Event
- Event ID
- 591
- Quality
- Description
The incident affected a hydrogen gas purification unit of a chemical plant. A hydrogen release and ignition occurred at the joint between a pressure gauge attached to the inlet piping of an adsorption cylinder.
The pressure gauge attached had been removed for periodic inspection. It was calibrated and then reinstalled in its original position. However, the joint of the pressure gauge valve became loose, causing hydrogen gas to leak and ignite.- Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- fire
- Macro-region
- Asia
- Country
- Japan
- Date
- Component involved
- gauge/instrument (connection)
- Failure mode
- leak & ignition
- Initiating cause
- loss of tightness (wrong operation)
- Root CAUSE analysis
The INITIATING CAUSE was the loosening of a joint on a hydrogen pipe.
The KHK report attributes the ROOT CAUSE to a wrong re-installation, without specifying if this was mainly a human error or a shortcoming of the installation procedure.- Root causes
- Date entry in HIAD
- 01/05/2025
Facility
- Application
- Chemical industry
- Sub-application
- hydrogen purification unit
- Hydrogen supply chain stage
- All components affected
connection, pressure gauge
- Location type
- Unknown
- Location
- unknown
- Operational condition
- Pre-event occurrences
The pressure gauge had been removed for maintenance and calibration, and re-installed.
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 1
- Post-event summary
minor injury
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Probable IGNITION SOURCE
References
- Sources categories
- KHK
- Reference & weblink
High Pressure Gas Accident Cases Database of the KHK (High Pressure Gas Safety Association):
https://www.khk.or.jp/public_information/incident_investigation/hpg_inc…
(accessed May 2025)The first entry in HIAD was coming from RISCAD, which is now closed.
