CHECK OUT OUR MOST RELEVANT INCIDENT LISTINGS!
Disclaimer: The Lessons Learned Database includes the incidents that were voluntarily submitted. The database is not a comprehensive source for all incidents that have occurred.
An important aspect of the reliability of a valve is the condition of the stem seal which tends to deteriorate with time and wear. Valves used in hydrogen service should be packed with the correct valve packing material and periodically checked…
Personnel were focused on the AGES system test and results, not the compatibility of the test equipment. The manual valve was needed to successfully test the system, however the fact that this particular valve could not accommodate the full…
Because the bottle was located outside at the time of the event, and the hydrogen did not find a source of ignition while venting through the relief valve, nothing serious happened. The failed regulator was replaced and operations continued.…
The following actions were proposed as a result of this incident: The company in charge of valve calibration and maintenance will be subject to approval of the plant service inspection team. Plant operating procedures will be improved. The…
Follow the rules (e.g., using a torque-amplifying device requires supervisor approval).
Some valves are susceptible to disassembly, with potentially significant consequences, if excessive torque is applied to the handwheel.
Active GH2 sensors should be installed and continuously monitored in all enclosed buildings near GH2 sources. All buildings near areas where hydrogen is used should be designed to preclude GH2 entrapment (e.g., sloping roof with ventilation at…
Recommendations:
The using organization should define necessary activities in order to place hydrogen systems in long-term periods of inactivity. The defined activities should address requirements for rendering inert, isolation (i.e.,…
To prevent a similar flashback, the following measures have been taken:
The valve is opened slowly to avoid a major leading shock into the venting line.
A special nozzle (Laval or similar) is mounted directly after the opening…
The following corrective actions have been taken:
The non-return valve was dismantled, cleaned, and tested. Following positive testing, the system was restarted and pressurized without any further malfunctioning.
The hydrogen…
Included inspection on monthly preventive maintenance plan and evaluated alternate materials for better cold-weather performance.
1. Ensure that equipment and materials exposed to hydrogen are compatible with a hydrogen environment (even hydrogen-service-rated equipment).
2. Equipment designs in a hydrogen environment that use the fracture toughness for 17-4…
The packing in the flow control valve should be replaced periodically. A planned investigation will determine the optimum time period for packing replacement.
Maintenance work scopes must be adhered to. If added work is approved, it must be tracked and reviewed to ensure that the equipment is inspected by operations personnel. Scheduled work and extra work should be listed and checked off for proper…
Excessive venting of hydrogen from the tank due to lower facility consumption, in combination with extreme temperature conditions, placed thermal stress on the gland nut, causing a leak. The low consumption of hydrogen resulted from the shutdown…
Proper installation of check valves and other equipment should be visually inspected prior to pressurization.
Investigation determined that internal galling has caused the failure rendering the needle valve unusable. The galling was caused by a stainless steel stem acting against a stainless steel seat. This failure mode had been observed before and the…
The plant tried to increase production and decrease workload, but failed to notice the potential negative outcomes of this change.
It is necessary to thoroughly simulate all potential negative outcomes of a change in procedures.
…
Fail-safe position of control valves in supply lines must be set correctly to prevent damage to pressure vessels.
Recommendation
Set all valves for fail safe operation (open or closed) according to needs before installation in…
Lessons Learned
Construction errors are difficult to detect once construction is complete. It is important to develop and use a systematic oversight process for minimizing construction errors during the construction process.
…
Extra caution should be taken when working around elevated pressure storage tanks. Pressure relief valve settings should be checked and then verified by a second party if possible. Proper procedures need to be followed at all times.
Key:
- = No Ignition
- = Explosion
- = Fire
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 |
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 | |||||||
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