JPH0631680B2 - Fluid system shutoff device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to piping, pipelines and stockpiling for combustible gases and liquids in plant equipment such as petroleum refining, petrochemicals, fine chemicals, city gas, and nuclear plants. The present invention relates to a shutoff device provided in a fluid system such as a drain in a tank.

<Prior Art> In this type of plant equipment, a shut-off valve is installed in the piping and pipeline to form an important safety and security system in the plant equipment.

This shut-off valve 1 is provided with a pipe 2 as shown in FIG. 7, for example.
It is installed inside, and if some abnormality occurs in a part of the plant, it has the purpose of emergency operation and shutting off the piping surely to prevent or minimize plant disasters etc. It is a thing.

<Problems to be Solved by the Invention> Since the shutoff valve 1 as described above is not operated except in an emergency, the shutoff valve 1 is left in the alarm state for a long time without being operated. Since the shut-off valve 1 is required to have the highest reliability in the mission that it must operate reliably in an emergency, it is necessary to inspect its operating state once a year.

However, conventionally, when performing such an inspection, it is necessary to stop the operation of the plant and check the operation of the shutoff valve 1.
Therefore, there has been a problem that the operating rate of the plant is lowered and, as a result, the operating cost becomes large, resulting in a great economic loss.

Also, it was difficult to check for leaks on the seat surface of the shutoff valve 1 during operation of the plant.

In view of such a conventional situation, the present invention can easily confirm the operation of the shutoff function unit while continuously operating the plant and the like, and moreover, the leak test of the shutoff function unit can be easily performed during the operation of the plant. It is an object of the present invention to provide a highly reliable shutoff device that can be constantly operated.

<Means for Solving Problems> Therefore, according to the present invention, at least the first opening / closing valve is provided in the main fluid passage in which the first opening / closing valve that is opened during the operation of the fluid system is interposed. A bypass sub-fluid passage is connected to the sub-fluid passage, and at least a second opening / closing valve that is closed during the operation of the fluid system is provided in the sub-fluid passage. A three-way valve capable of switching between the two fluid passages so as to allow a fluid to flow through the passage is provided, and a shutoff valve device is constituted by the second on-off valve and the three-way valve, while a three-way valve and a first on-off valve of the main fluid passage are provided. A fluid system shutoff device is provided with a discharge valve that can be opened and closed, respectively, between the three-way valve and the second on-off valve of the intermediate fluid passage and the second fluid passage.

<Operation> Then, in the above configuration, during operation of a normal plant or the like,
Since the first on-off valve is opened and the second on-off valve is closed, when the three-way valve is switched to the main fluid passage side, the fluid flows through the main fluid passage. For example, at the time of emergency shutoff, if the three-way valve is switched to the sub-fluid passage side, the fluid reaches the shut-off sub-fluid passage and the fluid flow is cut off.

On the other hand, at the time of the operation confirmation inspection of the three-way valve, both the first and second opening / closing valves are opened and the three-way valve is switched to perform the operation confirmation after ensuring the fluid circulation state.

Further, at the time of the leak confirmation inspection of the three-way valve and the first and second on-off valves, the discharge valve between the three-way valve and the second on-off valve of the sub-fluid passage is opened from the normal operating state of the plant or the like. Alternatively, the three-way valve is switched to the sub-fluid passage side, the first opening / closing valve is closed, the second opening / closing valve is opened, and the discharge valve between the three-way valve and the first opening / closing valve in the main fluid passage is opened. Close the other drain valve. This makes it possible to confirm a leak by fluid leakage from the discharge valve, and at this time, the fluid flows directly to the main fluid passage or to the main fluid passage via the sub-fluid passage. You can do it after doing it.

<Example> Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 6.

In FIG. 1, for example, a first manual valve 4 as a first on-off valve that is opened at least during operation of the plant equipment is provided in a main pipe 3 that constitutes a main fluid passage in the plant equipment as a fluid system. Is installed. This main piping 3
Is connected to a sub-pipe 5 as a sub-fluid passage that bypasses the first manual valve 4, and the sub-pipe 5 is provided with a second opening / closing valve that is closed at least during operation of the plant equipment. The manual valve 6 is installed.

A three-way valve 7 is provided which can switch the two pipes 3 and 5 so that the main pipe 3 is always supplied with fluid and the sub-pipe 5 is supplied with fluid in an emergency.

Here, in this embodiment, the three-way valve 7 is provided at the branch portion of the auxiliary pipe 5 from the main pipe 3.

In this case, a port C of a three-way valve 7 whose structure will be described later is connected to the main pipe 3a on the upstream side of the branch portion, and the other two ports A and B of the three-way valve are connected to the main pipe on the downstream side of the branch portion. The pipe 3b and the sub pipe 5 are connected to each other.

In the above embodiment, the three-way valve 7 and the pipes 3a, 3
b and 5 are all connected using a flange provided at each connection end.

Here, as the three-way valve 7, for example, a three-way ball valve is used. There are two types of three-way ball valves, an L port and a T port, and in this embodiment, an L port type as shown in FIG. 6 is used.

As is well known, this L-port three-way ball valve includes two ports A and B facing the valve body 7a and one port C extending in the axial direction orthogonal to the axial direction of the ports A and B. , A hole 8 extending in an L shape in the valve body 7a
6 is provided with a ball 8 having a, and the ball 8 is rotated through a stem not shown in FIG.
A form for connecting the port A and the port C as shown in (a) and a form for connecting the port B and the port C as shown in (b) of the figure can be switched.

A three-way ball valve with T port may be used,
Since this one has a large number of foams that can be switched by rotating the ball and the desired foam may not be obtained due to an erroneous operation, it is preferable to use an L port three-way ball valve that surely achieves the desired foam. .

In the configuration so far, the shutoff valve device is configured by the second manual valve 6 and the three-way valve 7.

The three-way valve 7 is a hydraulic type that is operated based on a signal from an abnormality detection device (sensor) according to the disaster prevention system,
The valve is designed to be closed by an automatic operation by an air type actuator, a direct electric signal or the like, or by a manual operation.

Examples of the abnormality detection device include automatic detection of occurrence of disaster, automatic detection of occurrence of earthquake, etc., automatic detection of gas, oil leak, etc.

On the other hand, between the three-way valve 7 and the first manual valve 4 of the main pipe 3 and between the three-way valve 7 and the second manual valve 6 of the sub-pipe 5, drain valves 9 and 10 as open / closed discharge valves are provided. It is provided.

Next, the operation of the blocking device having such a configuration will be described.

When a normal puant or the like is in operation, as shown in FIG. 1, the first manual valve 4 is opened and the second manual valve 6 is closed. When the three-way valve 7 is formed into a form that connects the port A and the port C as shown in FIG. 6 (a), when switching to the main pipe 3 side, the fluid flows through the main pipe 3.

At the time of emergency shutoff when some abnormality occurs in a part of the plant, as shown in FIG. 2, the three-way valve 7 is switched to the auxiliary pipe side, that is, the three-way valve 7 is shown in FIG. 6 (b). By using the foam for connecting the port B and the port C as described above, the fluid reaches the sub-pipe 5 that is blocked by the second manual valve 6, and the fluid flow is cut off.

Therefore, the flow of the fluid to the main pipe 3 can be surely blocked, and a plant disaster or the like can be prevented or minimized.

On the other hand, at the time of checking the operation of the three-way valve 7, as shown in FIG. 3, both the first and second manual valves 4 and 6 are opened so that the three-way valve 7 is switched to check the operation, that is, the three-way valve. Check whether the valve 7 is surely switched.

In this case, since the main pipe 3 and the sub pipe 5 are both open, it is possible to ensure the fluid circulation state. The leak confirmation inspection of the three-way valve 7 and the first and second manual valves 4 and 6 is performed as follows.

First, the seat surface of the port B of the three-way valve 7 and the second manual valve 6
At the time of the leak check, the drain valve 10 between the three-way valve 7 of the sub-pipe 5 and the second manual valve 6 is opened from the operating state of the plant equipment shown in FIG. 1 as shown in FIG.

In this state, the seat surface of the port B of the three-way valve 7 and the second
If the manual valve 6 leaks, the fluid is recovered from the drain valve 10.

Further, at the time of leak check of the seat surface of the port A of the three-way valve 7 and the first manual valve 4, the three-way valve 7 is switched to the auxiliary pipe 5 side and the first manual valve 4 is closed as shown in FIG. , The second manual valve 6 is opened, the drain valve 9 between the three-way valve 7 of the main pipe 3 and the first on-off valve 4 is opened, and the other drain valve 10 is closed. As a result, port A of the three-way valve 7
If there is a leak in the seat surface of the above and the first manual valve 4, the fluid is recovered from the drain valve 9.

Since the main pipe 3 or the sub-pipe 5 is opened, the leak inspection can be performed after ensuring the fluid circulation state.

In order to facilitate the escape of fluid from the drain valves 9 and 10 during the above-mentioned leak inspection, as shown in FIGS. 4 and 5, vent valves 11 and 12 are further connected to the main pipe 3 as discharge valves. It should be installed in the sub-pipe 5.

In this case, the drain valves 9 and 10 are provided on the lower side of the line, while the vent valves 11 and 12 are provided on the higher side of the line.

Then, at the time of the leak check shown in FIG. 4, the vent valve 12 provided in the auxiliary pipe 5 may be opened, and at the time of the leak check shown in FIG. 5, the vent valve 11 provided in the main pipe 3 may be opened. .

When the fluid in the fluid system is liquid, only the drain valves 9 and 10 may be used as discharge valves, but when the gas is gas, not only the drain valves 9 and 10 but also vent valves 11 and 12 may be provided as discharge valves. good.

According to the configuration of the abnormal shutoff device, the inspection of the three-way valve 7 and the manual valves 4 and 6 can be easily performed without affecting the operation of the plant equipment during the operation of the plant equipment.

As a result, there is no need to stop the operation of the plant,
Can prevent financial loss.

In other words, the economic effect due to the loss and danger of the product and utility costs associated with the shutdown and start of operation of the plant becomes great.

In the embodiment shown in FIG. 1, the main pipe 3a of the auxiliary pipe 5 is
Although the three-way valve 7 is provided at the branch portion from 1 to 3, the three-way valve 7 may be provided at the collecting portion of the sub-pipe 5 to the main pipe 3c as shown in FIG.

<Effects of the Invention> As described above, according to the present invention, the operation of the plant or the like can be continuously performed, and the confirmation of the interruption function unit can be easily performed, and the interruption function can be performed during the operation of the plant or the like. It is possible to provide a highly reliable interrupting device that can always perform a leak test of a part.

[Brief description of drawings]

1 to 5 are schematic views for explaining the structure and operation of the fluid system shutoff device according to the present invention, respectively, and FIG. 6 (a),
(b) is a cross-sectional view showing the structure and operation of the three-way valve in the above embodiment, FIG. 7 is a schematic view showing another embodiment, and FIG. 8 is a schematic view of a conventional fluid system cutoff device. 3, 3a, 3b, 3c ... Main piping, 4 ... First manual valve, 5 ... Sub piping, 6 ... Second manual valve, 7 ... Three-way valve, 9,10 ... Drain valve, 11, 12 …… Vent valve

Claims (1)

[Claims] 1. A sub-fluid passage that bypasses the first on-off valve is connected to a main fluid passage in which a first on-off valve that is opened at least during operation of a fluid system is connected. A second opening / closing valve, which is closed at least during the operation of the fluid system, is provided in the passage, and the fluid is normally caused to flow in the main fluid passage,
A three-way valve capable of switching between the two fluid passages so as to allow the fluid to flow to the sub-fluid passage at the time of shutoff is provided, and the shutoff valve device is constituted by the second on-off valve and the three-way valve, while the three-way valve of the main fluid passage and the A shutoff device for a fluid system, characterized in that a discharge valve that is openable and closable is provided between the first on-off valve and between the three-way valve and the second on-off valve of the sub-fluid passage.