Emergency Isolation for Hazardous Material Fluid Transfer Systems – Applications and Limitations of Excess Flow Valve

 https://archive.epa.gov/emergencies/docs/chem/web/pdf/efv_alert.pdf

ARE YOU IDENTIFYING ALL SOURCES OF ENERGY FOR LOTOTO?

On October xx, 2009, an employee was working for the XXX Public Utilities Commission-Wastewater Enterprise as a trainee. There were four people to perform preventive maintenance for the fans at the wastewater treatment plant that day. The employee and a Coworker #1 were servicing the fans in Room Number 201 while the foreman and Coworker #2 were in an adjacent room. There were four supply fans. The employee was working onXX1-1 while Coworker #1 was working on an adjacent fan.
The fans were shut down, tagged-out, and locked-out. The employee proceeded to remove the enclosure metal guard to expose the belt and pulley drive for the inspection. Although the fan was tagged and locked- out, it was not blocked-out. The exhaust fans in a room below were not stopped. Their operation created an airflow which traveled through the same duct system as for the supply fans upstairs. The air flow through the duct caused the supply fan blades to spin freely. The fan blades were not blocked before servicing. At approximately 8:30 a.m., when the employee was removing the enclosure guard for the V-belt and pulley drive of the spinning fan, the in-running nip point amputated his left middle finger. He
screamed as Coworker #1 came to his aid. He was taken to XXX Hospital by Coworker #1. He was treated and released the same day.

3 Employees Killed, 2 Injured By Hydrogen Sulfide Exposure

 Employee #1 was inside a frac tank shoveling residue (called BS) to one end of the tank for subsequent vacuuming and removal. As he completed the task, the tank was washed down with waste water containing hydrogen sulfide. Approximately 8 minutes following the waste water entrance, Employee #1 collapsed from exposure to the chemical. Employee #2 entered the tank and attempted to rescue Employee #1, but he too collapsed. Apparently Employees #3 and #4 entered the tank and attempted a rescue and but succumbed also. Employee #5 attempted to revive Employee #1 through an opening at the end of the frac tank. He was affected by the hydrogen sulfide gas but was able to call the city's first responders. Employees #1, #3, and #4 died of hydrogen sulfide exposure. Employees #2 and #5 were hospitalized. 

Source:Osha.gov

EXPLOSION IN SALT WATER TANK

At approximately 2:30 a.m. on July 30, 2011, Employee #1 was working the night shift at a saltwater disposal facility. Specifically, the facility specializes in the disposal of salt water that is contaminated with field oil waste. The water would usually be separated from the oil and petroleum based materials in a settling tank. The water would then pumped back into the ground through an injection well, while the oil based material is gravity drained into a series of collection tanks. The oil would then sold to oil recyclers. During Employee #1's shift, he was monitoring two oil collection tanks that were connected to a separation drum tank. 

The first of the two tanks was also connected to the second tank to allow for spillover as the amount of liquid rose. Under normal operation, the tanks would take several days to become full; however, facility operators would frequent the catwalk area that was accessed by way of a ladder to gauge the tanks levels. After receiving a water delivery from a full tanker-truck, Employee #1 accessed the catwalk to gauge the water level. Soon after reaching the tank area, an explosion occurred. The truck driver, who was leaving the facility, observed the explosion and following fireball in his rear view mirror. The driver immediately stopped his truck and contacted emergency services. Despite the fire spreading to both tanks, Employee #1 was able to escape the fire crazed area; however, his clothes were completely burned off and over ninety percent of his body was burned. Employee #1 collapsed on the front porch area of the facility office, where emergency personnel, a short time later, began treatment. Employee #1 was taken by helicopter to Ardmore Hospital, where he died. The accident investigation revealed that Employee #1 had a history of smoking near the storage tanks and had been warned by the employer to stop several times. 

Source:Osha.gov

"Sewage systems on vessels are known as Marine Sanitation Devices (MSDs) or Collection, Holding and Transfer Tanks (CHTs). Cleaning these systems is required for operations such as routine surveys and surface preservation, equipment modification, repairs and maintenance. Entering and cleaning
sewage tanks, piping and components present specific hazards to workers that put them at risk for injuries and illnesses if they are not properly protected (29 CFR 1915.13).
Workers are often exposed to dangerous atmospheres during tank opening and venting; manual pumping and stripping; breaking or dismantling components and piping; and pressure
washing, mucking, and scaling (29 CFR 1915.11(b); 1915.12). A dangerous atmosphere may expose workers to the risk of death, incapacitation, injury, chronic or acute illness, or impaired ability
to escape unaided from a confined or enclosed space (29 CFR 1915.11(b)). When working on CHTs/MSDs, special attention should be given to good hygiene practices, proper use of personal
protective equipment and safe confined space entry procedures (29 CFR 1915.88; 1915 Subparts B & I).
The information in this document can help prevent exposing workers to the known and unknown dangers of handling treated or untreated sewage and gray water tanks during tank opening, entry,
cleaning and related operations. Related components/operations include: piping, aeration, vacuuming, settling, and treatment tanks and apparatus; sewage-contaminated water tanks or waste oil
tanks, bilges, or sumps; and valves, pumps, grinders, macerators and other contaminated equipment".

https://www.osha.gov/sites/default/files/publications/OSHA_FS_3587.pdf

Source:Osha.gov

CHLORINE EXPOSURE INCIDENT

 On April 2, 2002, Employee #1 and a coworker, employees of a water treatment plant as waste water treatment operators, were changing out five 1-Ton cylinders, located in a chlorine cylinder room. Employee #1 attempted to disconnect the yoke number two of the five 1-Ton cylinders, but a high pressure leak of chlorine gas escaped from the cylinder into his breathing zone. Employee #1 was able to immediately tighten the yoke connection, stopping the leak, but required the coworker to finish the task. With Employee #1 sitting to the side, the coworker, after a couple of attempts, was able to disconnect the yoke connection without any further chlorine gas escaping. After notifying management of the incident, the coworker drove Employee #1 to Hospital Emergency Room. Once admitted, Employee #1 was treated for chlorine gas exposure and diagnosed with bilateral lower lobe pneumonia.

 A 42-year-old laborer leak testing joints inside a 54-inch round pipe suffered fatal blunt force injuries in October 2015, when an inflatable ¿bladder¿ ruptured at a waste-water treatment plant. Inspectors from the U.S. Department of Labor¿s Occupational Safety and Health Administration found his employer failed to train him properly on the testing procedure.

Workers can be killed when employers fail to protect construction workers from the many dangers in confined spaces, said Assistant Secretary of Labor for Occupational Safety and Health Dr. David Michaels. These are among the first citations under OSH¿s new Confined Space Standard. Employers can prevent more tragedies like this one if they ensure proper training of workers and communication among multiple employers whose workers are on the same site.

In August 2015, OSHA implemented its confined space in construction standard after research showed proper safety procedures would protect hundreds of workers each year from life-threatening hazards. Hazards include the risks of toxic exposure, electrocution, explosion and asphyxiation present for workers in confined spaces such as pipes, manholes, crawl spaces and tanks. In an emergency, it can be difficult to exit these spaces quickly or for rescuers to enter safely.

The agencys investigation also found the four companies failed to continuously monitor confined spaces for atmospheric and other hazards and train workers in hazards. 

Source:Osha.gov

ARE YOU PERFORMING YOUR PSSR'S CORRECTLY?

A closure of an UV (shutoff valve) was provided in the design of the plant, to avoid two phase flow when carryover occurred.  During an abnormality, the shutdown system activated the UV but the UV did not close. The RCA revealed that the UV did not close due to excessive friction caused by the presence of construction debris left behind that prevented the UV from closing

WASTE WATER TANK INCIDENT

On September 9, 2003, Employees #1 and #2 were extending the guardrail system to the hatch and platform area on top of a tank located on the Brewery property. The tank was used for the storage of solid waste at the waste water treatment facility. The tank was 40 ft in height and 48 ft in diameter. The employees were arc welding the guardrail system, 40 ft above the ground, when an explosion occurred. Employee #1 fell to the ground receiving fatal injuries. Employee #2 fell to the inside of the tank, an opening of approximately 10 ft left due to the explosion. The tank had to be drained in order to recover the body. Employee #2 apparently died from injuries due to the explosion

Credit:Osha.gov

ARE YOU INSPECTING YOUR PILOT OPERATED VALVES CORRECTLY?

A Pilot operated relief valve failed to lift during planned recertification in the workshop. The cause of failure to lift identified as a plug fitted in the pilot exhaust port. Plug was removed from pilot exhaust port and RV functioned as intended.  On inspection of three remaining RV’s on compressor discharge, it was
found that another RV also had a plug fitted in the pilot exhaust port.

ARE YOU CONSIDERING HUMAN FACTORS DURING YOUR HAZARD IDENTIFICATION?

 An ammonia leak occurred in the machinery room of an unoccupied arena. An employee was attempting to add oil to an ammonia compressor when he observed a leak (fill hose was not attached). Approximately 200 lbs ammonia was released.
Qualified person was trained, but with minimal experience in this procedure. No written procedure was available, and an error occurred while executing the procedure. The shut-off valve type (wrench-operated,
mufti-turn, no position indicator) added complexities to the process.

Source: British Columbia Safety Authority 

WHY HAZOP STUDY IS IMPORTANT

 Approximately 200 lbs ammonia was released to atmosphere. The condenser safety valve activated due to ‘no cooling’ in the condenser while the ammonia compressor was operating. While restarting the plant after a power failure, the operator forgot to start the condenser circulating pump (which should be started before starting the compressor). The compressor was started without condenser cooling, and as a result, ammonia gas temperature began to rise, thus raising the gas pressure in the system. Eventually the gas pressure rose more than the safety valve setting, activating the safety valve which released the
ammonia to atmosphere.
The compressor’s high pressure safety cut off did not activate. The high pressure cut off is supposed to activate and shut off the compressor unit when the system senses a high pressure condition.

Source: British Columbia Safety Authority 

ARE YOU SPECIFYING PRESSURE GAUGES CORRECTLY?

 Approximately 100lbs ammonia was released into an unoccupied processing room of an industrial facility when a pressure gauge failed on the liquid line to an ammonia evaporator. Inspection revealed that a second pressure gauge (on the hot gas line for the same installation) was pinned at maximum pressure. Both pressure gauges had a range of 0 to 150psi and were installed in a system with an operating pressure of 150 to 160psi. The pressure gauge failed from over-pressure operation.

Source: British Columbia Safety Authority

ARE YOU INPECTING SMALL BORE TUBING?

 An ammonia leak occurred at a commercial-industrial facility. Approximately 10 lbs ammonia entrained in approximately 200 litres of compressor oil was released when a suction side 3/8-inch pressure sensing line failed. The suction side oil pressure pushed approximately 200 litres of oil from the reservoir onto the floor where the entrained ammonia then escaped to atmosphere. The 3/8-inch stainless steel tubing within the compression fitting failed when a circumferential crack completely fractured. The crack within the
3/8-inch stainless steel compression fitting did not show up on external inspection. Metal fatigue appeared to be a factor, along with unit vibration and initial metal stress within this type of compression joint.
 

The refrigeration contractor identified the main cause and factors leading to the failure as a severe vibration condition of the compressor. This severe vibration condition only occurs when only happens when the control slide valve is at, or at near its minimum position. The vibration was so intense that the contractor immediately shut the compressor down. Also, the contractor’s investigation discovered the ‘PHD’ vibration monitoring system was inactive. When the monitoring system was activated, the compressor in fact shut down on ‘high vibration.’ 

Source: British Columbia Safety Authority

ARE YOUR SAFETY DEVICES WORKING?

Ammonia was released at a recreational facility. A high pressure cut out switch failed to shut down a compressor when the compressor experienced a high pressure condition. Pressure continued to build until a safety relief device operated releasing ammonia gas to atmosphere via the relief stack,
which triggered the ammonia alarm.
The water supply line to the condenser had no protection and was subject to freezing during cold weather. The high limit switch was old (1986) and is mounted on the compressor base subjecting it to vibration. The safety relief operated as designed, venting gas to atmosphere, preventing a possible
catastrophic failure.
Source: British Columbia Safety Authority

SAFETY IN DESIGN OF PIPING

 https://www.hydrocarbonprocessing.com/magazine/2018/february-2018/environment-and-safety/safety-in-design-during-piping-engineering

 "A process engineer must complete the preliminary preparations of process flow diagrams, material and energy balances, piping and instrumentation diagrams (P&IDs), process control philosophy, and identification of the hazardous nature of raw materials, chemicals, byproducts and final products. Afterward, documents including process equipment layout drawings (plan and elevation) and unit plot plans are issued to engineers from other disciplines.

Involving engineers from different disciplines in the design phase provides unique perspectives that add value to basic documents, such as improved safety design features. Discipline engineers are required to consider design and safety requirements that are applicable for their specific domain as per local, national, international, industry-specific and company standards and regulations, and good engineering practices.

The role of a piping engineer during the design of piping systems is explored here, as well as how that piping engineer can—from the initial design phase—lower the risks that can arise from handling hazardous materials, contribute to reducing potential liability and help create a safer environment for the public".

READ THE FULL ARTICLE IN LINK

 

CONTROL HAZARDOUS ENERGY

 https://www.aiche.org/ccps/control-hazardous-energy-lock-out-and-tag-out

"Lock-out and tag-out (LOTO) is a critical part of a strong all-around safety program. In LOTO, maintenance employees work with production employees to positively prevent all forms of hazardous energy from causing harm. Hazardous energy comes in many forms. Electrical energy can cause electrocution and burns, provide ignition to flammable atmospheres, and activate mechanical equipment. Steam can cause burns or initiate hazardous reactions. Nitrogen can cause asphyxiation. Chemical flow can cause uncontrolled reaction and injury. When a piece of equipment is being worked on, all sources of hazardous energy must be securely and positively locked out until the equipment is operational. Untold numbers of major process safety incidents and individual injuries have been caused by failure of LOTO. A prime example is the Bhopal catastrophe, one of the worst incidents ever to have occurred, which was caused in part by the failure of LOTO. Recently, a company process safety manager called CCPS asking for help in persuading a newly acquired facility within his company to implement a LOTO program. The manager was frustrated because, as the plant director stated, “We understand completely that maintenance workers are endangered if power or material flow were allowed to equipment they are servicing. That’s why no one would ever activate a switch or valve during a maintenance activity. LOTO is just extra, unnecessary work.” The company process safety manager knew that with the plant director’s attitude, the plant could be on the road to disaster. Could CCPS help him make the case for LOTO? At CCPS, we firmly believe that it is better to learn from the mistakes of others rather than to learn by painful, personal experience. So we asked CCPS member companies to give us examples of accidents caused by LOTO failures, and to provide testimonials about the importance of LOTO. The purpose of this article is to share this information with you, to help you lead the implementation or improvement of LOTO in your
company. A brief overview of LOTO procedures and tools are provided, as are references to more detailed resources." 

Reference: https://www.aiche.org/ccps/control-hazardous-energy-lock-out-and-tag-out

WHAT IS A BLEVE?

  http://www.hrdp-idrm.in/e5783/e17327/e27015/e27750/

For a BLEVE situation following four conditions must be present:-

1. There must be a substance in liquid form. Most of the destructive BELEV's that have occurred have involved flammable liquids and liquefied flammable gases. BLEVE can occur with any liquid, even water. The only difference is that with non¬flammable liquids there is no fireball. However, there will still be damaging effect including the propagating of creaks in the structure of the container together with possibility of subsequent failure and propulsion.
2. The liquid must be in a container like sphere, bullet, and road/rail tanker.
3. The contained liquid must be at a temperature above its normal boiling point at atmospheric pressure at the time container allows the pressure inside to build up above atmospheric pressure, the fluid, in the container is able to remain in the liquid state, even through its temperature is above its normal boiling point. This increase in pressure raises the Boiling point of the contained liquid above its boiling point.
4. There must be a failure of the container in order to have BLEVE. This container failure can be due to following courses:

• Flame impingement.
• Internal structural weakness of the container
• Failure of improperly designed SRV
• Impact from a mechanical cause such a road accident, tanker derailment allowing flammable liquid to flow out.

 

Lessons Learned: Pressure Vessels

SAFE ACCESSING OF PRESSURE VESSELS

 https://www.kan.de/en/publications/kanbrief/industry-40-vision-or-reality/safe-accessing-of-pressure-vessels

"Operatives and technicians must frequently climb into pressure vessels in order to perform construction, maintenance, repair and inspection work. However, the access points through which they must pass for this purpose are often so small that although access is possible, rescuing these personnel in the event of an accident presents considerable difficulties. The Polytechnic University of Milan has conducted a number of studies into this issue in the course of two degree theses."

SEE THE LINK FOR FULL ARTICLE

NON METALLIC GASKETS - AVOIDING LEAKS AND BLOWOUTS

 https://www.plantengineering.com/articles/nonmetallic-gaskets-avoiding-leaks-and-blow-outs/

"The compressive stress on a gasket plays a larger role in its ability to maintain pressure than its tensile strength.
By Dave Burgess October 1, 1999

The compressive stress on a gasket plays a larger role in its ability to maintain pressure than its tensile strength. Why is this significant? It is the reason for many gasketed joint problems!

In a classic scenario, a joint is assembled without controlled bolt loads; that is, without known and controlled bolt torques. The joint withstands a hydro test at 1.5 or 2 times rated pressure, yet leaks or blows out after a period of service at pressures well below the test pressure.

Was this failure due to a loss of gasket tensile strength? Probably not. Gasket tensile strength alone cannot be counted on to hold system pressures. What very likely occurred was loss of compressive stress on the gasket."

READ THE COMPLETE ARTICLE IN THE LINK

ETHYLENE OXIDE RELEASE INCIDENT

 https://dnrec.alpha.delaware.gov/croda-questions-answers/

 "What happened at the Croda Atlas Point plant?

At 4:15 p.m., Sunday, November 25, 2018 ethylene oxide (EO) was accidentally released into the air from Croda’s ethylene oxide plant. Since EO is very soluble in water, Croda deployed its water deluge system to contain as much of the release as possible. Croda personnel also began transferring the EO from the leaking vessel in the processing equipment to a secure containment vessel. Local responders and DNREC Emergency Response arrived. Water suppression continued. With input from Croda personnel, responders determined that by opening two nitrogen valves in the processing equipment, the remaining EO from the leaking vessel could be transferred to the non-leaking vessel, stopping the release."

 READ THE LINK FOR COMPLETE DETAILS...

 

 

 

 

 

 

 

SODIUM CYANIDE LEAK

 Incident
A plant operator responded to a bund alarm and observed sodium cyanide solution overflowing from a storage tank. A pool of approximately 84 000 litres of solution had formed and was contained within the tank bund. The site emergency plan was enacted and an exclusion zone was established around the area whilst the product in the bund was transferred to another tank. The concrete bund contained the spill, and the recovered solution and all of the washings were kept for use in future blending operations.

Cause
The combination of a faulty valve and failure by an operator to follow standard operating procedure, led to the tank overfilling. The overflow spilt into the bunded area and activated the bund alarm.

Consequences
The defective valve was repaired and the tank high-level critical alarm system has been reviewed and improved. The tank overflow piping is also under review to identify options to prevent recurrence. The responsible operator has been counselled on appropriate self-check work systems. There were no injuries or damage to any property as a result of the incident and the emergency response plan functioned as intended.

Source: Department of Minerals and Energy, Australia

CHLORINE LEAK DUE TO STRESS CORROSION CRACKING OF SS BOLTS

 Incident
Approximately 150 kg of chlorine gas was released over a period of 140 minutes, due to failure of bolts on a vacuum gas regulator attached to an on-line liquefied chlorine gas drum, used for water treatment. The incident occurred outside work hours, however plant operators were not called out, as the plant alarm system was not correctly programmed. Impact from the release to the surrounding community was limited to chlorine odour being detected by a passing motorist who reported the odour to the operator of the
site. The leak was isolated by a plant operator who arrived at the scene after the release was reported.
Cause
Inspection of the vacuum gas regulator revealed that the release was due to the failure of four bolts on the regulator. Material test results show that the failure of the stainless steel bolts was due to chloride-induced-stress cracking from chlorine attack, which is assumed to have resulted from an extremely small leak over a short duration.
Consequences
As part of the investigation, a number of changes to prevent recurrence of the event have been identified and implemented. These include introduction of a weekly leak check, the company committing to inspection of all vacuum regulators, the replacement of any inappropriate bolts and reprogramming of the chlorine alarm. In addition, the company will investigate the use of different alloy bolts.

Source: Department of Minerals and Energy, Australia 

NITROGEN HOSE BURST AND RELEASED AMMONIA

Incident
A release of ammonia occurred from a chemical plant when a hose burst following maintenance to an ammonia filter. The release of ammonia was detected by operators due to ammonia alarms and a high flow of ammonia to the plant. The site emergency siren was activated to alert people of the incident and operators isolated the supply of ammonia to the plant. Operators donned personal protective equipment
and doused the leak with water in order to gain access to the area to isolate the leak.
Cause
Ammonia filters were used to remove contaminants from the liquid ammonia, prior to it being processed in the plant. An essential step in the maintenance of filters is a nitrogen purge of the system. After purging occurs, the filter is changed, resealed and the nitrogen hose disconnected. The relevant valves are then opened to recommission the system with ammonia. In this instance, the nitrogen hose remained connected to the filter and drain valves were left open allowing the hose to become
pressurised with liquid ammonia. While the hose was suitable for the pressures normally experienced under service with nitrogen, the hose was not suitable for the much higher pressures of liquid ammonia and as a result the hose burst in two places.
Consequences
The incident occurred as a result of the failure to follow the appropriate procedure and the company has taken the action of reviewing the competence of each operator to carry out the task. The company has also reviewed the operating procedures associated with the filter cleaning process to ensure they are appropriate. 

Source: Department of Minerals and Energy, Australia

RELEASE OF TOXIC LIQUID THROUGH STEAM COIL LINE GASKET LEAK

 Incident
A release of toxic liquid (containing arsenic trioxide) from a storage tank occurred following the shutdown of a chemical plant. The release occurred from a steam coil passing through a storage tank used to store the solution during the shutdown. The release flowed into a surface-drainage system,through a series of secondary catchment sumps and ponds, into Cockburn Sound.
Cause
An investigation into the incident has identified that the toxic liquid was released through a hole in a gasket of a flange. The flange was located on the steam coil pipework within the tank. It was found that the steam-line terminated outside the bunded area in a partially-covered surface-drainage system.
Consequences
To prevent a recurrence, all steam-lines within the plant were cut to ensure that they terminated within the bunded area. The company has also decommissioned the plant and will commission a new plant that does not utilise arsenic compounds.

Source: Department of Minerals and Energy, Australia 

FAILED GASKET DURING START UP

 Incident
A mixture of process gases was released to the atmosphere through a failed gasket during the start-up of a chemical plant. Operators had just completed the start-up when they heard a large steam release and received alarms from ammonia detectors. The plant was shutdown, however the plume released travelled off-site necessitating the evacuation into refuges of a small number of workers on a neighbouring site. None was injured as a result of the release.
 

Cause
An investigation showed that the gasket failed as a result of a hole in a boiler tube which had allowed water to pass from the boiler side into the process side. The temperature generated during start-up caused the pooled water to rapidly boil leading to a surge in pressure which resulted in the failure of the gasket. Non-destructive testing of the boiler tubes showed gouge-type corrosion believed to have been caused by flow distribution problems in the boiler. This resulted in excessive metal temperature, which led to corrosion of the tube. 

Consequences
A complete boiler inspection has now been conducted and boiler tubes showing signs of corrosion have been plugged off. Actions to prevent a recurrence include the addition of insulation at the top of all boiler tubes and further investigation into the boiler water chemistry to minimise potential for corrosion. The company has also modified the boiler to incorporate a drain valve in order to provide early warning in the event of water leakage.

 Source: Department of Minerals and Energy, Australia

START UP INCIDENT IN AMMONIA PLANT

 Incident
A mixture of synthesis gas and ammonia was released from an ammonia plant during the start-up process following a shutdown for maintenance. The release occurred from a high vent after ammonia had been allowed to collect in the vent system through a valve left open as a result of failure to tag the valve as out of service.
During the start-up, operators failed to control levels in the process, resulting in a high level alarm in an ammonia catchpot which led to a release of synthesis gas (as designed) into the vent system. However, as the vent system already contained ammonia, the gas mixture was forced out of the high vent. The wind direction took the gas cloud over an adjacent construction area on the same site resulting in fourteen
contract employees experiencing irritation and discomfort and later seeking medical attention. Six of these contractors were physically affected as a result of the exposure but nobody suffered serious or long-term injuries. The ammonia release dispersed and was not detected at neighbouring premises.
Cause
The incident was caused by a combination of factors including a failure of the tagging system and the failure to adequately control the catchpot level during start-up.
Consequences
The tagging system for equipment which is out of service, has been reviewed to ensure during maintenance there is no unauthorised operation of equipment. Resource allocation has been reviewed to ensure that process control is secured and level indicators in the catchpot have been assessed to ensure accuracy for process control. Also, workers at the adjacent construction site will now carry gas respirators at all times and will be notified of any operating conditions, such as start-ups and shutdowns, with the potential to lead to releases of gas.

Source: Department of Minerals and Energy, Australia 

AMMONIA LEAK FROM REFRIGERATION SYSTEM

Incident
Approximately 56 kg of anhydrous ammonia was released to the atmosphere from
a 25-year-old refrigeration system. The emergency services stopped the leak by
closing an isolating valve. There was no injury. The site was not licensed for the
storage of anhydrous ammonia.
Causes
One valve failed to close and stop filling up the accumulator of the refrigerating
system. This resulted in flooding of the refrigeration compressor by liquefied
anhydrous ammonia, causing one of the compressor O-rings to fail, thereby causing
the release of anhydrous ammonia to the atmosphere. This points to an inadequate
maintenance program.
Consequences
The operator has been instructed to take appropriate measures so that the
refrigerating system complies with the relevant safety standard and the Dangerous
Goods Regulations. The operator was successfully prosecuted for failing to placard
the site and have a licence to store anhydrous ammonia.

Source: Department of Minerals and Energy, Australia

LOOSE BOLTS - CAUSES

 Www.smartbolts.com/insights/loose-bolts-causes-ways-prevent/

A pressurized bolted flange joint assembly begins to leak, creating a safety hazard. A rotor with its blades separates from the nacelle and spins off a wind turbine, crashing to the ground. Under constant vibration from the engine of an ocean freighter, loose bolts on a large piece of mining equipment work their way off the bolted joints and roll around the hull, inflicting further damage to the equipment.

AVOID GASKET SURPRISES

 https://www.chemicalprocessing.com/articles/2020/maintenance-avoid-gasket-surprises/

COMMON CAUSES OF FLANGE LEAKS AND THEIR SOLUTIONS

 https://www.sealxpert.com/common-causes-of-flange-leaks-and-their-solutions/

Classic Marmaduke: Marmy's First Lesson

Classic Marmaduke: Marmy's First Lesson: Steve Elonka began chronicling the exploits of Marmaduke Surfaceblow—a six-foot-four marine engineer with a steel brush mustache and a foghorn voice—in POWER in 1948, when Marmy raised the wooden mast of the SS Asia Sun with the help of two cobras and a case of Sandpaper Gin. Marmy’s simple solutions to seemingly intractable plant problems remain timeless. This Classic Marmaduke story, published more than 50 years ago, reminds us that even the most modern steam plant is only as good as its operators.

Is it Possible to Turnaround a Turnaround? - POWER Magazine

Is it Possible to Turnaround a Turnaround? - POWER Magazine: By Paul Muir, CRO, Mobideo Why are Turnarounds So Challenging “A large turnaround can include up to 150,000 individual activities. With this level of complexity, approximately half of all shutdown projects are delayed by more than 20% and 80% go over budget by more than 10%. Frequently, the work scope increases unexpectedly by up to […]

Use Dry Fog to Control Coal Dust Hazards

Use Dry Fog to Control Coal Dust Hazards: Fogging systems have been successfully used in the material-handling industry for more than 30 years to control explosive dust at transfer points. Today, fogging systems are an EPA Best Demonstrated Technology for subbituminous coal preparation plants.

Give Your Plant a Dust Control Tune-Up

Give Your Plant a Dust Control Tune-Up: Every piece of equipment that transports or processes coal creates some level of particulate matter. Having a strategy for coal dust management in your plant is essential.

Coping with Coal Dust

Coping with Coal Dust: Plants can no longer sweep coal dust under the rug and ignore the health and safety hazard it presents, because a single spark can cause a dust explosion that could put a plant out of service, perhaps permanently. Managing dust in a power plant begins with good housekeeping, followed by retrofits using properly designed equipment.

SMARTBOLTS.COM - LOOSE BOLTS - CAUSES

 http://www.smartbolts.com/insights/loose-bolts-causes-ways-prevent/

"A pressurized bolted flange joint assembly begins to leak, creating a safety hazard. A rotor with its blades separates from the nacelle and spins off a wind turbine, crashing to the ground. Under constant vibration from the engine of an ocean freighter, loose bolts on a large piece of mining equipment work their way off the bolted joints and roll around the hull, inflicting further damage to the equipment".

The Benefits of Explosion-Protected Cameras in High-Risk Environments

The Benefits of Explosion-Protected Cameras in High-Risk Environments: Many critical infrastructure sites contain areas that are classified as hazardous due to a high risk of explosion. What makes most of these locations

Safety and Digitalization Big Parts of Sustainability

Safety and Digitalization Big Parts of Sustainability: Company leaders around the globe are more focused than ever on sustainability. The trend has been driven not only by an innate human desire to “do the

Cybersecurity: The Biggest Threats Are Likely Within Your Organization

Cybersecurity: The Biggest Threats Are Likely Within Your Organization: Cybersecurity: The Biggest Threats Are Likely Within Your Organization

The Urgency of Protecting the Electric Grid from Cyberattacks

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Practical guidelines for determining electrical area classification

Practical guidelines for determining electrical area classification: Hazardous area classification is a method used to identify where an explosive environment may exist. Codes offer guidance for electrical area classification

Safe Temporary Power and Lighting Strategies For Refinery Turn-around Activities

 https://www.electricalsafetypub.com/news-headlines/safe-temporary-power-and-lighting-strategies-for-refinery-turn-around-activities/

IGNITION SOURCES - IDENTIFICATION AND CONTROL HSE UK

 Ignition sources may be:

Flames;
Direct fired space and process heating;
Use of cigarettes/matches etc;
Cutting and welding flames;
Hot surfaces;
Heated process vessels such as dryers and furnaces;
Hot process vessels;
Space heating equipment;
Mechanical machinery;
Electrical equipment and lights
Spontaneous heating;
Friction heating or sparks;
Impact sparks;
Sparks from electrical equipment;
Stray currents from electrical equipment
Electrostatic discharge sparks:
Lightning strikes.
Electromagnetic radiation of different wavelengths
Vehicles, unless specially designed or modified are likely to contain a range of potential ignition sources

Sources of ignition should be effectively controlled in all hazardous areas by a combination of design measures, and systems of work:
Using electrical equipment and instrumentation classified for the zone in which it is located. New mechanical equipment will need to be selected in the same way. (See above);
Earthing of all plant/ equipment (see Technical Measures Document on Earthing)
Elimination of surfaces above auto-ignition temperatures of flammable materials being handled/stored (see above);
Provision of lightning protection
Correct selection of vehicles/internal combustion engines that have to work in the zoned areas (see Technical Measures Document on Permit to Work Systems);
Correct selection of equipment to avoid high intensity electromagnetic radiation sources, e.g. limitations on the power input to fibre optic systems, avoidance of high intensity lasers or sources of infrared radiation
Prohibition of smoking/use of matches/lighters
Controls over the use of normal vehicles
Controls over activities that create intermittent hazardous areas, e.g. tanker loading/unloading
Control of maintenance activities that may cause sparks/hot surfaces/naked flames through a Permit to Work System
Precautions to control the risk from pyrophoric scale, usually associated with formation of ferrous sulphide inside process equipment
Direct Fired Heaters, Hot Oil Systems and Processes Operating Above Auto-Ignition Temperatures

SOURCE: https://www.hse.gov.uk/comah/sragtech/techmeasareaclas.htm

Explosion Relief Vents for Highly Effective and Economical Explosion Protection

 https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/explosion-relief-vents-for-highly-effective-and-economical-explosion-protection/

Newson Gale - 5 Reasons why you should specify ATEX, IECEx and FM Approv...

PREVENTING COMBUSTIBLE DUST EXPLOSIONS

 https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/preventing-combustible-dust-explosions/

IGNITION RISKS OF ELECTROSTATIC CHARGE

 https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/background-to-the-ignition-risks-of-electrostatic-charge/

SUGAR AS AN EXPLOSION RISK

 https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/sugar-explosion-risk-grounding-helps/

DUST EXPLOSION HAZARDS

 https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/dust-explosion-hazards/

IS TRUCK GROUNDING NECESSARY?

 https://bulkinside.com/bulk-solids-handling/explosion-protection-process-safety/is-truck-grounding-necessary/

WISH YOU A HAPPY NEW YEAR!

 To all my readers, wish you a very Happy and Healthy 2022! Play your part in avoiding LOPC's!

Explosion due to hydrocarbon being drawn into boiler firebox

A leak in a hydrocarbon refrigerant system formed a vapor cloud that was drawn into the inlet of a steam boiler. The increased fuel to the boiler caused rapidly rising pressure within a steam drum. The rapidly rising pressure exceeded the capacity of the boiler’s safety valve and the steam drum ruptured. The boiler rupture was close enough to the gas leak to ignite the vapor cloud and produce an explosion due the confined nature of the gas lea  and an ensuing fireball. The fire took eight hours to extinguish. The explosions and fire destroyed a portion to the LNG plant and caused 27 deaths, and injury to 72 more.

LNG leak causes sewer explosion

 LNG leak from open run-down line during a pipe modification project. LNG entered an underground
concrete storm sewer system and underwent a rapid vapor expansion that overpressured and ruptured
the sewer pipes. Storm sewer system substantially damaged.

SULPHURIC ACID EMERGENCY REPSONSE AND CASE STUDIES

http://www.greatersudbury.ca/content/div_emergprep/documents/norfalco_presentation_nov23_07.pdf

The Case of the FATAL TANK ENTRY

 https://www.assp.org/docs/default-source/psj-articles/mtricketts_0220.pdf?sfvrsn=ba188947_2

Health and Safety Risks for Workers Involved in Manual Tank Gauging and Sampling at Oil and Gas Extraction Sites

https://www.osha.gov/sites/default/files/publications/OSHA3843.pdf

Case study of death of an engineer due to burns

 https://britanniapandi.com/wp-content/uploads/2020/11/BSafe-Case-Study-No.1-Burns-Fatality-Commentary-No.1.pdf

SAFETY ALERT SIGHT GLASS INCIDENT

 https://www.bsee.gov/sites/bsee_prod.opengov.ibmcloud.com/files/safety-alerts/incident-and-investigations/safety-alert-no-76.pdf

ANOTHER ANNIVERSARY OF BHOPAL.....National Process Safety Week on anniversary of Bhopal disaster December 3rd

Tonight is the 37th anniversary of the Bhopal gas disaster. We still do not seem to learn from Bhopal. The same mistakes that occurred at Bhopal keep recurring in various incidents around the World. Production pressures along with cost cutting measures take a toll on process safety. Just like the National safety week in march, I mooted the idea of having a National Process Safety Week every year on the anniversary of Bhopal for all chemical industries in India. During this week, the root causes of the Bhopal disaster and process incidents in individual organisations can be discussed with all  employees including top management. The root causes are again given below: They are still relevant today:

1. Do not cut costs without looking at the effects on process safety
2. Maintain all your layers of defense including asset integrity
3. Continually ensure that competency of personnel operating and maintaining plants are updated and current
4. Be prepared for the worst case scenario.
5. Understand the risks and measures to eliminate / reduce or control them
6. Learn from your past incidents. Those who do not learn are condemned to repeat the incidents.
7. Pay heed to your process safety management system audit reports

 I am again attaching the link of some pictures of the victims of Bhopal, lest we forget..........

" Mothers didn't know their children had died, children didn't know their mothers had died, and men didn't know their whole families had died" - Ahmed Khan, Bhopal resident on the Bhopal disaster

How to Avoid Common Genset Room Design Mistakes

How to Avoid Common Genset Room Design Mistakes: The room and building that a power generating set will be located in must comply with all genset room design requirements to ensure reliable operation.

How to Clean Natural Gas Piping with Gas Blows

How to Clean Natural Gas Piping with Gas Blows: Before new fuel gas piping can be connected to a combustion turbine (CT), it must be cleaned by “decompression” gas blows. Here's how to do it.

New Lockout-Tagout Program Improves Safety

New Lockout-Tagout Program Improves Safety: To improve overall employee safety across plants and facilities, switch from a tagout-based safety program to a lockout-tagout (LOTO) program.

Understanding the Dangers of Hydrogen Sulfide Gas

Understanding the Dangers of Hydrogen Sulfide Gas: Hydrogen sulfide (H2S) gas is produced as a result of the microbial breakdown of organic materials in the absence of oxygen. It can be found in tanks,

Cultivating a Safety Culture Amid Constant Change

Cultivating a Safety Culture Amid Constant Change: Developing a power plant safety culture takes time and constant effort, but the payoff is priceless, safety leaders at three major power companies said

How to Conduct Steam Blowing Procedures with Remote Personnel

How to Conduct Steam Blowing Procedures with Remote Personnel: Many power projects have been disrupted due to COVID-19. However, managers at Larsen & Toubro Ltd. found a way to complete steam blow requirements in spite of the pandemic, using secure internet

Common Mistakes When Conducting a HAZOP and How to Avoid Them - Chemical Engineering

Common Mistakes When Conducting a HAZOP and How to Avoid Them - Chemical Engineering: An important part of ensuring the success of a HAZOP study is to understand the errors that can cause the team to lose focus

Principles-Based Operations: A Military-Proven Method Part II

Principles-Based Operations: A Military-Proven Method Part II: Part II of Principles-Based Operations focuses on level of knowledge, forceful backup, questioning attitude, procedural compliance, and formality.

Principles-Based Operations: A Military-Proven Method Part I

Principles-Based Operations: A Military-Proven Method Part I: Many organizations have begun applying operational principles used with great success in the millitary. The foundation for postive outcomes is integrity.

Employee Location Monitoring in a Post-Pandemic World

Employee Location Monitoring in a Post-Pandemic World: The COVID-19 pandemic has unearthed a number of challenges for power plant managers. However, technology exists to keep workers safe. Through the use of Location Anchors and WirelessHART infrastructure

Improving Asset Inspections with Drones and AI

Improving Asset Inspections with Drones and AI: The U.S. bulk electric system has more than 360,000 miles of transmission lines, which means power companies have a lot to inspect. Drones and AI can help.

Flame-Resistant Clothing: Everything You Need to Know

Flame-Resistant Clothing: Everything You Need to Know: Flame-resistant (FR) garments are an important safety item for workers in the power industry. However, protection varies based on the arc rating of the clothing. Wearers must understand how the FR clothing

Protecting Battery Energy Storage Systems from Fire and Explosion Hazards

Protecting Battery Energy Storage Systems from Fire and Explosion Hazards: There are serious risks associated with lithium-ion battery energy storage systems. Thermal runaway can release toxic and explosive gases, and the problem can spread from one malfunctioning cell to neighboring cells, resulting in catastrophe.

Preventing and Mitigating Oil Fires in Power Plants

Preventing and Mitigating Oil Fires in Power Plants: It has been said that a picture is worth a thousand words. However, photos of the conflagrations that have resulted from ignition of minor lube oil leaks on a typical steam turbine room floor will leave you speechless. Full-scale physical simulations of oil fires by the insurance company FM Global leave no doubt that power plant fire prevention and mitigation is a judicious blend of art and science.

Does your safety observation system create victims, villains?

Does your safety observation system create victims, villains?: Chances are you have a behavior-based safety (BBS) process in place for all of your projects. And the reason you have that BBS process to begin with is to reduce accidents.

FATALITY DUE TO EXPLOSION IN NITRIC ACID TANK

 A small steel process tank was filled with multiple metal baskets of tantalum capacitors cooked overnight in hot nitric acid. The hot nitric acid was used to remove some of the epoxy resin encapsulant from a tantalum anode. The nitric acid was drained each morning after the capacitors were cooked. The baskets of cooked capacitors were removed and rinsed in water. Mostly tantalum anodes remained. Employee #1 was killed and five other employees were seriously injured as a residue, containing picric acid, exploded, when Employee #1 placed a basket back into the drained tank, presumably to remove more encapsulant. Picric acid (trinitrophenol), and possibly other unstable nitrated compounds, formed in a nitration reaction between nitric acid and the bisphenol moiety of the epoxy resin. These nitrated compounds precipitated out of the nitric acid solution. Over time, as the spent nitric acid was drained from the tank after each batch, the precipitated nitrated compounds would accumulate on the inside surface of the tank. The spent nitric acid was typically used for multiple batches further concentrating unstable nitrated compounds on the tank's surface. Placement of the basket was likely the source of ignition. The explosion was estimated to be of a magnitude similar to an explosion involving more than 5 pounds of trinitrotoluene. The five seriously injured employees were treated for burns and bruises at a local hospital. 

 Source:OSHA.gov

How to Prevent Fire Hazards Associated with Static Electricity

How to Prevent Fire Hazards Associated with Static Electricity: When combustible materials are handled, static electricity can be dangerous as the work environment then becomes at risk for fires and explosions.

Best Practices for Preventing Business Disruption from Ransomware Attacks

https://us-cert.cisa.gov/ncas/alerts/aa21-131a

CORROSION COUPON PLUG EJECTED FROM PRESSURISED PIPE

 https://ogcenergy.com/ogp-safety-alert/

Worker seriously injured when pipe assembly failed pressure test

 http://www.resourcesandenergy.nsw.gov.au/__data/assets/pdf_file/0006/587193/SA15-08-Worker-seriously-injured-when-pipe-failed-pressure-test.pdf

Safety Alert for Installation of Installation of Spring SupportsSpring Supports

 https://pipingtech.com/wp-content/uploads/2017/10/travelstop.pdf

Pipe supports failure

 https://www.youtube.com/watch?v=YC8Lip9BIUY

Employee Inhales Toxic Gas, Later Dies

At 6:15 a.m. on May 22, 2020, an employee and a coworker were in the process of transferring chemicals from totes on a delivery truck into tanks inside the facility. The employee was responsible for hooking up the hose to the fill line on the building and monitoring the transfer from inside the facility. The coworker was responsible for hooking up the hose to the pump and tote inside the truck. The employee accidentally hooked up the bleach hose to the fluoride fill line, causing a reaction when the chemicals mixed. A toxic gas, presumably chlorine, was given off and the employee inhaled the gas. The employee was hospitalized from t he inhalation of the toxic gas, and died from the injury.  

Source:OSHA.gov

Two Employees Receive Corrosive Burns From Sanitizing

 At 12:00 p.m. on April 19, 2019, Employee #1 and Employee #2 were observing a food establishment's sanitation and cleaning process during an investigation. During the observations of the employees and processes, they used a foaming cleanser, quaternary ammonium, and a spot acid clear for cleaning and sanitizing. A pun gent smell believed to be chlorine was being released into the air. Employees #1 and #2 noted that their eyes, skin, and mucosal linings of the mouth, throat, and nose were irritated and burning. Employee #2 measured the quaternary ammonium solution, and it was found to be in excess of 200 PPM, which is higher than recommended levels. Hospitalization was not required. 

 Source:OSHA.gov

Steam cap failure incident

 At 8:12 a.m. on November 13, 2020, Employee #1 and a coworker, employed by an HV AC company, were repairing a steam piping system leak in the mechanical room of a medical care campus building. The employees did not utilize a lockout and/or tagout device. Following the repair, as the steam line was being re-energized, a threaded drip cap at the bottom of the vertical steam pipe riser apparently failed. The room immediately filled with pressurized steam. The interior door was in the closed position, and the employees were unable to exit the room. Employee #1 was killed. 

Source:Osha.gov

15 Power Plant Safety Tips

 15 Power Plant Safety Tips

 https://www.babcock.com/resources/learning-center/15-power-plant-safety-tips

The dangers of hydrogen generation during chemical cleaning

 Real Life Accident: Boiler Explosion Kills Chemical Cleaning Expert On LNG Tanker

 By MARS Reports | In: Case Studies | Last Updated on November 19, 2020

 https://www.marineinsight.com/case-studies/boiler-explosion-kills-chemical-cleaning-expert-on-lng-tanker/

 The employees were charging a furnace for an alloy melt. Employee #1 had just placed the final two pigs on the lip of the furnace door and had backed his lift truck at an angle to a distance of 15 feet from the furnace. Employee #3 had previously pushed seven pigs into the furnace. As he pushed the final two pigs into the furnace, there were two separate explosions inside the furnace. The first explosion caused a wave of molten metal to flow over the open furnace sill outward to a distance of 40 feet. The second explosion caused a fan shaped flame that extended out 80 feet from the furnace. The flame touched the left front of Employee #1's lift truck and completely engulfed Employee #3's lift truck (located 30 feet directly in front of the furnace). Employee #2 was standing behind Employee #1's lift truck. All three employees were burned. Employee #3 died of his injuries. Water pockets inside the pigs apparently caused the explosions.

 Source: osha.gov

 Top Ten Boiler and Combustion Safety Issues to Avoid

 John R. Puskar, P.E.
Principal and Owner of CEC Combustion Services Group

Category: Operations

Summary: This article was originally published in the Summer 2010 National Board BULLETIN.

 https://www.nationalboard.org/Index.aspx?pageID=164&ID=439

 A game-changing approach to furnace safeguarding

This work is a follow-up article to “Automate furnace controls to improve safety and energy efficiency,” which was published in the June 2014 edition of Hydrocarbon Processing.

Mickity, D., Phillips 66

 

https://www.hydrocarbonprocessing.com/magazine/2018/september-2018/special-focus-refining-technology/a-game-changing-approach-to-furnace-safeguarding

 

Role of fired heater safety systems

A fully automated burner management system operating as a SIS for burner control can meet minimum safety targets, improve system availability and lower costs

NIKKI BISHOP and DAVID SHEPPARD
Emerson Process Management

Role of fired heater safety systems

Design Options for Overfill Protection for Aboveground Atmospheric Tanks - Best Practices

"Overfilling of a tank is an important safety hazard.  It may result in loss of tank fluid and potentially severe consequences if the fluid is flammable or environmentally sensitive.   Additionally, it is necessary to preserve the mechanical integrity of a tank.   This article first looks briefly at various ways liquid may overfill a tank, and then describes different design options as best practices to take care of situations where overfilling is a possibility.   The main paper will contain diagrams and appropriate references."

 See this link https://www.aiche.org/academy/videos/conference-presentations/design-options-overfill-protection-aboveground-atmospheric-tanks-best-practices

DONT UNDERESTIMATE OVERFILLING RISKS

 "Loss of level control has contributed to three significant industrial incidents:

 In Australia, the Esso Longford explosion in September 1998 resulted in two fatalities, eight injuries, and A$1.3 billion (more than U.S. $ 1 billion) in losses [1];In the U.S., the BP Texas City explosion in March 2005 caused 15 fatalities and more than 170 injuries, profoundly affected facility production for months afterwards, and incurred losses exceeding $1.6 billion on BP [2]; andIn the U.K., the Buncefield explosion in December 2005 injured 43 people, devastated the Hertfordshire Oil Storage Terminal, and led to total losses of as much as ₤1 billion (about $1.5 billion) [3, 4]."

Read the article at https://www.chemicalprocessing.com/articles/2010/143/

2019 Significant Process Safety Incidents

2019 Significant Process Safety Incidents: Use this summary of 2019's process safety incidents to learn and to help prevent incidents at your facility, whatever your industry. This video is a summary of significant process safety incidents during the year 2019. The purpose of maintaining awareness and sharing process safety incidents each year is to promote the Risk Based Process Safety (RBPS) approach to lessons-learned and to encourage industry to maintain a sense of vulnerability. This allows our members to be up to date on the latest news regarding process safety as we strive to be strong, smarter, and more effective in the ongoing effort to reduce process safety incidents to zero.

Alarm floods and plant incidents

Most of the incident investigations performed by the US Chemical Safety Board (CSB) cite alarm floods as being a significant contributing cause to industrial incidents. In fact, alarm management has become identified as one of the key issues listed on the cover of recent CSB investigation reports. The British-based organisation Engineering Equipment & Materials Users’ Association (EEMUA) came to the same finding in its report from 1999 when it analysed major incidents around the world, including Three Mile Island, Bhopal and Texaco Milford Haven.¹ Therefore, the connection of alarm floods to incidents has been well documented for over 12 years. On the whole, industrial progress controlling floods in those 12 years has been nil. Many corporations and plant locations are attempting to do so, but many engineers, including alarm management vendors, do not know what it takes to control floods under all operating conditions. This article shows examples of good alarm management programmes and how they successfully control alarm floods under all operating conditions.

 Read the article at Alarm floods and plant incidents

SIL and functional safety in rotating equipment

 SIL (safety integrity level) is a very important safety indicator that has been extensively discussed, described and often misunderstood within the industry over the past years. The purpose of this article is to provide operators, reliability engineers, instrumentation engineers and department managers with a practical overview of the areas where SIL and functional safety are important in their daily business life. Note that, in the light of the International Electro-technical Commission (IEC) and most other safety relevant standards, risk is strictly defined as “harm to health safety environment” (HSE).

 Read more at SIL and functional safety in rotating equipment

Process safety time for fired heaters

The fired heater is a common unit operation in the refining and petrochemical industries that is used to increase the temperature of a process fluid. Fired heaters are required when a process-to-process heat exchanger or a utility exchanger (steam condenser, hot oil heater) cannot provide sufficient driving force to raise the temperature of a process fluid for downstream processing. There are numerous applications for fired heaters, from preheating feed to process units to reboiling distillation towers.

During the course of normal operation a fired heater will be exposed to disturbances in the supply of fuel, combustion air, or process fluid that may lead to a potentially hazardous condition developing. To manage these disturbances and take appropriate action to safely operate and control the fired heater, several layers of protective systems are normally provided.¹ These protective systems are designed to take independent action that will prevent the fired heater from reaching a hazardous condition.

 Continue reading at Process safety time for fired heaters

REFINERY FIRE INCIDENT

Incident at Visakh Refinery Date of incident : 23.08.2013 Time: 16:46 hrs Entity: HPCL Location: VRCFP Cooling Tower, Visakh Refinery, Vishakhapatnam

Description:On August 23, 2013, one of the cells of the Salt Water Cooling Tower of Visakh refinery was being commissioned. During the opening of the water line at about 16:46 hours, there was a minor explosion and fire. The cooling tower burned down and collapsed. Due to the fire, workers working near other cells and surrounding area sustained burn injuries. There was one fatality (company employee) and 39 persons sustained injuries and were shifted to INS Kalyani and other hospitals in the city. On the next day, another 6 dead bodies were found in debris. 

Observation:

•One new cell was added to the existing cooling tower, and the existing cells were under maintenance.

•Hot jobs were going on in the nearby area.

•The ingress of hydrocarbon in the cooling water was due to leakage of cooler / condenser in process units connected with this return line.

•There was imbalance in load of two distribution headers on the top of cooling tower cells. To reduce the load on the cooling towers, a process modification scheme was issued whereby the cooling water return headers were proposed to be re-routed to the ground level and construction of riser pipes from the bottom header to the top of each cell, for uniform supply of hot cooling water to the Cooling Tower. With this, the load of return header, which earlier was on top of the cell, would be shifted from Cooling Tower structure to the separate supports outside the Cooling Tower.

•There is distinct possibility of entrapped / accumulated light hydrocarbon in the portion of the new line since it is located at an elevation and that there was no escape route for this entrapped hydrocarbon as the other end of the header was closed by valve.

•The entrapped hydrocarbon gushed into the Cooling Tower as soon as the cooling water return line valve to the new cell was opened. The hydrocarbon got ignited by the spark of welding jobs being carried out nearby causing explosion and major fire. The wooden structure of the Cooling Tower got ignited in the process which continued for about 45 minutes till the fire was extinguished by F&S personnel.

•The accident resulted in serious burn injuries and fatality to a number of persons working in the cooling tower area.

Cause:

•Gushing out of entrapped hydrocarbon from the cooling water return header to newcell, which got ignited since hot jobs were being carried out in close vicinity. The ingress of hydrocarbon was due to leakage of hydrocarbon in cooler/condenser in connected process units.

•Not adhering to the practice of stopping all work (especially hot work) and prohibiting all unrelated contractor and company personnel at site, before commissioning a new system/ facility. Also, carrying out hazard analysis/ risk assessment would have probably indicated that there could be trapped HC gas, and prompted commissioning/ operation team to vent out entrapped gases.

•Undertaking commissioning activities, even though several jobs were unfinished: HC and H2S detectors were not installed. Instrument cabling, cooling fan jobs were still unfinished.Decision to go ahead with commissioning was taken at fag end of the day.Improper coordination amongst Operation, Maintenance and Project departments.Non – liquidation of the gaps identified in internal safety audit & operation check-list before commissioning.

Recommendations:

•Do not allow simultaneous hot work and commissioning activity at site as this increasemanifolds the chances of accidents.

•While commissioning activity is planned/ undertaken, it must be ensured that other than the required personnel, nobody should be allowed to be present at the work site.

•Hazard analysis must be done prior to commissioning of any new facility.

•Hazard Identification and Risk Assessment must be carried out before commissioning of any new/ temporary facility / system; this analysis by a multi-disciplinary group can easily identify the risks involved and suggest measures to overcome the same.

•Facility(s) must not be commissioned unless pre-com audit is carried out.•No facility should be commissioned unless it is ensured that internal audit points / precom check-list points are liquidated; further a multi-disciplinary group must carry out the internal audit.

•There must be a proper coordination amongst the various departments; in the instant case there was clear communication gap and lack of coordination amongst Operation, Project and Maintenance Departments.

•No facility must be commissioned unless safety devices like Hydrocarbon or Hydrogen Sulphide detectors are installed.

•Standard Operating Procedure must be prepared; shared with operating personnel and ensured its display at site prior to commissioning.

•Proper house-keeping must be done at the commissioning site; the site should be clear of unwanted materials and debris.

Source: https://www.pngrb.gov.in/pdf/ERDMP/Analysis of incidents reported to PNGRB from July 2013 to Dec 2014

Incident due to ineffective PSM system

 OSHA's inspection identified several serious deficiencies in a company's process safety management program, a detailed set of requirements and procedures employers must follow to proactively address hazards associated with processes and equipment that involve large amounts of hazardous chemicals. In this case, the chemical was acetone, used in a PSM-covered process known as direct solvation. On the day of the explosion, a valve on a transfer line inadvertently was left open, resulting in the release of flammable acetone vapors. The vapors exploded after being ignited by an undetermined source.

"In this case, the company knew from prior third party and internal compliance audits conducted at the plant that aspects of its PSM program were incomplete or inadequate, and misclassified electrical equipment was in use. The company did not take adequate steps to address those conditions,"

"Luckily, the explosion happened when there were few workers in the plant. Otherwise, this incident could have resulted in a catastrophic loss of life."

Specifically, OSHA found that the process safety information for the solvation process was incomplete. The employer's analysis of hazards related to the process did not address previous incidents with a potential for catastrophic results, such as forklifts that struck process equipment, and did not address human factors such as operator error, communication between shift changes and employee fatigue from excessive overtime. In addition, the company did not ensure that a forklift and electrical equipment, such as a light fixture, switches and a motor, were approved for use in Class 1 hazardous locations where flammable gases or vapors are present. 

Source:OSHA.gov