Gas supply apparatus and air or nitrogen supply apparatus of nuclear plant

摘要

A gas supply apparatus of the present invention includes: an operating valve that is placed in the middle of a piping for letting at least gas in a plant flow and that operates a valve main body by the gas flowing in the piping; a first electromagnetic valve 2A that is placed in the middle of the piping and that opens or closes a flow of the gas to the operating valve; and a gas supply source that supplies the first electromagnetic valve 2A with the gas. A gas discharge line of the first electromagnetic valve has a switching valve 3 placed therein and has a second electromagnetic valve 2C placed between the switching valve 3 and the gas supply source. The switching valve 3 switches between a gas discharge from the first electromagnetic valve 2A and a gas supply to the first electromagnetic valve 2A. When a power source is lost, the switching valve 3 is switched to connection to the gas supply source so as to supply the first electromagnetic valve 2A with the gas. At the time of a normal operation, the second electromagnetic valve 2C opens a gas discharge line side and closes a switching valve side, and when the power source is lost, the second electromagnetic valve 2C opens the switching valve side and closes the gas discharge line side. In this way, even when the power source is lost, an operating valve such as an air-operated valve can not only be operated remotely but also be operated safely by a remote operator.