GAS SUPPLY SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a gas supply system capable of more reliably and early detecting a minute breakage of a diaphragm in a constant-pressure valve.SOLUTION: There are provided: a valve port provided on a cutoff wall between a primary side flow passage and a secondary side flow passage; a valve body that regulates opening of the valve port; a diaphragm that deforms in accordance with pressure of the secondary side flow passage; a valve-body drive mechanism that drives the valve body in conjunction with deformation of the diaphragm; a pressure receiving chamber partitioned by the diaphragm and communicating with the secondary side flow passage; and a back pressure chamber partitioned by the diaphragm and communicating with atmosphere. The gas supply system comprises: a constant-pressure valve V2 for leading gas, which is introduced from the primary side flow passage under a primary pressure, through the secondary side flow passage under a secondary pressure; pressure detecting means 53 for detecting pressure of the back pressure chamber; a gas line 51a connected to the primary side flow passage of the constant-pressure valve V2; an opening-closing valve V3; and a control part 54 for controlling the opening-closing valve V3 so as to put the gas line 51a into a closed state when the pressure of the back pressure chamber, which is detected by the pressure detecting means 53, exceeds a threshold pressure.