Coupling device, and method for flushing same

A self-closing emergency coupling and release device for the transport of cryogenic fluid, comprising

• two fluid transport pipes extending in a longitudinal direction and each comprising, at a connection end, a valve mechanism configured to automatically close the pipe when the connection ends are separated and to open the pipe when the connection ends are coupled,
• an outer tube that is disposed around each transport pipe and defines a space under vacuum for thermal insulation of the transport pipe, the device being configured to delimit a determined fluid-tight dead volume between the coupled connection ends, and
• a system for purging the dead volume, the purge system comprising a fluidic circuit fluidically connected to said dead volume,
• wherein the fluidic circuit of the purge system comprises a transfer pipe having an end leading into the dead volume, at least one reservoir of pressurized purging and/or inerting gas connected to the transfer pipe and configured to supply gas to the dead volume, the purge system comprising a gas discharge means for the gas, and
• wherein, when the connection ends are fluid-tightly coupled with the valve mechanism closed, the purge system is configured to purge the dead volume via the gas discharge means.