Patent ID: 7536786

Claim:
A method for replacing an open-close valve for a hydrogen storage tank, wherein the hydrogen tank includes a tank body accommodating hydrogen absorption material and a main passage used to supply hydrogen gas to the tank body and release hydrogen gas from the tank body, and the open-close valve is connected to the main passage to open and close the main passage, the method comprising: arranging a sub-passage in the hydrogen storage tank independently from the main passage; releasing hydrogen gas from the tank body through the main passage by opening the main passage with the open-close valve in a state in which the sub-passage is closed; supplying inert gas through the sub-passage to the tank body from which hydrogen gas has been released by opening the sub-passage; replacing the open-close valve while continuing to supply inert gas to the tank body; discharging inert gas from the tank body through the main passage or the sub-passage after the open-close valve is replaced; and supplying hydrogen gas to the tank body through the main passage after the open- close valve is replaced.