Fire on a compressor at a hydro-tretement unit

A fire developed at a recycle gas compressor of a refinery. During recommissioning, the compressor, belonging to a hydro-treatement unit, was overpressurised. The cylinder head was blown off, resulting in an explosive decompression and fire. It was found that the discharge valve was installed in the wrong direction.

Investigations into the accident showed that the INITIATING CAUSE was the installation of one of the discharge valves in the reverse direction. This results in the build up of pressure within the cylinder.

The criticality of the task to replace the valve had not been understood or reflected in procedures. Although the compressor was purchased according to the API 618 standard, which requires a design that prevent valves from being installed in the wrong direction, the equipment did not meet specification.
The ROOT CAUSES were shortcoming in maintenance procedure and in quality assurance when dealing with contractors/manufacturers.

valve, compressor head, compressor,

The ICHEME report used the term Hydrofiner: this is an industrial unit, primarily in oil refineries, that uses hydrogen and catalysts to remove impurities (sulphur, nitrogen, aromatics) from petroleum fractions, improving fuel quality (like gasoline, diesel, jet fuels). The more generic term is catalytic hydrotreating process to "clean" oil products, making them cleaner burning and more valuable.
The report does not specify the composition of the process gas, but it is known the the recycled gas consists mainly of hydrogen with traces of H2S.

Production losses and repair costs were estimated at $500,000 (1995) (£318,300) and $400,000 (£254,600) (1995), respectively.

The lesson learnt from this event was that the company had to review and improve the quality control and assurance of the products obtained from third parties. This review must consider all components playing a critical role in guaranteeing safety of the plant.