Fire on a heat exchanger at refinery

In a petrochemical plant, visual inspection detects fumes under the heat insulation of a heat exchanger operating under hydrogen pressure.
The first intervention team was mobilized and the unit stopped for depressurization and cooling.
A risk analysis was conducted before erecting a scaffold, decalcifying the exchanger and inspecting it under safe conditions. After having defined the fire protection and fire prevention strategy, the operator decided to put the unit back under pressure.
During this rise in pressure, a resumption of fire on the flange justified the triggering of the emergency plan. The intervention team managed the fire.
No injuries or impacts outside the site are to be deplored.
At the time of the accident, the plant was shut down due to a staff strike. The unit, usually operated under a mixture of butane and hydrogen, according to the supplier's recommendations, was filled with hydrogen only.

A leaking seal on a flange is the cause of the accident.

heat exchanger operating under hydrogen pressure

At the time of the accident, the plant was shut down due to a staff strike. The unit, usually operated under a mixture of butane and hydrogen, was filled with pure hydrogen according to supplier's recommendations.

No injuries or impacts outside the site are to be deplored. At the time of the accident, the plant was shut down due to a staff strike.

The action plan put in place to reduce the probability of re-occurrence of the accident comprises:
1. the study of the possibility of cooling and re-pressurizing the heat exchanger under helium or nitrogen,
2. preventive replacement of all connections under hydrogen
3. regular technical inspection.