Case Ditails

Scenario
Case Name Leakage and fire caused due to start-up with a hose connected to an opened vent valve at inlet piping of a furnace at a fuel oil desulfurization unit
Pictograph
Date January 6, 1997
Place Sendai, Miyagi, Japan
Location Refinery
Overview A newly constructed fuel oil desulfurization unit underwent an emergency shutdown during a trial run. At restart after investigating the causes, high-temperature oil leaked from a vent nozzle at the heating furnace inlet piping, and there was a fire. The cause of the fire was that the hose, which was connected to the vent nozzle, was left with the valve open. There was a construction error in leaving the hose without being detached and the vent valve open. There was also a line-up error by the operator in charge of the operation.
Incident Leakage and a fire occurred at a fuel oil desulfurization unit, which had been constructed at about half a year before the accident. There had been an emergency shutdown during a test run of the unit about one month before. To investigate the causes, a hose was connected to the vent nozzle at the inlet piping of the furnace, and the vent valve was opened. The unit was restarted with the hose and the valve unchanged. Just after start-up, there was a leak from the hose, and a fire occurred.
Processing Manufacture
Individual Process Reaction
Process Flow Fig2.Unit process flow
Chemical Reaction Hydro-desulfurization
Substance Vacuum gas oil
Type of Accident Fire
Sequence In September, 1996: the unit was completed.
In the end of September: a trial run of the unit started.
In December: the unit was shut down by an emergency shutdown system during the trial run. To investigate the cause, a high-pressure hose was connected to vent piping with the valve at the heating furnace inlet, and an investigation was performed by making nitrogen flow in.
In January, 1997: preparatory work was carried out for a full-scale run. The temperature at the point of the fire was over 200 °C.
On January 6th: the connected hose separated from the nozzle, and high-temperature oil spouted out.
Cause There was a human error. As there is no description in the "Course" column, the hose was not detached and the valve was not closed. In this case, leakage occurs naturally when a high-pressure and high-temperature condition is given. More accurately, the cause was a line-up error, which is a basic operation performed at start-up. It was a human error not by one operator but by the whole operation crew. It would be exceptional that operation starts while a high-pressure hose was still connected.
Line-up; One of the basic operation procedures. Before start-up, all valves must be confirmed to be at the correct positions, opened or closed, to establish operating conditions.
Response Self-defense fire fighting with so-called a three point set and public fire fighting.
Countermeasures 1. Establishing a construction management system with reliable documentation as construction records.
2. Retraining of employees on operation management such as a line-up.
It is an essential countermeasure to recognize that the cause is not a simple human error, and that improvement in the management of the organization is required.
Knowledge Comment 1. Documents should be prepared for non-routine construction work, and restoration should be based on the documents.
2. A line-up should be done on starting operation.
Background There were two errors; 1) a mistake in repair management, that is, the hose was not disconnected after repair was completed. 2) A mistake in operation management, that is, a line-up error was overlooked. Fundamentally, there seemed to be a lack of fundamental skills and knowledge. The valve with vent nozzle was mounted for construction reasons only and might not have been used for operation. Furthermore, the valve was mounted where it was not easily seen. There was a lack of consideration of using such a temporary valve. There might have been a serious defect in the management of the whole office if there was no habit of making confirmations by written records.
Incidental Discussion A motto of this refinery is "Polish your sensitivity against accidents.'
Reason for Adding to DB Example of fire caused due to lack of confirmation after repair
Scenario
Primary Scenario Ignorance of Procedure, Disregard of Procedure, Disregard of Work Procedure, Organizational Problems, Poor Management, Slackness of Management, Malicious Act, Rule Violation, Safety Rule Violation, Secondary Damage, External Damage, Leakage/Fire, Loss to Organization, Economic Loss, Manetary Damage 35 million yen
Sources Fire and Disaster Management Agency, Leakage, and fire of fuel oil from vent nozzle installed at oil piping in refinery. Accident cases of dangerous materials. pp.40-43. (1997)
National dangerous material safety association, Manufacturer. 100 cases of fires and accidents at facilities with dangerous materials, p8 (1999).
Number of Injuries 1
Physical Damage About 300 square meters of a distillation section of the fuel oil direct desulfurization unit was destroyed by fire. Parts of a horizontal beam and a floor plate of the structure were deformed and discolored. Lighting facilities and instrumentation in the duct were destroyed by fire. Heat insulation covers of piping were destroyed by fire.
Financial Cost ¥ 35 million (Fire and Disaster Management Agency).
Field Chemicals and Plants
Author KOSEKI, Hirosi (National Research Institute of Fire and Disaster)
TAMURA, Masamitsu (Center for Risk Management and Safety Sciences, Yokohama National University)
Scenario