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Concern Identified Regarding Installation and Commissioning of Compressed Gas Systems

Severity
Incident
Was Hydrogen Released?
Yes
Was There Ignition?
No
Incident Date
Incident Attributes
Describe the incident, including corrective steps taken and their result.

While research staff were working in a lab, a staff member opened the primary valve to a 0.2" (1500 psi) hydrogen gas line connected to a manifold supplying instruments in the lab. Upon opening the valve, the hydrogen gas line failed at a fitting on the switching manifold, releasing a small amount of hydrogen gas. The staff member closed the valve immediately, then inspected the gas line and found the front ferrule (of the compression-style fitting) to be missing. There were no injuries or damage to equipment.

In the follow-on discussion with research staff, it was learned that approximately one month earlier, a similar condition (front ferrule missing from a fitting) was found while performing a modification to a similar manifold. Following a critique, management expressed concerns relative to the installation and commissioning of compressed gas systems, specifically in regard to proper system installation and responsibility for required leak testing. Elevating this issue to a management concern will ensure that procedures and processes are reviewed and revised as necessary to clarify roles and responsibilities for compressed gas systems, further assuring users of new or modified systems that they have received proper reviews and testing.

Start-up testing was considered less than adequate because the appropriate level of testing did not occur for the type of system being installed or its intended use. The person installing the compressed gas line into a compression style fitting tee failed to include the front ferrule. Later, when the line was pressurized at 1500 psi, the fitting and line separated.

Lessons Learned

Installation

  1. Fittings need to be visually inspected to insure ferules are in place and correctly positioned prior to swageing.
  2. Research staff are responsible for communicating system specifications [gas type, Maximum Allowable Working Pressure(MAWP)] and testing requirements to service provider.
  3. Lines that run through ceilings and chases should be pressure-tested at the MAWP of the materials of that line.

Commissioning

  1. System owners/users should specify QA requirements such as leak testing and service providers/installers must provide appropriate documentation.
  2. System owners/users should document that they have accepted work.
  3. The system owner is responsible for tracking, through safety documentation such as IOPS or SOPs, system modifications and procedural changes. Use of safety documentation prevents off normal events that could arise through staff turnover.

Best practices related to fittings and joints in compressed hydrogen gas piping systems are discussed in the Hydrogen Safety Best Practices Manual.

Key:

  • = No Ignition
  • = Explosion
  • = Fire
Hydrogen Incident Summaries by Equipment and Primary Cause/Issue
Equipment / CauseEquipment Design or SelectionComponent FailureOperational ErrorInstallation or MaintenanceInadequate Gas or Flame DetectionEmergency Shutdown ResponseOther or Unknown
Hydrogen Gas Metal Cylinder or Regulator 3/31/2012
4/30/1995
2/6/2013
4/26/201012/31/1969  3/17/1999
11/1/2001
12/23/2003
Piping/Valves4/4/2002
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
2/7/20091/24/1999
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
1/1/19829/30/2004
10/7/2005
 10/7/2005 
Compressor 10/5/2009
6/10/2007
8/21/2008
1/15/2019
  10/5/20098/21/2008 
Liquid Hydrogen Tank or Delivery Truck4/27/198912/19/2004
1/19/2009
8/6/200412/31/1969 1/1/197412/17/2004
Pressure Relief Device7/25/2013
5/4/2012
1/15/2002
1/08/2007
12/31/1969    
Instrument1/15/20193/17/1999
12/31/1969
2/6/2013
  11/13/73  
Hydrogen Generation Equipment7/27/1999  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
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