A pre-assembled, pre-tested quench path outlet assembly for providing a cryogen egress path from a cryogen vessel. A quench valve (26) is mounted within a flange (28). A cryogen egress tube (32) is sealed in leak-tight manner to the flange, to define a cryogen egress path (40) extending through the cryogen egress tube, the flange and the quench valve. The cryogen egress path is closed by a burst disc (34). In use, the pre-assembled, pre-tested quench path outlet assembly is mounted onto the cryogen vessel such that thermal stratification of gas within the cryogen vessel under normal conditions causes a lower end of the cryogen egress tube to be at a temperature below the freezing points of common air components.