Abstract:

During the normal operation of cryogenic tank, the top flange of pump sump is subject to not only the periodic pressure and temperature changes but also the vibration load of pump in operation. Its unreasonable design may lead to the sealing failure of flange, the leakage of low temperature medium from flange seal and the local cold brittle cracking of tank roof near pump sump pipe, causing great hazard. This article analyzes the changes in temperature，pressure and load on the top flange of pump sump under various conditions, summarizes the possible causes of sealing failure of top flange, proposes some measures for avoiding the leakage at flange sealing face, and puts forward some suggestions for the reasonable design of top flange and fittings.

Key words:

cryogenic tank')">"> cryogenic tank, pump sump, flange, failure, leakage