The bulkhead between a liquid hydrogen tank and a liquid oxygen tank failed due to a series of events. Air services to the building were shut down for repairs and the facility had switched to an emergency nitrogen supply. Failure to switch back to service air when it became available, led to the mishap.

The emergency supply became depleted and two valves in the normal nitrogen purge system failed in the open position, releasing the high-pressure nitrogen gas from the manifold into the liquid hydrogen tank. The gas flow raised the liquid hydrogen tank pressure to 4.5 psig. That was sufficient to rupture the bulkhead wall.

A laboratory technician died and three others were injured when hydrogen gas being used in experiments leaked and ignited a flash fire.

The incident occurred in a 5,700-square-foot, single-story building of unprotected non-combustible construction. The building was not equipped with automatic gas detection or fire suppression systems.

Employees in the laboratory were conducting high-pressure, high-temperature experiments with animal and vegetable oils in a catalytic cracker under a gas blanket. They were using a liquefied petroleum gas burner to supply heat in the process.

Investigators believe that a large volume of hydrogen leaked into the room through a pump seal or a pipe union, spread throughout the laboratory, and ignited after coming into contact with the view more

An employee at a soap manufacturing plant died in a flash fire outside the facility's hydrogenation building. Responding personnel encountered a fire at the base of the plant's hydrogen storage towers, and they found the victim, who was burned over 90 percent of his body, some 50 feet away.

Officials determined that a pipe connection failed and that hydrogen, pressurized at 1,800 psi, ignited when it was released into the atmosphere, killing the plant operator.

According to reports, the pipe connection failure stemmed from pressures higher than design tolerance, which in turn were the result of over tightening that occurred during routine maintenance replacement. The new bolts were stronger than those they replaced, and the threads of the nuts had been partially view more

SummaryA fire occurred in a battery manufacturing plant that was about to cease operations for the night. The fire caused an estimated $2.4 million in property damage when an electrical source ignited combustible hydrogen vapors.BackgroundThe incident occurred in the forming room, where wet cell batteries were stored for charging on metal racks. The facility had a wet-pipe sprinkler system, but no automatic hydrogen detection equipment.Incident SynopsisAt 11:52 pm, a security guard on patrol noticed a free burning fire in the forming room and notified the fire department. It took fire fighters almost three hours to bring the fire under control.Although the facility was equipped with a wet-pipe sprinkler system, the forming room's branch had been disconnected 10 to 15 years before view more

Incident Synopsis
During a standard testing procedure, a 3,000 psig relief valve actuated at normal line pressure, releasing gaseous H2. The gaseous H2 combined with air, resulting in an explosion which damaged the test facility.

Cause
The relief valve was improperly set to open at line pressure, and the inspection was inadequate in that it didn't identify this error. Contributing cause was poor design of the venting system, which was installed in a horizontal position, causing inadequate venting and buildup of static electricity.

Incident Synopsis
While attempting to replace a rupture disk in a liquid H2 vessel, H2 gas was released and ignited. In fighting the fire, liquid N2 was sprayed onto a second liquid H2 vessel located nearby. This resulted in cracking of the outer mild steel vacuum jacket. The loss of the vacuum caused a rapid increase in pressure and rupture of the burst disk of the second vessel. H2 boiled off and was burned in the fire.

Cause
The rupture disk was being replaced with a load of liquid H2 in the vessel and no separating inerting gas. The H2-air mixture was probably ignited by static discharges. Rupture of the second vessel burst disk was caused by the low-temperature exposure of the mild steel vacuum jacket.

Incident Synopsis
During pressure testing of a H2 tank for investigation of quick-release manhole cover, the tank burst at a pressure between 60-67 psig. Flow regulators indicated peak pressure of 67 psig.

Cause
The tank was over pressurized. A mistake was made in interpreting the blueprint, believing the tank was designed to withstand 150 psig, yet the actual design limit was 50.7 psig.

Incident Synopsis
A H2 air explosion occurred near a H2 compressor, located outside. Gaseous H2 had been released from a vent stack when a relief valve was actuated. The source of ignition was not known, but considerable damage was inflicted onto the system by the ensuing fire and explosion. Following the explosion, the shut-off valves were closed and the system was vented.

Cause
Two relief valves were located in the 3,000 psig system downstream of a 5,000/3,000 regulator. The relief valves were sized to handle substantially different flows. (One was designed for another program.) The relief valve was believed to have opened when the pressure setting was being increased from 2,700 to 2,900 psig. The accuracy of the 5,000 psig gauge used to control the dome of the 5 view more

Summary

A gas-phase explosion in a storage tower with semichemical pulp at a paper mill has possibly been caused by combustion of a mixture of hydrogen and air. The hydrogen was formed by microorganisms in the pulp. Ignition may be due to electric sparks in connection with an electric field in the mist above the pulp.

Accident Description

A gas-phase explosion took place in a 1,300 m3 storage tower for semichemical pulp at a paper mill. The storage tower was 21 m high and equipped with an agitator at the bottom. By a pumping arrangement, the pulp was circulated from the bottom to the top through external pipes connected with the mill (Fig. 1).

On a given day the production was stopped at a time when the storage tower was loaded with 1,000 m3 pulp at a view more

An explosion occurred in an electrolysis system in a commercial facility. Electrolysis of a potassium hydroxide solution is used to produce hydrogen for a hydrogenation processes. The circular electrolysis cells are 1.5 m in diameter and 25 mm thick. Design current for the electrolyzer is 6,000 amps at 1.78 volts. Operating temperature and pressure is 70-90 °C and 435 psig. Hydrogen and oxygen product gases are separated from the electrolyte in separating drums. The system had been operating at the plant for 13 years prior to the explosion. Operating experiences had been generally favorable except for the need to periodically flush the system with water to remove sludge formations.

According to the investigative report, sludge deposits in the electrolyte passages started the view more

Key:

  • = No Ignition
  • = Explosion
  • = Fire
Hydrogen Incident Summaries by Equipment and Primary Cause/Issue
Equipment / Cause Equipment Design or Selection Component Failure Operational Error Installation or Maintenance Inadequate Gas or Flame Detection Emergency Shutdown Response Other or Unknown
Hydrogen Gas Metal Cylinder or Regulator   3/31/2012
4/30/1995
2/6/2013
4/26/2010 12/31/1969     3/17/1999
11/1/2001
12/23/2003
Piping/Valves 4/4/2002
2/2/2008
5/11/1999
4/20/1987
11/4/1997
12/31/1969
8/19/1986
7/27/1991
12/19/2004
2/6/2008
10/3/2008
4/5/2006
5/1/2007
9/19/2007
10/31/1980
2/7/2009 1/24/1999
2/24/2006
6/8/1998
12/31/1969
2/7/2009

9/1/1992
10/31/1980

10/3/2008  
Tubing/Fittings/Hose   9/23/1999
8/2/2004
8/6/2008
9/19/2007
1/1/1982 9/30/2004
10/7/2005
  10/7/2005  
Compressor   10/5/2009
6/10/2007
8/21/2008
1/15/2019
    10/5/2009 8/21/2008  
Liquid Hydrogen Tank or Delivery Truck 4/27/1989 12/19/2004
1/19/2009
8/6/2004 12/31/1969   1/1/1974 12/17/2004
Pressure Relief Device 7/25/2013
5/4/2012
1/15/2002
1/08/2007
12/31/1969        
Instrument 1/15/2019 3/17/1999
12/31/1969
2/6/2013
    11/13/73    
Hydrogen Generation Equipment 7/27/1999     10/23/2001      
Vehicle or Lift Truck   7/21/2011         2/8/2011
12/9/2010
Fuel Dispenser   8/2/2004
5/1/2007
6/11/2007
9/19/2007
  2/24/2006
1/22/2009
     
Fuel Cell Stack            

5/3/2004
12/9/2010
2/8/2011

Hydrogen Cooled Generator       12/31/1969
2/7/2009
     
Other (floor drain, lab
anaerobic chamber,
heated glassware,
test chamber,
gaseous hydrogen
composite cylinder,
delivery truck)
  11/14/1994
7/21/2011
7/27/1999
6/28/2010
8/21/2008
12/31/1969
3/22/2018
    6/10/2019
  • = No Ignition
  • = Explosion
  • = Fire