On June 18, 2014, a 41-year-old production supervisor with 19 years of mining experience was killed at a sand and gravel mine.  The victim and two contract workers were attempting to remove an impeller that was seized onto the threaded shaft of a centrifugal pump.  After several failed attempts to unscrew the impeller, heat from a torch was applied to the enclosed hub on the impeller.  While applying heat, the hub exploded and metal fragments struck the victim.

Best Practices

• Establish and discuss safe work procedures before beginning work. Identify and control all hazards associated with the work to be performed and use methods to properly protect persons.
• Train all persons to understand the hazards associated with the work being performed.
• Do not apply heat or open flame where enclosed spaces such as impeller hubs, mounted tires, suspension struts, or tanks may be subject to explosion except as directed by the manufacturer.
• Always examine materials before applying heat, cutting, or welding to ensure gases from the applied heat can vent.
• Never apply heat to materials before ensuring that flammables/combustibles/explosive materials are not present.
• Never apply heat to materials where pressure build up is possible.
• Do not apply heat or open flame where lubricants, oil, or grease are present.
• Use special tools, provided by the manufacturer, to loosen an impeller on a pump.
• Refer to the maintenance manual, warning labels on the pump, or contact the manufacturer for special safety precautions.

Click here for: MSHA Preliminary Report (pdf), MSHA Investigation Report (pdf), Overview (powerpoint), Overview (pdf).