Severity
Incident
Was Hydrogen Released?
Yes
Was There Ignition?
Yes
Describe the incident, including corrective steps taken and their result.
Incident Synopsis
A hydrogen compressor had been shut down for repairs and was being put back into service when an explosion occurred, resulting in property damage. The compressor was equipped with interchangeable intake and outlet valves.
Cause
The discharge valve was installed in the intake valve position, causing the cylinder head to blow off and release H2 to the atmosphere. The ignition source was not indicated.
Lessons Learned
All valves and connectors should be clearly labeled to minimize chances for mis-connection. All technicians must be trained on proper procedures for both taking systems offline and bringing them back online.
Valves for compressed hydrogen gas service are discussed in the Hydrogen Safety Best Practices Manual.