VIBRATION-SENSITIVE CUTOFF DEVICE FOR GAS PIPELINE

摘要

PROBLEM TO BE SOLVED: To stop blow-out of a gas when vibrations are sensed.SOLUTION: In a vibration-sensitive cutoff device for a gas pipeline, a cutoff valve 10 is interposed in a gas pipeline P, and the cutoff valve is closed in accordance with a signal from a vibration sensor 30. The cutoff valve and the vibration sensor are connected by a gas piping 44. The vibration sensor is mechanical and includes an on-off valve 32, a gas a1 is introduced from the gas pipeline P, and the on-off valve 32 passes a gas a2 to the gas piping 44 by sensing of vibration. The cutoff valve 10 is closed by gas introduction that becomes a signal from the gas piping 44. Thus, since the cutoff valve is operated by a closed circuit, gas cutoff during earthquake can be performed without requiring a power soure and in such a case, gas leakage is also prevented. The cutoff valve including an upper limit pressure cutoff function is adopted and the gas a2 from the vibration sensor is applied to the cutoff valve to be equal to or higher than upper limit pressure, such that the cutoff valve is closed.