Failures in cabin type hydrocarbon heaters due to inadequate fuel control

The causes of recent fires in hydrocarbon heaters are discussed in this paper. In particular, failures are chosen for which root causes involve trying to get around existing operational shortcomings by making changes to control, instead of carrying out a proper Root Cause Analysis to identify actual causes of deficiencies. In one case, the heater would extinguish due to the poor characteristics of fuel gas. A restart routine was devised, in which previous purging was avoided. In the other case, turning off one burner would turn off the remaining. Instead of addressing the reason why a burner would turn off, the operator modified gas inlet control so that the remaining burners would remain on. Details are given of the chain of events that led to these failures. It is concluded that heaters should be carefully chosen or designed to meet specific operation requirements. Modifications should be avoided whenever possible and carefully planned, in association with the manufacturer when they are unavoidable. In every case, safety systems should be in accordance with modern safety standards.

► Root causes for fires and explosions in hydrocarbon heaters.
► Normal features of in-service degradation leading to heaters failure.
► Investigation in deficiencies in design of control systems.
► How construction drawbacks affected heaters performance.
► Chain of errors introduced by modifications meant to deal with deficiencies.