JPH0565768B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an emergency shutoff device, particularly an emergency shutoff device that detects the occurrence of an emergency situation such as an earthquake and shuts off a pipe flow path for supplying a fluid such as city gas. Regarding equipment.

BACKGROUND ART A gas supply system that supplies fluid such as city gas through piping is equipped with an emergency shutoff device that detects the occurrence of an emergency situation such as an earthquake or a fire, and emergency shuts off the piping flow path. ing. Conventionally, such emergency shutoff devices detect the occurrence of the above-mentioned emergency situation and shut off the flow path by detecting the gas pressure in the flow path and shutting off the flow path when the gas pressure reaches an abnormal pressure exceeding a predetermined pressure. It had the function of either closing the shutoff valve or closing the shutoff valve by supplying an external signal from the operation of an earthquake sensor or the like.

Problems to be Solved by the Invention However, the conventional emergency shutoff device described above has a function of detecting abnormal pressure in the flow path and shutting off the flow path, and a function of shutting off the flow path based on an external signal from a sensor such as an earthquake or fire. For example, when detecting the pressure in the flow path, the shutoff function due to pressure detection does not operate at night when the inlet pressure of the pipe flow path decreases, or during piping work. Also,
Conventional devices that detect the occurrence of an emergency situation using signals from a sensor have the disadvantage that the cutoff function does not operate if the line that supplies the signal from the sensor is severed due to an earthquake, etc. There was a drawback that vibrations caused by the passage of water could cause the piping to be activated and block the piping flow path.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an emergency shutoff device that eliminates the above drawbacks.

Means and Effects for Solving Problems The present invention includes a shutoff valve provided in a pipe that supplies fluid, an emergency shutoff signal output means that outputs an emergency shutoff signal in the event of an emergency, and a pipe outlet that is normally connected to a shutoff valve. The pressure on the pipe inlet side is supplied to the cutoff valve, and the switching valve is switched to supply the pressure on the pipe inlet side to the cutoff valve in response to an emergency cutoff signal from the emergency cutoff signal output means. Further, the shutoff valve shuts off the piping flow path in response to either the abnormal pressure on the outlet side of the pipe or a signal from the emergency shutoff signal output means, so that the emergency shutoff occurs when abnormal pressure in the flow path cannot be detected. The shutoff valve is actuated to close by the emergency shutoff signal from the signal output means, and even if the signal from the emergency shutoff signal output means is not supplied, the shutoff valve is closed by detecting abnormal pressure in the piping flow path to prevent an emergency situation. This is designed to ensure that incidents occur and improve reliability in emergencies.

Embodiment The figure shows an embodiment of the emergency activation device according to the present invention. In the figure, a fluid such as city gas is supplied to a flow path of a pipe 1 from an inlet 1a of the pipe 1 to an outlet 1b. An inlet stop valve 2, a strainer 3, a cutoff valve 4, a pressure control valve 5, and an outlet stop valve 6 are disposed in the middle of the pipe 1. The shutoff valve 4 is supplied with the pressure at the outlet 1b or the pressure at the inlet 1a of the pipe 1, and has a pressure detection section 4a that detects the supplied pressure. Further, when the pressure detection section 4a detects a pressure exceeding a predetermined pressure, the shutoff valve 4 is immediately operated to close the pipe 1.
block the flow path.

The pressure control valve 5 is connected to the outlet 1 of the pipe 1 via the pipe 7.
Fluid is introduced from the b side, and the valve opening degree is adjusted to achieve the desired pressure. Reference numeral 8 denotes a relief valve which opens when the pressure on the outlet 1b side of the pipe 1 increases to a certain value or more and discharges gas into the open tank 9.

10 is a bypass pipe, which communicates the inlet 1a side and the outlet 1b side of the pipe 1, and the stop valve 11,
12 is closed.

13 is a three-way solenoid valve, and a port 13a is connected to the pressure detection part 4a of the cutoff valve 4 via a pipe 14.
, a port 13b connected to the bypass pipe 10 via a pipe 15, and a port 13c connected to a pipe 16. In addition, the three-way solenoid valve 13 normally communicates ports 13a and 13b with port 1.
3c is closed, and the pressure on the outlet 1b side of the pipe 1 is supplied to the cutoff valve 4 via the bypass pipe 10 and pipes 15 and 14. Therefore, the shutoff valve 4 normally detects the pressure on the outlet 1b side of the piping 1, and performs a shutoff operation when abnormal pressure occurs on the outlet 1b side.

Reference numeral 17 denotes a pressure accumulator tank, which is connected via a check valve 18 to a pipe 19 branched from the inlet 1a side of the pipe 1. Therefore, the pressure on the inlet 1a side is always accumulated in the pressure accumulation tank 17. In addition, the pressure accumulator tank 17 is connected to the three-way solenoid valve 1 through the piping 16.
It is communicatively connected to the port 13c of No. 3.

Note that the pipe 16 is equipped with a filter 20 and a pressure reducing valve 2.
1. A safety valve 22 is provided. Accumulator tank 1
The pressure inside the shutoff valve 7 is adjusted by the pressure reducing valve 21 to a pressure higher than the upper limit of the operating pressure set by the pressure detection section 4a of the cutoff valve 4. In addition, when the pressure reducing valve 21 leaks and the pressure increases in the pipe 16, the gas in the pipe 16 is removed by a safety valve 22, which is provided branching off from the pipe 16.
It is discharged into the open tank 9 via the piping 23. 2
4 is an earthquake sensor which detects the occurrence of an earthquake and outputs a signal. A power outage detector 25 outputs a signal when a power outage occurs due to an earthquake or the like, for example. Reference numeral 26 denotes an operation panel, which is provided with a control circuit and the like inside, and is operated by being supplied with power from a power source 27.

Here, the operation of the emergency cutoff device in the event of an emergency such as an earthquake occurrence will be explained. For example, when an earthquake occurs and the piping on the outlet 1b side of the piping 1 is damaged, gas leaks from the damaged location and the pressure on the outlet 1b side drops rapidly. Then, when the pressure detection unit 4a detects a drop in pressure due to gas leakage, the cutoff valve 4 is operated to close. Therefore, since the shutoff valve 4 always detects the pressure on the outlet 1b side via the three-way solenoid valve 13, it detects that an emergency situation has occurred due to abnormal pressure on the outlet 1b side and promptly shuts off the pipe 1.
The flow path is shut off, and the gas supply to the outlet 1b side is stopped.

Next, when the earthquake sensor 24 detects the occurrence of an earthquake, a signal from the earthquake sensor 24 is supplied to the operation panel 26 . The operation panel 26 holds the signal from the earthquake sensor 24 for a certain period of time (for example, 60 seconds).
Then, when a signal is being supplied to the operation panel 26 from the power failure detector 25 after a certain period of time has elapsed, the operation panel 26
An emergency shutoff signal is output to the three-way solenoid valve 13. In addition, in the event of a relatively strong earthquake, electric lines etc. will be severed in various places and it will take a considerable amount of time to restore them. It is assumed that there is no risk of damage to the piping. Therefore, if no signal is output from the power outage detector 25 after a certain period of time has elapsed, the earthquake is a slight earthquake and there is no need to stop the gas supply. Therefore, no signal will be output from the operation panel 26 unless a power outage occurs a certain period of time after the earthquake sensor 24 detects the occurrence of an earthquake. That is, malfunctions caused by weak earthquakes or vibrations other than earthquakes are prevented.

In addition, if a signal is output from the power outage detector 25 after a certain period of time after the earthquake sensor 24 detects the occurrence of an earthquake, it is assumed that a strong earthquake has occurred, and an emergency shutoff signal is sent to the three-way solenoid valve 13. Output. As a result, the three-way solenoid valve 13 communicates between the switching ports 13a and 13c, and closes the port 13b that communicates with the outlet 1b of the pipe 1.
Therefore, the pressure accumulated in the pressure accumulation tank 17 is introduced into the port 13c via the pressure reducing valve 21, the piping 16, and the like. Therefore, the pressure adjusted to a predetermined pressure value by the pressure reducing valve 21 is supplied to the pressure detection section 4a via the three-way solenoid valve 13.

In addition, since the pressure storage tank 17 is connected to the pipe 1 via the check valve 18, the pressure on the inlet 1a side is always maintained.
Even if the side is damaged, the pressure detection part 4a of the shutoff valve 4
can supply pressure to Also, by using only the pressure in the pipe 1 to operate the shutoff valve 4,
Compatible with energy saving.

The pressure detection unit 4a is supplied with a pressure that exceeds the upper limit of the set pressure value, and detects abnormal pressure. For this reason, the shutoff valve 4 is activated and closed to cut off the flow path of the piping 1.

Therefore, if abnormal pressure occurs on the outlet 1b side after an earthquake occurs and before the emergency shutoff signal is output from the operation panel 26, the abnormal pressure will be introduced into the pressure detection section 4a via the three-way solenoid valve 13. be done. Also, before abnormal pressure is detected on the outlet 1b side, the operation panel 26
When a signal is supplied from the three-way solenoid valve 13, the three-way solenoid valve 13 performs a switching operation to supply the pressure in the pressure accumulating tank 17 to the pressure detecting section 4a. That is, the shutoff valve 4 is connected to the abnormal pressure in the piping 1 or the operation panel 2 via the three-way solenoid valve 13.
When either one of the signals from 6 is supplied, an emergency operation is performed to cut off the pipe 1.

Therefore, in the event of an earthquake, if the earthquake sensor 24 is out of order or if the cable that supplies signals from the operation panel 26 to the three-way solenoid valve 13 is cut, the shutoff valve 4 is operated to shut off by detecting abnormal pressure in the piping. be able to. In addition, the inlet 1a of the pipe 1
When the side pressure is reduced due to piping work or the like, the shutoff valve 4 can be urgently shut off by signals from the earthquake sensor 24 and the power outage detector 25. Therefore, after an earthquake occurs, the shutoff valve 4 is reliably closed and the gas supply is stopped.

It has been explained that when the operation panel 26 is supplied with signals from the earthquake sensor 24 and the power outage detector 25, the emergency cutoff signal is supplied to the three-way solenoid valve 13; however, the present invention is not limited to this. The shutoff valve 4 may be closed by outputting an emergency shutoff signal based on a signal from the valve or an emergency signal by manual operation.

Effects of the Invention As described above, the emergency shutoff device of the present invention can shut off the piping flow path in response to either detection of abnormal pressure in the pipe or an emergency shutoff signal from the outside by switching the switching valve. For example, even during piping construction or when external signals cannot be supplied, by activating one of the functions, the piping flow path can be reliably shut off, improving the reliability of the device, and furthermore, both of the above functions can be activated. Since the functions are provided in the same device, the installation space can be reduced, and maintenance and management can be facilitated. Furthermore, for example, when both an earthquake sensor signal and a power outage detector signal are output, an emergency shutoff signal is output, which prevents malfunctions caused by microtremors or vibrations other than earthquakes. It has the advantage of being able to save energy by using only

[Brief explanation of the drawing]

The figure is a schematic system diagram of an embodiment of the emergency shutoff device according to the present invention. 1... Piping, 4... Shutoff valve, 5... Pressure control valve, 13... Three-way solenoid valve, 17... Pressure storage tank, 24... Earthquake sensor, 25... Power outage detector,
26...Operation panel.

Claims (1)

[Claims] 1. A shutoff valve provided in a pipe that supplies fluid;
an emergency shutoff signal output means that outputs an emergency shutoff signal in response to the occurrence of an emergency; and pressure on the outlet side of the pipe is normally supplied to the shutoff valve, and the emergency shutoff signal from the emergency shutoff signal output means The switching valve is configured to switch so as to supply the pressure on the inlet side of the pipe to the cutoff valve, and the cutoff valve is operated in response to either abnormal pressure on the outlet side of the pipe or a signal from the emergency cutoff signal output means. An emergency shutoff device characterized by shutting off the piping flow path. 2. The emergency cutoff signal output means includes a seismic sensor that detects the occurrence of an earthquake and a power outage detector that detects the occurrence of a power outage, and when a signal is output from the seismic sensor and the power outage detector, the emergency cutoff signal is output. The emergency shutoff device according to claim 1, characterized in that a shutoff signal is supplied to the switching valve. 3. An emergency shutoff device, wherein the switching valve supplies pressure from a pressure accumulating tank that accumulates pressure on the pipe inlet side to the shutoff valve when the emergency shutoff signal is supplied.