A thermal analysis of the slow depressurization of a high-pressure gas
-filled vessel in relation to operation safety is described. The inher
ent differences and similarities of simple mathematical models and the
ir solutions are discussed. A safety criterion to prevent the vessel w
all temperature from dropping below the ductile-brittle transition lim
it of the steel is established. The influences of some important syste
m parameters are investigated. (C) 1997 Elsevier Science Ltd.