PURPOSE: To prevent corrosion of the main body of a safety valve, by detecting the operation of the safety valve as bubbles in an oil tank for a gas purger, and preventing the intrusion of water into the outlet side of the safety valve from a discharge pipe by a blind packing.

CONSTITUTION: A safety valve 1 is connected to a refrigerating pressure container, a heat exchanger, and the like in a refrigerant device through an inlet valve 2 of the safety valve. A discharge pipe 3 is connected to the outlet side of the safety valve 1 and guides and discharges the refrigerant gas, which is blown out when the safety valve 1 is actuated, to the outside of a room, a ship, or the like. A blind packing 5 is provided between a pair of flanges 4 and 4, which are provided at the intermediate part of the discharge pipe 3. The packing is broken by a pressure of 4.8W5.0kg/cm2. One end of a pipe 12 is connected to a refrigerant inlet and air discharge port 10 of a gas purger 8 through a stop valve 11. The other end thereof is opened in the oil in a gas purger oil tank 9. The refrigerant gas, which is discharged as bubbles in the gas purger oil tank 9 is exhausted through an exhausting pipe 13.