Another Pipefitters Error

Pipefitters have occasionally installed reverse buckling rupture discs upside down. Depending on the rupture disc manufacturer s specifications, this usually means that the bursting pressure of the disc will be 50 percent higher than the manufacturer guaranteed as the relieving pressure. Such incidents must have happened at numerous plants and have been whispered about, but seldorn documented. 

The simple error of installing a rupture disc upside down is easy to do in a minute or two and can jeopardize the integrity of the overpressure protection system. Rupture disc manufacturer s representatives are available to discuss proper handling with engineers and craftsman such training can be very helpful. 

A Cooling Water System Is Safeguarded and an Explosion Occurs Some Months Later 

David Mansfield, in an article in the British Loss Prevention Bulletin, captures the focus on the need for an effective Management of Change Policy in his introductory paragraph Every once in a while an apparently subtle change to a process or method of operation gives rise to a new or at least totally unexpected hazard. [6] 

After the accident, the cooling water tests revealed 14-percent ethylene glycol (antifreeze) in the system. Tests were conducted with the biocide and the ethylene glycol solution. Investigators learned that after a dormant period of several days, the temperature of the mixture suddenly increased and the solution released bromine gas. Testing showed that at elevated temperatures of about 140° F (60° C), the reaction occurred without the delay. 

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