Valve including a device for immobilizing a journal, energy conversion installation/fluid distribution network including such a valve and method of demounting such a valve

A valve integrated into a fluid distribution network and enabling selective interruption or authorization of the circulation of a fluid in a feed pipe, the valve comprising:

• a fluid blocking member driven in rotation by an actuator device of the valve alternately to block or to authorize the passage of the fluid and which includes at least one journal,
• a hollow body inside which the blocking member is mobile and which defines at least one bore for receiving the journal,
• a bearing disposed around the journal and inside the bore of the body to support the journal and guide its rotation relative to the bore, thereby centering the journal,
• An immobilization device to immobilize the journal relative to the body of the valve, the immobilization device being on the same side of the bearing as the internal volume of the hollow body and being movable via a lining that is part of the bearing to go from a non-clamped first configuration in which it does not oppose the rotation of the journal in the bore to a clamped second configuration in which it immobilizes the journal in the bore and to go from the second configuration to the first configuration.