Event
- Event ID
- 639
- Quality
- Description
An operator on patrol discovered a flame coming from the heat exchanger flange of a gasoline hydrodesulphurisation plant and reported it. The plant was immediately shut down.
An investigation revealed that the bolts on the flange were not properly tightened, causing the release of gasoline and hydrogen and their ignition.- 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
- heat exchanger (flange)
- Failure mode
- leak & ignition
- Initiating cause
- loss of tightness
- Root CAUSE analysis
The INITIATING CAUSE was loss of tightness of a flange due to loose bolts, for an unknown reason (by proxy, the reason could be loosening by thermal cycling).
The ROOT CAUSE could be attributed to incorrect tightening of the bolts during installation, which was not able to compensate for the differential thermal expansion of bolts and flange.- Root causes
- Date entry in HIAD
- 01/05/2025
Facility
- Application
- Petrochemical industry
- Sub-application
- Hydrodesulphurisation process
- Hydrogen supply chain stage
- All components affected
Flange, heat exchanger
- Process temperature range [C]
- High temperature (100°C to 500°C)
- Process pressure range [MPa]
- medium to high pressure (10 to 50 MPa)
- Location type
- Unknown
- Location
- industrial area
- Operational condition
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
In-depth data
- Release type
- gas mixture
- Involved substances (% vol)
- H2
gasoline - 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.
