Refinery-wide failures

Consideration of Plant-wide or Refinery-wide Failure - Although not... 

Consideration of Plant - wide or refinery wide failures - Although not normally used as a basis for sizing pressure relieving facUities, the following general steam failmes must be considered ... 

Apart from the technical details of this incident, there were some organizational issues worthy of note. Shell operates refineries and chemical plants in many locations around the world. Before the incident at Deer Park, a similar failure had occurred in a pneumatic valve manufactured by the same supplier at another Shell refinery in the Middle East. A company-wide bulletin had been issued warning of the potential for failure with this type of valve, but no follow-up action appeared to have been taken. 

As refineries have evolved, distillation has remained the prime means by which petroleum is refined (Speight, 1999). Indeed, the distillation section of a modem refinery is the most flexible unit in the refinery since conditions can be adjusted to process a wide range of refinery feedstocks from the lighter cmde oils to the heavier, more viscous cmde oils. However, the maximum permissible temperature (in the vaporizing furnace or heater) to which the feedstock can be subjected is 350°C (660°F). The rate of thermal decomposition increases markedly above this temperature if decomposition occurs within a distillation unit, it can lead to coke deposition in the heater pipes or in the tower itself with the resulting failure of the unit. 

In Pease v. Sinclair Refinery Co., a manufacturer of chemistry teachers demonstration kits offered one kit which contained sample tubes of different liquids, one of which was supposed to be kerosene. Unfortunately, since kerosene has the same physical appearance as water, the manufacturer substituted water for kerosene in the tube, perhaps in an effort to save costs. A severe injury occurred when the water was inadvertently mixed with a chemical which was explosive in the presence of water. The court held that the manufacturer should have foreseen that, in a chemistry classroom setting, a number of chemicals might come in contact with each other, most certainly with water. The court balanced the gravity of the possible harm - explosion, against what it viewed as the ease with which the manufacturer could have provided a warning. Compare the results in that case, however, with the Croteau v. Borden Co.f where a chemical manufacturer was held not liable to a laboratory technician for a failure to warn that if one of its chemicals was mixed with a wide variety of other chemicals an explosion might be produced. 

Most of the water used industrially removes heat from production processes. It is one of the major applications for water and is a major factor in siting plants and processes. Cooling systems suffer many forms of corrosion and failure. The diversity of attack stems from wide differences in cooling water system design, temperature, flow, water chemistry, alloy composition, and operation. An almost endless variation of process stream chemistries may be involved in cooling water systems. Refinery and chemical process industries can employ hundreds of heat exchangers at a single plant, each with a different process stream chemistry [14]. 

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