First, the ball valve 5 is rotated by the valve driving unit 7 so that both ends of the communication hole 4 of the ball valve 5 are directed toward the fluid inlet 1 and the fluid outlet 2 as shown in FIG. As a result, the internal fluid on the fluid inlet 1 side flows through the communication hole 4 of the ball valve body 5 to the fluid outlet 2 side satisfactorily.

Next, from such a state, the ball valve element 5 is further rotated by about 90 ° about the rotation axis 6 thereof, as shown in FIG.
In the state shown in (2), the space between the fluid inlet 1 and the fluid outlet 2 is closed by the ball valve element 5 and the flow of the internal fluid stops instantaneously. The pressure on the upstream side, that is, the pressure on the fluid inlet 1 side is higher than that on the downstream fluid outlet 2 side, so that the internal fluid on the fluid inlet 1 side closes the gap between the ball valve body 5 and the valve body 3. Passes through and attempts to leak to the fluid outlet 2 side.

Therefore, as shown in FIG. 4 (2), the space between the fluid inlet 1 and the fluid outlet 2 is closed by the ball valve element 5 or immediately before that into the valve body 3 from the sealing fluid supply port P. A sealing fluid having a higher pressure than the pressure of the fluid is supplied. Then, the inside of the communication hole 4 of the valve body 3 is filled with the sealing fluid, and the internal pressure thereof becomes higher than the pressure on the upstream side thereof, and a part of the sealing fluid is passed through the guide grooves 8, 8 to the ball valve. After flowing into the gap between the body 5 and the valve body 3, it flows out to the fluid inlet 1 side and the fluid outlet 2 side.

As a result, the gap between the ball valve body 5 and the valve body 3 as well as the inside of the communication hole 4 is filled and sealed with the sealing fluid having a higher pressure than the internal fluid, and the internal fluid on the fluid inlet 1 side is sealed. Since it does not flow into the gap, leakage of the internal fluid can be completely prevented.

Accordingly, since the leakage of the internal fluid can be completely prevented by one ball valve A, it is not necessary to provide two ball valves in one place as in the conventional case, and as a result, the entire plant can be used. The number of ball valves to be used can be greatly reduced, and a significant cost reduction can be achieved.

In this embodiment, at the moment when the ball valve element 5 is closed, the internal fluid accumulated in the communication hole 4 is pushed out by the press-fitting of the sealing fluid, and a part of the internal fluid is downstream for a while together with the sealing fluid. Leakage to the side is conceivable. Therefore, as shown in FIG. 5, notches 10, 10 extending in the rotation direction are formed at both ends of the communication hole 4, respectively, so that the internal fluid accumulated in the communication hole 4 is press-fitted from the sealing fluid supply port P for sealing. Fluid inlet 1 by fluid
It may be configured to forcibly push it to the side.

That is, by forming the notches 10 and 10 extending in the rotation direction at both ends of the communication hole 4, respectively, the valve is opened from the state shown in FIG. 5 (1) to the valve closed state shown in FIG. 5 (3). On the way, as shown in FIG. 5B, the sealing fluid supply port P and the fluid inlet 1 side are temporarily in communication via the communication hole 4. At this moment, the internal fluid accumulated in the communication hole 4 is pushed out to the fluid inlet 1 side by the sealing fluid at a stretch as shown by the arrow in the drawing, and the inside of the communication hole 4 is replaced with the sealing fluid. Leakage of the internal fluid accumulated inside can be almost completely prevented.

Further, in this embodiment, one seal fluid supply port P is provided on the side surface of the valve body 3 so as to be orthogonal to the flow of the fluid. The present invention is not limited to this. For example, two or more places may be attached so as to face each other, and the attachment position and the angle may be finely adjusted to an optimum position. .

Further, in the present embodiment, the ball valve 5
Although the guide grooves 8, 8 are provided on the surface of the ball valve body 5 in order to quickly discharge the internal fluid therein, the leakage of the fluid of about the amount accumulated in the ball valve body 5 can be tolerated. In this case, the guide grooves 8, 8 are not always necessary.

[0029]

In summary, according to the present invention, the leakage can be reliably prevented by one valve, so that the number of ball valves used can be greatly reduced. As a result, an excellent effect such as a significant reduction in the cost of the valve required for controlling the fluid can be exhibited.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a ball valve according to the present invention.

FIG. 2 is a sectional view taken along line XX in FIG.

FIG. 3 is a perspective view showing a ball valve body of the ball valve according to the present invention.

FIG. 4 is a cross-sectional view showing a state where a ball valve according to the present invention is opened. (2) is sectional drawing which shows the state which closed the ball valve which concerns on this invention.

FIG. 5 is a longitudinal sectional view showing another embodiment of the ball valve according to the present invention.

FIG. 6 is a longitudinal sectional view showing the operation of a conventional ball valve.

FIG. 7 is a conceptual view showing a mounting state of a conventional ball valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid inlet 2 Fluid outlet 3 Valve body 4 Through-hole 5 Ball valve body 6 Rotating shaft 7 Valve drive unit 8 Guide groove 10 Cut A Ball valve P Seal fluid supply port

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H051 AA07 BB10 CC11 FF01 FF02 3H054 AA03 BB02 CA07 CC03 GG01 GG02

Claims (4)

[Claims] 1. A ball valve which rotatably accommodates a ball valve body in a valve body provided in a piping system and communicates and closes between a fluid inlet and a fluid outlet thereof. A ball valve connected with a sealing fluid supply port for press-fitting a sealing fluid having a pressure higher than a pressure of a flowing internal fluid. 2. A ball valve wherein a guide groove for guiding a press-fitted sealing fluid to the fluid inlet and the fluid outlet is formed on a surface of the ball valve body. 3. A ball valve, wherein a cutout extending in the rotation direction is formed at an end of the communication hole of the ball valve body. 4. The method for controlling a ball valve according to claim 1, wherein the ball valve element is rotated from the communicating state in the closing direction at the same time as or immediately before the rotation from the sealing fluid supply port. A method of controlling a ball valve, wherein a sealing fluid having a pressure higher than a pressure of an internal fluid flowing through the piping system is press-fitted into a valve body.