Patent attributes
A valve device for a gas tank, includes a body and a check valve provided in an injection passage to inject gas into the gas tank. The check valve includes a valve seat, a case fixed in the injection passage while a space is provided between an inner peripheral surface of the injection passage and the case to enable gas to flow through the space, and a valve element accommodated in the case. The case includes a cylindrical portion, and is configured such that the bottom of the cylindrical portion, provided at an opposite side to the valve seat, defines a range where the valve element is axially movable. The valve element includes a head portion that can block a valve hole of the valve seat, and a sliding portion formed to be axially movable with respect to the cylindrical portion.