. In addition to health and safety risks from ammonia exposure, these types of large-scale releases can result in de agration1 if an ignition source is present with concentrations of ammonia in the ammable range.2
In 2007, hydraulic shock caused a similar ammonia release incident that resulted in an explosion at another cold storage company. Electric arching from a nearby water fountain provided an ignition source when the ammonia cloud reached an explosible concentration.3
This bulletin describes the mechanism of hydraulic shock involved in the 2010 ammonia release at Millard Refrigerated Services and summarizes the investigation’s lessons learned that aim to prevent future occurrences of hydraulic shock in the ammonia refrigeration industry.