A vertical cylindrical hydrodesulfurisation reactor charge heater was being started up with hydrogen flow only rather than hydrogen plus oil as in normal operation. As a result of the low heat load only a couple of the burners were being fired. The uneven firing resulted in one pass of the furnace being overfired and a tube ruptured. This problem was solved by installing a single centre burner for start-up. In addition multiple skin thermocouples were installed on each tube pass at the hottest points.

A vertical cylindrical fired heater was used on the charge to a hydrodesulfurisation reactor. The flow was two phase at the heater inlet (hydrogen and hydrocarbon). The distribution of flow to the multiple tube passes depends on symmetrical pipework and the pressure drop through the passes. There were no individual pass flow meters.During start-up when the flow was low a radiant tube ruptured in one pass. This was though to be due to static head in the U tubes of that pass with liquid in the up legs and vapour in the down. Thus there was no flow in that pass and it overheated.

A short circuit developed in the wiring of a fire eye system on one of two 600 psig boilers serving a refinery. This triggered a rapid sequence of events that resulted in a one week shutdown of much of the refinery. Fortunately no one was injured and equipment damage was negligible.When the hydrocracker make-up compressor started slowing down, the control system at the reformer released the excess hydrogen to the flare. However, no increase flame was observed at the flare and the crude unit pressure went over 50 psig. The trouble was quickly diagnosed as a blockage in the flare system.

The fire ignited roofing materials which had fallen down as the result of the explosion.The operator, who was outside the plant when the explosion occurred, pulled the emergency switch which shut down all the compressors. Although in a dazed condition he then checked in the motor room that all the motors had stopped. He was subsequently taken to hospital where he was found to have no physical injuries but was moderately shocked. The fire alarm was raised by the Gatekeeper who had heard the explosion and seen flames and smoke in the vicinity of the hydrogen plant.

The fire started as a result of an explosion in the process section of a refinery. An open structure of steelwork protected with reinforced concrete housed the usual furnaces, reactors, heat exchangers, storage vessels, overhead pipe racking, pumps and ancillary equipment associated with the refining of crude oils.Also included in the area were three 46m (150 ft.) high stripping and drying columns built on a concrete base approximately 91m x 21m (300 ft.

A weld on a 1 inch diameter instrument tapping from a Octafiner reactor overhead line fractured, resulting in a small but intense fire, lasting about 50 minutes until the unit was nitrogen purged.The fire was always under control and the fire fighting effort was directed solely to cooling the surrounding metal with fire steam lances. Plant Inspection reported that the failure was due to hydrogen embrittlement of the heat affected zone of the tapping and probably resulted from improper or no stress relieving of the connection during construction.

Following a catalyst regeneration a fire occurred on a hydrocracking unit during unit pressure testing prior to start-up. The fire resulted from ignition of high - pressure hydrogen-rich gas that was escaping from two shell-to-shell nozzle flanges on the hydrocracker reactor charge - effluent exchangers. Four pipefitters who were in the process of tightening the leaking flanges when the gas ignited, received first and second degree burns. The unit was depressurised to the relief system and the fire was extinguished after burning for approximately 45 minutes.

A tube in a hydrorefiner heater ruptured resulting in an extensive fire inside and outside the furnace. The main fire in the furnace was extinguished within 15 minutes and the escaping gas / vapour release from the ruptured tubes allowed to burn under controlled conditions. There were no injuries to personnel but the furnace suffered damage estimated at 10,000 (1973), which included four distorted tubes and certain refractory damage.

During repairs of a heat exchanger in a benzene plant, a mixed gas (methane and hydrogen) contained in the cold box attached to the exchanger leaked and caught fire from a welding spark. The exchanger was severely damaged by the fire.The cause of the incident: The valve was not provided with a blind plate, the cold box was in a incomplete closed position.

A fire and explosion occurred at a catalytic reformer unit. The fire centred between the reactors and fired heaters of the reformer and resulted in extensive damage to the unit.The explosion rocked the nearby refinery control centre and broke windows half a mile away. There were no injuries. After the explosion, the operating crew isolated all hydrocarbon and utilities lines at the unit battery limit. The columns and vessels could not be pumped out due to total loss of power.