Patent attributes
A valve device includes a body, a joint, a check valve, a valve seat fixation member having an outer peripheral surface on which an external thread is provided, and a sealing member. The body has an attachment hole that attaches the joint and the valve seat fixation member from an outside of the body in a sequence of the joint and the valve seat fixation member, and that has an inner peripheral surface in which an internal thread screwed to the external thread of the valve seat fixation member is provided. The sealing member is provided between the joint and the valve seat fixation member. An outer peripheral edge of the sealing member is located radially inward of a screwed region of the internal thread and the external thread.