Accidents pump explosions

An explosion was experienced dining work up of an epoxide opening reaction involving acidified sodium azide in a dichloromethane/dimethyl sulfoxide solvent. The author ascribes this to diazidomethane formation from dichloromethane [1]. A second report of an analoguous accident, also attributed to diazidomethane, almost certainly involved hydrogen azide for the cold traps of a vacuum pump on a rotary evaporator were involved this implies an explosive more volatile than dichloromethane. It is recommended that halogenated solvents be not used for azide reactions [2]. 

More than two years later a similar accident occurred in the same company, again the pump bearing overheated but on this occasion it was not the pump which exploded but a tanker refilling at a storage tank. The explosive decomposition had not been stopped by the cold transportation hose, as in 1999, which allowed it to enter the vehicle s tank and explode. The explosion caused injury to 11 people and severe damage to the immediate surroundings. 

In search for similar accidents with the same re-occurring deviations prior to the accident, two cases were identified here. In both cases an explosion occurred during the unloading of a tanker when a pump overheated causing a decomposition of N2O vapour, resulting in an explosion. 

Sometimes two other incidents are attributed to LNG The first one - a construction accident on Staten Island in 1973 - was cited as a LNG accident because work was carried out inside an empty LNG tank. The second - an electrical seal failure on a LNG pump that failed in 1979 - caused an explosion because gas (not LNG) entered an enclosed building. This event gave rise to a thorough revision of the code for electrical seals used with all flammable fluids underpressure [10],... 

Centrifugal pumps serve the industries well, but can be involved in accidents even if they are correctly sized and specified, made of the correct materials, and properly installed. Three pump incidents follow. This first case history involves an explosive incident that occurred during maintenance to remove a defective pump. Incidents two and three occurred during operations. 

The consequences of the accident were exacerbated by the lack of a water system dedicated to fire fighting, and by deficiencies in the shared system. When the process water system was extensively damaged by the explosion, the plant s water supply for fighting fires was also disrupted. The water pressure was inadequate for fire fighting. The force of the explosion ruptured water-lines and adjacent vessels containing flammable and combustible materials. The ruptured water lines could not be isolated to restore water pressure because the valves to do so were engulfed in flames. Of the three backup diesel pumps, one had been taken out of service and was unavailable, and another soon ran... 

Low liquid levels can be as troublesome as high liquid levels. When bottom level is lost, vapor can flow out of the column bottom. In one incident (210), such vapor flow ruptured the bottom product storage tank. Low bottom levels can also cause cavitation and overhehting of bottom pumps. In some services, a low bottom level can excessively cottCentrate some chemicals, inducing an undesirable reaction. If these chemicals are unstable (e.g., peroxides, acetylenic compounds), an explosion may result. Some reported accidents (97, 275) were initiated by low liquid levels at the bottom sump. 

An accident happened when a nitration reaction using liquid nitrogen dioxide as the nitrating agent was scaled up from laboratory to pilot plant scale. The explosion was triggered by excessive friction in the packing of a pump. The... 

In the Piper Alpha Enquiry [1], Cullen reviewed evidence from survivors and experts and tried to reconstruct events. This was difficult because many of the people most directly involved in events had died. Cullen concluded that the most likely cause of the explosions and fire was because a member of the nightshift operations team, George Vernon, had started up a condensate (light hydrocarbon) pump, here called pump A, when it was still under maintenance with an outstanding Permit to Work, and was therefore not in a safe condition. George Vernon died in the accident. 

As can be seen in Table 1 and Figure 1, these findings are similar to findings of other analyses. The similarities are probably the result of using the same basic equipment (pumps, tanks, vessels columns, etc.) and similar processes. So, fires and explosions, including Vapour Cloud Explosions, are the major accidents with which the oil and gas industry are faced. The most common is fire, however explosion has more potential damage in terms of fatalities and loss of property (Khan Abbasi, 1999). 

See Rock Blasting and Explosives Engineering, 75. The accident referenced involved the pumping of a water gel explosive. 

---