Abstract: It is very important to prevent thewater-jacketheater from accidents, improve its reliability, and expand its using life for safety of oil& gas gathering and transmission. The fault tree analysis is the causality of failures from the top tree event to the bottom tree event. the analysiswas conducted from the results to the causes, from the top to the bottom. Themethod is the characteristics of simplicity, easy understanding, flexibility, an effectivemethod for reliability analysis and evaluation of engineering. All factors thatmaymake the water- jacket heater failure was analyzed in the paper, and builds a fault treewith failure of water-jacketheater as top eventwas setup. W ith the fault tree analysis, theminimum cut-set of the fault tree was obtained.With the calculation of structure significance of bottom events,theweakest factorwas found. The majorway of water-jacket heater failure was determined. And the corresponding measures were presented in paper.

Key words: water-jacket heater, failure, analysis, fault tree, structure significance