Explosion in a flammable gases pipelines system

A fire occurred in a pipe trench containing about 50 pipelines.
The pipelines were carrying a wide variety of hydrocarbons from crude oil to residuals. In addition, there were lines with steam, fuel gas, hydrogen, amine solutions and sour water pipelines.
Within 10 minutes of the fire, an explosion occurred followed by larger explosions in the pipe trench as pipelines ruptured. The fire spread to a diesel tank. The refinery had to be taken offline. The fires were extinguished after 12 hours. A lagging fire was concluded with excessive oil in the trench. The pipes ruptured due to no relief valve and being blocked in.

The INITIATING CAUSE was a fire in a trench populated with several fuel pipes

The reason for the fire is not given. It could be speculated that a flammable substance leaked from one of the pipes and ignited, engulfing the other pipes. The explosions noticed after the fire started could have been caused by the individual rupture of other pipes.

The ROOT CAUSE of the fire is unknown.

hydrocarbons pipeline

The refinery had to be taken offline.
The fires were extinguished after 12 hours

1. Provide adequate clearance below pipes so that drainage is adequate to prevent accumulation of oil.
2. Remove steam and other high temperature lines from main pipe alleys to reduce ignition sources.
3. Install additional fire fighting water turret monitors to improve first response fire fighting ability.
4. Provide a fire break to reduce pipe alley fire exposure.
5. Emphasize improved housekeeping, as related to free oil and oil soaked insulation.
6. Minimize piping inside tank firewalls.