Role of Seismic Monitoring System
１.Control of Emergency Shutdown Valve
When earthquake occurs, it is not always true that people take action right away for emergency control.Therefore, seismometers are used in large numbers to operate emergency shut-off valves to prevent leakage of hazardous substances and water supply.
Example of water supply system installation
Examples of petroleum and scientific installations
Example of semiconductor manufacturing equipment installation
In semiconductor plants, for example, when an earthquake occurs, controls are applied to prevent gas leakage accidents, etc., in conjunction with the shutdown of the plant line. In the event of an earthquake at a lower level than line stoppage or gas shutdown, only an evacuation alarm is broadcast to encourage workers to evacuate.
As huge costs are incurred in the event of line stoppages, many semiconductor plants have adopted 2 out of 3 (multiple control units) to prevent stoppages due to malfunctions, and seismometers are also playing an active role in improving reliability.
２.Rotection of Facilities
In some cases, generators and other equipment are installed as emergency power sources (back-up power sources) in the event of an earthquake and power failure. However, during large-scale earthquakes, there have been many cases where equipment has failed because the floor surface where the generator is fixed has shifted due to ground cracking or subsidence, forcing the generator to operate in a distorted state. Therefore, it is necessary to apply controls so that emergency generators operate automatically during normal electrical power supply, but not when power is cut off due to an earthquake. Seismometers also serve to protect such equipment.
In seismic monitoring system, automatic announcement and mechanical operation are controlled by alarm output according to the level of earthquake.
Examples of factory evacuation
Examples of public facility