JPH044989Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention is applicable to piping and pipelines for flammable gases and liquids in plant equipment such as oil refining, petrochemical, fine chemical, city gas, and nuclear power plants. The present invention also relates to a shutoff device installed in a fluid system such as a drain in a storage tank.

<Prior Art> In this type of plant equipment, a shutoff device is provided in the pipes and pipelines to constitute an important safety and security system in the plant equipment.

For example, as shown in FIG. 7, this shutoff device includes a shutoff valve 2 interposed in a piping 1 of a fluid system, and is used for controlling an air cylinder drive unit 3 as a fluid actuator that drives the shutoff valve 2. The operation of the cutoff valve 2 is controlled by a three-way solenoid valve 5 as a control valve provided in the fluid line 4.

If some abnormality occurs in a part of the plant, the three-way solenoid valve 5 is operated in an emergency manner to supply the control fluid from the control fluid line to the air cylinder drive section 3 to drive the air cylinder. The section 3 is driven to cause the shutoff valve 2 to perform a shutoff operation to reliably shut off the pipe 1, thereby preventing or minimizing plant disasters.

<Problems to be Solved by the Invention> Since the above-mentioned shutoff devices are not operated except in emergencies, they remain inactive for a long period of time in an alarming state. Since the highest reliability is required for the shutoff device because it must operate reliably in the event of an emergency, it is necessary to inspect its operating condition once a year.

However, conventionally, such inspections confirm whether or not the shutoff device actually performs the shutoff function, so it is necessary to temporarily stop plant operation during this inspection. The problem was that the operating rate of the system decreased, resulting in large operating costs and other major economic losses.

In view of the conventional situation, it is an object of the present invention to provide a highly reliable device that can easily perform an operation check of a shutoff device while continuously operating a plant or the like.

<Means for Solving the Problems> For this reason, the present invention provides a shutoff valve interposed in a fluid system, and a control valve provided in a fluid line for controlling a fluid actuator that drives the shutoff valve. Therefore, in the fluid system cutoff device configured to control the cutoff valve, a test fluid passage branching from the fluid supply section of the fluid actuator is provided,
A three-way valve is provided in the branch part, and is capable of switching both fluid passages so that the fluid supply part is normally open and the test fluid passage is closed, and during testing, the fluid supply part is closed and the test fluid passage is open. While providing
The inspection fluid passage is provided with means for confirming the presence or absence of fluid flow.

<Operation> In the above configuration, during normal plant operation, the fluid supply to the fluid supply passage of the control fluid line of the fluid actuator is stopped, and
Switch the three-way valve to the fluid supply side. In this state, the shutoff valve is not operated to shut off. For example, at the time of emergency shutoff, when fluid is supplied to the fluid supply passage while the three-way valve remains as it is, the fluid actuator is driven and the shutoff valve is closed. Next, when testing the operation of the shutoff device, fluid is supplied to the fluid supply section and the three-way valve is switched to the test fluid passage side. The state is such that fluid can flow, and the presence or absence of fluid flow can be confirmed by means such as a pressure gauge.

At this time, the shutoff valve is held in the state before the inspection, that is, in the open or closed state, so its operation can be confirmed after ensuring the fluid flow state.

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

In FIG. 1, for example, piping 6 constituting a main fluid passage in plant equipment as a fluid system.
A shutoff valve 7 is interposed therein. This cutoff valve 7 is provided with a spring return type (single action) air cylinder drive section 8 as a fluid actuator for driving the shutoff valve 7. This air cylinder drive unit 8 includes, for example, a piston that can freely slide inside the cylinder, a rack that slides integrally with the piston, and a sector gear that meshes with the rack, and includes a piston that can freely slide inside the cylinder, and a sector gear that meshes with the rack. The piston is pressed and moved by air pressure, and the output of the piston is converted into rotational motion via a rack and a sector gear.The valve stem of the shutoff valve 7 is connected to the sector gear, and the shutoff valve 7 is Rotate the . The shutoff valve 7 is controlled by the operation of a control valve provided in the control fluid line of the air cylinder drive section 8.

That is, the control fluid line consists of a control fluid pipe 9 led from an air source and connected to the inside of the cylinder of the air cylinder drive unit 8, and the control fluid pipe 9 includes a first valve as a control valve. Three-way solenoid valve 1
0 is set.

As shown in FIG. 4, this first three-way solenoid valve 10 has three piping connections on a main body 11, namely, two piping connections A and B facing each other, and two piping connections A and B that are orthogonal to each other. It has one piping connection port C (not shown) that opens in the direction, and has two valve parts 12 and 13 in the main body 11, one valve part 12 is always open and the other valve part 13 is always closed. There is. Then, as shown in FIG. 4b, when the electromagnetic section 14 is excited and the movable core 15 is attracted, the valve section 13 is opened and the opposing piping connection ports A and B communicate with each other. Valve section 12 is closed. Also, Figure 4a
As shown in , when the electromagnetic part 14 is demagnetized and the movable core 15 is lowered, the valve part 13 is closed and the other valve part 12 is opened, so that one of the opposing piping connection ports B
and the piping connection port C (see Fig. 1) communicate with each other.

In the first three-way solenoid valve 10, the above-mentioned pair of opposing piping connection ports A and B are connected to the control fluid piping 9, respectively, and the piping connection port C is open to the atmosphere.

On the other hand, in the control fluid piping 9, the first
A test fluid pipe 16 as a test fluid passage branching from between the three-way solenoid valve 10 and the air cylinder drive section 8 is connected. The branch part is provided with both channels so that fluid normally flows through the control fluid piping 9, and fluid from the control fluid piping 9 flows into the test fluid piping 16 during an operation confirmation test of the shutoff device, which will be described later. A second three-way solenoid valve 17 for switching the pipes 16 and 9 is provided.

In this second three-way solenoid valve 17, a pair of opposing piping connection ports A and B are connected to the control fluid piping 9, respectively, and the other piping connection port C is connected to the inspection fluid piping 16.
It is connected to the. In this second three-way solenoid valve 17, when the electromagnetic part is energized, one valve part is closed and the other valve part is opened, and one of the opposing piping connection ports A and C is connected to each other. communicate. Moreover, when the electromagnetic part is demagnetized, one valve part is opened and the opposing piping connection ports A and B communicate with each other, and the other valve part is closed, so that the first three-way This configuration is such that the opening and closing states of the valve portion are contradictory when the solenoid valve 10 is energized and de-energized.

Here, the inspection fluid piping 16 is provided with means for checking the presence or absence of fluid flow.

In this embodiment, the inspection fluid piping 16 is opened to the atmosphere, a manual valve 18 is interposed in the middle, and a pressure gauge 19 is provided upstream of the manual valve 18 as a means for checking the presence or absence of fluid flow. There is.

In addition, in the figure, 20 is the first three-way solenoid valve 10.
This is a power supply line, and a normally open cutoff switch 21 that is closed when cutoff, which will be described later, is interposed. 2
2 is a power line for the second three-way solenoid valve 17;
A normally open inspection switch 28 that is closed during inspection, which will be described later, and two lamps L1 and L2 are interposed. One lamp L1 is placed near the test switch 23, and the other lamp L2 is placed near the cutoff switch 21.

Next, the operation of the shutoff device having such a configuration will be explained.

During normal plant operation, as shown in FIG. 1, the first three-way solenoid valve 10 is demagnetized, and the piping connections B and C of the first three-way solenoid valve 10 are communicated with each other. The second three-way solenoid valve 17 is demagnetized, and the piping connections A and B of the second three-way solenoid valve 17 are communicated with each other.

Therefore, in such a state, the inside of the cylinder of the air cylinder drive section 8 is connected to the first and second three-way solenoid valves 1.
0,17, and the air cylinder drive section 8 is connected to the shutoff valve 7 by a return spring.
is maintained in an open state, and plant fluid flows through the pipe 6.

For example, in the event of an emergency shutdown when some kind of abnormality occurs in a part of the plant, the second three-way solenoid valve 17 remains in place and the shut-off switch 21 is closed to shut off the first valve, as shown in FIG. Three-way solenoid valve 10
When energized and the piping connections A and B of the first three-way solenoid valve 10 are communicated with each other, air pressure from the air source is applied to the piston in the cylinder of the air cylinder drive unit 8, pushing and moving the piston. Then, the shutoff valve 7 is rotated and closed as described above.

Therefore, the fluid flow to the pipe 6 is reliably blocked, and disasters in the plant can be prevented or minimized.

Next, when inspecting the operation of the shutoff device, the manual valve 18 is closed and the shutoff switch 2 is turned off, as shown in FIG.
1 is closed, the first three-way solenoid valve 10 is energized, and the piping connection ports A and B of the first three-way solenoid valve 10 are
At the same time, the inspection switch 23 is closed to put the second three-way solenoid valve 17 in an excited state, and the piping connection ports A and C of the second three-way solenoid valve 17 are brought into communication with each other. This allows the air from the air source to
and is guided to the inspection piping 16 via the second three-way solenoid valves 10 and 17.

At this time, lamps L1 and L2 are lit, respectively.
Specify that the operation is being inspected.

Here, the first and second three-way solenoid valves 10, 17
If there is no abnormality in the control fluid system including
Since pressure 9 is higher than the required pressure, check the pressure gauge 19 to determine whether it is normal or abnormal.

At this time, the piping connection port B of the second three-way solenoid valve 17
is closed, air is trapped in the cylinder of the air cylinder drive unit 8, and the shutoff valve 7 is maintained in the state before the inspection, that is, the open state during normal use or the closed state during shutoff, so that its operation is Confirmation can be performed after ensuring the state of fluid flow in the piping.

Further, in this embodiment, the following tests are also performed.

This is done by opening the cutoff switch 21 from the above state to put the first three-way solenoid valve 10 in a demagnetized state, and thereby connecting the pipe connection ports B and C of the first three-way solenoid valve 10 with each other. In this case, if there is no abnormality in the control fluid system including the first and second three-way solenoid valves 10 and 17, the inspection piping 16 communicates with the atmosphere via the piping connection port C of the first three-way solenoid valve 10. Therefore, the pressure on the pressure gauge 19 becomes 0, so the pressure gauge 19 is checked to determine whether it is normal or abnormal.

Of the functions of the above-mentioned shutoff device, the inspection method will be explained in more detail using the flowchart shown in FIG.

That is, in the figure, when the inspection is started, at step 1 (denoted as S in the figure), the manual valve 1 is
8 is closed. If it is closed (YES), proceed to step 2. If it is not closed (NO), close the manual valve 18 in step 3 and proceed to step 2. In step 2, the inspection switch 23 is closed to energize the second three-way solenoid valve 17, and in step 4, the second three-way solenoid valve 17 is energized.
Piping connection ports A and C communicate with each other. Step 5
Then, the cutoff switch 21 is closed to bring the first three-way solenoid valve 17 into an energized state, and in step 6, the pipe connection ports A and B of the first three-way solenoid valve 17 are communicated with each other. In step 7, it is determined whether the pressure in the pressure gauge 19 is greater than or equal to the specified value. If the pressure is greater than or equal to the specified value (YES), proceed to step 8; if not (NO), proceed to step 9. , it is determined that there is an abnormality, and this abnormality confirmation repair is carried out in step 10.
In step 8, the cutoff switch 21 is opened to demagnetize the first three-way solenoid valve 10, and in step 11
Then, the piping connection ports B and C of the first three-way solenoid valve 10 communicate with each other. Then, in step 12, pressure gauge 1
Determine whether the pressure in step 9 is 0 or not. If it is 0 (YES), proceed to step 13; if it is not 0 (NO), proceed to step 14, determine that it is abnormal, and confirm this abnormality in step 15. Perform repairs and return to the start. In step 13, the inspection switch 23 is opened to demagnetize the second three-way solenoid valve 17, and
In step 16, the pipe connection ports A and B of the second three-way solenoid valve 17 are communicated with each other, and in step 17, the normal state is returned to complete the inspection.

According to the above configuration, the operation of the shutoff device can be easily confirmed without affecting the operation of the plant during operation of the plant.

As a result, there is no need to stop plant operation, and economic losses can be prevented.

In other words, the economic effect is significant because there is no loss of products or utility costs and no risk associated with the shutdown and start-up of the plant.

Furthermore, even if the inspection line should fail, such as when the electrical signal line of the second three-way solenoid valve 17 is cut off, normal and shut-off operations will not be hindered.

In the above embodiments, the first three-way solenoid valve 10 is such that when the solenoid part is excited, the opposing piping connection ports A and B communicate with each other, and the other valve part is closed. However, when it is demagnetized on the contrary,
It is also possible to use a configuration in which the opposing piping connection ports A and B are out of communication with each other and the other valve portion is open. Further, the second three-way solenoid valve 17 is also energized,
It is also possible to use a configuration in which the open and closed states of the valve portion are opposite when not energized. Further, the manual valve 18 in this embodiment is not essential, and it may be removed and the pressure gauge 19 directly connected to the end of the inspection piping 16, or the pressure gauge 19 may be left in the same position.
The end of the inspection pipe 16 may be closed with a plug or the like.

Further, the second three-way solenoid valve 17 may be operated manually, and the means for checking the presence or absence of fluid flow provided in the test fluid piping 16 is not limited to the pressure gauge 19. In addition, a pneumatic position indicator, pressure switch, pressure transmitter, etc., or a sight glass may be used.

Further, in this embodiment, the shutoff valve 7 is equipped with a single-acting air cylinder drive section 8 as a fluid actuator for driving it, but a double-acting air cylinder drive section is also used. You may also use

FIG. 6 shows another embodiment of the present invention, in which a two-way solenoid valve 24 is installed in the control fluid line instead of the first three-way solenoid valve 10.

The two-way solenoid valve 24 has a pair of opposing piping connection ports A and B connected to the control fluid piping 9, respectively.

Therefore, during normal plant operation, the manual valve 18 is opened and the piping connections B and C of the second three-way solenoid valve 17 are communicated with each other.

Therefore, in such a state, the inside of the cylinder of the air cylinder drive unit 8 communicates with the atmosphere via the second three-way solenoid valve 17 and the manual valve 18, and the air cylinder drive unit 8 closes the cutoff valve 7 by the return spring.
is maintained in an open state, and plant fluid flows through the pipe 6.

For example, in the event of an emergency shutdown when some abnormality occurs in a part of the plant, the piping connections A and B of the second three-way solenoid valve 17 are communicated with each other, and the two-way solenoid valve 24 is opened. , air pressure from the air source is applied to the piston in the cylinder of the air cylinder drive unit 8 to press and move the piston,
The shutoff valve 7 is rotated and closed, and the fluid flow to the pipe 6 is shut off.

Next, when inspecting the operation of the shutoff device, the manual valve 1
8 is closed, the two-way solenoid valve 24 is opened, and the piping connection ports A and C of the first three-way solenoid valve 17 are communicated with each other.

As a result, air from the air source is guided to the inspection piping 16 via the two-way solenoid valve 24 and the second three-way solenoid valve 17, and the pressure gauge 10 is checked to determine whether it is normal or abnormal. .

At this time, the piping connection port B of the second three-way solenoid valve 17
is closed, air is trapped in the cylinder of the air cylinder drive unit 8, and as in the previous embodiment, the shutoff valve 7 is in the state before the inspection, that is, the open state during normal use or the closed state when shutting off. Therefore, its operation can be confirmed after ensuring the state of fluid flow in the piping.

In this embodiment, the manual valve 18 is essential.

<Effects of the invention> As explained above, according to the invention, a shutoff valve is interposed in a fluid system, and the control valve provided in the control fluid line of the fluid actuator that drives the shutoff valve is activated. Therefore, in the shutoff device for a fluid system configured to control the shutoff valve, a fluid passage for inspection is provided in the control fluid line, and the fluid from the control fluid line can flow through the fluid passage, and further By providing a means to check the presence or absence of fluid flow in the fluid passage for inspection, we have created a highly reliable shutoff device that can be easily checked while continuously operating the fluid plant. The practical effect it can provide is the first one.

[Brief explanation of the drawing]

Figures 1 to 3 are schematic diagrams illustrating the configuration and operation of a fluid system shutoff device according to the present invention, and Figures 4a and 4b illustrate the structure and operation of a three-way solenoid valve in the same embodiment. FIG. 5 is a flowchart explaining the operation of the embodiment, FIG. 6 is a schematic diagram showing another embodiment, and FIG. 7 is a schematic diagram showing a conventional fluid system cutoff device. 6...Piping, 7...Shutoff valve, 8...Air cylinder drive section, 9...Control fluid piping, 10...First
Three-way solenoid valve, 16...Fluid piping for inspection, 17...
...Second three-way solenoid valve, 19...Pressure gauge, 24...
Two-way solenoid valve.

Claims (1)

[Scope of utility model registration request] A shutoff device for a fluid system, wherein a shutoff valve is interposed in a fluid system, and the shutoff valve is controlled by actuation of a control valve provided in a fluid line for controlling a fluid actuator that drives the shutoff valve. In,
A testing fluid passage branching from the fluid supply section of the fluid actuator is provided, and the fluid supply section is normally opened and the testing fluid passage is closed, and the fluid supply section is closed during testing. A shutoff device for a fluid system, characterized in that a three-way valve capable of switching both fluid passages to open the testing fluid passage is provided, and a means for confirming the presence or absence of fluid flow is provided in the testing fluid passage.