Patent attributes
A safety valve comprises a pressure receiving hole (20), an actuation chamber (21), a discharging hole (22) and an alloy accommodating chamber (25). An alloy (27) of a low-temperature melting point is accommodated within the alloy accommodating chamber (25). A sealing plate (33) seals the pressure receiving hole (20). This sealing plate (33) has a portion, which faces the pressure receiving hole (20), provided with a breakable sealing portion (35) that breaks up with a predetermined pressure. An actuator (28) is arranged within the actuation chamber (21). The actuator (28) has one end formed with a first back-up portion (30) which supports the breakable sealing portion (35) and has the other end formed with a second back-up portion (31) which is supported by the alloy (27).