Safety Incident Topic: Explotion Incident
Location of Incident: Texas, USA
Date of Incident: Unknown
Brief Account Of Incident
A trailer being towed by a forklift snagged and pulled a small drain valve out of a strainer in a liquid propylene system. Escaping propylene rapidly vaporized, forming a large flammable vapor cloud. Two minutes after the released the vapor ignited creating an explosion. The explosion knocked down several and burned two (one seriously) operators exiting the unit. Flames from the fire reached more than 500 feet in the air .Because of the size of the fire, Formosa initiated a site-wide evacuation. Fourteen workers sustained minor injuries including
scrapes and smoke inhalation. The extensive damage shut down Olefins II unit for 5 months
Incident Analysis
1. Vehicle Impact Protection
The polypropylene involved in this incident protruded into an open space, yet had no impact protection. Formosa has administrative safeguards for vehicle operation in the unit but not specifically address the operating safe area. The plant design drawing are also not marked in the unit. Guidance about protecting control pipelines is stated that protective measure should be in place to prevent impact.
2. Structual Steel Fire Protection
During the fire , part of a stucture suppoting the relief valves and emergency piping to flare header collapsed. Passive fire protection was installed only on three of four support column rows and the column supported the pressure relief valves and emergency vent pipe had no firefroofing. The API “Fire froofing Practices In Petroleum And Petrochemical Processing Plants” publication was issued after Kellogs was contracted for the early design. If had the steel been firefroof as API recommend. The consequences of this incident would likely have been less severe.
3. Remote Equipment Isolation
A check valve and remote isolation valve located downstream of the leak prevented the backflow of propylene from storage product. Operator were unable to reach the manual valve to isolate the leak as well as local control station to turn off pump supplying propylene. Kellogg specified the remote operation of islotaion valves and equipment only at the local.
4. Flame Resistance Clothing
Neither of the two operators burned in this incident were wearing FRC. Had they been heir injury wolud likely have been less severe. Formosa point comfort evaluated requiring FRC following two incident where static electricity was suspected og igniting hydrocarbon releases but decided not require FRC for operator in the Olefin II Unit except for those involved in emergency response.
Lesson Learned
Hazard Reviews
While Formosa conducted a preliminary hazard analysis, a process hazard analysis, a siting analysis, and a PSSR prior to operating the Olefins II unit, these reviews did not fully address protection of specific process equipment from vehicle impact or the use of remotely actuated valves to control a catastrophic release.When performing a hazard analysis, facility siting analysis, or pre-startup safety review, vehicle impact and remote isolation of catastrophic releases should be investigated.
Flame resistant clothing
Formosa had prior incidents of flash fires from hydrocarbon leaks and evaluated the use of FRC. However, Formosa did not require FRC for operators working within the unit, even though the large flammable liquid and gas inventory may put operators at risk of injury from flash fires.In process plants with large flammable liquid and/or gas inventories, mechanical failures can result in flash fires that endanger workers. The use of FRC may limit the severity of injury to employees who work in plants with large inventories of flammable gases and liquids.
Use of Current Standards
The the plant design used at Formosa multiple times between the mid-1980s and 2000. However, the design was not updated to incorporate improved recommended practices with respect to fireproofing structural steel that supports critical safety systems.
Evaluate the applicability and use of current consensus safety standards when designing and constructing a chemical or petrochemical process plant. This should include reviewing and updating earlier designs used for new facilities.
09 September 2007
07 September 2007
Gas Leak Out of Broken Drain Pipe
Safety Incident Topic: A Crack On the Weld of a Pump Drainage Pipe
Location of Incident: Lingen, Germany
Date of Incident: 10 May, 2005
Brief Account of Incident
May, 10 2005, while a contract worker performed assembly work on the Feed pump he accidentally damaged a drain pipe of the pump housing. This causes a strong gas leakage out of the broken drain pipe.
RESULT: Formation of light gasoline gas cloud at the downstream of the furnace reformer. The pump is stopped and changed over, while applying adequate PSA. The cloud is dispersed by steam with involvement of the fire brigade team.
What Went Well
· The contractor informed control room operators immediately.
· Quick identification of the problem on site
· Quick and safe change over the pump and using breathing mask as well as fire brigade support
· Fortunately the wind direction was turned away from the furnace.
What Went Wrong
As a general rule, it is prohibited to step onto piping regardless if assembly work is done or during operations. Unfortunately this cannot always be avoided due to the location of valves and piping. A weld failed at a location which was not fulfilling the required quality levels.
Direct Causes
1. Leakage due to stepping on the drain pipe.
2. Insufficient weld at the pump drainage.
Causes In The System
Reconsider of Integrity management for inspection and documentation of nozzles.
Direct Measurements
1. Immediate repair of the defect weld.
2. Inspection of neighbouring welds, also at the parallel feed pump GA-1804A via x-rays (without findings).
3. Clarifying discussion with the contractor, who can demonstrate long lasting experience in the Lingen refinery.
Lessons Learned
1. Leakages even on small pipes could have serious consequences for people and equipment
2. Nozzle inspection programs must be completed and well documented
3. For limitation of damages process units have to be divided up into smaller, containable sections.
Location of Incident: Lingen, Germany
Date of Incident: 10 May, 2005
Brief Account of Incident
May, 10 2005, while a contract worker performed assembly work on the Feed pump he accidentally damaged a drain pipe of the pump housing. This causes a strong gas leakage out of the broken drain pipe.
RESULT: Formation of light gasoline gas cloud at the downstream of the furnace reformer. The pump is stopped and changed over, while applying adequate PSA. The cloud is dispersed by steam with involvement of the fire brigade team.
What Went Well
· The contractor informed control room operators immediately.
· Quick identification of the problem on site
· Quick and safe change over the pump and using breathing mask as well as fire brigade support
· Fortunately the wind direction was turned away from the furnace.
What Went Wrong
As a general rule, it is prohibited to step onto piping regardless if assembly work is done or during operations. Unfortunately this cannot always be avoided due to the location of valves and piping. A weld failed at a location which was not fulfilling the required quality levels.
Direct Causes
1. Leakage due to stepping on the drain pipe.
2. Insufficient weld at the pump drainage.
Causes In The System
Reconsider of Integrity management for inspection and documentation of nozzles.
Direct Measurements
1. Immediate repair of the defect weld.
2. Inspection of neighbouring welds, also at the parallel feed pump GA-1804A via x-rays (without findings).
3. Clarifying discussion with the contractor, who can demonstrate long lasting experience in the Lingen refinery.
Lessons Learned
1. Leakages even on small pipes could have serious consequences for people and equipment
2. Nozzle inspection programs must be completed and well documented
3. For limitation of damages process units have to be divided up into smaller, containable sections.
Electrical Failure
Safety Incident Topic: Electrical Failure
Location of Incidetn: Coryton, UK
Date of Incident: 15 September, 2005
Brief Account of Incident
On 15th September at 08:45hrs local time, a fault developed on the external electrical distribution network that ultimately resulted in all Refinery Units apart from the crude unit and the Boiler House shutting down. The Refinery HV protection system sensed the fault and disconnected the Refinery from the external grid. This resulted in the automatic operation of the Refinery power load shedding system. Prior to the incident the refinery was operating normally.
As a result of the initial disturbance some electrical drives tripped, but either re-accelerated or auto-started. However, on the Continuous Catalytic Reformer (CCR) the Waste Heat Boiler Feed Water Pump (BFW) did not auto-start, resulting in a controlled shutdown of the CCR Unit. The CCR is the only hydrogen producing unit for the Refinery and the loss of a hydrogen supply resulted in a domino shutdown of other hydrogen dependent units.
At approx. 08:55hrs, critical control equipment on the Cracking Complex control console in the Central Control Building (CCB) started to fail due to a fluctuating supply voltage. In response to the lack of unit displays and with the knowledge that the majority of Refinery units were shutting down, the decision was made to shutdown the Cracking Complex whilst control was still available.
Outcome
There were no injuries or any significant environmental emissions during the Refinery shutdown. The lost opportunity cost of the shutdown has been estimated at $10.5MM.
Critical Factors
1. Incorrect co-ordination between the external power supply network and Refinery network protection systems.
2. Failure of the CCR BFW pump-motor drive to auto-start.
3. Voltage fluctuations on the Uninterruptible Power Supply (UPS) system distribution network supplying the CCB.
System Causes
1. Inadequate technical design,input obsolote – Refinery and the external power supply protection system settings are not properly coordinated.
2. Insufficient knowldege transfer – there was a lack of understanding around the full functionality of the auto-start facility when only the duty pump/motor was available.
3. Inadequate evaluation and/or documentation of change – the wiring mode were not adequately evaluated and technical query was not issued.
What Went Wrong
- Poor operation/reliability of Production radio communications system.
- Delays in start-up due to piping failures in Product Movement Area.
What Went Well
- There were no injuries or significant environmental incidents during the Refinery shutdown.
- The Refinery power load shedding system (SCADA) operated as per design.
- The Major Incident Team effectively managed the incident with tremendous team support from all Refinery Departments.
- Boiler House facilities including steam and power generation remained on-line.
- All units were made safe and abnormal start-up procedures instigated and followed.
Location of Incidetn: Coryton, UK
Date of Incident: 15 September, 2005
Brief Account of Incident
On 15th September at 08:45hrs local time, a fault developed on the external electrical distribution network that ultimately resulted in all Refinery Units apart from the crude unit and the Boiler House shutting down. The Refinery HV protection system sensed the fault and disconnected the Refinery from the external grid. This resulted in the automatic operation of the Refinery power load shedding system. Prior to the incident the refinery was operating normally.
As a result of the initial disturbance some electrical drives tripped, but either re-accelerated or auto-started. However, on the Continuous Catalytic Reformer (CCR) the Waste Heat Boiler Feed Water Pump (BFW) did not auto-start, resulting in a controlled shutdown of the CCR Unit. The CCR is the only hydrogen producing unit for the Refinery and the loss of a hydrogen supply resulted in a domino shutdown of other hydrogen dependent units.
At approx. 08:55hrs, critical control equipment on the Cracking Complex control console in the Central Control Building (CCB) started to fail due to a fluctuating supply voltage. In response to the lack of unit displays and with the knowledge that the majority of Refinery units were shutting down, the decision was made to shutdown the Cracking Complex whilst control was still available.
Outcome
There were no injuries or any significant environmental emissions during the Refinery shutdown. The lost opportunity cost of the shutdown has been estimated at $10.5MM.
Critical Factors
1. Incorrect co-ordination between the external power supply network and Refinery network protection systems.
2. Failure of the CCR BFW pump-motor drive to auto-start.
3. Voltage fluctuations on the Uninterruptible Power Supply (UPS) system distribution network supplying the CCB.
System Causes
1. Inadequate technical design,input obsolote – Refinery and the external power supply protection system settings are not properly coordinated.
2. Insufficient knowldege transfer – there was a lack of understanding around the full functionality of the auto-start facility when only the duty pump/motor was available.
3. Inadequate evaluation and/or documentation of change – the wiring mode were not adequately evaluated and technical query was not issued.
What Went Wrong
- Poor operation/reliability of Production radio communications system.
- Delays in start-up due to piping failures in Product Movement Area.
What Went Well
- There were no injuries or significant environmental incidents during the Refinery shutdown.
- The Refinery power load shedding system (SCADA) operated as per design.
- The Major Incident Team effectively managed the incident with tremendous team support from all Refinery Departments.
- Boiler House facilities including steam and power generation remained on-line.
- All units were made safe and abnormal start-up procedures instigated and followed.
Falling Motor During Lifting
Safety Incident Topic: Falling Motor During Lifting Work
Location of Incident: Geel, Belgium
Date of Incident: 10 April, 2002
Brief Account of Incident
· Cover plate of the electrical connecting box was removed to enable motor removal from equipment.
· Removal of cover plate created sharp edge that made contact with the lifting strap.
· During reinstallation, the workers experienced problems to position the motor and had to man oeuvre it to enable reconnection.
· The lifting strap was cut over sharp edge of the connecting box.
· The motor fell down on the leg of one of the workers.
A second worker jumped away and experienced a slight cut.
· The lifting chain caught the motor and kept it hanging in the air and prevented the motor from falling on the next platform 2 m down.
What Went Wrong
· The lifting works were not stopped to evaluate the situation at the moment the job was perceived to be more complex than initially anticipated.
· The sharp edge was not noticed (was covered with plastic bag) and so the risk was not seen.
· A lifting strap was used that was overdue on approval.
Potential Outcome: DAFW–case (more serious injury) or Fatality
What Went Well
· Medical treatment and follow -up.
· Quick response from mechanics involved to safely position motor.
Lessons Learned
· Lifting training is needed that covers how to deal with sharp edges.
· Evaluate who should be trained to do (manual) lifting works.
· Improve warehouse storage process to have sufficient approved safety material available.
· Evaluate what ideas can be copied from TAR’s during a smaller stop (eg container with safety material in unit).
· Evaluate need for a plant-wide procedure/checklist for doing (manual) lifting works.
Location of Incident: Geel, Belgium
Date of Incident: 10 April, 2002
Brief Account of Incident
· Cover plate of the electrical connecting box was removed to enable motor removal from equipment.
· Removal of cover plate created sharp edge that made contact with the lifting strap.
· During reinstallation, the workers experienced problems to position the motor and had to man oeuvre it to enable reconnection.
· The lifting strap was cut over sharp edge of the connecting box.
· The motor fell down on the leg of one of the workers.
A second worker jumped away and experienced a slight cut.
· The lifting chain caught the motor and kept it hanging in the air and prevented the motor from falling on the next platform 2 m down.
What Went Wrong
· The lifting works were not stopped to evaluate the situation at the moment the job was perceived to be more complex than initially anticipated.
· The sharp edge was not noticed (was covered with plastic bag) and so the risk was not seen.
· A lifting strap was used that was overdue on approval.
Potential Outcome: DAFW–case (more serious injury) or Fatality
What Went Well
· Medical treatment and follow -up.
· Quick response from mechanics involved to safely position motor.
Lessons Learned
· Lifting training is needed that covers how to deal with sharp edges.
· Evaluate who should be trained to do (manual) lifting works.
· Improve warehouse storage process to have sufficient approved safety material available.
· Evaluate what ideas can be copied from TAR’s during a smaller stop (eg container with safety material in unit).
· Evaluate need for a plant-wide procedure/checklist for doing (manual) lifting works.
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