Unauthorized field modified equipment, drain lines cause control cabinet explosion

A sealed, unclassified electrical control enclosure, part of a listed and certified force-ventilated commercial hydrogen processing unit enclosure, exploded when the equipment manufacturer’s technician pressed the machine stop switch to complete factory commissioning procedure. The technician was forcefully hit by the flying metal panel holding the switch and sustained serious injuries requiring lengthy hospitalization and rehabilitation. Two were hospitalized. Two others were injured.

Unauthorized field modified equipment, drain lines cause control cabinet explosion

A sealed, unclassified electrical control enclosure, part of a listed and certified force-ventilated commercial hydrogen processing unit enclosure, exploded when the equipment manufacturer’s technician pressed the machine stop switch to complete factory commissioning procedure. The technician was forcefully hit by the flying metal panel holding the switch and sustained serious injuries requiring lengthy hospitalization and rehabilitation. Two were hospitalized. Two others were injured.

Fueling station high pressure storage leak

A hydrogen leak originating from a tank within a high-pressure storage unit serving a hydrogen vehicle fueling station resulted in fire and explosion. Emergency responders were on scene within 7 minutes and contained the fire within 3 hours. No damage was reported to the separate forecourt H2 dispenser or to other major station components within the station backcourt compound.

Fueling station high pressure storage leak

A hydrogen leak originating from a tank within a high-pressure storage unit serving a hydrogen vehicle fueling station resulted in fire and explosion. Emergency responders were on scene within 7 minutes and contained the fire within 3 hours. No damage was reported to the separate forecourt H2 dispenser or to other major station components within the station backcourt compound.

Liquid Hydrogen Delivery Truck Fire

First Name
Andy
Last Name
Piatt

A fire erupted from a tanker truck delivering liquid hydrogen to a factory. The ignition of leaking vapors created a plume of flames that rose dozens of feet into the air. The flames receded within seconds, leaving the truck with little damage and its driver unharmed.

The truck was off-loading hydrogen into a tank behind the plant when the incident occurred. The plant reported no delays in its production. It uses the hydrogen in various processes.

Hydrogen Cylinder Leak

First Name
Andy
Last Name
Piatt

A hydrogen cylinder was initially located in an adjacent laboratory, with tubing going through the wall into the laboratory in use. When the cylinder was moved to the laboratory in use, a required leak check was not performed. Unfortunately, a leak had developed that was sufficient to cause an accumulation of hydrogen to a level above the Lower Flammability Limit. The hydrogen ignited when a computer power plug was pulled from an outlet. The exact configuration of the leak location and the outlet plug is unknown.

Small Electrical Fire Resulting from Improper Equipment Configuration

First Name
Andy
Last Name
Piatt

An employee noticed an unusual smell in a fuel cell laboratory. A shunt inside experimental equipment overheated and caused insulation on conductors to burn. Flames were approximately one inch high and very localized. The employee de-energized equipment and blew out the flames. No combustible material was in the vicinity of the experiment. The fire was contained within the fuel cell and resulted in no damage to equipment.

Storage Tank LFL Analyzer Reading Out of Surveillance Limits

First Name
Andy
Last Name
Piatt

As a prerequisite to a storage tank slurry pump run, a tank operator identified a Lower Flammability Limit (LFL) Analyzer surveillance reading to the control room that was out of limits low. The reading was a negative zero % LFL indication (-0 % LFL). The tank operator roundsheet limits are 0 to 10% LFL. The "null" value (value read on analyzer when air with 0% LFL is drawn through the analyzer) as directed by the LFL Analyzer loop calibration procedure is set between 0 and 4% LFL.

Swagelok Fittings Under High Pressure

First Name
Andy
Last Name
Piatt

A shop supervisor determined that a second shift would be necessary to complete some priority work on the spare hydrogen mitigation pump. The work scope for the shift would be dedicated to continued fabrication of designed tubing runs, repairs to existing tubing with known leaks and pressure testing of other various tubing runs. The shift craft complement would include three pipe fitters, one welder, one QC inspector and a shift supervisor.

Improper Line Break During Cleaning Run

First Name
Andy
Last Name
Piatt

An operator began preparations for a cleaning run, and was unaware that a maintenance task to calibrate a pressure transducer was scheduled to also take place that morning. The calibration required a break on a hydrogen line in order to install a Measuring and Test Equipment (M&TE) gage, which was used in the calibration. At the time the operator was informed of the calibration, the cleaning run procedure had been initiated but the actual cleaning had not yet begun.

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